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![Pavel Begunkov](/assets/img/avatar_default.png)
We can't just go over linked requests because it may race with linked timeouts. Take ctx->completion_lock in that case. Cc: stable@vger.kernel.org # v5.7+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
9777 lines
235 KiB
C
9777 lines
235 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Shared application/kernel submission and completion ring pairs, for
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* supporting fast/efficient IO.
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*
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* A note on the read/write ordering memory barriers that are matched between
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* the application and kernel side.
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*
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* After the application reads the CQ ring tail, it must use an
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* appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
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* before writing the tail (using smp_load_acquire to read the tail will
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* do). It also needs a smp_mb() before updating CQ head (ordering the
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* entry load(s) with the head store), pairing with an implicit barrier
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* through a control-dependency in io_get_cqring (smp_store_release to
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* store head will do). Failure to do so could lead to reading invalid
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* CQ entries.
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*
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* Likewise, the application must use an appropriate smp_wmb() before
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* writing the SQ tail (ordering SQ entry stores with the tail store),
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* which pairs with smp_load_acquire in io_get_sqring (smp_store_release
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* to store the tail will do). And it needs a barrier ordering the SQ
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* head load before writing new SQ entries (smp_load_acquire to read
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* head will do).
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*
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* When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
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* needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
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* updating the SQ tail; a full memory barrier smp_mb() is needed
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* between.
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*
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* Also see the examples in the liburing library:
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*
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* git://git.kernel.dk/liburing
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*
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* io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
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* from data shared between the kernel and application. This is done both
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* for ordering purposes, but also to ensure that once a value is loaded from
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* data that the application could potentially modify, it remains stable.
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*
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* Copyright (C) 2018-2019 Jens Axboe
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* Copyright (c) 2018-2019 Christoph Hellwig
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/syscalls.h>
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#include <linux/compat.h>
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#include <net/compat.h>
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#include <linux/refcount.h>
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#include <linux/uio.h>
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#include <linux/bits.h>
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#include <linux/sched/signal.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/percpu.h>
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#include <linux/slab.h>
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#include <linux/kthread.h>
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#include <linux/blkdev.h>
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#include <linux/bvec.h>
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#include <linux/net.h>
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#include <net/sock.h>
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#include <net/af_unix.h>
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#include <net/scm.h>
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#include <linux/anon_inodes.h>
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#include <linux/sched/mm.h>
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#include <linux/uaccess.h>
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#include <linux/nospec.h>
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#include <linux/sizes.h>
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#include <linux/hugetlb.h>
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#include <linux/highmem.h>
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#include <linux/namei.h>
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#include <linux/fsnotify.h>
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#include <linux/fadvise.h>
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#include <linux/eventpoll.h>
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#include <linux/fs_struct.h>
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#include <linux/splice.h>
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#include <linux/task_work.h>
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#include <linux/pagemap.h>
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#include <linux/io_uring.h>
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#include <linux/blk-cgroup.h>
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#include <linux/audit.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/io_uring.h>
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#include <uapi/linux/io_uring.h>
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#include "internal.h"
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#include "io-wq.h"
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#define IORING_MAX_ENTRIES 32768
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#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
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/*
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* Shift of 9 is 512 entries, or exactly one page on 64-bit archs
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*/
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#define IORING_FILE_TABLE_SHIFT 9
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#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
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#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
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#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
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#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
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IORING_REGISTER_LAST + IORING_OP_LAST)
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struct io_uring {
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u32 head ____cacheline_aligned_in_smp;
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u32 tail ____cacheline_aligned_in_smp;
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};
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/*
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* This data is shared with the application through the mmap at offsets
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* IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
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*
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* The offsets to the member fields are published through struct
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* io_sqring_offsets when calling io_uring_setup.
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*/
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struct io_rings {
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/*
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* Head and tail offsets into the ring; the offsets need to be
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* masked to get valid indices.
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*
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* The kernel controls head of the sq ring and the tail of the cq ring,
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* and the application controls tail of the sq ring and the head of the
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* cq ring.
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*/
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struct io_uring sq, cq;
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/*
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* Bitmasks to apply to head and tail offsets (constant, equals
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* ring_entries - 1)
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*/
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u32 sq_ring_mask, cq_ring_mask;
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/* Ring sizes (constant, power of 2) */
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u32 sq_ring_entries, cq_ring_entries;
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/*
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* Number of invalid entries dropped by the kernel due to
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* invalid index stored in array
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*
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* Written by the kernel, shouldn't be modified by the
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* application (i.e. get number of "new events" by comparing to
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* cached value).
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*
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* After a new SQ head value was read by the application this
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* counter includes all submissions that were dropped reaching
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* the new SQ head (and possibly more).
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*/
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u32 sq_dropped;
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/*
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* Runtime SQ flags
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*
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* Written by the kernel, shouldn't be modified by the
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* application.
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*
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* The application needs a full memory barrier before checking
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* for IORING_SQ_NEED_WAKEUP after updating the sq tail.
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*/
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u32 sq_flags;
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/*
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* Runtime CQ flags
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*
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* Written by the application, shouldn't be modified by the
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* kernel.
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*/
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u32 cq_flags;
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/*
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* Number of completion events lost because the queue was full;
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* this should be avoided by the application by making sure
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* there are not more requests pending than there is space in
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* the completion queue.
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*
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* Written by the kernel, shouldn't be modified by the
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* application (i.e. get number of "new events" by comparing to
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* cached value).
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*
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* As completion events come in out of order this counter is not
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* ordered with any other data.
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*/
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u32 cq_overflow;
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/*
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* Ring buffer of completion events.
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*
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* The kernel writes completion events fresh every time they are
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* produced, so the application is allowed to modify pending
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* entries.
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*/
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struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
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};
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struct io_mapped_ubuf {
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u64 ubuf;
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size_t len;
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struct bio_vec *bvec;
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unsigned int nr_bvecs;
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unsigned long acct_pages;
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};
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struct fixed_file_table {
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struct file **files;
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};
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struct fixed_file_ref_node {
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struct percpu_ref refs;
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struct list_head node;
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struct list_head file_list;
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struct fixed_file_data *file_data;
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struct llist_node llist;
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};
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struct fixed_file_data {
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struct fixed_file_table *table;
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struct io_ring_ctx *ctx;
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struct fixed_file_ref_node *node;
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struct percpu_ref refs;
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struct completion done;
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struct list_head ref_list;
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spinlock_t lock;
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};
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struct io_buffer {
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struct list_head list;
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__u64 addr;
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__s32 len;
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__u16 bid;
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};
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struct io_restriction {
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DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
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DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
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u8 sqe_flags_allowed;
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u8 sqe_flags_required;
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bool registered;
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};
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struct io_sq_data {
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refcount_t refs;
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struct mutex lock;
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/* ctx's that are using this sqd */
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struct list_head ctx_list;
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struct list_head ctx_new_list;
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struct mutex ctx_lock;
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struct task_struct *thread;
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struct wait_queue_head wait;
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};
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struct io_ring_ctx {
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struct {
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struct percpu_ref refs;
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} ____cacheline_aligned_in_smp;
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struct {
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unsigned int flags;
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unsigned int compat: 1;
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unsigned int limit_mem: 1;
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unsigned int cq_overflow_flushed: 1;
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unsigned int drain_next: 1;
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unsigned int eventfd_async: 1;
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unsigned int restricted: 1;
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/*
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* Ring buffer of indices into array of io_uring_sqe, which is
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* mmapped by the application using the IORING_OFF_SQES offset.
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*
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* This indirection could e.g. be used to assign fixed
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* io_uring_sqe entries to operations and only submit them to
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* the queue when needed.
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*
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* The kernel modifies neither the indices array nor the entries
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* array.
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*/
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u32 *sq_array;
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unsigned cached_sq_head;
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unsigned sq_entries;
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unsigned sq_mask;
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unsigned sq_thread_idle;
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unsigned cached_sq_dropped;
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unsigned cached_cq_overflow;
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unsigned long sq_check_overflow;
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struct list_head defer_list;
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struct list_head timeout_list;
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struct list_head cq_overflow_list;
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wait_queue_head_t inflight_wait;
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struct io_uring_sqe *sq_sqes;
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} ____cacheline_aligned_in_smp;
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struct io_rings *rings;
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/* IO offload */
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struct io_wq *io_wq;
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/*
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* For SQPOLL usage - we hold a reference to the parent task, so we
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* have access to the ->files
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*/
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struct task_struct *sqo_task;
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/* Only used for accounting purposes */
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struct mm_struct *mm_account;
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#ifdef CONFIG_BLK_CGROUP
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struct cgroup_subsys_state *sqo_blkcg_css;
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#endif
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struct io_sq_data *sq_data; /* if using sq thread polling */
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struct wait_queue_head sqo_sq_wait;
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struct wait_queue_entry sqo_wait_entry;
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struct list_head sqd_list;
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/*
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* If used, fixed file set. Writers must ensure that ->refs is dead,
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* readers must ensure that ->refs is alive as long as the file* is
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* used. Only updated through io_uring_register(2).
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*/
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struct fixed_file_data *file_data;
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unsigned nr_user_files;
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/* if used, fixed mapped user buffers */
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unsigned nr_user_bufs;
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struct io_mapped_ubuf *user_bufs;
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struct user_struct *user;
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const struct cred *creds;
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#ifdef CONFIG_AUDIT
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kuid_t loginuid;
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unsigned int sessionid;
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#endif
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struct completion ref_comp;
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struct completion sq_thread_comp;
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/* if all else fails... */
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struct io_kiocb *fallback_req;
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#if defined(CONFIG_UNIX)
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struct socket *ring_sock;
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#endif
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struct idr io_buffer_idr;
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struct idr personality_idr;
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struct {
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unsigned cached_cq_tail;
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unsigned cq_entries;
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unsigned cq_mask;
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atomic_t cq_timeouts;
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unsigned long cq_check_overflow;
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struct wait_queue_head cq_wait;
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struct fasync_struct *cq_fasync;
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struct eventfd_ctx *cq_ev_fd;
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} ____cacheline_aligned_in_smp;
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struct {
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struct mutex uring_lock;
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wait_queue_head_t wait;
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} ____cacheline_aligned_in_smp;
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struct {
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spinlock_t completion_lock;
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/*
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* ->iopoll_list is protected by the ctx->uring_lock for
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* io_uring instances that don't use IORING_SETUP_SQPOLL.
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* For SQPOLL, only the single threaded io_sq_thread() will
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* manipulate the list, hence no extra locking is needed there.
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*/
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struct list_head iopoll_list;
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struct hlist_head *cancel_hash;
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unsigned cancel_hash_bits;
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bool poll_multi_file;
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spinlock_t inflight_lock;
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struct list_head inflight_list;
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} ____cacheline_aligned_in_smp;
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struct delayed_work file_put_work;
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struct llist_head file_put_llist;
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struct work_struct exit_work;
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struct io_restriction restrictions;
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};
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/*
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* First field must be the file pointer in all the
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* iocb unions! See also 'struct kiocb' in <linux/fs.h>
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*/
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struct io_poll_iocb {
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struct file *file;
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union {
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struct wait_queue_head *head;
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u64 addr;
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};
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__poll_t events;
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bool done;
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bool canceled;
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struct wait_queue_entry wait;
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};
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struct io_close {
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struct file *file;
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struct file *put_file;
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int fd;
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};
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struct io_timeout_data {
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struct io_kiocb *req;
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struct hrtimer timer;
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struct timespec64 ts;
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enum hrtimer_mode mode;
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};
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struct io_accept {
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struct file *file;
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struct sockaddr __user *addr;
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int __user *addr_len;
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int flags;
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unsigned long nofile;
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};
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struct io_sync {
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struct file *file;
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loff_t len;
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loff_t off;
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int flags;
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int mode;
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};
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struct io_cancel {
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struct file *file;
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u64 addr;
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};
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struct io_timeout {
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struct file *file;
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u32 off;
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u32 target_seq;
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struct list_head list;
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};
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struct io_timeout_rem {
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struct file *file;
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u64 addr;
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};
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struct io_rw {
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/* NOTE: kiocb has the file as the first member, so don't do it here */
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struct kiocb kiocb;
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u64 addr;
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u64 len;
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};
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struct io_connect {
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struct file *file;
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struct sockaddr __user *addr;
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int addr_len;
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};
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struct io_sr_msg {
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struct file *file;
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union {
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struct user_msghdr __user *umsg;
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void __user *buf;
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};
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int msg_flags;
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int bgid;
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size_t len;
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struct io_buffer *kbuf;
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};
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struct io_open {
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struct file *file;
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int dfd;
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struct filename *filename;
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struct open_how how;
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unsigned long nofile;
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};
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struct io_files_update {
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struct file *file;
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u64 arg;
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u32 nr_args;
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u32 offset;
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};
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struct io_fadvise {
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struct file *file;
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u64 offset;
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u32 len;
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u32 advice;
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};
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struct io_madvise {
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struct file *file;
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u64 addr;
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u32 len;
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u32 advice;
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};
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struct io_epoll {
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|
struct file *file;
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|
int epfd;
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int op;
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int fd;
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struct epoll_event event;
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};
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struct io_splice {
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struct file *file_out;
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struct file *file_in;
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loff_t off_out;
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loff_t off_in;
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u64 len;
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unsigned int flags;
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};
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struct io_provide_buf {
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struct file *file;
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__u64 addr;
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__s32 len;
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__u32 bgid;
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__u16 nbufs;
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__u16 bid;
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};
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|
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struct io_statx {
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struct file *file;
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int dfd;
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unsigned int mask;
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unsigned int flags;
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const char __user *filename;
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struct statx __user *buffer;
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};
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struct io_completion {
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struct file *file;
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struct list_head list;
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int cflags;
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};
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|
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struct io_async_connect {
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struct sockaddr_storage address;
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};
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struct io_async_msghdr {
|
|
struct iovec fast_iov[UIO_FASTIOV];
|
|
struct iovec *iov;
|
|
struct sockaddr __user *uaddr;
|
|
struct msghdr msg;
|
|
struct sockaddr_storage addr;
|
|
};
|
|
|
|
struct io_async_rw {
|
|
struct iovec fast_iov[UIO_FASTIOV];
|
|
const struct iovec *free_iovec;
|
|
struct iov_iter iter;
|
|
size_t bytes_done;
|
|
struct wait_page_queue wpq;
|
|
};
|
|
|
|
enum {
|
|
REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
|
|
REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
|
|
REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
|
|
REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
|
|
REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
|
|
REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
|
|
|
|
REQ_F_LINK_HEAD_BIT,
|
|
REQ_F_FAIL_LINK_BIT,
|
|
REQ_F_INFLIGHT_BIT,
|
|
REQ_F_CUR_POS_BIT,
|
|
REQ_F_NOWAIT_BIT,
|
|
REQ_F_LINK_TIMEOUT_BIT,
|
|
REQ_F_ISREG_BIT,
|
|
REQ_F_NEED_CLEANUP_BIT,
|
|
REQ_F_POLLED_BIT,
|
|
REQ_F_BUFFER_SELECTED_BIT,
|
|
REQ_F_NO_FILE_TABLE_BIT,
|
|
REQ_F_WORK_INITIALIZED_BIT,
|
|
REQ_F_LTIMEOUT_ACTIVE_BIT,
|
|
|
|
/* not a real bit, just to check we're not overflowing the space */
|
|
__REQ_F_LAST_BIT,
|
|
};
|
|
|
|
enum {
|
|
/* ctx owns file */
|
|
REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
|
|
/* drain existing IO first */
|
|
REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
|
|
/* linked sqes */
|
|
REQ_F_LINK = BIT(REQ_F_LINK_BIT),
|
|
/* doesn't sever on completion < 0 */
|
|
REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
|
|
/* IOSQE_ASYNC */
|
|
REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
|
|
/* IOSQE_BUFFER_SELECT */
|
|
REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
|
|
|
|
/* head of a link */
|
|
REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
|
|
/* fail rest of links */
|
|
REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
|
|
/* on inflight list */
|
|
REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
|
|
/* read/write uses file position */
|
|
REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
|
|
/* must not punt to workers */
|
|
REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
|
|
/* has or had linked timeout */
|
|
REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
|
|
/* regular file */
|
|
REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
|
|
/* needs cleanup */
|
|
REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
|
|
/* already went through poll handler */
|
|
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
|
|
/* buffer already selected */
|
|
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
|
|
/* doesn't need file table for this request */
|
|
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
|
|
/* io_wq_work is initialized */
|
|
REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
|
|
/* linked timeout is active, i.e. prepared by link's head */
|
|
REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT),
|
|
};
|
|
|
|
struct async_poll {
|
|
struct io_poll_iocb poll;
|
|
struct io_poll_iocb *double_poll;
|
|
};
|
|
|
|
/*
|
|
* NOTE! Each of the iocb union members has the file pointer
|
|
* as the first entry in their struct definition. So you can
|
|
* access the file pointer through any of the sub-structs,
|
|
* or directly as just 'ki_filp' in this struct.
|
|
*/
|
|
struct io_kiocb {
|
|
union {
|
|
struct file *file;
|
|
struct io_rw rw;
|
|
struct io_poll_iocb poll;
|
|
struct io_accept accept;
|
|
struct io_sync sync;
|
|
struct io_cancel cancel;
|
|
struct io_timeout timeout;
|
|
struct io_timeout_rem timeout_rem;
|
|
struct io_connect connect;
|
|
struct io_sr_msg sr_msg;
|
|
struct io_open open;
|
|
struct io_close close;
|
|
struct io_files_update files_update;
|
|
struct io_fadvise fadvise;
|
|
struct io_madvise madvise;
|
|
struct io_epoll epoll;
|
|
struct io_splice splice;
|
|
struct io_provide_buf pbuf;
|
|
struct io_statx statx;
|
|
/* use only after cleaning per-op data, see io_clean_op() */
|
|
struct io_completion compl;
|
|
};
|
|
|
|
/* opcode allocated if it needs to store data for async defer */
|
|
void *async_data;
|
|
u8 opcode;
|
|
/* polled IO has completed */
|
|
u8 iopoll_completed;
|
|
|
|
u16 buf_index;
|
|
u32 result;
|
|
|
|
struct io_ring_ctx *ctx;
|
|
unsigned int flags;
|
|
refcount_t refs;
|
|
struct task_struct *task;
|
|
u64 user_data;
|
|
|
|
struct list_head link_list;
|
|
|
|
/*
|
|
* 1. used with ctx->iopoll_list with reads/writes
|
|
* 2. to track reqs with ->files (see io_op_def::file_table)
|
|
*/
|
|
struct list_head inflight_entry;
|
|
|
|
struct percpu_ref *fixed_file_refs;
|
|
struct callback_head task_work;
|
|
/* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
|
|
struct hlist_node hash_node;
|
|
struct async_poll *apoll;
|
|
struct io_wq_work work;
|
|
};
|
|
|
|
struct io_defer_entry {
|
|
struct list_head list;
|
|
struct io_kiocb *req;
|
|
u32 seq;
|
|
};
|
|
|
|
#define IO_IOPOLL_BATCH 8
|
|
|
|
struct io_comp_state {
|
|
unsigned int nr;
|
|
struct list_head list;
|
|
struct io_ring_ctx *ctx;
|
|
};
|
|
|
|
struct io_submit_state {
|
|
struct blk_plug plug;
|
|
|
|
/*
|
|
* io_kiocb alloc cache
|
|
*/
|
|
void *reqs[IO_IOPOLL_BATCH];
|
|
unsigned int free_reqs;
|
|
|
|
/*
|
|
* Batch completion logic
|
|
*/
|
|
struct io_comp_state comp;
|
|
|
|
/*
|
|
* File reference cache
|
|
*/
|
|
struct file *file;
|
|
unsigned int fd;
|
|
unsigned int has_refs;
|
|
unsigned int ios_left;
|
|
};
|
|
|
|
struct io_op_def {
|
|
/* needs req->file assigned */
|
|
unsigned needs_file : 1;
|
|
/* don't fail if file grab fails */
|
|
unsigned needs_file_no_error : 1;
|
|
/* hash wq insertion if file is a regular file */
|
|
unsigned hash_reg_file : 1;
|
|
/* unbound wq insertion if file is a non-regular file */
|
|
unsigned unbound_nonreg_file : 1;
|
|
/* opcode is not supported by this kernel */
|
|
unsigned not_supported : 1;
|
|
/* set if opcode supports polled "wait" */
|
|
unsigned pollin : 1;
|
|
unsigned pollout : 1;
|
|
/* op supports buffer selection */
|
|
unsigned buffer_select : 1;
|
|
/* must always have async data allocated */
|
|
unsigned needs_async_data : 1;
|
|
/* size of async data needed, if any */
|
|
unsigned short async_size;
|
|
unsigned work_flags;
|
|
};
|
|
|
|
static const struct io_op_def io_op_defs[] = {
|
|
[IORING_OP_NOP] = {},
|
|
[IORING_OP_READV] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.buffer_select = 1,
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_WRITEV] = {
|
|
.needs_file = 1,
|
|
.hash_reg_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
|
|
IO_WQ_WORK_FSIZE,
|
|
},
|
|
[IORING_OP_FSYNC] = {
|
|
.needs_file = 1,
|
|
.work_flags = IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_READ_FIXED] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_WRITE_FIXED] = {
|
|
.needs_file = 1,
|
|
.hash_reg_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE |
|
|
IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_POLL_ADD] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
},
|
|
[IORING_OP_POLL_REMOVE] = {},
|
|
[IORING_OP_SYNC_FILE_RANGE] = {
|
|
.needs_file = 1,
|
|
.work_flags = IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_SENDMSG] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_async_msghdr),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
|
|
IO_WQ_WORK_FS,
|
|
},
|
|
[IORING_OP_RECVMSG] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.buffer_select = 1,
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_async_msghdr),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
|
|
IO_WQ_WORK_FS,
|
|
},
|
|
[IORING_OP_TIMEOUT] = {
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_timeout_data),
|
|
.work_flags = IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_TIMEOUT_REMOVE] = {},
|
|
[IORING_OP_ACCEPT] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
|
|
},
|
|
[IORING_OP_ASYNC_CANCEL] = {},
|
|
[IORING_OP_LINK_TIMEOUT] = {
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_timeout_data),
|
|
.work_flags = IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_CONNECT] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.needs_async_data = 1,
|
|
.async_size = sizeof(struct io_async_connect),
|
|
.work_flags = IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_FALLOCATE] = {
|
|
.needs_file = 1,
|
|
.work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE,
|
|
},
|
|
[IORING_OP_OPENAT] = {
|
|
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG |
|
|
IO_WQ_WORK_FS,
|
|
},
|
|
[IORING_OP_CLOSE] = {
|
|
.needs_file = 1,
|
|
.needs_file_no_error = 1,
|
|
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_FILES_UPDATE] = {
|
|
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM,
|
|
},
|
|
[IORING_OP_STATX] = {
|
|
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM |
|
|
IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_READ] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.buffer_select = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_WRITE] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.async_size = sizeof(struct io_async_rw),
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
|
|
IO_WQ_WORK_FSIZE,
|
|
},
|
|
[IORING_OP_FADVISE] = {
|
|
.needs_file = 1,
|
|
.work_flags = IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_MADVISE] = {
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_SEND] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollout = 1,
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_RECV] = {
|
|
.needs_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.pollin = 1,
|
|
.buffer_select = 1,
|
|
.work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_OPENAT2] = {
|
|
.work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS |
|
|
IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_EPOLL_CTL] = {
|
|
.unbound_nonreg_file = 1,
|
|
.work_flags = IO_WQ_WORK_FILES,
|
|
},
|
|
[IORING_OP_SPLICE] = {
|
|
.needs_file = 1,
|
|
.hash_reg_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
.work_flags = IO_WQ_WORK_BLKCG,
|
|
},
|
|
[IORING_OP_PROVIDE_BUFFERS] = {},
|
|
[IORING_OP_REMOVE_BUFFERS] = {},
|
|
[IORING_OP_TEE] = {
|
|
.needs_file = 1,
|
|
.hash_reg_file = 1,
|
|
.unbound_nonreg_file = 1,
|
|
},
|
|
};
|
|
|
|
enum io_mem_account {
|
|
ACCT_LOCKED,
|
|
ACCT_PINNED,
|
|
};
|
|
|
|
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
|
|
struct io_comp_state *cs);
|
|
static void io_cqring_fill_event(struct io_kiocb *req, long res);
|
|
static void io_put_req(struct io_kiocb *req);
|
|
static void io_put_req_deferred(struct io_kiocb *req, int nr);
|
|
static void io_double_put_req(struct io_kiocb *req);
|
|
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
|
|
static void __io_queue_linked_timeout(struct io_kiocb *req);
|
|
static void io_queue_linked_timeout(struct io_kiocb *req);
|
|
static int __io_sqe_files_update(struct io_ring_ctx *ctx,
|
|
struct io_uring_files_update *ip,
|
|
unsigned nr_args);
|
|
static void __io_clean_op(struct io_kiocb *req);
|
|
static struct file *io_file_get(struct io_submit_state *state,
|
|
struct io_kiocb *req, int fd, bool fixed);
|
|
static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs);
|
|
static void io_file_put_work(struct work_struct *work);
|
|
|
|
static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
|
|
struct iovec **iovec, struct iov_iter *iter,
|
|
bool needs_lock);
|
|
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
|
|
const struct iovec *fast_iov,
|
|
struct iov_iter *iter, bool force);
|
|
|
|
static struct kmem_cache *req_cachep;
|
|
|
|
static const struct file_operations io_uring_fops;
|
|
|
|
struct sock *io_uring_get_socket(struct file *file)
|
|
{
|
|
#if defined(CONFIG_UNIX)
|
|
if (file->f_op == &io_uring_fops) {
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
return ctx->ring_sock->sk;
|
|
}
|
|
#endif
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(io_uring_get_socket);
|
|
|
|
static inline void io_clean_op(struct io_kiocb *req)
|
|
{
|
|
if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED |
|
|
REQ_F_INFLIGHT))
|
|
__io_clean_op(req);
|
|
}
|
|
|
|
static void io_sq_thread_drop_mm(void)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
|
|
if (mm) {
|
|
kthread_unuse_mm(mm);
|
|
mmput(mm);
|
|
current->mm = NULL;
|
|
}
|
|
}
|
|
|
|
static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
|
|
{
|
|
struct mm_struct *mm;
|
|
|
|
if (current->mm)
|
|
return 0;
|
|
|
|
/* Should never happen */
|
|
if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL)))
|
|
return -EFAULT;
|
|
|
|
task_lock(ctx->sqo_task);
|
|
mm = ctx->sqo_task->mm;
|
|
if (unlikely(!mm || !mmget_not_zero(mm)))
|
|
mm = NULL;
|
|
task_unlock(ctx->sqo_task);
|
|
|
|
if (mm) {
|
|
kthread_use_mm(mm);
|
|
return 0;
|
|
}
|
|
|
|
return -EFAULT;
|
|
}
|
|
|
|
static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx,
|
|
struct io_kiocb *req)
|
|
{
|
|
if (!(io_op_defs[req->opcode].work_flags & IO_WQ_WORK_MM))
|
|
return 0;
|
|
return __io_sq_thread_acquire_mm(ctx);
|
|
}
|
|
|
|
static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx,
|
|
struct cgroup_subsys_state **cur_css)
|
|
|
|
{
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
/* puts the old one when swapping */
|
|
if (*cur_css != ctx->sqo_blkcg_css) {
|
|
kthread_associate_blkcg(ctx->sqo_blkcg_css);
|
|
*cur_css = ctx->sqo_blkcg_css;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void io_sq_thread_unassociate_blkcg(void)
|
|
{
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
kthread_associate_blkcg(NULL);
|
|
#endif
|
|
}
|
|
|
|
static inline void req_set_fail_links(struct io_kiocb *req)
|
|
{
|
|
if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
|
|
req->flags |= REQ_F_FAIL_LINK;
|
|
}
|
|
|
|
/*
|
|
* None of these are dereferenced, they are simply used to check if any of
|
|
* them have changed. If we're under current and check they are still the
|
|
* same, we're fine to grab references to them for actual out-of-line use.
|
|
*/
|
|
static void io_init_identity(struct io_identity *id)
|
|
{
|
|
id->files = current->files;
|
|
id->mm = current->mm;
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
rcu_read_lock();
|
|
id->blkcg_css = blkcg_css();
|
|
rcu_read_unlock();
|
|
#endif
|
|
id->creds = current_cred();
|
|
id->nsproxy = current->nsproxy;
|
|
id->fs = current->fs;
|
|
id->fsize = rlimit(RLIMIT_FSIZE);
|
|
#ifdef CONFIG_AUDIT
|
|
id->loginuid = current->loginuid;
|
|
id->sessionid = current->sessionid;
|
|
#endif
|
|
refcount_set(&id->count, 1);
|
|
}
|
|
|
|
static inline void __io_req_init_async(struct io_kiocb *req)
|
|
{
|
|
memset(&req->work, 0, sizeof(req->work));
|
|
req->flags |= REQ_F_WORK_INITIALIZED;
|
|
}
|
|
|
|
/*
|
|
* Note: must call io_req_init_async() for the first time you
|
|
* touch any members of io_wq_work.
|
|
*/
|
|
static inline void io_req_init_async(struct io_kiocb *req)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (req->flags & REQ_F_WORK_INITIALIZED)
|
|
return;
|
|
|
|
__io_req_init_async(req);
|
|
|
|
/* Grab a ref if this isn't our static identity */
|
|
req->work.identity = tctx->identity;
|
|
if (tctx->identity != &tctx->__identity)
|
|
refcount_inc(&req->work.identity->count);
|
|
}
|
|
|
|
static inline bool io_async_submit(struct io_ring_ctx *ctx)
|
|
{
|
|
return ctx->flags & IORING_SETUP_SQPOLL;
|
|
}
|
|
|
|
static void io_ring_ctx_ref_free(struct percpu_ref *ref)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
|
|
|
|
complete(&ctx->ref_comp);
|
|
}
|
|
|
|
static inline bool io_is_timeout_noseq(struct io_kiocb *req)
|
|
{
|
|
return !req->timeout.off;
|
|
}
|
|
|
|
static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
int hash_bits;
|
|
|
|
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
|
|
if (!ctx)
|
|
return NULL;
|
|
|
|
ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
|
|
if (!ctx->fallback_req)
|
|
goto err;
|
|
|
|
/*
|
|
* Use 5 bits less than the max cq entries, that should give us around
|
|
* 32 entries per hash list if totally full and uniformly spread.
|
|
*/
|
|
hash_bits = ilog2(p->cq_entries);
|
|
hash_bits -= 5;
|
|
if (hash_bits <= 0)
|
|
hash_bits = 1;
|
|
ctx->cancel_hash_bits = hash_bits;
|
|
ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
|
|
GFP_KERNEL);
|
|
if (!ctx->cancel_hash)
|
|
goto err;
|
|
__hash_init(ctx->cancel_hash, 1U << hash_bits);
|
|
|
|
if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
|
|
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
|
|
goto err;
|
|
|
|
ctx->flags = p->flags;
|
|
init_waitqueue_head(&ctx->sqo_sq_wait);
|
|
INIT_LIST_HEAD(&ctx->sqd_list);
|
|
init_waitqueue_head(&ctx->cq_wait);
|
|
INIT_LIST_HEAD(&ctx->cq_overflow_list);
|
|
init_completion(&ctx->ref_comp);
|
|
init_completion(&ctx->sq_thread_comp);
|
|
idr_init(&ctx->io_buffer_idr);
|
|
idr_init(&ctx->personality_idr);
|
|
mutex_init(&ctx->uring_lock);
|
|
init_waitqueue_head(&ctx->wait);
|
|
spin_lock_init(&ctx->completion_lock);
|
|
INIT_LIST_HEAD(&ctx->iopoll_list);
|
|
INIT_LIST_HEAD(&ctx->defer_list);
|
|
INIT_LIST_HEAD(&ctx->timeout_list);
|
|
init_waitqueue_head(&ctx->inflight_wait);
|
|
spin_lock_init(&ctx->inflight_lock);
|
|
INIT_LIST_HEAD(&ctx->inflight_list);
|
|
INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
|
|
init_llist_head(&ctx->file_put_llist);
|
|
return ctx;
|
|
err:
|
|
if (ctx->fallback_req)
|
|
kmem_cache_free(req_cachep, ctx->fallback_req);
|
|
kfree(ctx->cancel_hash);
|
|
kfree(ctx);
|
|
return NULL;
|
|
}
|
|
|
|
static bool req_need_defer(struct io_kiocb *req, u32 seq)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
return seq != ctx->cached_cq_tail
|
|
+ READ_ONCE(ctx->cached_cq_overflow);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void __io_commit_cqring(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
|
|
/* order cqe stores with ring update */
|
|
smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
|
|
|
|
if (wq_has_sleeper(&ctx->cq_wait)) {
|
|
wake_up_interruptible(&ctx->cq_wait);
|
|
kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
|
|
}
|
|
}
|
|
|
|
static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req)
|
|
{
|
|
if (req->work.identity == &tctx->__identity)
|
|
return;
|
|
if (refcount_dec_and_test(&req->work.identity->count))
|
|
kfree(req->work.identity);
|
|
}
|
|
|
|
static void io_req_clean_work(struct io_kiocb *req)
|
|
{
|
|
if (!(req->flags & REQ_F_WORK_INITIALIZED))
|
|
return;
|
|
|
|
req->flags &= ~REQ_F_WORK_INITIALIZED;
|
|
|
|
if (req->work.flags & IO_WQ_WORK_MM) {
|
|
mmdrop(req->work.identity->mm);
|
|
req->work.flags &= ~IO_WQ_WORK_MM;
|
|
}
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
if (req->work.flags & IO_WQ_WORK_BLKCG) {
|
|
css_put(req->work.identity->blkcg_css);
|
|
req->work.flags &= ~IO_WQ_WORK_BLKCG;
|
|
}
|
|
#endif
|
|
if (req->work.flags & IO_WQ_WORK_CREDS) {
|
|
put_cred(req->work.identity->creds);
|
|
req->work.flags &= ~IO_WQ_WORK_CREDS;
|
|
}
|
|
if (req->work.flags & IO_WQ_WORK_FS) {
|
|
struct fs_struct *fs = req->work.identity->fs;
|
|
|
|
spin_lock(&req->work.identity->fs->lock);
|
|
if (--fs->users)
|
|
fs = NULL;
|
|
spin_unlock(&req->work.identity->fs->lock);
|
|
if (fs)
|
|
free_fs_struct(fs);
|
|
req->work.flags &= ~IO_WQ_WORK_FS;
|
|
}
|
|
|
|
io_put_identity(req->task->io_uring, req);
|
|
}
|
|
|
|
/*
|
|
* Create a private copy of io_identity, since some fields don't match
|
|
* the current context.
|
|
*/
|
|
static bool io_identity_cow(struct io_kiocb *req)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
const struct cred *creds = NULL;
|
|
struct io_identity *id;
|
|
|
|
if (req->work.flags & IO_WQ_WORK_CREDS)
|
|
creds = req->work.identity->creds;
|
|
|
|
id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL);
|
|
if (unlikely(!id)) {
|
|
req->work.flags |= IO_WQ_WORK_CANCEL;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* We can safely just re-init the creds we copied Either the field
|
|
* matches the current one, or we haven't grabbed it yet. The only
|
|
* exception is ->creds, through registered personalities, so handle
|
|
* that one separately.
|
|
*/
|
|
io_init_identity(id);
|
|
if (creds)
|
|
req->work.identity->creds = creds;
|
|
|
|
/* add one for this request */
|
|
refcount_inc(&id->count);
|
|
|
|
/* drop tctx and req identity references, if needed */
|
|
if (tctx->identity != &tctx->__identity &&
|
|
refcount_dec_and_test(&tctx->identity->count))
|
|
kfree(tctx->identity);
|
|
if (req->work.identity != &tctx->__identity &&
|
|
refcount_dec_and_test(&req->work.identity->count))
|
|
kfree(req->work.identity);
|
|
|
|
req->work.identity = id;
|
|
tctx->identity = id;
|
|
return true;
|
|
}
|
|
|
|
static bool io_grab_identity(struct io_kiocb *req)
|
|
{
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
struct io_identity *id = req->work.identity;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (def->work_flags & IO_WQ_WORK_FSIZE) {
|
|
if (id->fsize != rlimit(RLIMIT_FSIZE))
|
|
return false;
|
|
req->work.flags |= IO_WQ_WORK_FSIZE;
|
|
}
|
|
|
|
if (!(req->work.flags & IO_WQ_WORK_FILES) &&
|
|
(def->work_flags & IO_WQ_WORK_FILES) &&
|
|
!(req->flags & REQ_F_NO_FILE_TABLE)) {
|
|
if (id->files != current->files ||
|
|
id->nsproxy != current->nsproxy)
|
|
return false;
|
|
atomic_inc(&id->files->count);
|
|
get_nsproxy(id->nsproxy);
|
|
req->flags |= REQ_F_INFLIGHT;
|
|
|
|
spin_lock_irq(&ctx->inflight_lock);
|
|
list_add(&req->inflight_entry, &ctx->inflight_list);
|
|
spin_unlock_irq(&ctx->inflight_lock);
|
|
req->work.flags |= IO_WQ_WORK_FILES;
|
|
}
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
if (!(req->work.flags & IO_WQ_WORK_BLKCG) &&
|
|
(def->work_flags & IO_WQ_WORK_BLKCG)) {
|
|
rcu_read_lock();
|
|
if (id->blkcg_css != blkcg_css()) {
|
|
rcu_read_unlock();
|
|
return false;
|
|
}
|
|
/*
|
|
* This should be rare, either the cgroup is dying or the task
|
|
* is moving cgroups. Just punt to root for the handful of ios.
|
|
*/
|
|
if (css_tryget_online(id->blkcg_css))
|
|
req->work.flags |= IO_WQ_WORK_BLKCG;
|
|
rcu_read_unlock();
|
|
}
|
|
#endif
|
|
if (!(req->work.flags & IO_WQ_WORK_CREDS)) {
|
|
if (id->creds != current_cred())
|
|
return false;
|
|
get_cred(id->creds);
|
|
req->work.flags |= IO_WQ_WORK_CREDS;
|
|
}
|
|
#ifdef CONFIG_AUDIT
|
|
if (!uid_eq(current->loginuid, id->loginuid) ||
|
|
current->sessionid != id->sessionid)
|
|
return false;
|
|
#endif
|
|
if (!(req->work.flags & IO_WQ_WORK_FS) &&
|
|
(def->work_flags & IO_WQ_WORK_FS)) {
|
|
if (current->fs != id->fs)
|
|
return false;
|
|
spin_lock(&id->fs->lock);
|
|
if (!id->fs->in_exec) {
|
|
id->fs->users++;
|
|
req->work.flags |= IO_WQ_WORK_FS;
|
|
} else {
|
|
req->work.flags |= IO_WQ_WORK_CANCEL;
|
|
}
|
|
spin_unlock(¤t->fs->lock);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static void io_prep_async_work(struct io_kiocb *req)
|
|
{
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_identity *id;
|
|
|
|
io_req_init_async(req);
|
|
id = req->work.identity;
|
|
|
|
if (req->flags & REQ_F_FORCE_ASYNC)
|
|
req->work.flags |= IO_WQ_WORK_CONCURRENT;
|
|
|
|
if (req->flags & REQ_F_ISREG) {
|
|
if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
|
|
io_wq_hash_work(&req->work, file_inode(req->file));
|
|
} else {
|
|
if (def->unbound_nonreg_file)
|
|
req->work.flags |= IO_WQ_WORK_UNBOUND;
|
|
}
|
|
|
|
/* ->mm can never change on us */
|
|
if (!(req->work.flags & IO_WQ_WORK_MM) &&
|
|
(def->work_flags & IO_WQ_WORK_MM)) {
|
|
mmgrab(id->mm);
|
|
req->work.flags |= IO_WQ_WORK_MM;
|
|
}
|
|
|
|
/* if we fail grabbing identity, we must COW, regrab, and retry */
|
|
if (io_grab_identity(req))
|
|
return;
|
|
|
|
if (!io_identity_cow(req))
|
|
return;
|
|
|
|
/* can't fail at this point */
|
|
if (!io_grab_identity(req))
|
|
WARN_ON(1);
|
|
}
|
|
|
|
static void io_prep_async_link(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *cur;
|
|
|
|
io_prep_async_work(req);
|
|
if (req->flags & REQ_F_LINK_HEAD)
|
|
list_for_each_entry(cur, &req->link_list, link_list)
|
|
io_prep_async_work(cur);
|
|
}
|
|
|
|
static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *link = io_prep_linked_timeout(req);
|
|
|
|
trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
|
|
&req->work, req->flags);
|
|
io_wq_enqueue(ctx->io_wq, &req->work);
|
|
return link;
|
|
}
|
|
|
|
static void io_queue_async_work(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *link;
|
|
|
|
/* init ->work of the whole link before punting */
|
|
io_prep_async_link(req);
|
|
link = __io_queue_async_work(req);
|
|
|
|
if (link)
|
|
io_queue_linked_timeout(link);
|
|
}
|
|
|
|
static void io_kill_timeout(struct io_kiocb *req)
|
|
{
|
|
struct io_timeout_data *io = req->async_data;
|
|
int ret;
|
|
|
|
ret = hrtimer_try_to_cancel(&io->timer);
|
|
if (ret != -1) {
|
|
atomic_set(&req->ctx->cq_timeouts,
|
|
atomic_read(&req->ctx->cq_timeouts) + 1);
|
|
list_del_init(&req->timeout.list);
|
|
io_cqring_fill_event(req, 0);
|
|
io_put_req_deferred(req, 1);
|
|
}
|
|
}
|
|
|
|
static bool io_task_match(struct io_kiocb *req, struct task_struct *tsk)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!tsk || req->task == tsk)
|
|
return true;
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
if (ctx->sq_data && req->task == ctx->sq_data->thread)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Returns true if we found and killed one or more timeouts
|
|
*/
|
|
static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk)
|
|
{
|
|
struct io_kiocb *req, *tmp;
|
|
int canceled = 0;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
|
|
if (io_task_match(req, tsk)) {
|
|
io_kill_timeout(req);
|
|
canceled++;
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
return canceled != 0;
|
|
}
|
|
|
|
static void __io_queue_deferred(struct io_ring_ctx *ctx)
|
|
{
|
|
do {
|
|
struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
|
|
struct io_defer_entry, list);
|
|
struct io_kiocb *link;
|
|
|
|
if (req_need_defer(de->req, de->seq))
|
|
break;
|
|
list_del_init(&de->list);
|
|
/* punt-init is done before queueing for defer */
|
|
link = __io_queue_async_work(de->req);
|
|
if (link) {
|
|
__io_queue_linked_timeout(link);
|
|
/* drop submission reference */
|
|
io_put_req_deferred(link, 1);
|
|
}
|
|
kfree(de);
|
|
} while (!list_empty(&ctx->defer_list));
|
|
}
|
|
|
|
static void io_flush_timeouts(struct io_ring_ctx *ctx)
|
|
{
|
|
while (!list_empty(&ctx->timeout_list)) {
|
|
struct io_kiocb *req = list_first_entry(&ctx->timeout_list,
|
|
struct io_kiocb, timeout.list);
|
|
|
|
if (io_is_timeout_noseq(req))
|
|
break;
|
|
if (req->timeout.target_seq != ctx->cached_cq_tail
|
|
- atomic_read(&ctx->cq_timeouts))
|
|
break;
|
|
|
|
list_del_init(&req->timeout.list);
|
|
io_kill_timeout(req);
|
|
}
|
|
}
|
|
|
|
static void io_commit_cqring(struct io_ring_ctx *ctx)
|
|
{
|
|
io_flush_timeouts(ctx);
|
|
__io_commit_cqring(ctx);
|
|
|
|
if (unlikely(!list_empty(&ctx->defer_list)))
|
|
__io_queue_deferred(ctx);
|
|
}
|
|
|
|
static inline bool io_sqring_full(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *r = ctx->rings;
|
|
|
|
return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
|
|
}
|
|
|
|
static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
unsigned tail;
|
|
|
|
tail = ctx->cached_cq_tail;
|
|
/*
|
|
* writes to the cq entry need to come after reading head; the
|
|
* control dependency is enough as we're using WRITE_ONCE to
|
|
* fill the cq entry
|
|
*/
|
|
if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
|
|
return NULL;
|
|
|
|
ctx->cached_cq_tail++;
|
|
return &rings->cqes[tail & ctx->cq_mask];
|
|
}
|
|
|
|
static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!ctx->cq_ev_fd)
|
|
return false;
|
|
if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
|
|
return false;
|
|
if (!ctx->eventfd_async)
|
|
return true;
|
|
return io_wq_current_is_worker();
|
|
}
|
|
|
|
static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
|
|
{
|
|
if (waitqueue_active(&ctx->wait))
|
|
wake_up(&ctx->wait);
|
|
if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
|
|
wake_up(&ctx->sq_data->wait);
|
|
if (io_should_trigger_evfd(ctx))
|
|
eventfd_signal(ctx->cq_ev_fd, 1);
|
|
}
|
|
|
|
static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
|
|
{
|
|
if (list_empty(&ctx->cq_overflow_list)) {
|
|
clear_bit(0, &ctx->sq_check_overflow);
|
|
clear_bit(0, &ctx->cq_check_overflow);
|
|
ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
|
|
}
|
|
}
|
|
|
|
static inline bool __io_match_files(struct io_kiocb *req,
|
|
struct files_struct *files)
|
|
{
|
|
return ((req->flags & REQ_F_WORK_INITIALIZED) &&
|
|
(req->work.flags & IO_WQ_WORK_FILES)) &&
|
|
req->work.identity->files == files;
|
|
}
|
|
|
|
static bool io_match_files(struct io_kiocb *req,
|
|
struct files_struct *files)
|
|
{
|
|
struct io_kiocb *link;
|
|
|
|
if (!files)
|
|
return true;
|
|
if (__io_match_files(req, files))
|
|
return true;
|
|
if (req->flags & REQ_F_LINK_HEAD) {
|
|
list_for_each_entry(link, &req->link_list, link_list) {
|
|
if (__io_match_files(link, files))
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Returns true if there are no backlogged entries after the flush */
|
|
static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
|
|
struct task_struct *tsk,
|
|
struct files_struct *files)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
struct io_kiocb *req, *tmp;
|
|
struct io_uring_cqe *cqe;
|
|
unsigned long flags;
|
|
LIST_HEAD(list);
|
|
|
|
if (!force) {
|
|
if (list_empty_careful(&ctx->cq_overflow_list))
|
|
return true;
|
|
if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) ==
|
|
rings->cq_ring_entries))
|
|
return false;
|
|
}
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
|
|
/* if force is set, the ring is going away. always drop after that */
|
|
if (force)
|
|
ctx->cq_overflow_flushed = 1;
|
|
|
|
cqe = NULL;
|
|
list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
|
|
if (tsk && req->task != tsk)
|
|
continue;
|
|
if (!io_match_files(req, files))
|
|
continue;
|
|
|
|
cqe = io_get_cqring(ctx);
|
|
if (!cqe && !force)
|
|
break;
|
|
|
|
list_move(&req->compl.list, &list);
|
|
if (cqe) {
|
|
WRITE_ONCE(cqe->user_data, req->user_data);
|
|
WRITE_ONCE(cqe->res, req->result);
|
|
WRITE_ONCE(cqe->flags, req->compl.cflags);
|
|
} else {
|
|
ctx->cached_cq_overflow++;
|
|
WRITE_ONCE(ctx->rings->cq_overflow,
|
|
ctx->cached_cq_overflow);
|
|
}
|
|
}
|
|
|
|
io_commit_cqring(ctx);
|
|
io_cqring_mark_overflow(ctx);
|
|
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
io_cqring_ev_posted(ctx);
|
|
|
|
while (!list_empty(&list)) {
|
|
req = list_first_entry(&list, struct io_kiocb, compl.list);
|
|
list_del(&req->compl.list);
|
|
io_put_req(req);
|
|
}
|
|
|
|
return cqe != NULL;
|
|
}
|
|
|
|
static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_uring_cqe *cqe;
|
|
|
|
trace_io_uring_complete(ctx, req->user_data, res);
|
|
|
|
/*
|
|
* If we can't get a cq entry, userspace overflowed the
|
|
* submission (by quite a lot). Increment the overflow count in
|
|
* the ring.
|
|
*/
|
|
cqe = io_get_cqring(ctx);
|
|
if (likely(cqe)) {
|
|
WRITE_ONCE(cqe->user_data, req->user_data);
|
|
WRITE_ONCE(cqe->res, res);
|
|
WRITE_ONCE(cqe->flags, cflags);
|
|
} else if (ctx->cq_overflow_flushed ||
|
|
atomic_read(&req->task->io_uring->in_idle)) {
|
|
/*
|
|
* If we're in ring overflow flush mode, or in task cancel mode,
|
|
* then we cannot store the request for later flushing, we need
|
|
* to drop it on the floor.
|
|
*/
|
|
ctx->cached_cq_overflow++;
|
|
WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow);
|
|
} else {
|
|
if (list_empty(&ctx->cq_overflow_list)) {
|
|
set_bit(0, &ctx->sq_check_overflow);
|
|
set_bit(0, &ctx->cq_check_overflow);
|
|
ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW;
|
|
}
|
|
io_clean_op(req);
|
|
req->result = res;
|
|
req->compl.cflags = cflags;
|
|
refcount_inc(&req->refs);
|
|
list_add_tail(&req->compl.list, &ctx->cq_overflow_list);
|
|
}
|
|
}
|
|
|
|
static void io_cqring_fill_event(struct io_kiocb *req, long res)
|
|
{
|
|
__io_cqring_fill_event(req, res, 0);
|
|
}
|
|
|
|
static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
__io_cqring_fill_event(req, res, cflags);
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
io_cqring_ev_posted(ctx);
|
|
}
|
|
|
|
static void io_submit_flush_completions(struct io_comp_state *cs)
|
|
{
|
|
struct io_ring_ctx *ctx = cs->ctx;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
while (!list_empty(&cs->list)) {
|
|
struct io_kiocb *req;
|
|
|
|
req = list_first_entry(&cs->list, struct io_kiocb, compl.list);
|
|
list_del(&req->compl.list);
|
|
__io_cqring_fill_event(req, req->result, req->compl.cflags);
|
|
|
|
/*
|
|
* io_free_req() doesn't care about completion_lock unless one
|
|
* of these flags is set. REQ_F_WORK_INITIALIZED is in the list
|
|
* because of a potential deadlock with req->work.fs->lock
|
|
*/
|
|
if (req->flags & (REQ_F_FAIL_LINK|REQ_F_LINK_TIMEOUT
|
|
|REQ_F_WORK_INITIALIZED)) {
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
io_put_req(req);
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
} else {
|
|
io_put_req(req);
|
|
}
|
|
}
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
io_cqring_ev_posted(ctx);
|
|
cs->nr = 0;
|
|
}
|
|
|
|
static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags,
|
|
struct io_comp_state *cs)
|
|
{
|
|
if (!cs) {
|
|
io_cqring_add_event(req, res, cflags);
|
|
io_put_req(req);
|
|
} else {
|
|
io_clean_op(req);
|
|
req->result = res;
|
|
req->compl.cflags = cflags;
|
|
list_add_tail(&req->compl.list, &cs->list);
|
|
if (++cs->nr >= 32)
|
|
io_submit_flush_completions(cs);
|
|
}
|
|
}
|
|
|
|
static void io_req_complete(struct io_kiocb *req, long res)
|
|
{
|
|
__io_req_complete(req, res, 0, NULL);
|
|
}
|
|
|
|
static inline bool io_is_fallback_req(struct io_kiocb *req)
|
|
{
|
|
return req == (struct io_kiocb *)
|
|
((unsigned long) req->ctx->fallback_req & ~1UL);
|
|
}
|
|
|
|
static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_kiocb *req;
|
|
|
|
req = ctx->fallback_req;
|
|
if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
|
|
return req;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
|
|
struct io_submit_state *state)
|
|
{
|
|
if (!state->free_reqs) {
|
|
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
|
|
size_t sz;
|
|
int ret;
|
|
|
|
sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
|
|
ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
|
|
|
|
/*
|
|
* Bulk alloc is all-or-nothing. If we fail to get a batch,
|
|
* retry single alloc to be on the safe side.
|
|
*/
|
|
if (unlikely(ret <= 0)) {
|
|
state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
|
|
if (!state->reqs[0])
|
|
goto fallback;
|
|
ret = 1;
|
|
}
|
|
state->free_reqs = ret;
|
|
}
|
|
|
|
state->free_reqs--;
|
|
return state->reqs[state->free_reqs];
|
|
fallback:
|
|
return io_get_fallback_req(ctx);
|
|
}
|
|
|
|
static inline void io_put_file(struct io_kiocb *req, struct file *file,
|
|
bool fixed)
|
|
{
|
|
if (fixed)
|
|
percpu_ref_put(req->fixed_file_refs);
|
|
else
|
|
fput(file);
|
|
}
|
|
|
|
static void io_dismantle_req(struct io_kiocb *req)
|
|
{
|
|
io_clean_op(req);
|
|
|
|
if (req->async_data)
|
|
kfree(req->async_data);
|
|
if (req->file)
|
|
io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
|
|
|
|
io_req_clean_work(req);
|
|
}
|
|
|
|
static void __io_free_req(struct io_kiocb *req)
|
|
{
|
|
struct io_uring_task *tctx = req->task->io_uring;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_dismantle_req(req);
|
|
|
|
percpu_counter_dec(&tctx->inflight);
|
|
if (atomic_read(&tctx->in_idle))
|
|
wake_up(&tctx->wait);
|
|
put_task_struct(req->task);
|
|
|
|
if (likely(!io_is_fallback_req(req)))
|
|
kmem_cache_free(req_cachep, req);
|
|
else
|
|
clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
static void io_kill_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *link;
|
|
bool cancelled = false;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
link = list_first_entry_or_null(&req->link_list, struct io_kiocb,
|
|
link_list);
|
|
/*
|
|
* Can happen if a linked timeout fired and link had been like
|
|
* req -> link t-out -> link t-out [-> ...]
|
|
*/
|
|
if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) {
|
|
struct io_timeout_data *io = link->async_data;
|
|
int ret;
|
|
|
|
list_del_init(&link->link_list);
|
|
ret = hrtimer_try_to_cancel(&io->timer);
|
|
if (ret != -1) {
|
|
io_cqring_fill_event(link, -ECANCELED);
|
|
io_commit_cqring(ctx);
|
|
cancelled = true;
|
|
}
|
|
}
|
|
req->flags &= ~REQ_F_LINK_TIMEOUT;
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
if (cancelled) {
|
|
io_cqring_ev_posted(ctx);
|
|
io_put_req(link);
|
|
}
|
|
}
|
|
|
|
static struct io_kiocb *io_req_link_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt;
|
|
|
|
/*
|
|
* The list should never be empty when we are called here. But could
|
|
* potentially happen if the chain is messed up, check to be on the
|
|
* safe side.
|
|
*/
|
|
if (unlikely(list_empty(&req->link_list)))
|
|
return NULL;
|
|
|
|
nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list);
|
|
list_del_init(&req->link_list);
|
|
if (!list_empty(&nxt->link_list))
|
|
nxt->flags |= REQ_F_LINK_HEAD;
|
|
return nxt;
|
|
}
|
|
|
|
/*
|
|
* Called if REQ_F_LINK_HEAD is set, and we fail the head request
|
|
*/
|
|
static void io_fail_links(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
while (!list_empty(&req->link_list)) {
|
|
struct io_kiocb *link = list_first_entry(&req->link_list,
|
|
struct io_kiocb, link_list);
|
|
|
|
list_del_init(&link->link_list);
|
|
trace_io_uring_fail_link(req, link);
|
|
|
|
io_cqring_fill_event(link, -ECANCELED);
|
|
|
|
/*
|
|
* It's ok to free under spinlock as they're not linked anymore,
|
|
* but avoid REQ_F_WORK_INITIALIZED because it may deadlock on
|
|
* work.fs->lock.
|
|
*/
|
|
if (link->flags & REQ_F_WORK_INITIALIZED)
|
|
io_put_req_deferred(link, 2);
|
|
else
|
|
io_double_put_req(link);
|
|
}
|
|
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
io_cqring_ev_posted(ctx);
|
|
}
|
|
|
|
static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
|
|
{
|
|
req->flags &= ~REQ_F_LINK_HEAD;
|
|
if (req->flags & REQ_F_LINK_TIMEOUT)
|
|
io_kill_linked_timeout(req);
|
|
|
|
/*
|
|
* If LINK is set, we have dependent requests in this chain. If we
|
|
* didn't fail this request, queue the first one up, moving any other
|
|
* dependencies to the next request. In case of failure, fail the rest
|
|
* of the chain.
|
|
*/
|
|
if (likely(!(req->flags & REQ_F_FAIL_LINK)))
|
|
return io_req_link_next(req);
|
|
io_fail_links(req);
|
|
return NULL;
|
|
}
|
|
|
|
static struct io_kiocb *io_req_find_next(struct io_kiocb *req)
|
|
{
|
|
if (likely(!(req->flags & REQ_F_LINK_HEAD)))
|
|
return NULL;
|
|
return __io_req_find_next(req);
|
|
}
|
|
|
|
static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok)
|
|
{
|
|
struct task_struct *tsk = req->task;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
enum task_work_notify_mode notify;
|
|
int ret;
|
|
|
|
if (tsk->flags & PF_EXITING)
|
|
return -ESRCH;
|
|
|
|
/*
|
|
* SQPOLL kernel thread doesn't need notification, just a wakeup. For
|
|
* all other cases, use TWA_SIGNAL unconditionally to ensure we're
|
|
* processing task_work. There's no reliable way to tell if TWA_RESUME
|
|
* will do the job.
|
|
*/
|
|
notify = TWA_NONE;
|
|
if (!(ctx->flags & IORING_SETUP_SQPOLL) && twa_signal_ok)
|
|
notify = TWA_SIGNAL;
|
|
|
|
ret = task_work_add(tsk, &req->task_work, notify);
|
|
if (!ret)
|
|
wake_up_process(tsk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __io_req_task_cancel(struct io_kiocb *req, int error)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
io_cqring_fill_event(req, error);
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
io_cqring_ev_posted(ctx);
|
|
req_set_fail_links(req);
|
|
io_double_put_req(req);
|
|
}
|
|
|
|
static void io_req_task_cancel(struct callback_head *cb)
|
|
{
|
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
__io_req_task_cancel(req, -ECANCELED);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
static void __io_req_task_submit(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!__io_sq_thread_acquire_mm(ctx)) {
|
|
mutex_lock(&ctx->uring_lock);
|
|
__io_queue_sqe(req, NULL);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
} else {
|
|
__io_req_task_cancel(req, -EFAULT);
|
|
}
|
|
}
|
|
|
|
static void io_req_task_submit(struct callback_head *cb)
|
|
{
|
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
__io_req_task_submit(req);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
static void io_req_task_queue(struct io_kiocb *req)
|
|
{
|
|
int ret;
|
|
|
|
init_task_work(&req->task_work, io_req_task_submit);
|
|
percpu_ref_get(&req->ctx->refs);
|
|
|
|
ret = io_req_task_work_add(req, true);
|
|
if (unlikely(ret)) {
|
|
struct task_struct *tsk;
|
|
|
|
init_task_work(&req->task_work, io_req_task_cancel);
|
|
tsk = io_wq_get_task(req->ctx->io_wq);
|
|
task_work_add(tsk, &req->task_work, TWA_NONE);
|
|
wake_up_process(tsk);
|
|
}
|
|
}
|
|
|
|
static void io_queue_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt = io_req_find_next(req);
|
|
|
|
if (nxt)
|
|
io_req_task_queue(nxt);
|
|
}
|
|
|
|
static void io_free_req(struct io_kiocb *req)
|
|
{
|
|
io_queue_next(req);
|
|
__io_free_req(req);
|
|
}
|
|
|
|
struct req_batch {
|
|
void *reqs[IO_IOPOLL_BATCH];
|
|
int to_free;
|
|
|
|
struct task_struct *task;
|
|
int task_refs;
|
|
};
|
|
|
|
static inline void io_init_req_batch(struct req_batch *rb)
|
|
{
|
|
rb->to_free = 0;
|
|
rb->task_refs = 0;
|
|
rb->task = NULL;
|
|
}
|
|
|
|
static void __io_req_free_batch_flush(struct io_ring_ctx *ctx,
|
|
struct req_batch *rb)
|
|
{
|
|
kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
|
|
percpu_ref_put_many(&ctx->refs, rb->to_free);
|
|
rb->to_free = 0;
|
|
}
|
|
|
|
static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
|
|
struct req_batch *rb)
|
|
{
|
|
if (rb->to_free)
|
|
__io_req_free_batch_flush(ctx, rb);
|
|
if (rb->task) {
|
|
struct io_uring_task *tctx = rb->task->io_uring;
|
|
|
|
percpu_counter_sub(&tctx->inflight, rb->task_refs);
|
|
put_task_struct_many(rb->task, rb->task_refs);
|
|
rb->task = NULL;
|
|
}
|
|
}
|
|
|
|
static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
|
|
{
|
|
if (unlikely(io_is_fallback_req(req))) {
|
|
io_free_req(req);
|
|
return;
|
|
}
|
|
if (req->flags & REQ_F_LINK_HEAD)
|
|
io_queue_next(req);
|
|
|
|
if (req->task != rb->task) {
|
|
if (rb->task) {
|
|
struct io_uring_task *tctx = rb->task->io_uring;
|
|
|
|
percpu_counter_sub(&tctx->inflight, rb->task_refs);
|
|
put_task_struct_many(rb->task, rb->task_refs);
|
|
}
|
|
rb->task = req->task;
|
|
rb->task_refs = 0;
|
|
}
|
|
rb->task_refs++;
|
|
|
|
io_dismantle_req(req);
|
|
rb->reqs[rb->to_free++] = req;
|
|
if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
|
|
__io_req_free_batch_flush(req->ctx, rb);
|
|
}
|
|
|
|
/*
|
|
* Drop reference to request, return next in chain (if there is one) if this
|
|
* was the last reference to this request.
|
|
*/
|
|
static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt = NULL;
|
|
|
|
if (refcount_dec_and_test(&req->refs)) {
|
|
nxt = io_req_find_next(req);
|
|
__io_free_req(req);
|
|
}
|
|
return nxt;
|
|
}
|
|
|
|
static void io_put_req(struct io_kiocb *req)
|
|
{
|
|
if (refcount_dec_and_test(&req->refs))
|
|
io_free_req(req);
|
|
}
|
|
|
|
static void io_put_req_deferred_cb(struct callback_head *cb)
|
|
{
|
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
|
|
|
|
io_free_req(req);
|
|
}
|
|
|
|
static void io_free_req_deferred(struct io_kiocb *req)
|
|
{
|
|
int ret;
|
|
|
|
init_task_work(&req->task_work, io_put_req_deferred_cb);
|
|
ret = io_req_task_work_add(req, true);
|
|
if (unlikely(ret)) {
|
|
struct task_struct *tsk;
|
|
|
|
tsk = io_wq_get_task(req->ctx->io_wq);
|
|
task_work_add(tsk, &req->task_work, TWA_NONE);
|
|
wake_up_process(tsk);
|
|
}
|
|
}
|
|
|
|
static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
|
|
{
|
|
if (refcount_sub_and_test(refs, &req->refs))
|
|
io_free_req_deferred(req);
|
|
}
|
|
|
|
static struct io_wq_work *io_steal_work(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt;
|
|
|
|
/*
|
|
* A ref is owned by io-wq in which context we're. So, if that's the
|
|
* last one, it's safe to steal next work. False negatives are Ok,
|
|
* it just will be re-punted async in io_put_work()
|
|
*/
|
|
if (refcount_read(&req->refs) != 1)
|
|
return NULL;
|
|
|
|
nxt = io_req_find_next(req);
|
|
return nxt ? &nxt->work : NULL;
|
|
}
|
|
|
|
static void io_double_put_req(struct io_kiocb *req)
|
|
{
|
|
/* drop both submit and complete references */
|
|
if (refcount_sub_and_test(2, &req->refs))
|
|
io_free_req(req);
|
|
}
|
|
|
|
static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
|
|
if (test_bit(0, &ctx->cq_check_overflow)) {
|
|
/*
|
|
* noflush == true is from the waitqueue handler, just ensure
|
|
* we wake up the task, and the next invocation will flush the
|
|
* entries. We cannot safely to it from here.
|
|
*/
|
|
if (noflush && !list_empty(&ctx->cq_overflow_list))
|
|
return -1U;
|
|
|
|
io_cqring_overflow_flush(ctx, false, NULL, NULL);
|
|
}
|
|
|
|
/* See comment at the top of this file */
|
|
smp_rmb();
|
|
return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
|
|
}
|
|
|
|
static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
|
|
/* make sure SQ entry isn't read before tail */
|
|
return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
|
|
}
|
|
|
|
static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
|
|
{
|
|
unsigned int cflags;
|
|
|
|
cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
|
|
cflags |= IORING_CQE_F_BUFFER;
|
|
req->flags &= ~REQ_F_BUFFER_SELECTED;
|
|
kfree(kbuf);
|
|
return cflags;
|
|
}
|
|
|
|
static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
|
|
{
|
|
struct io_buffer *kbuf;
|
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
|
|
return io_put_kbuf(req, kbuf);
|
|
}
|
|
|
|
static inline bool io_run_task_work(void)
|
|
{
|
|
/*
|
|
* Not safe to run on exiting task, and the task_work handling will
|
|
* not add work to such a task.
|
|
*/
|
|
if (unlikely(current->flags & PF_EXITING))
|
|
return false;
|
|
if (current->task_works) {
|
|
__set_current_state(TASK_RUNNING);
|
|
task_work_run();
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void io_iopoll_queue(struct list_head *again)
|
|
{
|
|
struct io_kiocb *req;
|
|
|
|
do {
|
|
req = list_first_entry(again, struct io_kiocb, inflight_entry);
|
|
list_del(&req->inflight_entry);
|
|
__io_complete_rw(req, -EAGAIN, 0, NULL);
|
|
} while (!list_empty(again));
|
|
}
|
|
|
|
/*
|
|
* Find and free completed poll iocbs
|
|
*/
|
|
static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
|
|
struct list_head *done)
|
|
{
|
|
struct req_batch rb;
|
|
struct io_kiocb *req;
|
|
LIST_HEAD(again);
|
|
|
|
/* order with ->result store in io_complete_rw_iopoll() */
|
|
smp_rmb();
|
|
|
|
io_init_req_batch(&rb);
|
|
while (!list_empty(done)) {
|
|
int cflags = 0;
|
|
|
|
req = list_first_entry(done, struct io_kiocb, inflight_entry);
|
|
if (READ_ONCE(req->result) == -EAGAIN) {
|
|
req->result = 0;
|
|
req->iopoll_completed = 0;
|
|
list_move_tail(&req->inflight_entry, &again);
|
|
continue;
|
|
}
|
|
list_del(&req->inflight_entry);
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED)
|
|
cflags = io_put_rw_kbuf(req);
|
|
|
|
__io_cqring_fill_event(req, req->result, cflags);
|
|
(*nr_events)++;
|
|
|
|
if (refcount_dec_and_test(&req->refs))
|
|
io_req_free_batch(&rb, req);
|
|
}
|
|
|
|
io_commit_cqring(ctx);
|
|
if (ctx->flags & IORING_SETUP_SQPOLL)
|
|
io_cqring_ev_posted(ctx);
|
|
io_req_free_batch_finish(ctx, &rb);
|
|
|
|
if (!list_empty(&again))
|
|
io_iopoll_queue(&again);
|
|
}
|
|
|
|
static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
|
|
long min)
|
|
{
|
|
struct io_kiocb *req, *tmp;
|
|
LIST_HEAD(done);
|
|
bool spin;
|
|
int ret;
|
|
|
|
/*
|
|
* Only spin for completions if we don't have multiple devices hanging
|
|
* off our complete list, and we're under the requested amount.
|
|
*/
|
|
spin = !ctx->poll_multi_file && *nr_events < min;
|
|
|
|
ret = 0;
|
|
list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
|
|
/*
|
|
* Move completed and retryable entries to our local lists.
|
|
* If we find a request that requires polling, break out
|
|
* and complete those lists first, if we have entries there.
|
|
*/
|
|
if (READ_ONCE(req->iopoll_completed)) {
|
|
list_move_tail(&req->inflight_entry, &done);
|
|
continue;
|
|
}
|
|
if (!list_empty(&done))
|
|
break;
|
|
|
|
ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
/* iopoll may have completed current req */
|
|
if (READ_ONCE(req->iopoll_completed))
|
|
list_move_tail(&req->inflight_entry, &done);
|
|
|
|
if (ret && spin)
|
|
spin = false;
|
|
ret = 0;
|
|
}
|
|
|
|
if (!list_empty(&done))
|
|
io_iopoll_complete(ctx, nr_events, &done);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
|
|
* non-spinning poll check - we'll still enter the driver poll loop, but only
|
|
* as a non-spinning completion check.
|
|
*/
|
|
static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
|
|
long min)
|
|
{
|
|
while (!list_empty(&ctx->iopoll_list) && !need_resched()) {
|
|
int ret;
|
|
|
|
ret = io_do_iopoll(ctx, nr_events, min);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (*nr_events >= min)
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* We can't just wait for polled events to come to us, we have to actively
|
|
* find and complete them.
|
|
*/
|
|
static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
while (!list_empty(&ctx->iopoll_list)) {
|
|
unsigned int nr_events = 0;
|
|
|
|
io_do_iopoll(ctx, &nr_events, 0);
|
|
|
|
/* let it sleep and repeat later if can't complete a request */
|
|
if (nr_events == 0)
|
|
break;
|
|
/*
|
|
* Ensure we allow local-to-the-cpu processing to take place,
|
|
* in this case we need to ensure that we reap all events.
|
|
* Also let task_work, etc. to progress by releasing the mutex
|
|
*/
|
|
if (need_resched()) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
cond_resched();
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
|
|
{
|
|
unsigned int nr_events = 0;
|
|
int iters = 0, ret = 0;
|
|
|
|
/*
|
|
* We disallow the app entering submit/complete with polling, but we
|
|
* still need to lock the ring to prevent racing with polled issue
|
|
* that got punted to a workqueue.
|
|
*/
|
|
mutex_lock(&ctx->uring_lock);
|
|
do {
|
|
/*
|
|
* Don't enter poll loop if we already have events pending.
|
|
* If we do, we can potentially be spinning for commands that
|
|
* already triggered a CQE (eg in error).
|
|
*/
|
|
if (io_cqring_events(ctx, false))
|
|
break;
|
|
|
|
/*
|
|
* If a submit got punted to a workqueue, we can have the
|
|
* application entering polling for a command before it gets
|
|
* issued. That app will hold the uring_lock for the duration
|
|
* of the poll right here, so we need to take a breather every
|
|
* now and then to ensure that the issue has a chance to add
|
|
* the poll to the issued list. Otherwise we can spin here
|
|
* forever, while the workqueue is stuck trying to acquire the
|
|
* very same mutex.
|
|
*/
|
|
if (!(++iters & 7)) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
io_run_task_work();
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
|
|
ret = io_iopoll_getevents(ctx, &nr_events, min);
|
|
if (ret <= 0)
|
|
break;
|
|
ret = 0;
|
|
} while (min && !nr_events && !need_resched());
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
return ret;
|
|
}
|
|
|
|
static void kiocb_end_write(struct io_kiocb *req)
|
|
{
|
|
/*
|
|
* Tell lockdep we inherited freeze protection from submission
|
|
* thread.
|
|
*/
|
|
if (req->flags & REQ_F_ISREG) {
|
|
struct inode *inode = file_inode(req->file);
|
|
|
|
__sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
|
|
}
|
|
file_end_write(req->file);
|
|
}
|
|
|
|
static void io_complete_rw_common(struct kiocb *kiocb, long res,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
|
|
int cflags = 0;
|
|
|
|
if (kiocb->ki_flags & IOCB_WRITE)
|
|
kiocb_end_write(req);
|
|
|
|
if (res != req->result)
|
|
req_set_fail_links(req);
|
|
if (req->flags & REQ_F_BUFFER_SELECTED)
|
|
cflags = io_put_rw_kbuf(req);
|
|
__io_req_complete(req, res, cflags, cs);
|
|
}
|
|
|
|
#ifdef CONFIG_BLOCK
|
|
static bool io_resubmit_prep(struct io_kiocb *req, int error)
|
|
{
|
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
|
|
ssize_t ret = -ECANCELED;
|
|
struct iov_iter iter;
|
|
int rw;
|
|
|
|
if (error) {
|
|
ret = error;
|
|
goto end_req;
|
|
}
|
|
|
|
switch (req->opcode) {
|
|
case IORING_OP_READV:
|
|
case IORING_OP_READ_FIXED:
|
|
case IORING_OP_READ:
|
|
rw = READ;
|
|
break;
|
|
case IORING_OP_WRITEV:
|
|
case IORING_OP_WRITE_FIXED:
|
|
case IORING_OP_WRITE:
|
|
rw = WRITE;
|
|
break;
|
|
default:
|
|
printk_once(KERN_WARNING "io_uring: bad opcode in resubmit %d\n",
|
|
req->opcode);
|
|
goto end_req;
|
|
}
|
|
|
|
if (!req->async_data) {
|
|
ret = io_import_iovec(rw, req, &iovec, &iter, false);
|
|
if (ret < 0)
|
|
goto end_req;
|
|
ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false);
|
|
if (!ret)
|
|
return true;
|
|
kfree(iovec);
|
|
} else {
|
|
return true;
|
|
}
|
|
end_req:
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
static bool io_rw_reissue(struct io_kiocb *req, long res)
|
|
{
|
|
#ifdef CONFIG_BLOCK
|
|
umode_t mode = file_inode(req->file)->i_mode;
|
|
int ret;
|
|
|
|
if (!S_ISBLK(mode) && !S_ISREG(mode))
|
|
return false;
|
|
if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
|
|
return false;
|
|
|
|
ret = io_sq_thread_acquire_mm(req->ctx, req);
|
|
|
|
if (io_resubmit_prep(req, ret)) {
|
|
refcount_inc(&req->refs);
|
|
io_queue_async_work(req);
|
|
return true;
|
|
}
|
|
|
|
#endif
|
|
return false;
|
|
}
|
|
|
|
static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
|
|
struct io_comp_state *cs)
|
|
{
|
|
if (!io_rw_reissue(req, res))
|
|
io_complete_rw_common(&req->rw.kiocb, res, cs);
|
|
}
|
|
|
|
static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
|
|
{
|
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
|
|
|
|
__io_complete_rw(req, res, res2, NULL);
|
|
}
|
|
|
|
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
|
|
{
|
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
|
|
|
|
if (kiocb->ki_flags & IOCB_WRITE)
|
|
kiocb_end_write(req);
|
|
|
|
if (res != -EAGAIN && res != req->result)
|
|
req_set_fail_links(req);
|
|
|
|
WRITE_ONCE(req->result, res);
|
|
/* order with io_poll_complete() checking ->result */
|
|
smp_wmb();
|
|
WRITE_ONCE(req->iopoll_completed, 1);
|
|
}
|
|
|
|
/*
|
|
* After the iocb has been issued, it's safe to be found on the poll list.
|
|
* Adding the kiocb to the list AFTER submission ensures that we don't
|
|
* find it from a io_iopoll_getevents() thread before the issuer is done
|
|
* accessing the kiocb cookie.
|
|
*/
|
|
static void io_iopoll_req_issued(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
/*
|
|
* Track whether we have multiple files in our lists. This will impact
|
|
* how we do polling eventually, not spinning if we're on potentially
|
|
* different devices.
|
|
*/
|
|
if (list_empty(&ctx->iopoll_list)) {
|
|
ctx->poll_multi_file = false;
|
|
} else if (!ctx->poll_multi_file) {
|
|
struct io_kiocb *list_req;
|
|
|
|
list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
|
|
inflight_entry);
|
|
if (list_req->file != req->file)
|
|
ctx->poll_multi_file = true;
|
|
}
|
|
|
|
/*
|
|
* For fast devices, IO may have already completed. If it has, add
|
|
* it to the front so we find it first.
|
|
*/
|
|
if (READ_ONCE(req->iopoll_completed))
|
|
list_add(&req->inflight_entry, &ctx->iopoll_list);
|
|
else
|
|
list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
|
|
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) &&
|
|
wq_has_sleeper(&ctx->sq_data->wait))
|
|
wake_up(&ctx->sq_data->wait);
|
|
}
|
|
|
|
static void __io_state_file_put(struct io_submit_state *state)
|
|
{
|
|
if (state->has_refs)
|
|
fput_many(state->file, state->has_refs);
|
|
state->file = NULL;
|
|
}
|
|
|
|
static inline void io_state_file_put(struct io_submit_state *state)
|
|
{
|
|
if (state->file)
|
|
__io_state_file_put(state);
|
|
}
|
|
|
|
/*
|
|
* Get as many references to a file as we have IOs left in this submission,
|
|
* assuming most submissions are for one file, or at least that each file
|
|
* has more than one submission.
|
|
*/
|
|
static struct file *__io_file_get(struct io_submit_state *state, int fd)
|
|
{
|
|
if (!state)
|
|
return fget(fd);
|
|
|
|
if (state->file) {
|
|
if (state->fd == fd) {
|
|
state->has_refs--;
|
|
return state->file;
|
|
}
|
|
__io_state_file_put(state);
|
|
}
|
|
state->file = fget_many(fd, state->ios_left);
|
|
if (!state->file)
|
|
return NULL;
|
|
|
|
state->fd = fd;
|
|
state->has_refs = state->ios_left - 1;
|
|
return state->file;
|
|
}
|
|
|
|
static bool io_bdev_nowait(struct block_device *bdev)
|
|
{
|
|
#ifdef CONFIG_BLOCK
|
|
return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
|
|
#else
|
|
return true;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* If we tracked the file through the SCM inflight mechanism, we could support
|
|
* any file. For now, just ensure that anything potentially problematic is done
|
|
* inline.
|
|
*/
|
|
static bool io_file_supports_async(struct file *file, int rw)
|
|
{
|
|
umode_t mode = file_inode(file)->i_mode;
|
|
|
|
if (S_ISBLK(mode)) {
|
|
if (io_bdev_nowait(file->f_inode->i_bdev))
|
|
return true;
|
|
return false;
|
|
}
|
|
if (S_ISCHR(mode) || S_ISSOCK(mode))
|
|
return true;
|
|
if (S_ISREG(mode)) {
|
|
if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
|
|
file->f_op != &io_uring_fops)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* any ->read/write should understand O_NONBLOCK */
|
|
if (file->f_flags & O_NONBLOCK)
|
|
return true;
|
|
|
|
if (!(file->f_mode & FMODE_NOWAIT))
|
|
return false;
|
|
|
|
if (rw == READ)
|
|
return file->f_op->read_iter != NULL;
|
|
|
|
return file->f_op->write_iter != NULL;
|
|
}
|
|
|
|
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
unsigned ioprio;
|
|
int ret;
|
|
|
|
if (S_ISREG(file_inode(req->file)->i_mode))
|
|
req->flags |= REQ_F_ISREG;
|
|
|
|
kiocb->ki_pos = READ_ONCE(sqe->off);
|
|
if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
|
|
req->flags |= REQ_F_CUR_POS;
|
|
kiocb->ki_pos = req->file->f_pos;
|
|
}
|
|
kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
|
|
kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
|
|
ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
ioprio = READ_ONCE(sqe->ioprio);
|
|
if (ioprio) {
|
|
ret = ioprio_check_cap(ioprio);
|
|
if (ret)
|
|
return ret;
|
|
|
|
kiocb->ki_ioprio = ioprio;
|
|
} else
|
|
kiocb->ki_ioprio = get_current_ioprio();
|
|
|
|
/* don't allow async punt if RWF_NOWAIT was requested */
|
|
if (kiocb->ki_flags & IOCB_NOWAIT)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
|
|
if (ctx->flags & IORING_SETUP_IOPOLL) {
|
|
if (!(kiocb->ki_flags & IOCB_DIRECT) ||
|
|
!kiocb->ki_filp->f_op->iopoll)
|
|
return -EOPNOTSUPP;
|
|
|
|
kiocb->ki_flags |= IOCB_HIPRI;
|
|
kiocb->ki_complete = io_complete_rw_iopoll;
|
|
req->iopoll_completed = 0;
|
|
} else {
|
|
if (kiocb->ki_flags & IOCB_HIPRI)
|
|
return -EINVAL;
|
|
kiocb->ki_complete = io_complete_rw;
|
|
}
|
|
|
|
req->rw.addr = READ_ONCE(sqe->addr);
|
|
req->rw.len = READ_ONCE(sqe->len);
|
|
req->buf_index = READ_ONCE(sqe->buf_index);
|
|
return 0;
|
|
}
|
|
|
|
static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
|
|
{
|
|
switch (ret) {
|
|
case -EIOCBQUEUED:
|
|
break;
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTART_RESTARTBLOCK:
|
|
/*
|
|
* We can't just restart the syscall, since previously
|
|
* submitted sqes may already be in progress. Just fail this
|
|
* IO with EINTR.
|
|
*/
|
|
ret = -EINTR;
|
|
fallthrough;
|
|
default:
|
|
kiocb->ki_complete(kiocb, ret, 0);
|
|
}
|
|
}
|
|
|
|
static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
|
|
struct io_async_rw *io = req->async_data;
|
|
|
|
/* add previously done IO, if any */
|
|
if (io && io->bytes_done > 0) {
|
|
if (ret < 0)
|
|
ret = io->bytes_done;
|
|
else
|
|
ret += io->bytes_done;
|
|
}
|
|
|
|
if (req->flags & REQ_F_CUR_POS)
|
|
req->file->f_pos = kiocb->ki_pos;
|
|
if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
|
|
__io_complete_rw(req, ret, 0, cs);
|
|
else
|
|
io_rw_done(kiocb, ret);
|
|
}
|
|
|
|
static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
|
|
struct iov_iter *iter)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
size_t len = req->rw.len;
|
|
struct io_mapped_ubuf *imu;
|
|
u16 index, buf_index = req->buf_index;
|
|
size_t offset;
|
|
u64 buf_addr;
|
|
|
|
if (unlikely(buf_index >= ctx->nr_user_bufs))
|
|
return -EFAULT;
|
|
index = array_index_nospec(buf_index, ctx->nr_user_bufs);
|
|
imu = &ctx->user_bufs[index];
|
|
buf_addr = req->rw.addr;
|
|
|
|
/* overflow */
|
|
if (buf_addr + len < buf_addr)
|
|
return -EFAULT;
|
|
/* not inside the mapped region */
|
|
if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
|
|
return -EFAULT;
|
|
|
|
/*
|
|
* May not be a start of buffer, set size appropriately
|
|
* and advance us to the beginning.
|
|
*/
|
|
offset = buf_addr - imu->ubuf;
|
|
iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
|
|
|
|
if (offset) {
|
|
/*
|
|
* Don't use iov_iter_advance() here, as it's really slow for
|
|
* using the latter parts of a big fixed buffer - it iterates
|
|
* over each segment manually. We can cheat a bit here, because
|
|
* we know that:
|
|
*
|
|
* 1) it's a BVEC iter, we set it up
|
|
* 2) all bvecs are PAGE_SIZE in size, except potentially the
|
|
* first and last bvec
|
|
*
|
|
* So just find our index, and adjust the iterator afterwards.
|
|
* If the offset is within the first bvec (or the whole first
|
|
* bvec, just use iov_iter_advance(). This makes it easier
|
|
* since we can just skip the first segment, which may not
|
|
* be PAGE_SIZE aligned.
|
|
*/
|
|
const struct bio_vec *bvec = imu->bvec;
|
|
|
|
if (offset <= bvec->bv_len) {
|
|
iov_iter_advance(iter, offset);
|
|
} else {
|
|
unsigned long seg_skip;
|
|
|
|
/* skip first vec */
|
|
offset -= bvec->bv_len;
|
|
seg_skip = 1 + (offset >> PAGE_SHIFT);
|
|
|
|
iter->bvec = bvec + seg_skip;
|
|
iter->nr_segs -= seg_skip;
|
|
iter->count -= bvec->bv_len + offset;
|
|
iter->iov_offset = offset & ~PAGE_MASK;
|
|
}
|
|
}
|
|
|
|
return len;
|
|
}
|
|
|
|
static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
|
|
{
|
|
if (needs_lock)
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
|
|
{
|
|
/*
|
|
* "Normal" inline submissions always hold the uring_lock, since we
|
|
* grab it from the system call. Same is true for the SQPOLL offload.
|
|
* The only exception is when we've detached the request and issue it
|
|
* from an async worker thread, grab the lock for that case.
|
|
*/
|
|
if (needs_lock)
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
|
|
static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
|
|
int bgid, struct io_buffer *kbuf,
|
|
bool needs_lock)
|
|
{
|
|
struct io_buffer *head;
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED)
|
|
return kbuf;
|
|
|
|
io_ring_submit_lock(req->ctx, needs_lock);
|
|
|
|
lockdep_assert_held(&req->ctx->uring_lock);
|
|
|
|
head = idr_find(&req->ctx->io_buffer_idr, bgid);
|
|
if (head) {
|
|
if (!list_empty(&head->list)) {
|
|
kbuf = list_last_entry(&head->list, struct io_buffer,
|
|
list);
|
|
list_del(&kbuf->list);
|
|
} else {
|
|
kbuf = head;
|
|
idr_remove(&req->ctx->io_buffer_idr, bgid);
|
|
}
|
|
if (*len > kbuf->len)
|
|
*len = kbuf->len;
|
|
} else {
|
|
kbuf = ERR_PTR(-ENOBUFS);
|
|
}
|
|
|
|
io_ring_submit_unlock(req->ctx, needs_lock);
|
|
|
|
return kbuf;
|
|
}
|
|
|
|
static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
|
|
bool needs_lock)
|
|
{
|
|
struct io_buffer *kbuf;
|
|
u16 bgid;
|
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
|
|
bgid = req->buf_index;
|
|
kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
|
|
if (IS_ERR(kbuf))
|
|
return kbuf;
|
|
req->rw.addr = (u64) (unsigned long) kbuf;
|
|
req->flags |= REQ_F_BUFFER_SELECTED;
|
|
return u64_to_user_ptr(kbuf->addr);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
|
|
bool needs_lock)
|
|
{
|
|
struct compat_iovec __user *uiov;
|
|
compat_ssize_t clen;
|
|
void __user *buf;
|
|
ssize_t len;
|
|
|
|
uiov = u64_to_user_ptr(req->rw.addr);
|
|
if (!access_ok(uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
if (__get_user(clen, &uiov->iov_len))
|
|
return -EFAULT;
|
|
if (clen < 0)
|
|
return -EINVAL;
|
|
|
|
len = clen;
|
|
buf = io_rw_buffer_select(req, &len, needs_lock);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
iov[0].iov_base = buf;
|
|
iov[0].iov_len = (compat_size_t) len;
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
|
|
bool needs_lock)
|
|
{
|
|
struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
|
|
void __user *buf;
|
|
ssize_t len;
|
|
|
|
if (copy_from_user(iov, uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
|
|
len = iov[0].iov_len;
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
buf = io_rw_buffer_select(req, &len, needs_lock);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
iov[0].iov_base = buf;
|
|
iov[0].iov_len = len;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
|
|
bool needs_lock)
|
|
{
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) {
|
|
struct io_buffer *kbuf;
|
|
|
|
kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
|
|
iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
|
|
iov[0].iov_len = kbuf->len;
|
|
return 0;
|
|
}
|
|
if (!req->rw.len)
|
|
return 0;
|
|
else if (req->rw.len > 1)
|
|
return -EINVAL;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (req->ctx->compat)
|
|
return io_compat_import(req, iov, needs_lock);
|
|
#endif
|
|
|
|
return __io_iov_buffer_select(req, iov, needs_lock);
|
|
}
|
|
|
|
static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
|
|
struct iovec **iovec, struct iov_iter *iter,
|
|
bool needs_lock)
|
|
{
|
|
void __user *buf = u64_to_user_ptr(req->rw.addr);
|
|
size_t sqe_len = req->rw.len;
|
|
ssize_t ret;
|
|
u8 opcode;
|
|
|
|
opcode = req->opcode;
|
|
if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
|
|
*iovec = NULL;
|
|
return io_import_fixed(req, rw, iter);
|
|
}
|
|
|
|
/* buffer index only valid with fixed read/write, or buffer select */
|
|
if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
|
|
return -EINVAL;
|
|
|
|
if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
req->rw.len = sqe_len;
|
|
}
|
|
|
|
ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
|
|
*iovec = NULL;
|
|
return ret < 0 ? ret : sqe_len;
|
|
}
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
ret = io_iov_buffer_select(req, *iovec, needs_lock);
|
|
if (!ret) {
|
|
ret = (*iovec)->iov_len;
|
|
iov_iter_init(iter, rw, *iovec, 1, ret);
|
|
}
|
|
*iovec = NULL;
|
|
return ret;
|
|
}
|
|
|
|
return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
|
|
req->ctx->compat);
|
|
}
|
|
|
|
static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
|
|
struct iovec **iovec, struct iov_iter *iter,
|
|
bool needs_lock)
|
|
{
|
|
struct io_async_rw *iorw = req->async_data;
|
|
|
|
if (!iorw)
|
|
return __io_import_iovec(rw, req, iovec, iter, needs_lock);
|
|
*iovec = NULL;
|
|
return iov_iter_count(&iorw->iter);
|
|
}
|
|
|
|
static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
|
|
{
|
|
return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
|
|
}
|
|
|
|
/*
|
|
* For files that don't have ->read_iter() and ->write_iter(), handle them
|
|
* by looping over ->read() or ->write() manually.
|
|
*/
|
|
static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
|
|
{
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
struct file *file = req->file;
|
|
ssize_t ret = 0;
|
|
|
|
/*
|
|
* Don't support polled IO through this interface, and we can't
|
|
* support non-blocking either. For the latter, this just causes
|
|
* the kiocb to be handled from an async context.
|
|
*/
|
|
if (kiocb->ki_flags & IOCB_HIPRI)
|
|
return -EOPNOTSUPP;
|
|
if (kiocb->ki_flags & IOCB_NOWAIT)
|
|
return -EAGAIN;
|
|
|
|
while (iov_iter_count(iter)) {
|
|
struct iovec iovec;
|
|
ssize_t nr;
|
|
|
|
if (!iov_iter_is_bvec(iter)) {
|
|
iovec = iov_iter_iovec(iter);
|
|
} else {
|
|
iovec.iov_base = u64_to_user_ptr(req->rw.addr);
|
|
iovec.iov_len = req->rw.len;
|
|
}
|
|
|
|
if (rw == READ) {
|
|
nr = file->f_op->read(file, iovec.iov_base,
|
|
iovec.iov_len, io_kiocb_ppos(kiocb));
|
|
} else {
|
|
nr = file->f_op->write(file, iovec.iov_base,
|
|
iovec.iov_len, io_kiocb_ppos(kiocb));
|
|
}
|
|
|
|
if (nr < 0) {
|
|
if (!ret)
|
|
ret = nr;
|
|
break;
|
|
}
|
|
ret += nr;
|
|
if (nr != iovec.iov_len)
|
|
break;
|
|
req->rw.len -= nr;
|
|
req->rw.addr += nr;
|
|
iov_iter_advance(iter, nr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
|
|
const struct iovec *fast_iov, struct iov_iter *iter)
|
|
{
|
|
struct io_async_rw *rw = req->async_data;
|
|
|
|
memcpy(&rw->iter, iter, sizeof(*iter));
|
|
rw->free_iovec = iovec;
|
|
rw->bytes_done = 0;
|
|
/* can only be fixed buffers, no need to do anything */
|
|
if (iter->type == ITER_BVEC)
|
|
return;
|
|
if (!iovec) {
|
|
unsigned iov_off = 0;
|
|
|
|
rw->iter.iov = rw->fast_iov;
|
|
if (iter->iov != fast_iov) {
|
|
iov_off = iter->iov - fast_iov;
|
|
rw->iter.iov += iov_off;
|
|
}
|
|
if (rw->fast_iov != fast_iov)
|
|
memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
|
|
sizeof(struct iovec) * iter->nr_segs);
|
|
} else {
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
}
|
|
}
|
|
|
|
static inline int __io_alloc_async_data(struct io_kiocb *req)
|
|
{
|
|
WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
|
|
req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
|
|
return req->async_data == NULL;
|
|
}
|
|
|
|
static int io_alloc_async_data(struct io_kiocb *req)
|
|
{
|
|
if (!io_op_defs[req->opcode].needs_async_data)
|
|
return 0;
|
|
|
|
return __io_alloc_async_data(req);
|
|
}
|
|
|
|
static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
|
|
const struct iovec *fast_iov,
|
|
struct iov_iter *iter, bool force)
|
|
{
|
|
if (!force && !io_op_defs[req->opcode].needs_async_data)
|
|
return 0;
|
|
if (!req->async_data) {
|
|
if (__io_alloc_async_data(req))
|
|
return -ENOMEM;
|
|
|
|
io_req_map_rw(req, iovec, fast_iov, iter);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
|
|
{
|
|
struct io_async_rw *iorw = req->async_data;
|
|
struct iovec *iov = iorw->fast_iov;
|
|
ssize_t ret;
|
|
|
|
ret = __io_import_iovec(rw, req, &iov, &iorw->iter, false);
|
|
if (unlikely(ret < 0))
|
|
return ret;
|
|
|
|
iorw->bytes_done = 0;
|
|
iorw->free_iovec = iov;
|
|
if (iov)
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
return 0;
|
|
}
|
|
|
|
static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = io_prep_rw(req, sqe);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (unlikely(!(req->file->f_mode & FMODE_READ)))
|
|
return -EBADF;
|
|
|
|
/* either don't need iovec imported or already have it */
|
|
if (!req->async_data)
|
|
return 0;
|
|
return io_rw_prep_async(req, READ);
|
|
}
|
|
|
|
/*
|
|
* This is our waitqueue callback handler, registered through lock_page_async()
|
|
* when we initially tried to do the IO with the iocb armed our waitqueue.
|
|
* This gets called when the page is unlocked, and we generally expect that to
|
|
* happen when the page IO is completed and the page is now uptodate. This will
|
|
* queue a task_work based retry of the operation, attempting to copy the data
|
|
* again. If the latter fails because the page was NOT uptodate, then we will
|
|
* do a thread based blocking retry of the operation. That's the unexpected
|
|
* slow path.
|
|
*/
|
|
static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
|
|
int sync, void *arg)
|
|
{
|
|
struct wait_page_queue *wpq;
|
|
struct io_kiocb *req = wait->private;
|
|
struct wait_page_key *key = arg;
|
|
int ret;
|
|
|
|
wpq = container_of(wait, struct wait_page_queue, wait);
|
|
|
|
if (!wake_page_match(wpq, key))
|
|
return 0;
|
|
|
|
req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
|
|
list_del_init(&wait->entry);
|
|
|
|
init_task_work(&req->task_work, io_req_task_submit);
|
|
percpu_ref_get(&req->ctx->refs);
|
|
|
|
/* submit ref gets dropped, acquire a new one */
|
|
refcount_inc(&req->refs);
|
|
ret = io_req_task_work_add(req, true);
|
|
if (unlikely(ret)) {
|
|
struct task_struct *tsk;
|
|
|
|
/* queue just for cancelation */
|
|
init_task_work(&req->task_work, io_req_task_cancel);
|
|
tsk = io_wq_get_task(req->ctx->io_wq);
|
|
task_work_add(tsk, &req->task_work, TWA_NONE);
|
|
wake_up_process(tsk);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* This controls whether a given IO request should be armed for async page
|
|
* based retry. If we return false here, the request is handed to the async
|
|
* worker threads for retry. If we're doing buffered reads on a regular file,
|
|
* we prepare a private wait_page_queue entry and retry the operation. This
|
|
* will either succeed because the page is now uptodate and unlocked, or it
|
|
* will register a callback when the page is unlocked at IO completion. Through
|
|
* that callback, io_uring uses task_work to setup a retry of the operation.
|
|
* That retry will attempt the buffered read again. The retry will generally
|
|
* succeed, or in rare cases where it fails, we then fall back to using the
|
|
* async worker threads for a blocking retry.
|
|
*/
|
|
static bool io_rw_should_retry(struct io_kiocb *req)
|
|
{
|
|
struct io_async_rw *rw = req->async_data;
|
|
struct wait_page_queue *wait = &rw->wpq;
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
|
|
/* never retry for NOWAIT, we just complete with -EAGAIN */
|
|
if (req->flags & REQ_F_NOWAIT)
|
|
return false;
|
|
|
|
/* Only for buffered IO */
|
|
if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
|
|
return false;
|
|
|
|
/*
|
|
* just use poll if we can, and don't attempt if the fs doesn't
|
|
* support callback based unlocks
|
|
*/
|
|
if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
|
|
return false;
|
|
|
|
wait->wait.func = io_async_buf_func;
|
|
wait->wait.private = req;
|
|
wait->wait.flags = 0;
|
|
INIT_LIST_HEAD(&wait->wait.entry);
|
|
kiocb->ki_flags |= IOCB_WAITQ;
|
|
kiocb->ki_flags &= ~IOCB_NOWAIT;
|
|
kiocb->ki_waitq = wait;
|
|
return true;
|
|
}
|
|
|
|
static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
|
|
{
|
|
if (req->file->f_op->read_iter)
|
|
return call_read_iter(req->file, &req->rw.kiocb, iter);
|
|
else if (req->file->f_op->read)
|
|
return loop_rw_iter(READ, req, iter);
|
|
else
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int io_read(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
struct iov_iter __iter, *iter = &__iter;
|
|
struct io_async_rw *rw = req->async_data;
|
|
ssize_t io_size, ret, ret2;
|
|
size_t iov_count;
|
|
bool no_async;
|
|
|
|
if (rw)
|
|
iter = &rw->iter;
|
|
|
|
ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
|
|
if (ret < 0)
|
|
return ret;
|
|
iov_count = iov_iter_count(iter);
|
|
io_size = ret;
|
|
req->result = io_size;
|
|
ret = 0;
|
|
|
|
/* Ensure we clear previously set non-block flag */
|
|
if (!force_nonblock)
|
|
kiocb->ki_flags &= ~IOCB_NOWAIT;
|
|
else
|
|
kiocb->ki_flags |= IOCB_NOWAIT;
|
|
|
|
|
|
/* If the file doesn't support async, just async punt */
|
|
no_async = force_nonblock && !io_file_supports_async(req->file, READ);
|
|
if (no_async)
|
|
goto copy_iov;
|
|
|
|
ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), iov_count);
|
|
if (unlikely(ret))
|
|
goto out_free;
|
|
|
|
ret = io_iter_do_read(req, iter);
|
|
|
|
if (!ret) {
|
|
goto done;
|
|
} else if (ret == -EIOCBQUEUED) {
|
|
ret = 0;
|
|
goto out_free;
|
|
} else if (ret == -EAGAIN) {
|
|
/* IOPOLL retry should happen for io-wq threads */
|
|
if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
goto done;
|
|
/* no retry on NONBLOCK marked file */
|
|
if (req->file->f_flags & O_NONBLOCK)
|
|
goto done;
|
|
/* some cases will consume bytes even on error returns */
|
|
iov_iter_revert(iter, iov_count - iov_iter_count(iter));
|
|
ret = 0;
|
|
goto copy_iov;
|
|
} else if (ret < 0) {
|
|
/* make sure -ERESTARTSYS -> -EINTR is done */
|
|
goto done;
|
|
}
|
|
|
|
/* read it all, or we did blocking attempt. no retry. */
|
|
if (!iov_iter_count(iter) || !force_nonblock ||
|
|
(req->file->f_flags & O_NONBLOCK))
|
|
goto done;
|
|
|
|
io_size -= ret;
|
|
copy_iov:
|
|
ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
|
|
if (ret2) {
|
|
ret = ret2;
|
|
goto out_free;
|
|
}
|
|
if (no_async)
|
|
return -EAGAIN;
|
|
rw = req->async_data;
|
|
/* it's copied and will be cleaned with ->io */
|
|
iovec = NULL;
|
|
/* now use our persistent iterator, if we aren't already */
|
|
iter = &rw->iter;
|
|
retry:
|
|
rw->bytes_done += ret;
|
|
/* if we can retry, do so with the callbacks armed */
|
|
if (!io_rw_should_retry(req)) {
|
|
kiocb->ki_flags &= ~IOCB_WAITQ;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/*
|
|
* Now retry read with the IOCB_WAITQ parts set in the iocb. If we
|
|
* get -EIOCBQUEUED, then we'll get a notification when the desired
|
|
* page gets unlocked. We can also get a partial read here, and if we
|
|
* do, then just retry at the new offset.
|
|
*/
|
|
ret = io_iter_do_read(req, iter);
|
|
if (ret == -EIOCBQUEUED) {
|
|
ret = 0;
|
|
goto out_free;
|
|
} else if (ret > 0 && ret < io_size) {
|
|
/* we got some bytes, but not all. retry. */
|
|
goto retry;
|
|
}
|
|
done:
|
|
kiocb_done(kiocb, ret, cs);
|
|
ret = 0;
|
|
out_free:
|
|
/* it's reportedly faster than delegating the null check to kfree() */
|
|
if (iovec)
|
|
kfree(iovec);
|
|
return ret;
|
|
}
|
|
|
|
static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
ssize_t ret;
|
|
|
|
ret = io_prep_rw(req, sqe);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
|
|
return -EBADF;
|
|
|
|
/* either don't need iovec imported or already have it */
|
|
if (!req->async_data)
|
|
return 0;
|
|
return io_rw_prep_async(req, WRITE);
|
|
}
|
|
|
|
static int io_write(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
|
|
struct kiocb *kiocb = &req->rw.kiocb;
|
|
struct iov_iter __iter, *iter = &__iter;
|
|
struct io_async_rw *rw = req->async_data;
|
|
size_t iov_count;
|
|
ssize_t ret, ret2, io_size;
|
|
|
|
if (rw)
|
|
iter = &rw->iter;
|
|
|
|
ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
|
|
if (ret < 0)
|
|
return ret;
|
|
iov_count = iov_iter_count(iter);
|
|
io_size = ret;
|
|
req->result = io_size;
|
|
|
|
/* Ensure we clear previously set non-block flag */
|
|
if (!force_nonblock)
|
|
kiocb->ki_flags &= ~IOCB_NOWAIT;
|
|
else
|
|
kiocb->ki_flags |= IOCB_NOWAIT;
|
|
|
|
/* If the file doesn't support async, just async punt */
|
|
if (force_nonblock && !io_file_supports_async(req->file, WRITE))
|
|
goto copy_iov;
|
|
|
|
/* file path doesn't support NOWAIT for non-direct_IO */
|
|
if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
|
|
(req->flags & REQ_F_ISREG))
|
|
goto copy_iov;
|
|
|
|
ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), iov_count);
|
|
if (unlikely(ret))
|
|
goto out_free;
|
|
|
|
/*
|
|
* Open-code file_start_write here to grab freeze protection,
|
|
* which will be released by another thread in
|
|
* io_complete_rw(). Fool lockdep by telling it the lock got
|
|
* released so that it doesn't complain about the held lock when
|
|
* we return to userspace.
|
|
*/
|
|
if (req->flags & REQ_F_ISREG) {
|
|
__sb_start_write(file_inode(req->file)->i_sb,
|
|
SB_FREEZE_WRITE, true);
|
|
__sb_writers_release(file_inode(req->file)->i_sb,
|
|
SB_FREEZE_WRITE);
|
|
}
|
|
kiocb->ki_flags |= IOCB_WRITE;
|
|
|
|
if (req->file->f_op->write_iter)
|
|
ret2 = call_write_iter(req->file, kiocb, iter);
|
|
else if (req->file->f_op->write)
|
|
ret2 = loop_rw_iter(WRITE, req, iter);
|
|
else
|
|
ret2 = -EINVAL;
|
|
|
|
/*
|
|
* Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
|
|
* retry them without IOCB_NOWAIT.
|
|
*/
|
|
if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
|
|
ret2 = -EAGAIN;
|
|
/* no retry on NONBLOCK marked file */
|
|
if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK))
|
|
goto done;
|
|
if (!force_nonblock || ret2 != -EAGAIN) {
|
|
/* IOPOLL retry should happen for io-wq threads */
|
|
if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
|
|
goto copy_iov;
|
|
done:
|
|
kiocb_done(kiocb, ret2, cs);
|
|
} else {
|
|
copy_iov:
|
|
/* some cases will consume bytes even on error returns */
|
|
iov_iter_revert(iter, iov_count - iov_iter_count(iter));
|
|
ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
|
|
if (!ret)
|
|
return -EAGAIN;
|
|
}
|
|
out_free:
|
|
/* it's reportedly faster than delegating the null check to kfree() */
|
|
if (iovec)
|
|
kfree(iovec);
|
|
return ret;
|
|
}
|
|
|
|
static int __io_splice_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_splice* sp = &req->splice;
|
|
unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
|
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
sp->file_in = NULL;
|
|
sp->len = READ_ONCE(sqe->len);
|
|
sp->flags = READ_ONCE(sqe->splice_flags);
|
|
|
|
if (unlikely(sp->flags & ~valid_flags))
|
|
return -EINVAL;
|
|
|
|
sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in),
|
|
(sp->flags & SPLICE_F_FD_IN_FIXED));
|
|
if (!sp->file_in)
|
|
return -EBADF;
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
|
|
if (!S_ISREG(file_inode(sp->file_in)->i_mode)) {
|
|
/*
|
|
* Splice operation will be punted aync, and here need to
|
|
* modify io_wq_work.flags, so initialize io_wq_work firstly.
|
|
*/
|
|
io_req_init_async(req);
|
|
req->work.flags |= IO_WQ_WORK_UNBOUND;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int io_tee_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
|
|
return -EINVAL;
|
|
return __io_splice_prep(req, sqe);
|
|
}
|
|
|
|
static int io_tee(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
struct io_splice *sp = &req->splice;
|
|
struct file *in = sp->file_in;
|
|
struct file *out = sp->file_out;
|
|
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
|
|
long ret = 0;
|
|
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
if (sp->len)
|
|
ret = do_tee(in, out, sp->len, flags);
|
|
|
|
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
|
|
if (ret != sp->len)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_splice* sp = &req->splice;
|
|
|
|
sp->off_in = READ_ONCE(sqe->splice_off_in);
|
|
sp->off_out = READ_ONCE(sqe->off);
|
|
return __io_splice_prep(req, sqe);
|
|
}
|
|
|
|
static int io_splice(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
struct io_splice *sp = &req->splice;
|
|
struct file *in = sp->file_in;
|
|
struct file *out = sp->file_out;
|
|
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
|
|
loff_t *poff_in, *poff_out;
|
|
long ret = 0;
|
|
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
|
|
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
|
|
|
|
if (sp->len)
|
|
ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
|
|
|
|
io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
|
|
if (ret != sp->len)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* IORING_OP_NOP just posts a completion event, nothing else.
|
|
*/
|
|
static int io_nop(struct io_kiocb *req, struct io_comp_state *cs)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
__io_req_complete(req, 0, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!req->file)
|
|
return -EBADF;
|
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
|
|
return -EINVAL;
|
|
|
|
req->sync.flags = READ_ONCE(sqe->fsync_flags);
|
|
if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
|
|
return -EINVAL;
|
|
|
|
req->sync.off = READ_ONCE(sqe->off);
|
|
req->sync.len = READ_ONCE(sqe->len);
|
|
return 0;
|
|
}
|
|
|
|
static int io_fsync(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
loff_t end = req->sync.off + req->sync.len;
|
|
int ret;
|
|
|
|
/* fsync always requires a blocking context */
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
ret = vfs_fsync_range(req->file, req->sync.off,
|
|
end > 0 ? end : LLONG_MAX,
|
|
req->sync.flags & IORING_FSYNC_DATASYNC);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_fallocate_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
|
|
return -EINVAL;
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
req->sync.off = READ_ONCE(sqe->off);
|
|
req->sync.len = READ_ONCE(sqe->addr);
|
|
req->sync.mode = READ_ONCE(sqe->len);
|
|
return 0;
|
|
}
|
|
|
|
static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
int ret;
|
|
|
|
/* fallocate always requiring blocking context */
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
|
|
req->sync.len);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
const char __user *fname;
|
|
int ret;
|
|
|
|
if (unlikely(sqe->ioprio || sqe->buf_index))
|
|
return -EINVAL;
|
|
if (unlikely(req->flags & REQ_F_FIXED_FILE))
|
|
return -EBADF;
|
|
|
|
/* open.how should be already initialised */
|
|
if (!(req->open.how.flags & O_PATH) && force_o_largefile())
|
|
req->open.how.flags |= O_LARGEFILE;
|
|
|
|
req->open.dfd = READ_ONCE(sqe->fd);
|
|
fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
req->open.filename = getname(fname);
|
|
if (IS_ERR(req->open.filename)) {
|
|
ret = PTR_ERR(req->open.filename);
|
|
req->open.filename = NULL;
|
|
return ret;
|
|
}
|
|
req->open.nofile = rlimit(RLIMIT_NOFILE);
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
return 0;
|
|
}
|
|
|
|
static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
u64 flags, mode;
|
|
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
mode = READ_ONCE(sqe->len);
|
|
flags = READ_ONCE(sqe->open_flags);
|
|
req->open.how = build_open_how(flags, mode);
|
|
return __io_openat_prep(req, sqe);
|
|
}
|
|
|
|
static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct open_how __user *how;
|
|
size_t len;
|
|
int ret;
|
|
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
|
|
len = READ_ONCE(sqe->len);
|
|
if (len < OPEN_HOW_SIZE_VER0)
|
|
return -EINVAL;
|
|
|
|
ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
|
|
len);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return __io_openat_prep(req, sqe);
|
|
}
|
|
|
|
static int io_openat2(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
struct open_flags op;
|
|
struct file *file;
|
|
int ret;
|
|
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
ret = build_open_flags(&req->open.how, &op);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
|
|
if (ret < 0)
|
|
goto err;
|
|
|
|
file = do_filp_open(req->open.dfd, req->open.filename, &op);
|
|
if (IS_ERR(file)) {
|
|
put_unused_fd(ret);
|
|
ret = PTR_ERR(file);
|
|
} else {
|
|
fsnotify_open(file);
|
|
fd_install(ret, file);
|
|
}
|
|
err:
|
|
putname(req->open.filename);
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_openat(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
return io_openat2(req, force_nonblock);
|
|
}
|
|
|
|
static int io_remove_buffers_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_provide_buf *p = &req->pbuf;
|
|
u64 tmp;
|
|
|
|
if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off)
|
|
return -EINVAL;
|
|
|
|
tmp = READ_ONCE(sqe->fd);
|
|
if (!tmp || tmp > USHRT_MAX)
|
|
return -EINVAL;
|
|
|
|
memset(p, 0, sizeof(*p));
|
|
p->nbufs = tmp;
|
|
p->bgid = READ_ONCE(sqe->buf_group);
|
|
return 0;
|
|
}
|
|
|
|
static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
|
|
int bgid, unsigned nbufs)
|
|
{
|
|
unsigned i = 0;
|
|
|
|
/* shouldn't happen */
|
|
if (!nbufs)
|
|
return 0;
|
|
|
|
/* the head kbuf is the list itself */
|
|
while (!list_empty(&buf->list)) {
|
|
struct io_buffer *nxt;
|
|
|
|
nxt = list_first_entry(&buf->list, struct io_buffer, list);
|
|
list_del(&nxt->list);
|
|
kfree(nxt);
|
|
if (++i == nbufs)
|
|
return i;
|
|
}
|
|
i++;
|
|
kfree(buf);
|
|
idr_remove(&ctx->io_buffer_idr, bgid);
|
|
|
|
return i;
|
|
}
|
|
|
|
static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_provide_buf *p = &req->pbuf;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_buffer *head;
|
|
int ret = 0;
|
|
|
|
io_ring_submit_lock(ctx, !force_nonblock);
|
|
|
|
lockdep_assert_held(&ctx->uring_lock);
|
|
|
|
ret = -ENOENT;
|
|
head = idr_find(&ctx->io_buffer_idr, p->bgid);
|
|
if (head)
|
|
ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
|
|
|
|
io_ring_submit_lock(ctx, !force_nonblock);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_provide_buffers_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_provide_buf *p = &req->pbuf;
|
|
u64 tmp;
|
|
|
|
if (sqe->ioprio || sqe->rw_flags)
|
|
return -EINVAL;
|
|
|
|
tmp = READ_ONCE(sqe->fd);
|
|
if (!tmp || tmp > USHRT_MAX)
|
|
return -E2BIG;
|
|
p->nbufs = tmp;
|
|
p->addr = READ_ONCE(sqe->addr);
|
|
p->len = READ_ONCE(sqe->len);
|
|
|
|
if (!access_ok(u64_to_user_ptr(p->addr), (p->len * p->nbufs)))
|
|
return -EFAULT;
|
|
|
|
p->bgid = READ_ONCE(sqe->buf_group);
|
|
tmp = READ_ONCE(sqe->off);
|
|
if (tmp > USHRT_MAX)
|
|
return -E2BIG;
|
|
p->bid = tmp;
|
|
return 0;
|
|
}
|
|
|
|
static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
|
|
{
|
|
struct io_buffer *buf;
|
|
u64 addr = pbuf->addr;
|
|
int i, bid = pbuf->bid;
|
|
|
|
for (i = 0; i < pbuf->nbufs; i++) {
|
|
buf = kmalloc(sizeof(*buf), GFP_KERNEL);
|
|
if (!buf)
|
|
break;
|
|
|
|
buf->addr = addr;
|
|
buf->len = pbuf->len;
|
|
buf->bid = bid;
|
|
addr += pbuf->len;
|
|
bid++;
|
|
if (!*head) {
|
|
INIT_LIST_HEAD(&buf->list);
|
|
*head = buf;
|
|
} else {
|
|
list_add_tail(&buf->list, &(*head)->list);
|
|
}
|
|
}
|
|
|
|
return i ? i : -ENOMEM;
|
|
}
|
|
|
|
static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_provide_buf *p = &req->pbuf;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_buffer *head, *list;
|
|
int ret = 0;
|
|
|
|
io_ring_submit_lock(ctx, !force_nonblock);
|
|
|
|
lockdep_assert_held(&ctx->uring_lock);
|
|
|
|
list = head = idr_find(&ctx->io_buffer_idr, p->bgid);
|
|
|
|
ret = io_add_buffers(p, &head);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (!list) {
|
|
ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
|
|
GFP_KERNEL);
|
|
if (ret < 0) {
|
|
__io_remove_buffers(ctx, head, p->bgid, -1U);
|
|
goto out;
|
|
}
|
|
}
|
|
out:
|
|
io_ring_submit_unlock(ctx, !force_nonblock);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_epoll_ctl_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
#if defined(CONFIG_EPOLL)
|
|
if (sqe->ioprio || sqe->buf_index)
|
|
return -EINVAL;
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
|
|
req->epoll.epfd = READ_ONCE(sqe->fd);
|
|
req->epoll.op = READ_ONCE(sqe->len);
|
|
req->epoll.fd = READ_ONCE(sqe->off);
|
|
|
|
if (ep_op_has_event(req->epoll.op)) {
|
|
struct epoll_event __user *ev;
|
|
|
|
ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
#else
|
|
return -EOPNOTSUPP;
|
|
#endif
|
|
}
|
|
|
|
static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
#if defined(CONFIG_EPOLL)
|
|
struct io_epoll *ie = &req->epoll;
|
|
int ret;
|
|
|
|
ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
|
|
if (force_nonblock && ret == -EAGAIN)
|
|
return -EAGAIN;
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
#else
|
|
return -EOPNOTSUPP;
|
|
#endif
|
|
}
|
|
|
|
static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
|
|
if (sqe->ioprio || sqe->buf_index || sqe->off)
|
|
return -EINVAL;
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
req->madvise.addr = READ_ONCE(sqe->addr);
|
|
req->madvise.len = READ_ONCE(sqe->len);
|
|
req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
|
|
return 0;
|
|
#else
|
|
return -EOPNOTSUPP;
|
|
#endif
|
|
}
|
|
|
|
static int io_madvise(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
|
|
struct io_madvise *ma = &req->madvise;
|
|
int ret;
|
|
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
#else
|
|
return -EOPNOTSUPP;
|
|
#endif
|
|
}
|
|
|
|
static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
if (sqe->ioprio || sqe->buf_index || sqe->addr)
|
|
return -EINVAL;
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
req->fadvise.offset = READ_ONCE(sqe->off);
|
|
req->fadvise.len = READ_ONCE(sqe->len);
|
|
req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
|
|
return 0;
|
|
}
|
|
|
|
static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
struct io_fadvise *fa = &req->fadvise;
|
|
int ret;
|
|
|
|
if (force_nonblock) {
|
|
switch (fa->advice) {
|
|
case POSIX_FADV_NORMAL:
|
|
case POSIX_FADV_RANDOM:
|
|
case POSIX_FADV_SEQUENTIAL:
|
|
break;
|
|
default:
|
|
return -EAGAIN;
|
|
}
|
|
}
|
|
|
|
ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->buf_index)
|
|
return -EINVAL;
|
|
if (req->flags & REQ_F_FIXED_FILE)
|
|
return -EBADF;
|
|
|
|
req->statx.dfd = READ_ONCE(sqe->fd);
|
|
req->statx.mask = READ_ONCE(sqe->len);
|
|
req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
|
|
req->statx.flags = READ_ONCE(sqe->statx_flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int io_statx(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
struct io_statx *ctx = &req->statx;
|
|
int ret;
|
|
|
|
if (force_nonblock) {
|
|
/* only need file table for an actual valid fd */
|
|
if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
|
|
req->flags |= REQ_F_NO_FILE_TABLE;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
|
|
ctx->buffer);
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
/*
|
|
* If we queue this for async, it must not be cancellable. That would
|
|
* leave the 'file' in an undeterminate state, and here need to modify
|
|
* io_wq_work.flags, so initialize io_wq_work firstly.
|
|
*/
|
|
io_req_init_async(req);
|
|
req->work.flags |= IO_WQ_WORK_NO_CANCEL;
|
|
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
|
|
sqe->rw_flags || sqe->buf_index)
|
|
return -EINVAL;
|
|
if (req->flags & REQ_F_FIXED_FILE)
|
|
return -EBADF;
|
|
|
|
req->close.fd = READ_ONCE(sqe->fd);
|
|
if ((req->file && req->file->f_op == &io_uring_fops))
|
|
return -EBADF;
|
|
|
|
req->close.put_file = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static int io_close(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_close *close = &req->close;
|
|
int ret;
|
|
|
|
/* might be already done during nonblock submission */
|
|
if (!close->put_file) {
|
|
ret = __close_fd_get_file(close->fd, &close->put_file);
|
|
if (ret < 0)
|
|
return (ret == -ENOENT) ? -EBADF : ret;
|
|
}
|
|
|
|
/* if the file has a flush method, be safe and punt to async */
|
|
if (close->put_file->f_op->flush && force_nonblock) {
|
|
/* was never set, but play safe */
|
|
req->flags &= ~REQ_F_NOWAIT;
|
|
/* avoid grabbing files - we don't need the files */
|
|
req->flags |= REQ_F_NO_FILE_TABLE;
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/* No ->flush() or already async, safely close from here */
|
|
ret = filp_close(close->put_file, req->work.identity->files);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
fput(close->put_file);
|
|
close->put_file = NULL;
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!req->file)
|
|
return -EBADF;
|
|
|
|
if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
|
|
return -EINVAL;
|
|
|
|
req->sync.off = READ_ONCE(sqe->off);
|
|
req->sync.len = READ_ONCE(sqe->len);
|
|
req->sync.flags = READ_ONCE(sqe->sync_range_flags);
|
|
return 0;
|
|
}
|
|
|
|
static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
|
|
{
|
|
int ret;
|
|
|
|
/* sync_file_range always requires a blocking context */
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
ret = sync_file_range(req->file, req->sync.off, req->sync.len,
|
|
req->sync.flags);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
#if defined(CONFIG_NET)
|
|
static int io_setup_async_msg(struct io_kiocb *req,
|
|
struct io_async_msghdr *kmsg)
|
|
{
|
|
struct io_async_msghdr *async_msg = req->async_data;
|
|
|
|
if (async_msg)
|
|
return -EAGAIN;
|
|
if (io_alloc_async_data(req)) {
|
|
if (kmsg->iov != kmsg->fast_iov)
|
|
kfree(kmsg->iov);
|
|
return -ENOMEM;
|
|
}
|
|
async_msg = req->async_data;
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
memcpy(async_msg, kmsg, sizeof(*kmsg));
|
|
return -EAGAIN;
|
|
}
|
|
|
|
static int io_sendmsg_copy_hdr(struct io_kiocb *req,
|
|
struct io_async_msghdr *iomsg)
|
|
{
|
|
iomsg->iov = iomsg->fast_iov;
|
|
iomsg->msg.msg_name = &iomsg->addr;
|
|
return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
|
|
req->sr_msg.msg_flags, &iomsg->iov);
|
|
}
|
|
|
|
static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_async_msghdr *async_msg = req->async_data;
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
int ret;
|
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
sr->msg_flags = READ_ONCE(sqe->msg_flags);
|
|
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
sr->len = READ_ONCE(sqe->len);
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (req->ctx->compat)
|
|
sr->msg_flags |= MSG_CMSG_COMPAT;
|
|
#endif
|
|
|
|
if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
|
|
return 0;
|
|
ret = io_sendmsg_copy_hdr(req, async_msg);
|
|
if (!ret)
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
return ret;
|
|
}
|
|
|
|
static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_async_msghdr iomsg, *kmsg;
|
|
struct socket *sock;
|
|
unsigned flags;
|
|
int ret;
|
|
|
|
sock = sock_from_file(req->file, &ret);
|
|
if (unlikely(!sock))
|
|
return ret;
|
|
|
|
if (req->async_data) {
|
|
kmsg = req->async_data;
|
|
kmsg->msg.msg_name = &kmsg->addr;
|
|
/* if iov is set, it's allocated already */
|
|
if (!kmsg->iov)
|
|
kmsg->iov = kmsg->fast_iov;
|
|
kmsg->msg.msg_iter.iov = kmsg->iov;
|
|
} else {
|
|
ret = io_sendmsg_copy_hdr(req, &iomsg);
|
|
if (ret)
|
|
return ret;
|
|
kmsg = &iomsg;
|
|
}
|
|
|
|
flags = req->sr_msg.msg_flags;
|
|
if (flags & MSG_DONTWAIT)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
else if (force_nonblock)
|
|
flags |= MSG_DONTWAIT;
|
|
|
|
ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
|
|
if (force_nonblock && ret == -EAGAIN)
|
|
return io_setup_async_msg(req, kmsg);
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
|
|
if (kmsg->iov != kmsg->fast_iov)
|
|
kfree(kmsg->iov);
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_send(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
struct msghdr msg;
|
|
struct iovec iov;
|
|
struct socket *sock;
|
|
unsigned flags;
|
|
int ret;
|
|
|
|
sock = sock_from_file(req->file, &ret);
|
|
if (unlikely(!sock))
|
|
return ret;
|
|
|
|
ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
|
|
msg.msg_name = NULL;
|
|
msg.msg_control = NULL;
|
|
msg.msg_controllen = 0;
|
|
msg.msg_namelen = 0;
|
|
|
|
flags = req->sr_msg.msg_flags;
|
|
if (flags & MSG_DONTWAIT)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
else if (force_nonblock)
|
|
flags |= MSG_DONTWAIT;
|
|
|
|
msg.msg_flags = flags;
|
|
ret = sock_sendmsg(sock, &msg);
|
|
if (force_nonblock && ret == -EAGAIN)
|
|
return -EAGAIN;
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
|
|
struct io_async_msghdr *iomsg)
|
|
{
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
struct iovec __user *uiov;
|
|
size_t iov_len;
|
|
int ret;
|
|
|
|
ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
|
|
&iomsg->uaddr, &uiov, &iov_len);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
if (iov_len > 1)
|
|
return -EINVAL;
|
|
if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
sr->len = iomsg->iov[0].iov_len;
|
|
iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1,
|
|
sr->len);
|
|
iomsg->iov = NULL;
|
|
} else {
|
|
ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
|
|
&iomsg->iov, &iomsg->msg.msg_iter,
|
|
false);
|
|
if (ret > 0)
|
|
ret = 0;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
|
|
struct io_async_msghdr *iomsg)
|
|
{
|
|
struct compat_msghdr __user *msg_compat;
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
struct compat_iovec __user *uiov;
|
|
compat_uptr_t ptr;
|
|
compat_size_t len;
|
|
int ret;
|
|
|
|
msg_compat = (struct compat_msghdr __user *) sr->umsg;
|
|
ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
|
|
&ptr, &len);
|
|
if (ret)
|
|
return ret;
|
|
|
|
uiov = compat_ptr(ptr);
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
compat_ssize_t clen;
|
|
|
|
if (len > 1)
|
|
return -EINVAL;
|
|
if (!access_ok(uiov, sizeof(*uiov)))
|
|
return -EFAULT;
|
|
if (__get_user(clen, &uiov->iov_len))
|
|
return -EFAULT;
|
|
if (clen < 0)
|
|
return -EINVAL;
|
|
sr->len = iomsg->iov[0].iov_len;
|
|
iomsg->iov = NULL;
|
|
} else {
|
|
ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
|
|
UIO_FASTIOV, &iomsg->iov,
|
|
&iomsg->msg.msg_iter, true);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int io_recvmsg_copy_hdr(struct io_kiocb *req,
|
|
struct io_async_msghdr *iomsg)
|
|
{
|
|
iomsg->msg.msg_name = &iomsg->addr;
|
|
iomsg->iov = iomsg->fast_iov;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (req->ctx->compat)
|
|
return __io_compat_recvmsg_copy_hdr(req, iomsg);
|
|
#endif
|
|
|
|
return __io_recvmsg_copy_hdr(req, iomsg);
|
|
}
|
|
|
|
static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
|
|
bool needs_lock)
|
|
{
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
struct io_buffer *kbuf;
|
|
|
|
kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
|
|
if (IS_ERR(kbuf))
|
|
return kbuf;
|
|
|
|
sr->kbuf = kbuf;
|
|
req->flags |= REQ_F_BUFFER_SELECTED;
|
|
return kbuf;
|
|
}
|
|
|
|
static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
|
|
{
|
|
return io_put_kbuf(req, req->sr_msg.kbuf);
|
|
}
|
|
|
|
static int io_recvmsg_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_async_msghdr *async_msg = req->async_data;
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
int ret;
|
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
sr->msg_flags = READ_ONCE(sqe->msg_flags);
|
|
sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
sr->len = READ_ONCE(sqe->len);
|
|
sr->bgid = READ_ONCE(sqe->buf_group);
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (req->ctx->compat)
|
|
sr->msg_flags |= MSG_CMSG_COMPAT;
|
|
#endif
|
|
|
|
if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
|
|
return 0;
|
|
ret = io_recvmsg_copy_hdr(req, async_msg);
|
|
if (!ret)
|
|
req->flags |= REQ_F_NEED_CLEANUP;
|
|
return ret;
|
|
}
|
|
|
|
static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_async_msghdr iomsg, *kmsg;
|
|
struct socket *sock;
|
|
struct io_buffer *kbuf;
|
|
unsigned flags;
|
|
int ret, cflags = 0;
|
|
|
|
sock = sock_from_file(req->file, &ret);
|
|
if (unlikely(!sock))
|
|
return ret;
|
|
|
|
if (req->async_data) {
|
|
kmsg = req->async_data;
|
|
kmsg->msg.msg_name = &kmsg->addr;
|
|
/* if iov is set, it's allocated already */
|
|
if (!kmsg->iov)
|
|
kmsg->iov = kmsg->fast_iov;
|
|
kmsg->msg.msg_iter.iov = kmsg->iov;
|
|
} else {
|
|
ret = io_recvmsg_copy_hdr(req, &iomsg);
|
|
if (ret)
|
|
return ret;
|
|
kmsg = &iomsg;
|
|
}
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
kbuf = io_recv_buffer_select(req, !force_nonblock);
|
|
if (IS_ERR(kbuf))
|
|
return PTR_ERR(kbuf);
|
|
kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
|
|
iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
|
|
1, req->sr_msg.len);
|
|
}
|
|
|
|
flags = req->sr_msg.msg_flags;
|
|
if (flags & MSG_DONTWAIT)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
else if (force_nonblock)
|
|
flags |= MSG_DONTWAIT;
|
|
|
|
ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
|
|
kmsg->uaddr, flags);
|
|
if (force_nonblock && ret == -EAGAIN)
|
|
return io_setup_async_msg(req, kmsg);
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECTED)
|
|
cflags = io_put_recv_kbuf(req);
|
|
if (kmsg->iov != kmsg->fast_iov)
|
|
kfree(kmsg->iov);
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, cflags, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_recv(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_buffer *kbuf;
|
|
struct io_sr_msg *sr = &req->sr_msg;
|
|
struct msghdr msg;
|
|
void __user *buf = sr->buf;
|
|
struct socket *sock;
|
|
struct iovec iov;
|
|
unsigned flags;
|
|
int ret, cflags = 0;
|
|
|
|
sock = sock_from_file(req->file, &ret);
|
|
if (unlikely(!sock))
|
|
return ret;
|
|
|
|
if (req->flags & REQ_F_BUFFER_SELECT) {
|
|
kbuf = io_recv_buffer_select(req, !force_nonblock);
|
|
if (IS_ERR(kbuf))
|
|
return PTR_ERR(kbuf);
|
|
buf = u64_to_user_ptr(kbuf->addr);
|
|
}
|
|
|
|
ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
|
|
if (unlikely(ret))
|
|
goto out_free;
|
|
|
|
msg.msg_name = NULL;
|
|
msg.msg_control = NULL;
|
|
msg.msg_controllen = 0;
|
|
msg.msg_namelen = 0;
|
|
msg.msg_iocb = NULL;
|
|
msg.msg_flags = 0;
|
|
|
|
flags = req->sr_msg.msg_flags;
|
|
if (flags & MSG_DONTWAIT)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
else if (force_nonblock)
|
|
flags |= MSG_DONTWAIT;
|
|
|
|
ret = sock_recvmsg(sock, &msg, flags);
|
|
if (force_nonblock && ret == -EAGAIN)
|
|
return -EAGAIN;
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
out_free:
|
|
if (req->flags & REQ_F_BUFFER_SELECTED)
|
|
cflags = io_put_recv_kbuf(req);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, cflags, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_accept *accept = &req->accept;
|
|
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->len || sqe->buf_index)
|
|
return -EINVAL;
|
|
|
|
accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
|
|
accept->flags = READ_ONCE(sqe->accept_flags);
|
|
accept->nofile = rlimit(RLIMIT_NOFILE);
|
|
return 0;
|
|
}
|
|
|
|
static int io_accept(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_accept *accept = &req->accept;
|
|
unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
|
|
int ret;
|
|
|
|
if (req->file->f_flags & O_NONBLOCK)
|
|
req->flags |= REQ_F_NOWAIT;
|
|
|
|
ret = __sys_accept4_file(req->file, file_flags, accept->addr,
|
|
accept->addr_len, accept->flags,
|
|
accept->nofile);
|
|
if (ret == -EAGAIN && force_nonblock)
|
|
return -EAGAIN;
|
|
if (ret < 0) {
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
req_set_fail_links(req);
|
|
}
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_connect *conn = &req->connect;
|
|
struct io_async_connect *io = req->async_data;
|
|
|
|
if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags)
|
|
return -EINVAL;
|
|
|
|
conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
|
|
conn->addr_len = READ_ONCE(sqe->addr2);
|
|
|
|
if (!io)
|
|
return 0;
|
|
|
|
return move_addr_to_kernel(conn->addr, conn->addr_len,
|
|
&io->address);
|
|
}
|
|
|
|
static int io_connect(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_async_connect __io, *io;
|
|
unsigned file_flags;
|
|
int ret;
|
|
|
|
if (req->async_data) {
|
|
io = req->async_data;
|
|
} else {
|
|
ret = move_addr_to_kernel(req->connect.addr,
|
|
req->connect.addr_len,
|
|
&__io.address);
|
|
if (ret)
|
|
goto out;
|
|
io = &__io;
|
|
}
|
|
|
|
file_flags = force_nonblock ? O_NONBLOCK : 0;
|
|
|
|
ret = __sys_connect_file(req->file, &io->address,
|
|
req->connect.addr_len, file_flags);
|
|
if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
|
|
if (req->async_data)
|
|
return -EAGAIN;
|
|
if (io_alloc_async_data(req)) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
io = req->async_data;
|
|
memcpy(req->async_data, &__io, sizeof(__io));
|
|
return -EAGAIN;
|
|
}
|
|
if (ret == -ERESTARTSYS)
|
|
ret = -EINTR;
|
|
out:
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
#else /* !CONFIG_NET */
|
|
static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_send(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_recvmsg_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_recv(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_accept(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int io_connect(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif /* CONFIG_NET */
|
|
|
|
struct io_poll_table {
|
|
struct poll_table_struct pt;
|
|
struct io_kiocb *req;
|
|
int error;
|
|
};
|
|
|
|
static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
|
|
__poll_t mask, task_work_func_t func)
|
|
{
|
|
bool twa_signal_ok;
|
|
int ret;
|
|
|
|
/* for instances that support it check for an event match first: */
|
|
if (mask && !(mask & poll->events))
|
|
return 0;
|
|
|
|
trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
|
|
|
|
list_del_init(&poll->wait.entry);
|
|
|
|
req->result = mask;
|
|
init_task_work(&req->task_work, func);
|
|
percpu_ref_get(&req->ctx->refs);
|
|
|
|
/*
|
|
* If we using the signalfd wait_queue_head for this wakeup, then
|
|
* it's not safe to use TWA_SIGNAL as we could be recursing on the
|
|
* tsk->sighand->siglock on doing the wakeup. Should not be needed
|
|
* either, as the normal wakeup will suffice.
|
|
*/
|
|
twa_signal_ok = (poll->head != &req->task->sighand->signalfd_wqh);
|
|
|
|
/*
|
|
* If this fails, then the task is exiting. When a task exits, the
|
|
* work gets canceled, so just cancel this request as well instead
|
|
* of executing it. We can't safely execute it anyway, as we may not
|
|
* have the needed state needed for it anyway.
|
|
*/
|
|
ret = io_req_task_work_add(req, twa_signal_ok);
|
|
if (unlikely(ret)) {
|
|
struct task_struct *tsk;
|
|
|
|
WRITE_ONCE(poll->canceled, true);
|
|
tsk = io_wq_get_task(req->ctx->io_wq);
|
|
task_work_add(tsk, &req->task_work, TWA_NONE);
|
|
wake_up_process(tsk);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
|
|
__acquires(&req->ctx->completion_lock)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!req->result && !READ_ONCE(poll->canceled)) {
|
|
struct poll_table_struct pt = { ._key = poll->events };
|
|
|
|
req->result = vfs_poll(req->file, &pt) & poll->events;
|
|
}
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
if (!req->result && !READ_ONCE(poll->canceled)) {
|
|
add_wait_queue(poll->head, &poll->wait);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
|
|
{
|
|
/* pure poll stashes this in ->async_data, poll driven retry elsewhere */
|
|
if (req->opcode == IORING_OP_POLL_ADD)
|
|
return req->async_data;
|
|
return req->apoll->double_poll;
|
|
}
|
|
|
|
static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
|
|
{
|
|
if (req->opcode == IORING_OP_POLL_ADD)
|
|
return &req->poll;
|
|
return &req->apoll->poll;
|
|
}
|
|
|
|
static void io_poll_remove_double(struct io_kiocb *req)
|
|
{
|
|
struct io_poll_iocb *poll = io_poll_get_double(req);
|
|
|
|
lockdep_assert_held(&req->ctx->completion_lock);
|
|
|
|
if (poll && poll->head) {
|
|
struct wait_queue_head *head = poll->head;
|
|
|
|
spin_lock(&head->lock);
|
|
list_del_init(&poll->wait.entry);
|
|
if (poll->wait.private)
|
|
refcount_dec(&req->refs);
|
|
poll->head = NULL;
|
|
spin_unlock(&head->lock);
|
|
}
|
|
}
|
|
|
|
static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_poll_remove_double(req);
|
|
req->poll.done = true;
|
|
io_cqring_fill_event(req, error ? error : mangle_poll(mask));
|
|
io_commit_cqring(ctx);
|
|
}
|
|
|
|
static void io_poll_task_func(struct callback_head *cb)
|
|
{
|
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *nxt;
|
|
|
|
if (io_poll_rewait(req, &req->poll)) {
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
} else {
|
|
hash_del(&req->hash_node);
|
|
io_poll_complete(req, req->result, 0);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
nxt = io_put_req_find_next(req);
|
|
io_cqring_ev_posted(ctx);
|
|
if (nxt)
|
|
__io_req_task_submit(nxt);
|
|
}
|
|
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct io_kiocb *req = wait->private;
|
|
struct io_poll_iocb *poll = io_poll_get_single(req);
|
|
__poll_t mask = key_to_poll(key);
|
|
|
|
/* for instances that support it check for an event match first: */
|
|
if (mask && !(mask & poll->events))
|
|
return 0;
|
|
|
|
list_del_init(&wait->entry);
|
|
|
|
if (poll && poll->head) {
|
|
bool done;
|
|
|
|
spin_lock(&poll->head->lock);
|
|
done = list_empty(&poll->wait.entry);
|
|
if (!done)
|
|
list_del_init(&poll->wait.entry);
|
|
/* make sure double remove sees this as being gone */
|
|
wait->private = NULL;
|
|
spin_unlock(&poll->head->lock);
|
|
if (!done) {
|
|
/* use wait func handler, so it matches the rq type */
|
|
poll->wait.func(&poll->wait, mode, sync, key);
|
|
}
|
|
}
|
|
refcount_dec(&req->refs);
|
|
return 1;
|
|
}
|
|
|
|
static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
|
|
wait_queue_func_t wake_func)
|
|
{
|
|
poll->head = NULL;
|
|
poll->done = false;
|
|
poll->canceled = false;
|
|
poll->events = events;
|
|
INIT_LIST_HEAD(&poll->wait.entry);
|
|
init_waitqueue_func_entry(&poll->wait, wake_func);
|
|
}
|
|
|
|
static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
|
|
struct wait_queue_head *head,
|
|
struct io_poll_iocb **poll_ptr)
|
|
{
|
|
struct io_kiocb *req = pt->req;
|
|
|
|
/*
|
|
* If poll->head is already set, it's because the file being polled
|
|
* uses multiple waitqueues for poll handling (eg one for read, one
|
|
* for write). Setup a separate io_poll_iocb if this happens.
|
|
*/
|
|
if (unlikely(poll->head)) {
|
|
struct io_poll_iocb *poll_one = poll;
|
|
|
|
/* already have a 2nd entry, fail a third attempt */
|
|
if (*poll_ptr) {
|
|
pt->error = -EINVAL;
|
|
return;
|
|
}
|
|
poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
|
|
if (!poll) {
|
|
pt->error = -ENOMEM;
|
|
return;
|
|
}
|
|
io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake);
|
|
refcount_inc(&req->refs);
|
|
poll->wait.private = req;
|
|
*poll_ptr = poll;
|
|
}
|
|
|
|
pt->error = 0;
|
|
poll->head = head;
|
|
|
|
if (poll->events & EPOLLEXCLUSIVE)
|
|
add_wait_queue_exclusive(head, &poll->wait);
|
|
else
|
|
add_wait_queue(head, &poll->wait);
|
|
}
|
|
|
|
static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
|
|
struct poll_table_struct *p)
|
|
{
|
|
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
|
|
struct async_poll *apoll = pt->req->apoll;
|
|
|
|
__io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
|
|
}
|
|
|
|
static void io_async_task_func(struct callback_head *cb)
|
|
{
|
|
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
|
|
struct async_poll *apoll = req->apoll;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
|
|
|
|
if (io_poll_rewait(req, &apoll->poll)) {
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
percpu_ref_put(&ctx->refs);
|
|
return;
|
|
}
|
|
|
|
/* If req is still hashed, it cannot have been canceled. Don't check. */
|
|
if (hash_hashed(&req->hash_node))
|
|
hash_del(&req->hash_node);
|
|
|
|
io_poll_remove_double(req);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
if (!READ_ONCE(apoll->poll.canceled))
|
|
__io_req_task_submit(req);
|
|
else
|
|
__io_req_task_cancel(req, -ECANCELED);
|
|
|
|
percpu_ref_put(&ctx->refs);
|
|
kfree(apoll->double_poll);
|
|
kfree(apoll);
|
|
}
|
|
|
|
static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
|
|
void *key)
|
|
{
|
|
struct io_kiocb *req = wait->private;
|
|
struct io_poll_iocb *poll = &req->apoll->poll;
|
|
|
|
trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
|
|
key_to_poll(key));
|
|
|
|
return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
|
|
}
|
|
|
|
static void io_poll_req_insert(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct hlist_head *list;
|
|
|
|
list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
|
|
hlist_add_head(&req->hash_node, list);
|
|
}
|
|
|
|
static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
|
|
struct io_poll_iocb *poll,
|
|
struct io_poll_table *ipt, __poll_t mask,
|
|
wait_queue_func_t wake_func)
|
|
__acquires(&ctx->completion_lock)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
bool cancel = false;
|
|
|
|
INIT_HLIST_NODE(&req->hash_node);
|
|
io_init_poll_iocb(poll, mask, wake_func);
|
|
poll->file = req->file;
|
|
poll->wait.private = req;
|
|
|
|
ipt->pt._key = mask;
|
|
ipt->req = req;
|
|
ipt->error = -EINVAL;
|
|
|
|
mask = vfs_poll(req->file, &ipt->pt) & poll->events;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
if (likely(poll->head)) {
|
|
spin_lock(&poll->head->lock);
|
|
if (unlikely(list_empty(&poll->wait.entry))) {
|
|
if (ipt->error)
|
|
cancel = true;
|
|
ipt->error = 0;
|
|
mask = 0;
|
|
}
|
|
if (mask || ipt->error)
|
|
list_del_init(&poll->wait.entry);
|
|
else if (cancel)
|
|
WRITE_ONCE(poll->canceled, true);
|
|
else if (!poll->done) /* actually waiting for an event */
|
|
io_poll_req_insert(req);
|
|
spin_unlock(&poll->head->lock);
|
|
}
|
|
|
|
return mask;
|
|
}
|
|
|
|
static bool io_arm_poll_handler(struct io_kiocb *req)
|
|
{
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct async_poll *apoll;
|
|
struct io_poll_table ipt;
|
|
__poll_t mask, ret;
|
|
int rw;
|
|
|
|
if (!req->file || !file_can_poll(req->file))
|
|
return false;
|
|
if (req->flags & REQ_F_POLLED)
|
|
return false;
|
|
if (def->pollin)
|
|
rw = READ;
|
|
else if (def->pollout)
|
|
rw = WRITE;
|
|
else
|
|
return false;
|
|
/* if we can't nonblock try, then no point in arming a poll handler */
|
|
if (!io_file_supports_async(req->file, rw))
|
|
return false;
|
|
|
|
apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
|
|
if (unlikely(!apoll))
|
|
return false;
|
|
apoll->double_poll = NULL;
|
|
|
|
req->flags |= REQ_F_POLLED;
|
|
req->apoll = apoll;
|
|
|
|
mask = 0;
|
|
if (def->pollin)
|
|
mask |= POLLIN | POLLRDNORM;
|
|
if (def->pollout)
|
|
mask |= POLLOUT | POLLWRNORM;
|
|
|
|
/* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
|
|
if ((req->opcode == IORING_OP_RECVMSG) &&
|
|
(req->sr_msg.msg_flags & MSG_ERRQUEUE))
|
|
mask &= ~POLLIN;
|
|
|
|
mask |= POLLERR | POLLPRI;
|
|
|
|
ipt.pt._qproc = io_async_queue_proc;
|
|
|
|
ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
|
|
io_async_wake);
|
|
if (ret || ipt.error) {
|
|
io_poll_remove_double(req);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
kfree(apoll->double_poll);
|
|
kfree(apoll);
|
|
return false;
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
|
|
apoll->poll.events);
|
|
return true;
|
|
}
|
|
|
|
static bool __io_poll_remove_one(struct io_kiocb *req,
|
|
struct io_poll_iocb *poll)
|
|
{
|
|
bool do_complete = false;
|
|
|
|
spin_lock(&poll->head->lock);
|
|
WRITE_ONCE(poll->canceled, true);
|
|
if (!list_empty(&poll->wait.entry)) {
|
|
list_del_init(&poll->wait.entry);
|
|
do_complete = true;
|
|
}
|
|
spin_unlock(&poll->head->lock);
|
|
hash_del(&req->hash_node);
|
|
return do_complete;
|
|
}
|
|
|
|
static bool io_poll_remove_one(struct io_kiocb *req)
|
|
{
|
|
bool do_complete;
|
|
|
|
io_poll_remove_double(req);
|
|
|
|
if (req->opcode == IORING_OP_POLL_ADD) {
|
|
do_complete = __io_poll_remove_one(req, &req->poll);
|
|
} else {
|
|
struct async_poll *apoll = req->apoll;
|
|
|
|
/* non-poll requests have submit ref still */
|
|
do_complete = __io_poll_remove_one(req, &apoll->poll);
|
|
if (do_complete) {
|
|
io_put_req(req);
|
|
kfree(apoll->double_poll);
|
|
kfree(apoll);
|
|
}
|
|
}
|
|
|
|
if (do_complete) {
|
|
io_cqring_fill_event(req, -ECANCELED);
|
|
io_commit_cqring(req->ctx);
|
|
req_set_fail_links(req);
|
|
io_put_req_deferred(req, 1);
|
|
}
|
|
|
|
return do_complete;
|
|
}
|
|
|
|
/*
|
|
* Returns true if we found and killed one or more poll requests
|
|
*/
|
|
static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk)
|
|
{
|
|
struct hlist_node *tmp;
|
|
struct io_kiocb *req;
|
|
int posted = 0, i;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
|
|
struct hlist_head *list;
|
|
|
|
list = &ctx->cancel_hash[i];
|
|
hlist_for_each_entry_safe(req, tmp, list, hash_node) {
|
|
if (io_task_match(req, tsk))
|
|
posted += io_poll_remove_one(req);
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
if (posted)
|
|
io_cqring_ev_posted(ctx);
|
|
|
|
return posted != 0;
|
|
}
|
|
|
|
static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
|
|
{
|
|
struct hlist_head *list;
|
|
struct io_kiocb *req;
|
|
|
|
list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
|
|
hlist_for_each_entry(req, list, hash_node) {
|
|
if (sqe_addr != req->user_data)
|
|
continue;
|
|
if (io_poll_remove_one(req))
|
|
return 0;
|
|
return -EALREADY;
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static int io_poll_remove_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
|
|
sqe->poll_events)
|
|
return -EINVAL;
|
|
|
|
req->poll.addr = READ_ONCE(sqe->addr);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Find a running poll command that matches one specified in sqe->addr,
|
|
* and remove it if found.
|
|
*/
|
|
static int io_poll_remove(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
u64 addr;
|
|
int ret;
|
|
|
|
addr = req->poll.addr;
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
ret = io_poll_cancel(ctx, addr);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
return 0;
|
|
}
|
|
|
|
static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
|
|
void *key)
|
|
{
|
|
struct io_kiocb *req = wait->private;
|
|
struct io_poll_iocb *poll = &req->poll;
|
|
|
|
return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
|
|
}
|
|
|
|
static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
|
|
struct poll_table_struct *p)
|
|
{
|
|
struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
|
|
|
|
__io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data);
|
|
}
|
|
|
|
static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_poll_iocb *poll = &req->poll;
|
|
u32 events;
|
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
|
|
return -EINVAL;
|
|
|
|
events = READ_ONCE(sqe->poll32_events);
|
|
#ifdef __BIG_ENDIAN
|
|
events = swahw32(events);
|
|
#endif
|
|
poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP |
|
|
(events & EPOLLEXCLUSIVE);
|
|
return 0;
|
|
}
|
|
|
|
static int io_poll_add(struct io_kiocb *req)
|
|
{
|
|
struct io_poll_iocb *poll = &req->poll;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_poll_table ipt;
|
|
__poll_t mask;
|
|
|
|
ipt.pt._qproc = io_poll_queue_proc;
|
|
|
|
mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
|
|
io_poll_wake);
|
|
|
|
if (mask) { /* no async, we'd stolen it */
|
|
ipt.error = 0;
|
|
io_poll_complete(req, mask, 0);
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
if (mask) {
|
|
io_cqring_ev_posted(ctx);
|
|
io_put_req(req);
|
|
}
|
|
return ipt.error;
|
|
}
|
|
|
|
static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
|
|
{
|
|
struct io_timeout_data *data = container_of(timer,
|
|
struct io_timeout_data, timer);
|
|
struct io_kiocb *req = data->req;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
list_del_init(&req->timeout.list);
|
|
atomic_set(&req->ctx->cq_timeouts,
|
|
atomic_read(&req->ctx->cq_timeouts) + 1);
|
|
|
|
io_cqring_fill_event(req, -ETIME);
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
io_cqring_ev_posted(ctx);
|
|
req_set_fail_links(req);
|
|
io_put_req(req);
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static int __io_timeout_cancel(struct io_kiocb *req)
|
|
{
|
|
struct io_timeout_data *io = req->async_data;
|
|
int ret;
|
|
|
|
ret = hrtimer_try_to_cancel(&io->timer);
|
|
if (ret == -1)
|
|
return -EALREADY;
|
|
list_del_init(&req->timeout.list);
|
|
|
|
req_set_fail_links(req);
|
|
io_cqring_fill_event(req, -ECANCELED);
|
|
io_put_req_deferred(req, 1);
|
|
return 0;
|
|
}
|
|
|
|
static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
|
|
{
|
|
struct io_kiocb *req;
|
|
int ret = -ENOENT;
|
|
|
|
list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
|
|
if (user_data == req->user_data) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ret == -ENOENT)
|
|
return ret;
|
|
|
|
return __io_timeout_cancel(req);
|
|
}
|
|
|
|
static int io_timeout_remove_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->timeout_flags)
|
|
return -EINVAL;
|
|
|
|
req->timeout_rem.addr = READ_ONCE(sqe->addr);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Remove or update an existing timeout command
|
|
*/
|
|
static int io_timeout_remove(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
int ret;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
ret = io_timeout_cancel(ctx, req->timeout_rem.addr);
|
|
|
|
io_cqring_fill_event(req, ret);
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
io_cqring_ev_posted(ctx);
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_put_req(req);
|
|
return 0;
|
|
}
|
|
|
|
static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
|
|
bool is_timeout_link)
|
|
{
|
|
struct io_timeout_data *data;
|
|
unsigned flags;
|
|
u32 off = READ_ONCE(sqe->off);
|
|
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->buf_index || sqe->len != 1)
|
|
return -EINVAL;
|
|
if (off && is_timeout_link)
|
|
return -EINVAL;
|
|
flags = READ_ONCE(sqe->timeout_flags);
|
|
if (flags & ~IORING_TIMEOUT_ABS)
|
|
return -EINVAL;
|
|
|
|
req->timeout.off = off;
|
|
|
|
if (!req->async_data && io_alloc_async_data(req))
|
|
return -ENOMEM;
|
|
|
|
data = req->async_data;
|
|
data->req = req;
|
|
|
|
if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
|
|
return -EFAULT;
|
|
|
|
if (flags & IORING_TIMEOUT_ABS)
|
|
data->mode = HRTIMER_MODE_ABS;
|
|
else
|
|
data->mode = HRTIMER_MODE_REL;
|
|
|
|
hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
|
|
return 0;
|
|
}
|
|
|
|
static int io_timeout(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_timeout_data *data = req->async_data;
|
|
struct list_head *entry;
|
|
u32 tail, off = req->timeout.off;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
|
|
/*
|
|
* sqe->off holds how many events that need to occur for this
|
|
* timeout event to be satisfied. If it isn't set, then this is
|
|
* a pure timeout request, sequence isn't used.
|
|
*/
|
|
if (io_is_timeout_noseq(req)) {
|
|
entry = ctx->timeout_list.prev;
|
|
goto add;
|
|
}
|
|
|
|
tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
|
|
req->timeout.target_seq = tail + off;
|
|
|
|
/*
|
|
* Insertion sort, ensuring the first entry in the list is always
|
|
* the one we need first.
|
|
*/
|
|
list_for_each_prev(entry, &ctx->timeout_list) {
|
|
struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
|
|
timeout.list);
|
|
|
|
if (io_is_timeout_noseq(nxt))
|
|
continue;
|
|
/* nxt.seq is behind @tail, otherwise would've been completed */
|
|
if (off >= nxt->timeout.target_seq - tail)
|
|
break;
|
|
}
|
|
add:
|
|
list_add(&req->timeout.list, entry);
|
|
data->timer.function = io_timeout_fn;
|
|
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
return 0;
|
|
}
|
|
|
|
static bool io_cancel_cb(struct io_wq_work *work, void *data)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
|
|
return req->user_data == (unsigned long) data;
|
|
}
|
|
|
|
static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
|
|
{
|
|
enum io_wq_cancel cancel_ret;
|
|
int ret = 0;
|
|
|
|
cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false);
|
|
switch (cancel_ret) {
|
|
case IO_WQ_CANCEL_OK:
|
|
ret = 0;
|
|
break;
|
|
case IO_WQ_CANCEL_RUNNING:
|
|
ret = -EALREADY;
|
|
break;
|
|
case IO_WQ_CANCEL_NOTFOUND:
|
|
ret = -ENOENT;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
|
|
struct io_kiocb *req, __u64 sqe_addr,
|
|
int success_ret)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
|
|
if (ret != -ENOENT) {
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
goto done;
|
|
}
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
ret = io_timeout_cancel(ctx, sqe_addr);
|
|
if (ret != -ENOENT)
|
|
goto done;
|
|
ret = io_poll_cancel(ctx, sqe_addr);
|
|
done:
|
|
if (!ret)
|
|
ret = success_ret;
|
|
io_cqring_fill_event(req, ret);
|
|
io_commit_cqring(ctx);
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
io_cqring_ev_posted(ctx);
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
io_put_req(req);
|
|
}
|
|
|
|
static int io_async_cancel_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags)
|
|
return -EINVAL;
|
|
|
|
req->cancel.addr = READ_ONCE(sqe->addr);
|
|
return 0;
|
|
}
|
|
|
|
static int io_async_cancel(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
|
|
return 0;
|
|
}
|
|
|
|
static int io_files_update_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL))
|
|
return -EINVAL;
|
|
if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
|
|
return -EINVAL;
|
|
if (sqe->ioprio || sqe->rw_flags)
|
|
return -EINVAL;
|
|
|
|
req->files_update.offset = READ_ONCE(sqe->off);
|
|
req->files_update.nr_args = READ_ONCE(sqe->len);
|
|
if (!req->files_update.nr_args)
|
|
return -EINVAL;
|
|
req->files_update.arg = READ_ONCE(sqe->addr);
|
|
return 0;
|
|
}
|
|
|
|
static int io_files_update(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_uring_files_update up;
|
|
int ret;
|
|
|
|
if (force_nonblock)
|
|
return -EAGAIN;
|
|
|
|
up.offset = req->files_update.offset;
|
|
up.fds = req->files_update.arg;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
if (ret < 0)
|
|
req_set_fail_links(req);
|
|
__io_req_complete(req, ret, 0, cs);
|
|
return 0;
|
|
}
|
|
|
|
static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
switch (req->opcode) {
|
|
case IORING_OP_NOP:
|
|
return 0;
|
|
case IORING_OP_READV:
|
|
case IORING_OP_READ_FIXED:
|
|
case IORING_OP_READ:
|
|
return io_read_prep(req, sqe);
|
|
case IORING_OP_WRITEV:
|
|
case IORING_OP_WRITE_FIXED:
|
|
case IORING_OP_WRITE:
|
|
return io_write_prep(req, sqe);
|
|
case IORING_OP_POLL_ADD:
|
|
return io_poll_add_prep(req, sqe);
|
|
case IORING_OP_POLL_REMOVE:
|
|
return io_poll_remove_prep(req, sqe);
|
|
case IORING_OP_FSYNC:
|
|
return io_prep_fsync(req, sqe);
|
|
case IORING_OP_SYNC_FILE_RANGE:
|
|
return io_prep_sfr(req, sqe);
|
|
case IORING_OP_SENDMSG:
|
|
case IORING_OP_SEND:
|
|
return io_sendmsg_prep(req, sqe);
|
|
case IORING_OP_RECVMSG:
|
|
case IORING_OP_RECV:
|
|
return io_recvmsg_prep(req, sqe);
|
|
case IORING_OP_CONNECT:
|
|
return io_connect_prep(req, sqe);
|
|
case IORING_OP_TIMEOUT:
|
|
return io_timeout_prep(req, sqe, false);
|
|
case IORING_OP_TIMEOUT_REMOVE:
|
|
return io_timeout_remove_prep(req, sqe);
|
|
case IORING_OP_ASYNC_CANCEL:
|
|
return io_async_cancel_prep(req, sqe);
|
|
case IORING_OP_LINK_TIMEOUT:
|
|
return io_timeout_prep(req, sqe, true);
|
|
case IORING_OP_ACCEPT:
|
|
return io_accept_prep(req, sqe);
|
|
case IORING_OP_FALLOCATE:
|
|
return io_fallocate_prep(req, sqe);
|
|
case IORING_OP_OPENAT:
|
|
return io_openat_prep(req, sqe);
|
|
case IORING_OP_CLOSE:
|
|
return io_close_prep(req, sqe);
|
|
case IORING_OP_FILES_UPDATE:
|
|
return io_files_update_prep(req, sqe);
|
|
case IORING_OP_STATX:
|
|
return io_statx_prep(req, sqe);
|
|
case IORING_OP_FADVISE:
|
|
return io_fadvise_prep(req, sqe);
|
|
case IORING_OP_MADVISE:
|
|
return io_madvise_prep(req, sqe);
|
|
case IORING_OP_OPENAT2:
|
|
return io_openat2_prep(req, sqe);
|
|
case IORING_OP_EPOLL_CTL:
|
|
return io_epoll_ctl_prep(req, sqe);
|
|
case IORING_OP_SPLICE:
|
|
return io_splice_prep(req, sqe);
|
|
case IORING_OP_PROVIDE_BUFFERS:
|
|
return io_provide_buffers_prep(req, sqe);
|
|
case IORING_OP_REMOVE_BUFFERS:
|
|
return io_remove_buffers_prep(req, sqe);
|
|
case IORING_OP_TEE:
|
|
return io_tee_prep(req, sqe);
|
|
}
|
|
|
|
printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
|
|
req->opcode);
|
|
return-EINVAL;
|
|
}
|
|
|
|
static int io_req_defer_prep(struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
{
|
|
if (!sqe)
|
|
return 0;
|
|
if (io_alloc_async_data(req))
|
|
return -EAGAIN;
|
|
return io_req_prep(req, sqe);
|
|
}
|
|
|
|
static u32 io_get_sequence(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *pos;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
u32 total_submitted, nr_reqs = 1;
|
|
|
|
if (req->flags & REQ_F_LINK_HEAD)
|
|
list_for_each_entry(pos, &req->link_list, link_list)
|
|
nr_reqs++;
|
|
|
|
total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;
|
|
return total_submitted - nr_reqs;
|
|
}
|
|
|
|
static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_defer_entry *de;
|
|
int ret;
|
|
u32 seq;
|
|
|
|
/* Still need defer if there is pending req in defer list. */
|
|
if (likely(list_empty_careful(&ctx->defer_list) &&
|
|
!(req->flags & REQ_F_IO_DRAIN)))
|
|
return 0;
|
|
|
|
seq = io_get_sequence(req);
|
|
/* Still a chance to pass the sequence check */
|
|
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
|
|
return 0;
|
|
|
|
if (!req->async_data) {
|
|
ret = io_req_defer_prep(req, sqe);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
io_prep_async_link(req);
|
|
de = kmalloc(sizeof(*de), GFP_KERNEL);
|
|
if (!de)
|
|
return -ENOMEM;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
kfree(de);
|
|
io_queue_async_work(req);
|
|
return -EIOCBQUEUED;
|
|
}
|
|
|
|
trace_io_uring_defer(ctx, req, req->user_data);
|
|
de->req = req;
|
|
de->seq = seq;
|
|
list_add_tail(&de->list, &ctx->defer_list);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
return -EIOCBQUEUED;
|
|
}
|
|
|
|
static void io_req_drop_files(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->inflight_lock, flags);
|
|
list_del(&req->inflight_entry);
|
|
if (waitqueue_active(&ctx->inflight_wait))
|
|
wake_up(&ctx->inflight_wait);
|
|
spin_unlock_irqrestore(&ctx->inflight_lock, flags);
|
|
req->flags &= ~REQ_F_INFLIGHT;
|
|
put_files_struct(req->work.identity->files);
|
|
put_nsproxy(req->work.identity->nsproxy);
|
|
req->work.flags &= ~IO_WQ_WORK_FILES;
|
|
}
|
|
|
|
static void __io_clean_op(struct io_kiocb *req)
|
|
{
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) {
|
|
switch (req->opcode) {
|
|
case IORING_OP_READV:
|
|
case IORING_OP_READ_FIXED:
|
|
case IORING_OP_READ:
|
|
kfree((void *)(unsigned long)req->rw.addr);
|
|
break;
|
|
case IORING_OP_RECVMSG:
|
|
case IORING_OP_RECV:
|
|
kfree(req->sr_msg.kbuf);
|
|
break;
|
|
}
|
|
req->flags &= ~REQ_F_BUFFER_SELECTED;
|
|
}
|
|
|
|
if (req->flags & REQ_F_NEED_CLEANUP) {
|
|
switch (req->opcode) {
|
|
case IORING_OP_READV:
|
|
case IORING_OP_READ_FIXED:
|
|
case IORING_OP_READ:
|
|
case IORING_OP_WRITEV:
|
|
case IORING_OP_WRITE_FIXED:
|
|
case IORING_OP_WRITE: {
|
|
struct io_async_rw *io = req->async_data;
|
|
if (io->free_iovec)
|
|
kfree(io->free_iovec);
|
|
break;
|
|
}
|
|
case IORING_OP_RECVMSG:
|
|
case IORING_OP_SENDMSG: {
|
|
struct io_async_msghdr *io = req->async_data;
|
|
if (io->iov != io->fast_iov)
|
|
kfree(io->iov);
|
|
break;
|
|
}
|
|
case IORING_OP_SPLICE:
|
|
case IORING_OP_TEE:
|
|
io_put_file(req, req->splice.file_in,
|
|
(req->splice.flags & SPLICE_F_FD_IN_FIXED));
|
|
break;
|
|
case IORING_OP_OPENAT:
|
|
case IORING_OP_OPENAT2:
|
|
if (req->open.filename)
|
|
putname(req->open.filename);
|
|
break;
|
|
}
|
|
req->flags &= ~REQ_F_NEED_CLEANUP;
|
|
}
|
|
|
|
if (req->flags & REQ_F_INFLIGHT)
|
|
io_req_drop_files(req);
|
|
}
|
|
|
|
static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
|
|
struct io_comp_state *cs)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
int ret;
|
|
|
|
switch (req->opcode) {
|
|
case IORING_OP_NOP:
|
|
ret = io_nop(req, cs);
|
|
break;
|
|
case IORING_OP_READV:
|
|
case IORING_OP_READ_FIXED:
|
|
case IORING_OP_READ:
|
|
ret = io_read(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_WRITEV:
|
|
case IORING_OP_WRITE_FIXED:
|
|
case IORING_OP_WRITE:
|
|
ret = io_write(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_FSYNC:
|
|
ret = io_fsync(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_POLL_ADD:
|
|
ret = io_poll_add(req);
|
|
break;
|
|
case IORING_OP_POLL_REMOVE:
|
|
ret = io_poll_remove(req);
|
|
break;
|
|
case IORING_OP_SYNC_FILE_RANGE:
|
|
ret = io_sync_file_range(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_SENDMSG:
|
|
ret = io_sendmsg(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_SEND:
|
|
ret = io_send(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_RECVMSG:
|
|
ret = io_recvmsg(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_RECV:
|
|
ret = io_recv(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_TIMEOUT:
|
|
ret = io_timeout(req);
|
|
break;
|
|
case IORING_OP_TIMEOUT_REMOVE:
|
|
ret = io_timeout_remove(req);
|
|
break;
|
|
case IORING_OP_ACCEPT:
|
|
ret = io_accept(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_CONNECT:
|
|
ret = io_connect(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_ASYNC_CANCEL:
|
|
ret = io_async_cancel(req);
|
|
break;
|
|
case IORING_OP_FALLOCATE:
|
|
ret = io_fallocate(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_OPENAT:
|
|
ret = io_openat(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_CLOSE:
|
|
ret = io_close(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_FILES_UPDATE:
|
|
ret = io_files_update(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_STATX:
|
|
ret = io_statx(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_FADVISE:
|
|
ret = io_fadvise(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_MADVISE:
|
|
ret = io_madvise(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_OPENAT2:
|
|
ret = io_openat2(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_EPOLL_CTL:
|
|
ret = io_epoll_ctl(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_SPLICE:
|
|
ret = io_splice(req, force_nonblock);
|
|
break;
|
|
case IORING_OP_PROVIDE_BUFFERS:
|
|
ret = io_provide_buffers(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_REMOVE_BUFFERS:
|
|
ret = io_remove_buffers(req, force_nonblock, cs);
|
|
break;
|
|
case IORING_OP_TEE:
|
|
ret = io_tee(req, force_nonblock);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* If the op doesn't have a file, we're not polling for it */
|
|
if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
|
|
const bool in_async = io_wq_current_is_worker();
|
|
|
|
/* workqueue context doesn't hold uring_lock, grab it now */
|
|
if (in_async)
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
io_iopoll_req_issued(req);
|
|
|
|
if (in_async)
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
struct io_kiocb *timeout;
|
|
int ret = 0;
|
|
|
|
timeout = io_prep_linked_timeout(req);
|
|
if (timeout)
|
|
io_queue_linked_timeout(timeout);
|
|
|
|
/* if NO_CANCEL is set, we must still run the work */
|
|
if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
|
|
IO_WQ_WORK_CANCEL) {
|
|
ret = -ECANCELED;
|
|
}
|
|
|
|
if (!ret) {
|
|
do {
|
|
ret = io_issue_sqe(req, false, NULL);
|
|
/*
|
|
* We can get EAGAIN for polled IO even though we're
|
|
* forcing a sync submission from here, since we can't
|
|
* wait for request slots on the block side.
|
|
*/
|
|
if (ret != -EAGAIN)
|
|
break;
|
|
cond_resched();
|
|
} while (1);
|
|
}
|
|
|
|
if (ret) {
|
|
req_set_fail_links(req);
|
|
io_req_complete(req, ret);
|
|
}
|
|
|
|
return io_steal_work(req);
|
|
}
|
|
|
|
static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
|
|
int index)
|
|
{
|
|
struct fixed_file_table *table;
|
|
|
|
table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
|
|
return table->files[index & IORING_FILE_TABLE_MASK];
|
|
}
|
|
|
|
static struct file *io_file_get(struct io_submit_state *state,
|
|
struct io_kiocb *req, int fd, bool fixed)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct file *file;
|
|
|
|
if (fixed) {
|
|
if (unlikely((unsigned int)fd >= ctx->nr_user_files))
|
|
return NULL;
|
|
fd = array_index_nospec(fd, ctx->nr_user_files);
|
|
file = io_file_from_index(ctx, fd);
|
|
if (file) {
|
|
req->fixed_file_refs = &ctx->file_data->node->refs;
|
|
percpu_ref_get(req->fixed_file_refs);
|
|
}
|
|
} else {
|
|
trace_io_uring_file_get(ctx, fd);
|
|
file = __io_file_get(state, fd);
|
|
}
|
|
|
|
return file;
|
|
}
|
|
|
|
static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
|
|
int fd)
|
|
{
|
|
bool fixed;
|
|
|
|
fixed = (req->flags & REQ_F_FIXED_FILE) != 0;
|
|
if (unlikely(!fixed && io_async_submit(req->ctx)))
|
|
return -EBADF;
|
|
|
|
req->file = io_file_get(state, req, fd, fixed);
|
|
if (req->file || io_op_defs[req->opcode].needs_file_no_error)
|
|
return 0;
|
|
return -EBADF;
|
|
}
|
|
|
|
static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
|
|
{
|
|
struct io_timeout_data *data = container_of(timer,
|
|
struct io_timeout_data, timer);
|
|
struct io_kiocb *req = data->req;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *prev = NULL;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
|
|
/*
|
|
* We don't expect the list to be empty, that will only happen if we
|
|
* race with the completion of the linked work.
|
|
*/
|
|
if (!list_empty(&req->link_list)) {
|
|
prev = list_entry(req->link_list.prev, struct io_kiocb,
|
|
link_list);
|
|
if (refcount_inc_not_zero(&prev->refs))
|
|
list_del_init(&req->link_list);
|
|
else
|
|
prev = NULL;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
|
|
if (prev) {
|
|
req_set_fail_links(prev);
|
|
io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
|
|
io_put_req(prev);
|
|
} else {
|
|
io_req_complete(req, -ETIME);
|
|
}
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static void __io_queue_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
/*
|
|
* If the list is now empty, then our linked request finished before
|
|
* we got a chance to setup the timer
|
|
*/
|
|
if (!list_empty(&req->link_list)) {
|
|
struct io_timeout_data *data = req->async_data;
|
|
|
|
data->timer.function = io_link_timeout_fn;
|
|
hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
|
|
data->mode);
|
|
}
|
|
}
|
|
|
|
static void io_queue_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
__io_queue_linked_timeout(req);
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
/* drop submission reference */
|
|
io_put_req(req);
|
|
}
|
|
|
|
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt;
|
|
|
|
if (!(req->flags & REQ_F_LINK_HEAD))
|
|
return NULL;
|
|
if (req->flags & REQ_F_LINK_TIMEOUT)
|
|
return NULL;
|
|
|
|
nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
|
|
link_list);
|
|
if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
|
|
return NULL;
|
|
|
|
nxt->flags |= REQ_F_LTIMEOUT_ACTIVE;
|
|
req->flags |= REQ_F_LINK_TIMEOUT;
|
|
return nxt;
|
|
}
|
|
|
|
static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
|
|
{
|
|
struct io_kiocb *linked_timeout;
|
|
const struct cred *old_creds = NULL;
|
|
int ret;
|
|
|
|
again:
|
|
linked_timeout = io_prep_linked_timeout(req);
|
|
|
|
if ((req->flags & REQ_F_WORK_INITIALIZED) &&
|
|
(req->work.flags & IO_WQ_WORK_CREDS) &&
|
|
req->work.identity->creds != current_cred()) {
|
|
if (old_creds)
|
|
revert_creds(old_creds);
|
|
if (old_creds == req->work.identity->creds)
|
|
old_creds = NULL; /* restored original creds */
|
|
else
|
|
old_creds = override_creds(req->work.identity->creds);
|
|
}
|
|
|
|
ret = io_issue_sqe(req, true, cs);
|
|
|
|
/*
|
|
* We async punt it if the file wasn't marked NOWAIT, or if the file
|
|
* doesn't support non-blocking read/write attempts
|
|
*/
|
|
if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
|
|
if (!io_arm_poll_handler(req)) {
|
|
/*
|
|
* Queued up for async execution, worker will release
|
|
* submit reference when the iocb is actually submitted.
|
|
*/
|
|
io_queue_async_work(req);
|
|
}
|
|
|
|
if (linked_timeout)
|
|
io_queue_linked_timeout(linked_timeout);
|
|
} else if (likely(!ret)) {
|
|
/* drop submission reference */
|
|
req = io_put_req_find_next(req);
|
|
if (linked_timeout)
|
|
io_queue_linked_timeout(linked_timeout);
|
|
|
|
if (req) {
|
|
if (!(req->flags & REQ_F_FORCE_ASYNC))
|
|
goto again;
|
|
io_queue_async_work(req);
|
|
}
|
|
} else {
|
|
/* un-prep timeout, so it'll be killed as any other linked */
|
|
req->flags &= ~REQ_F_LINK_TIMEOUT;
|
|
req_set_fail_links(req);
|
|
io_put_req(req);
|
|
io_req_complete(req, ret);
|
|
}
|
|
|
|
if (old_creds)
|
|
revert_creds(old_creds);
|
|
}
|
|
|
|
static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
|
|
struct io_comp_state *cs)
|
|
{
|
|
int ret;
|
|
|
|
ret = io_req_defer(req, sqe);
|
|
if (ret) {
|
|
if (ret != -EIOCBQUEUED) {
|
|
fail_req:
|
|
req_set_fail_links(req);
|
|
io_put_req(req);
|
|
io_req_complete(req, ret);
|
|
}
|
|
} else if (req->flags & REQ_F_FORCE_ASYNC) {
|
|
if (!req->async_data) {
|
|
ret = io_req_defer_prep(req, sqe);
|
|
if (unlikely(ret))
|
|
goto fail_req;
|
|
}
|
|
io_queue_async_work(req);
|
|
} else {
|
|
if (sqe) {
|
|
ret = io_req_prep(req, sqe);
|
|
if (unlikely(ret))
|
|
goto fail_req;
|
|
}
|
|
__io_queue_sqe(req, cs);
|
|
}
|
|
}
|
|
|
|
static inline void io_queue_link_head(struct io_kiocb *req,
|
|
struct io_comp_state *cs)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
|
|
io_put_req(req);
|
|
io_req_complete(req, -ECANCELED);
|
|
} else
|
|
io_queue_sqe(req, NULL, cs);
|
|
}
|
|
|
|
static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
|
|
struct io_kiocb **link, struct io_comp_state *cs)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
int ret;
|
|
|
|
/*
|
|
* If we already have a head request, queue this one for async
|
|
* submittal once the head completes. If we don't have a head but
|
|
* IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
|
|
* submitted sync once the chain is complete. If none of those
|
|
* conditions are true (normal request), then just queue it.
|
|
*/
|
|
if (*link) {
|
|
struct io_kiocb *head = *link;
|
|
|
|
/*
|
|
* Taking sequential execution of a link, draining both sides
|
|
* of the link also fullfils IOSQE_IO_DRAIN semantics for all
|
|
* requests in the link. So, it drains the head and the
|
|
* next after the link request. The last one is done via
|
|
* drain_next flag to persist the effect across calls.
|
|
*/
|
|
if (req->flags & REQ_F_IO_DRAIN) {
|
|
head->flags |= REQ_F_IO_DRAIN;
|
|
ctx->drain_next = 1;
|
|
}
|
|
ret = io_req_defer_prep(req, sqe);
|
|
if (unlikely(ret)) {
|
|
/* fail even hard links since we don't submit */
|
|
head->flags |= REQ_F_FAIL_LINK;
|
|
return ret;
|
|
}
|
|
trace_io_uring_link(ctx, req, head);
|
|
list_add_tail(&req->link_list, &head->link_list);
|
|
|
|
/* last request of a link, enqueue the link */
|
|
if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
|
|
io_queue_link_head(head, cs);
|
|
*link = NULL;
|
|
}
|
|
} else {
|
|
if (unlikely(ctx->drain_next)) {
|
|
req->flags |= REQ_F_IO_DRAIN;
|
|
ctx->drain_next = 0;
|
|
}
|
|
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
|
|
req->flags |= REQ_F_LINK_HEAD;
|
|
INIT_LIST_HEAD(&req->link_list);
|
|
|
|
ret = io_req_defer_prep(req, sqe);
|
|
if (unlikely(ret))
|
|
req->flags |= REQ_F_FAIL_LINK;
|
|
*link = req;
|
|
} else {
|
|
io_queue_sqe(req, sqe, cs);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Batched submission is done, ensure local IO is flushed out.
|
|
*/
|
|
static void io_submit_state_end(struct io_submit_state *state)
|
|
{
|
|
if (!list_empty(&state->comp.list))
|
|
io_submit_flush_completions(&state->comp);
|
|
blk_finish_plug(&state->plug);
|
|
io_state_file_put(state);
|
|
if (state->free_reqs)
|
|
kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
|
|
}
|
|
|
|
/*
|
|
* Start submission side cache.
|
|
*/
|
|
static void io_submit_state_start(struct io_submit_state *state,
|
|
struct io_ring_ctx *ctx, unsigned int max_ios)
|
|
{
|
|
blk_start_plug(&state->plug);
|
|
state->comp.nr = 0;
|
|
INIT_LIST_HEAD(&state->comp.list);
|
|
state->comp.ctx = ctx;
|
|
state->free_reqs = 0;
|
|
state->file = NULL;
|
|
state->ios_left = max_ios;
|
|
}
|
|
|
|
static void io_commit_sqring(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
|
|
/*
|
|
* Ensure any loads from the SQEs are done at this point,
|
|
* since once we write the new head, the application could
|
|
* write new data to them.
|
|
*/
|
|
smp_store_release(&rings->sq.head, ctx->cached_sq_head);
|
|
}
|
|
|
|
/*
|
|
* Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
|
|
* that is mapped by userspace. This means that care needs to be taken to
|
|
* ensure that reads are stable, as we cannot rely on userspace always
|
|
* being a good citizen. If members of the sqe are validated and then later
|
|
* used, it's important that those reads are done through READ_ONCE() to
|
|
* prevent a re-load down the line.
|
|
*/
|
|
static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
|
|
{
|
|
u32 *sq_array = ctx->sq_array;
|
|
unsigned head;
|
|
|
|
/*
|
|
* The cached sq head (or cq tail) serves two purposes:
|
|
*
|
|
* 1) allows us to batch the cost of updating the user visible
|
|
* head updates.
|
|
* 2) allows the kernel side to track the head on its own, even
|
|
* though the application is the one updating it.
|
|
*/
|
|
head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
|
|
if (likely(head < ctx->sq_entries))
|
|
return &ctx->sq_sqes[head];
|
|
|
|
/* drop invalid entries */
|
|
ctx->cached_sq_dropped++;
|
|
WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
|
|
return NULL;
|
|
}
|
|
|
|
static inline void io_consume_sqe(struct io_ring_ctx *ctx)
|
|
{
|
|
ctx->cached_sq_head++;
|
|
}
|
|
|
|
/*
|
|
* Check SQE restrictions (opcode and flags).
|
|
*
|
|
* Returns 'true' if SQE is allowed, 'false' otherwise.
|
|
*/
|
|
static inline bool io_check_restriction(struct io_ring_ctx *ctx,
|
|
struct io_kiocb *req,
|
|
unsigned int sqe_flags)
|
|
{
|
|
if (!ctx->restricted)
|
|
return true;
|
|
|
|
if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
|
|
return false;
|
|
|
|
if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
|
|
ctx->restrictions.sqe_flags_required)
|
|
return false;
|
|
|
|
if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
|
|
ctx->restrictions.sqe_flags_required))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
|
|
IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
|
|
IOSQE_BUFFER_SELECT)
|
|
|
|
static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe,
|
|
struct io_submit_state *state)
|
|
{
|
|
unsigned int sqe_flags;
|
|
int id, ret;
|
|
|
|
req->opcode = READ_ONCE(sqe->opcode);
|
|
req->user_data = READ_ONCE(sqe->user_data);
|
|
req->async_data = NULL;
|
|
req->file = NULL;
|
|
req->ctx = ctx;
|
|
req->flags = 0;
|
|
/* one is dropped after submission, the other at completion */
|
|
refcount_set(&req->refs, 2);
|
|
req->task = current;
|
|
req->result = 0;
|
|
|
|
if (unlikely(req->opcode >= IORING_OP_LAST))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(io_sq_thread_acquire_mm(ctx, req)))
|
|
return -EFAULT;
|
|
|
|
sqe_flags = READ_ONCE(sqe->flags);
|
|
/* enforce forwards compatibility on users */
|
|
if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(!io_check_restriction(ctx, req, sqe_flags)))
|
|
return -EACCES;
|
|
|
|
if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
|
|
!io_op_defs[req->opcode].buffer_select)
|
|
return -EOPNOTSUPP;
|
|
|
|
id = READ_ONCE(sqe->personality);
|
|
if (id) {
|
|
struct io_identity *iod;
|
|
|
|
iod = idr_find(&ctx->personality_idr, id);
|
|
if (unlikely(!iod))
|
|
return -EINVAL;
|
|
refcount_inc(&iod->count);
|
|
|
|
__io_req_init_async(req);
|
|
get_cred(iod->creds);
|
|
req->work.identity = iod;
|
|
req->work.flags |= IO_WQ_WORK_CREDS;
|
|
}
|
|
|
|
/* same numerical values with corresponding REQ_F_*, safe to copy */
|
|
req->flags |= sqe_flags;
|
|
|
|
if (!io_op_defs[req->opcode].needs_file)
|
|
return 0;
|
|
|
|
ret = io_req_set_file(state, req, READ_ONCE(sqe->fd));
|
|
state->ios_left--;
|
|
return ret;
|
|
}
|
|
|
|
static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
|
|
{
|
|
struct io_submit_state state;
|
|
struct io_kiocb *link = NULL;
|
|
int i, submitted = 0;
|
|
|
|
/* if we have a backlog and couldn't flush it all, return BUSY */
|
|
if (test_bit(0, &ctx->sq_check_overflow)) {
|
|
if (!list_empty(&ctx->cq_overflow_list) &&
|
|
!io_cqring_overflow_flush(ctx, false, NULL, NULL))
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* make sure SQ entry isn't read before tail */
|
|
nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
|
|
|
|
if (!percpu_ref_tryget_many(&ctx->refs, nr))
|
|
return -EAGAIN;
|
|
|
|
percpu_counter_add(¤t->io_uring->inflight, nr);
|
|
refcount_add(nr, ¤t->usage);
|
|
|
|
io_submit_state_start(&state, ctx, nr);
|
|
|
|
for (i = 0; i < nr; i++) {
|
|
const struct io_uring_sqe *sqe;
|
|
struct io_kiocb *req;
|
|
int err;
|
|
|
|
sqe = io_get_sqe(ctx);
|
|
if (unlikely(!sqe)) {
|
|
io_consume_sqe(ctx);
|
|
break;
|
|
}
|
|
req = io_alloc_req(ctx, &state);
|
|
if (unlikely(!req)) {
|
|
if (!submitted)
|
|
submitted = -EAGAIN;
|
|
break;
|
|
}
|
|
io_consume_sqe(ctx);
|
|
/* will complete beyond this point, count as submitted */
|
|
submitted++;
|
|
|
|
err = io_init_req(ctx, req, sqe, &state);
|
|
if (unlikely(err)) {
|
|
fail_req:
|
|
io_put_req(req);
|
|
io_req_complete(req, err);
|
|
break;
|
|
}
|
|
|
|
trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
|
|
true, io_async_submit(ctx));
|
|
err = io_submit_sqe(req, sqe, &link, &state.comp);
|
|
if (err)
|
|
goto fail_req;
|
|
}
|
|
|
|
if (unlikely(submitted != nr)) {
|
|
int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
int unused = nr - ref_used;
|
|
|
|
percpu_ref_put_many(&ctx->refs, unused);
|
|
percpu_counter_sub(&tctx->inflight, unused);
|
|
put_task_struct_many(current, unused);
|
|
}
|
|
if (link)
|
|
io_queue_link_head(link, &state.comp);
|
|
io_submit_state_end(&state);
|
|
|
|
/* Commit SQ ring head once we've consumed and submitted all SQEs */
|
|
io_commit_sqring(ctx);
|
|
|
|
return submitted;
|
|
}
|
|
|
|
static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
|
|
{
|
|
/* Tell userspace we may need a wakeup call */
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
}
|
|
|
|
static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
|
|
{
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
}
|
|
|
|
static int io_sq_wake_function(struct wait_queue_entry *wqe, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(wqe, struct io_ring_ctx, sqo_wait_entry);
|
|
int ret;
|
|
|
|
ret = autoremove_wake_function(wqe, mode, sync, key);
|
|
if (ret) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
enum sq_ret {
|
|
SQT_IDLE = 1,
|
|
SQT_SPIN = 2,
|
|
SQT_DID_WORK = 4,
|
|
};
|
|
|
|
static enum sq_ret __io_sq_thread(struct io_ring_ctx *ctx,
|
|
unsigned long start_jiffies, bool cap_entries)
|
|
{
|
|
unsigned long timeout = start_jiffies + ctx->sq_thread_idle;
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
unsigned int to_submit;
|
|
int ret = 0;
|
|
|
|
again:
|
|
if (!list_empty(&ctx->iopoll_list)) {
|
|
unsigned nr_events = 0;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
if (!list_empty(&ctx->iopoll_list) && !need_resched())
|
|
io_do_iopoll(ctx, &nr_events, 0);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
to_submit = io_sqring_entries(ctx);
|
|
|
|
/*
|
|
* If submit got -EBUSY, flag us as needing the application
|
|
* to enter the kernel to reap and flush events.
|
|
*/
|
|
if (!to_submit || ret == -EBUSY || need_resched()) {
|
|
/*
|
|
* Drop cur_mm before scheduling, we can't hold it for
|
|
* long periods (or over schedule()). Do this before
|
|
* adding ourselves to the waitqueue, as the unuse/drop
|
|
* may sleep.
|
|
*/
|
|
io_sq_thread_drop_mm();
|
|
|
|
/*
|
|
* We're polling. If we're within the defined idle
|
|
* period, then let us spin without work before going
|
|
* to sleep. The exception is if we got EBUSY doing
|
|
* more IO, we should wait for the application to
|
|
* reap events and wake us up.
|
|
*/
|
|
if (!list_empty(&ctx->iopoll_list) || need_resched() ||
|
|
(!time_after(jiffies, timeout) && ret != -EBUSY &&
|
|
!percpu_ref_is_dying(&ctx->refs)))
|
|
return SQT_SPIN;
|
|
|
|
prepare_to_wait(&sqd->wait, &ctx->sqo_wait_entry,
|
|
TASK_INTERRUPTIBLE);
|
|
|
|
/*
|
|
* While doing polled IO, before going to sleep, we need
|
|
* to check if there are new reqs added to iopoll_list,
|
|
* it is because reqs may have been punted to io worker
|
|
* and will be added to iopoll_list later, hence check
|
|
* the iopoll_list again.
|
|
*/
|
|
if ((ctx->flags & IORING_SETUP_IOPOLL) &&
|
|
!list_empty_careful(&ctx->iopoll_list)) {
|
|
finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
|
|
goto again;
|
|
}
|
|
|
|
to_submit = io_sqring_entries(ctx);
|
|
if (!to_submit || ret == -EBUSY)
|
|
return SQT_IDLE;
|
|
}
|
|
|
|
finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
|
|
io_ring_clear_wakeup_flag(ctx);
|
|
|
|
/* if we're handling multiple rings, cap submit size for fairness */
|
|
if (cap_entries && to_submit > 8)
|
|
to_submit = 8;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
if (likely(!percpu_ref_is_dying(&ctx->refs)))
|
|
ret = io_submit_sqes(ctx, to_submit);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait))
|
|
wake_up(&ctx->sqo_sq_wait);
|
|
|
|
return SQT_DID_WORK;
|
|
}
|
|
|
|
static void io_sqd_init_new(struct io_sq_data *sqd)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
|
|
while (!list_empty(&sqd->ctx_new_list)) {
|
|
ctx = list_first_entry(&sqd->ctx_new_list, struct io_ring_ctx, sqd_list);
|
|
init_wait(&ctx->sqo_wait_entry);
|
|
ctx->sqo_wait_entry.func = io_sq_wake_function;
|
|
list_move_tail(&ctx->sqd_list, &sqd->ctx_list);
|
|
complete(&ctx->sq_thread_comp);
|
|
}
|
|
}
|
|
|
|
static int io_sq_thread(void *data)
|
|
{
|
|
struct cgroup_subsys_state *cur_css = NULL;
|
|
const struct cred *old_cred = NULL;
|
|
struct io_sq_data *sqd = data;
|
|
struct io_ring_ctx *ctx;
|
|
unsigned long start_jiffies;
|
|
|
|
start_jiffies = jiffies;
|
|
while (!kthread_should_stop()) {
|
|
enum sq_ret ret = 0;
|
|
bool cap_entries;
|
|
|
|
/*
|
|
* Any changes to the sqd lists are synchronized through the
|
|
* kthread parking. This synchronizes the thread vs users,
|
|
* the users are synchronized on the sqd->ctx_lock.
|
|
*/
|
|
if (kthread_should_park())
|
|
kthread_parkme();
|
|
|
|
if (unlikely(!list_empty(&sqd->ctx_new_list)))
|
|
io_sqd_init_new(sqd);
|
|
|
|
cap_entries = !list_is_singular(&sqd->ctx_list);
|
|
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
|
|
if (current->cred != ctx->creds) {
|
|
if (old_cred)
|
|
revert_creds(old_cred);
|
|
old_cred = override_creds(ctx->creds);
|
|
}
|
|
io_sq_thread_associate_blkcg(ctx, &cur_css);
|
|
#ifdef CONFIG_AUDIT
|
|
current->loginuid = ctx->loginuid;
|
|
current->sessionid = ctx->sessionid;
|
|
#endif
|
|
|
|
ret |= __io_sq_thread(ctx, start_jiffies, cap_entries);
|
|
|
|
io_sq_thread_drop_mm();
|
|
}
|
|
|
|
if (ret & SQT_SPIN) {
|
|
io_run_task_work();
|
|
cond_resched();
|
|
} else if (ret == SQT_IDLE) {
|
|
if (kthread_should_park())
|
|
continue;
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
|
|
io_ring_set_wakeup_flag(ctx);
|
|
schedule();
|
|
start_jiffies = jiffies;
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
|
|
io_ring_clear_wakeup_flag(ctx);
|
|
}
|
|
}
|
|
|
|
io_run_task_work();
|
|
|
|
if (cur_css)
|
|
io_sq_thread_unassociate_blkcg();
|
|
if (old_cred)
|
|
revert_creds(old_cred);
|
|
|
|
kthread_parkme();
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct io_wait_queue {
|
|
struct wait_queue_entry wq;
|
|
struct io_ring_ctx *ctx;
|
|
unsigned to_wait;
|
|
unsigned nr_timeouts;
|
|
};
|
|
|
|
static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush)
|
|
{
|
|
struct io_ring_ctx *ctx = iowq->ctx;
|
|
|
|
/*
|
|
* Wake up if we have enough events, or if a timeout occurred since we
|
|
* started waiting. For timeouts, we always want to return to userspace,
|
|
* regardless of event count.
|
|
*/
|
|
return io_cqring_events(ctx, noflush) >= iowq->to_wait ||
|
|
atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
|
|
}
|
|
|
|
static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
|
|
int wake_flags, void *key)
|
|
{
|
|
struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
|
|
wq);
|
|
|
|
/* use noflush == true, as we can't safely rely on locking context */
|
|
if (!io_should_wake(iowq, true))
|
|
return -1;
|
|
|
|
return autoremove_wake_function(curr, mode, wake_flags, key);
|
|
}
|
|
|
|
static int io_run_task_work_sig(void)
|
|
{
|
|
if (io_run_task_work())
|
|
return 1;
|
|
if (!signal_pending(current))
|
|
return 0;
|
|
if (current->jobctl & JOBCTL_TASK_WORK) {
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
current->jobctl &= ~JOBCTL_TASK_WORK;
|
|
recalc_sigpending();
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
return 1;
|
|
}
|
|
return -EINTR;
|
|
}
|
|
|
|
/*
|
|
* Wait until events become available, if we don't already have some. The
|
|
* application must reap them itself, as they reside on the shared cq ring.
|
|
*/
|
|
static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
|
|
const sigset_t __user *sig, size_t sigsz)
|
|
{
|
|
struct io_wait_queue iowq = {
|
|
.wq = {
|
|
.private = current,
|
|
.func = io_wake_function,
|
|
.entry = LIST_HEAD_INIT(iowq.wq.entry),
|
|
},
|
|
.ctx = ctx,
|
|
.to_wait = min_events,
|
|
};
|
|
struct io_rings *rings = ctx->rings;
|
|
int ret = 0;
|
|
|
|
do {
|
|
if (io_cqring_events(ctx, false) >= min_events)
|
|
return 0;
|
|
if (!io_run_task_work())
|
|
break;
|
|
} while (1);
|
|
|
|
if (sig) {
|
|
#ifdef CONFIG_COMPAT
|
|
if (in_compat_syscall())
|
|
ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
|
|
sigsz);
|
|
else
|
|
#endif
|
|
ret = set_user_sigmask(sig, sigsz);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
|
|
trace_io_uring_cqring_wait(ctx, min_events);
|
|
do {
|
|
prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
|
|
TASK_INTERRUPTIBLE);
|
|
/* make sure we run task_work before checking for signals */
|
|
ret = io_run_task_work_sig();
|
|
if (ret > 0)
|
|
continue;
|
|
else if (ret < 0)
|
|
break;
|
|
if (io_should_wake(&iowq, false))
|
|
break;
|
|
schedule();
|
|
} while (1);
|
|
finish_wait(&ctx->wait, &iowq.wq);
|
|
|
|
restore_saved_sigmask_unless(ret == -EINTR);
|
|
|
|
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
|
|
}
|
|
|
|
static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
|
|
{
|
|
#if defined(CONFIG_UNIX)
|
|
if (ctx->ring_sock) {
|
|
struct sock *sock = ctx->ring_sock->sk;
|
|
struct sk_buff *skb;
|
|
|
|
while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
|
|
kfree_skb(skb);
|
|
}
|
|
#else
|
|
int i;
|
|
|
|
for (i = 0; i < ctx->nr_user_files; i++) {
|
|
struct file *file;
|
|
|
|
file = io_file_from_index(ctx, i);
|
|
if (file)
|
|
fput(file);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void io_file_ref_kill(struct percpu_ref *ref)
|
|
{
|
|
struct fixed_file_data *data;
|
|
|
|
data = container_of(ref, struct fixed_file_data, refs);
|
|
complete(&data->done);
|
|
}
|
|
|
|
static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
|
|
{
|
|
struct fixed_file_data *data = ctx->file_data;
|
|
struct fixed_file_ref_node *ref_node = NULL;
|
|
unsigned nr_tables, i;
|
|
|
|
if (!data)
|
|
return -ENXIO;
|
|
|
|
spin_lock(&data->lock);
|
|
if (!list_empty(&data->ref_list))
|
|
ref_node = list_first_entry(&data->ref_list,
|
|
struct fixed_file_ref_node, node);
|
|
spin_unlock(&data->lock);
|
|
if (ref_node)
|
|
percpu_ref_kill(&ref_node->refs);
|
|
|
|
percpu_ref_kill(&data->refs);
|
|
|
|
/* wait for all refs nodes to complete */
|
|
flush_delayed_work(&ctx->file_put_work);
|
|
wait_for_completion(&data->done);
|
|
|
|
__io_sqe_files_unregister(ctx);
|
|
nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
|
|
for (i = 0; i < nr_tables; i++)
|
|
kfree(data->table[i].files);
|
|
kfree(data->table);
|
|
percpu_ref_exit(&data->refs);
|
|
kfree(data);
|
|
ctx->file_data = NULL;
|
|
ctx->nr_user_files = 0;
|
|
return 0;
|
|
}
|
|
|
|
static void io_put_sq_data(struct io_sq_data *sqd)
|
|
{
|
|
if (refcount_dec_and_test(&sqd->refs)) {
|
|
/*
|
|
* The park is a bit of a work-around, without it we get
|
|
* warning spews on shutdown with SQPOLL set and affinity
|
|
* set to a single CPU.
|
|
*/
|
|
if (sqd->thread) {
|
|
kthread_park(sqd->thread);
|
|
kthread_stop(sqd->thread);
|
|
}
|
|
|
|
kfree(sqd);
|
|
}
|
|
}
|
|
|
|
static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
|
|
{
|
|
struct io_ring_ctx *ctx_attach;
|
|
struct io_sq_data *sqd;
|
|
struct fd f;
|
|
|
|
f = fdget(p->wq_fd);
|
|
if (!f.file)
|
|
return ERR_PTR(-ENXIO);
|
|
if (f.file->f_op != &io_uring_fops) {
|
|
fdput(f);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
ctx_attach = f.file->private_data;
|
|
sqd = ctx_attach->sq_data;
|
|
if (!sqd) {
|
|
fdput(f);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
refcount_inc(&sqd->refs);
|
|
fdput(f);
|
|
return sqd;
|
|
}
|
|
|
|
static struct io_sq_data *io_get_sq_data(struct io_uring_params *p)
|
|
{
|
|
struct io_sq_data *sqd;
|
|
|
|
if (p->flags & IORING_SETUP_ATTACH_WQ)
|
|
return io_attach_sq_data(p);
|
|
|
|
sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
|
|
if (!sqd)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
refcount_set(&sqd->refs, 1);
|
|
INIT_LIST_HEAD(&sqd->ctx_list);
|
|
INIT_LIST_HEAD(&sqd->ctx_new_list);
|
|
mutex_init(&sqd->ctx_lock);
|
|
mutex_init(&sqd->lock);
|
|
init_waitqueue_head(&sqd->wait);
|
|
return sqd;
|
|
}
|
|
|
|
static void io_sq_thread_unpark(struct io_sq_data *sqd)
|
|
__releases(&sqd->lock)
|
|
{
|
|
if (!sqd->thread)
|
|
return;
|
|
kthread_unpark(sqd->thread);
|
|
mutex_unlock(&sqd->lock);
|
|
}
|
|
|
|
static void io_sq_thread_park(struct io_sq_data *sqd)
|
|
__acquires(&sqd->lock)
|
|
{
|
|
if (!sqd->thread)
|
|
return;
|
|
mutex_lock(&sqd->lock);
|
|
kthread_park(sqd->thread);
|
|
}
|
|
|
|
static void io_sq_thread_stop(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
|
|
if (sqd) {
|
|
if (sqd->thread) {
|
|
/*
|
|
* We may arrive here from the error branch in
|
|
* io_sq_offload_create() where the kthread is created
|
|
* without being waked up, thus wake it up now to make
|
|
* sure the wait will complete.
|
|
*/
|
|
wake_up_process(sqd->thread);
|
|
wait_for_completion(&ctx->sq_thread_comp);
|
|
|
|
io_sq_thread_park(sqd);
|
|
}
|
|
|
|
mutex_lock(&sqd->ctx_lock);
|
|
list_del(&ctx->sqd_list);
|
|
mutex_unlock(&sqd->ctx_lock);
|
|
|
|
if (sqd->thread) {
|
|
finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
|
|
io_sq_thread_unpark(sqd);
|
|
}
|
|
|
|
io_put_sq_data(sqd);
|
|
ctx->sq_data = NULL;
|
|
}
|
|
}
|
|
|
|
static void io_finish_async(struct io_ring_ctx *ctx)
|
|
{
|
|
io_sq_thread_stop(ctx);
|
|
|
|
if (ctx->io_wq) {
|
|
io_wq_destroy(ctx->io_wq);
|
|
ctx->io_wq = NULL;
|
|
}
|
|
}
|
|
|
|
#if defined(CONFIG_UNIX)
|
|
/*
|
|
* Ensure the UNIX gc is aware of our file set, so we are certain that
|
|
* the io_uring can be safely unregistered on process exit, even if we have
|
|
* loops in the file referencing.
|
|
*/
|
|
static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
|
|
{
|
|
struct sock *sk = ctx->ring_sock->sk;
|
|
struct scm_fp_list *fpl;
|
|
struct sk_buff *skb;
|
|
int i, nr_files;
|
|
|
|
fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
|
|
if (!fpl)
|
|
return -ENOMEM;
|
|
|
|
skb = alloc_skb(0, GFP_KERNEL);
|
|
if (!skb) {
|
|
kfree(fpl);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
skb->sk = sk;
|
|
|
|
nr_files = 0;
|
|
fpl->user = get_uid(ctx->user);
|
|
for (i = 0; i < nr; i++) {
|
|
struct file *file = io_file_from_index(ctx, i + offset);
|
|
|
|
if (!file)
|
|
continue;
|
|
fpl->fp[nr_files] = get_file(file);
|
|
unix_inflight(fpl->user, fpl->fp[nr_files]);
|
|
nr_files++;
|
|
}
|
|
|
|
if (nr_files) {
|
|
fpl->max = SCM_MAX_FD;
|
|
fpl->count = nr_files;
|
|
UNIXCB(skb).fp = fpl;
|
|
skb->destructor = unix_destruct_scm;
|
|
refcount_add(skb->truesize, &sk->sk_wmem_alloc);
|
|
skb_queue_head(&sk->sk_receive_queue, skb);
|
|
|
|
for (i = 0; i < nr_files; i++)
|
|
fput(fpl->fp[i]);
|
|
} else {
|
|
kfree_skb(skb);
|
|
kfree(fpl);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* If UNIX sockets are enabled, fd passing can cause a reference cycle which
|
|
* causes regular reference counting to break down. We rely on the UNIX
|
|
* garbage collection to take care of this problem for us.
|
|
*/
|
|
static int io_sqe_files_scm(struct io_ring_ctx *ctx)
|
|
{
|
|
unsigned left, total;
|
|
int ret = 0;
|
|
|
|
total = 0;
|
|
left = ctx->nr_user_files;
|
|
while (left) {
|
|
unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
|
|
|
|
ret = __io_sqe_files_scm(ctx, this_files, total);
|
|
if (ret)
|
|
break;
|
|
left -= this_files;
|
|
total += this_files;
|
|
}
|
|
|
|
if (!ret)
|
|
return 0;
|
|
|
|
while (total < ctx->nr_user_files) {
|
|
struct file *file = io_file_from_index(ctx, total);
|
|
|
|
if (file)
|
|
fput(file);
|
|
total++;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
#else
|
|
static int io_sqe_files_scm(struct io_ring_ctx *ctx)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int io_sqe_alloc_file_tables(struct fixed_file_data *file_data,
|
|
unsigned nr_tables, unsigned nr_files)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nr_tables; i++) {
|
|
struct fixed_file_table *table = &file_data->table[i];
|
|
unsigned this_files;
|
|
|
|
this_files = min(nr_files, IORING_MAX_FILES_TABLE);
|
|
table->files = kcalloc(this_files, sizeof(struct file *),
|
|
GFP_KERNEL);
|
|
if (!table->files)
|
|
break;
|
|
nr_files -= this_files;
|
|
}
|
|
|
|
if (i == nr_tables)
|
|
return 0;
|
|
|
|
for (i = 0; i < nr_tables; i++) {
|
|
struct fixed_file_table *table = &file_data->table[i];
|
|
kfree(table->files);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
|
|
{
|
|
#if defined(CONFIG_UNIX)
|
|
struct sock *sock = ctx->ring_sock->sk;
|
|
struct sk_buff_head list, *head = &sock->sk_receive_queue;
|
|
struct sk_buff *skb;
|
|
int i;
|
|
|
|
__skb_queue_head_init(&list);
|
|
|
|
/*
|
|
* Find the skb that holds this file in its SCM_RIGHTS. When found,
|
|
* remove this entry and rearrange the file array.
|
|
*/
|
|
skb = skb_dequeue(head);
|
|
while (skb) {
|
|
struct scm_fp_list *fp;
|
|
|
|
fp = UNIXCB(skb).fp;
|
|
for (i = 0; i < fp->count; i++) {
|
|
int left;
|
|
|
|
if (fp->fp[i] != file)
|
|
continue;
|
|
|
|
unix_notinflight(fp->user, fp->fp[i]);
|
|
left = fp->count - 1 - i;
|
|
if (left) {
|
|
memmove(&fp->fp[i], &fp->fp[i + 1],
|
|
left * sizeof(struct file *));
|
|
}
|
|
fp->count--;
|
|
if (!fp->count) {
|
|
kfree_skb(skb);
|
|
skb = NULL;
|
|
} else {
|
|
__skb_queue_tail(&list, skb);
|
|
}
|
|
fput(file);
|
|
file = NULL;
|
|
break;
|
|
}
|
|
|
|
if (!file)
|
|
break;
|
|
|
|
__skb_queue_tail(&list, skb);
|
|
|
|
skb = skb_dequeue(head);
|
|
}
|
|
|
|
if (skb_peek(&list)) {
|
|
spin_lock_irq(&head->lock);
|
|
while ((skb = __skb_dequeue(&list)) != NULL)
|
|
__skb_queue_tail(head, skb);
|
|
spin_unlock_irq(&head->lock);
|
|
}
|
|
#else
|
|
fput(file);
|
|
#endif
|
|
}
|
|
|
|
struct io_file_put {
|
|
struct list_head list;
|
|
struct file *file;
|
|
};
|
|
|
|
static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
|
|
{
|
|
struct fixed_file_data *file_data = ref_node->file_data;
|
|
struct io_ring_ctx *ctx = file_data->ctx;
|
|
struct io_file_put *pfile, *tmp;
|
|
|
|
list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
|
|
list_del(&pfile->list);
|
|
io_ring_file_put(ctx, pfile->file);
|
|
kfree(pfile);
|
|
}
|
|
|
|
spin_lock(&file_data->lock);
|
|
list_del(&ref_node->node);
|
|
spin_unlock(&file_data->lock);
|
|
|
|
percpu_ref_exit(&ref_node->refs);
|
|
kfree(ref_node);
|
|
percpu_ref_put(&file_data->refs);
|
|
}
|
|
|
|
static void io_file_put_work(struct work_struct *work)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
struct llist_node *node;
|
|
|
|
ctx = container_of(work, struct io_ring_ctx, file_put_work.work);
|
|
node = llist_del_all(&ctx->file_put_llist);
|
|
|
|
while (node) {
|
|
struct fixed_file_ref_node *ref_node;
|
|
struct llist_node *next = node->next;
|
|
|
|
ref_node = llist_entry(node, struct fixed_file_ref_node, llist);
|
|
__io_file_put_work(ref_node);
|
|
node = next;
|
|
}
|
|
}
|
|
|
|
static void io_file_data_ref_zero(struct percpu_ref *ref)
|
|
{
|
|
struct fixed_file_ref_node *ref_node;
|
|
struct io_ring_ctx *ctx;
|
|
bool first_add;
|
|
int delay = HZ;
|
|
|
|
ref_node = container_of(ref, struct fixed_file_ref_node, refs);
|
|
ctx = ref_node->file_data->ctx;
|
|
|
|
if (percpu_ref_is_dying(&ctx->file_data->refs))
|
|
delay = 0;
|
|
|
|
first_add = llist_add(&ref_node->llist, &ctx->file_put_llist);
|
|
if (!delay)
|
|
mod_delayed_work(system_wq, &ctx->file_put_work, 0);
|
|
else if (first_add)
|
|
queue_delayed_work(system_wq, &ctx->file_put_work, delay);
|
|
}
|
|
|
|
static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
|
|
struct io_ring_ctx *ctx)
|
|
{
|
|
struct fixed_file_ref_node *ref_node;
|
|
|
|
ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
|
|
if (!ref_node)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
|
|
0, GFP_KERNEL)) {
|
|
kfree(ref_node);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
INIT_LIST_HEAD(&ref_node->node);
|
|
INIT_LIST_HEAD(&ref_node->file_list);
|
|
ref_node->file_data = ctx->file_data;
|
|
return ref_node;
|
|
}
|
|
|
|
static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
|
|
{
|
|
percpu_ref_exit(&ref_node->refs);
|
|
kfree(ref_node);
|
|
}
|
|
|
|
static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
|
|
unsigned nr_args)
|
|
{
|
|
__s32 __user *fds = (__s32 __user *) arg;
|
|
unsigned nr_tables, i;
|
|
struct file *file;
|
|
int fd, ret = -ENOMEM;
|
|
struct fixed_file_ref_node *ref_node;
|
|
struct fixed_file_data *file_data;
|
|
|
|
if (ctx->file_data)
|
|
return -EBUSY;
|
|
if (!nr_args)
|
|
return -EINVAL;
|
|
if (nr_args > IORING_MAX_FIXED_FILES)
|
|
return -EMFILE;
|
|
|
|
file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
|
|
if (!file_data)
|
|
return -ENOMEM;
|
|
file_data->ctx = ctx;
|
|
init_completion(&file_data->done);
|
|
INIT_LIST_HEAD(&file_data->ref_list);
|
|
spin_lock_init(&file_data->lock);
|
|
|
|
nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
|
|
file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
|
|
GFP_KERNEL);
|
|
if (!file_data->table)
|
|
goto out_free;
|
|
|
|
if (percpu_ref_init(&file_data->refs, io_file_ref_kill,
|
|
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
|
|
goto out_free;
|
|
|
|
if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
|
|
goto out_ref;
|
|
ctx->file_data = file_data;
|
|
|
|
for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
|
|
struct fixed_file_table *table;
|
|
unsigned index;
|
|
|
|
if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
|
|
ret = -EFAULT;
|
|
goto out_fput;
|
|
}
|
|
/* allow sparse sets */
|
|
if (fd == -1)
|
|
continue;
|
|
|
|
file = fget(fd);
|
|
ret = -EBADF;
|
|
if (!file)
|
|
goto out_fput;
|
|
|
|
/*
|
|
* Don't allow io_uring instances to be registered. If UNIX
|
|
* isn't enabled, then this causes a reference cycle and this
|
|
* instance can never get freed. If UNIX is enabled we'll
|
|
* handle it just fine, but there's still no point in allowing
|
|
* a ring fd as it doesn't support regular read/write anyway.
|
|
*/
|
|
if (file->f_op == &io_uring_fops) {
|
|
fput(file);
|
|
goto out_fput;
|
|
}
|
|
table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT];
|
|
index = i & IORING_FILE_TABLE_MASK;
|
|
table->files[index] = file;
|
|
}
|
|
|
|
ret = io_sqe_files_scm(ctx);
|
|
if (ret) {
|
|
io_sqe_files_unregister(ctx);
|
|
return ret;
|
|
}
|
|
|
|
ref_node = alloc_fixed_file_ref_node(ctx);
|
|
if (IS_ERR(ref_node)) {
|
|
io_sqe_files_unregister(ctx);
|
|
return PTR_ERR(ref_node);
|
|
}
|
|
|
|
file_data->node = ref_node;
|
|
spin_lock(&file_data->lock);
|
|
list_add(&ref_node->node, &file_data->ref_list);
|
|
spin_unlock(&file_data->lock);
|
|
percpu_ref_get(&file_data->refs);
|
|
return ret;
|
|
out_fput:
|
|
for (i = 0; i < ctx->nr_user_files; i++) {
|
|
file = io_file_from_index(ctx, i);
|
|
if (file)
|
|
fput(file);
|
|
}
|
|
for (i = 0; i < nr_tables; i++)
|
|
kfree(file_data->table[i].files);
|
|
ctx->nr_user_files = 0;
|
|
out_ref:
|
|
percpu_ref_exit(&file_data->refs);
|
|
out_free:
|
|
kfree(file_data->table);
|
|
kfree(file_data);
|
|
ctx->file_data = NULL;
|
|
return ret;
|
|
}
|
|
|
|
static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
|
|
int index)
|
|
{
|
|
#if defined(CONFIG_UNIX)
|
|
struct sock *sock = ctx->ring_sock->sk;
|
|
struct sk_buff_head *head = &sock->sk_receive_queue;
|
|
struct sk_buff *skb;
|
|
|
|
/*
|
|
* See if we can merge this file into an existing skb SCM_RIGHTS
|
|
* file set. If there's no room, fall back to allocating a new skb
|
|
* and filling it in.
|
|
*/
|
|
spin_lock_irq(&head->lock);
|
|
skb = skb_peek(head);
|
|
if (skb) {
|
|
struct scm_fp_list *fpl = UNIXCB(skb).fp;
|
|
|
|
if (fpl->count < SCM_MAX_FD) {
|
|
__skb_unlink(skb, head);
|
|
spin_unlock_irq(&head->lock);
|
|
fpl->fp[fpl->count] = get_file(file);
|
|
unix_inflight(fpl->user, fpl->fp[fpl->count]);
|
|
fpl->count++;
|
|
spin_lock_irq(&head->lock);
|
|
__skb_queue_head(head, skb);
|
|
} else {
|
|
skb = NULL;
|
|
}
|
|
}
|
|
spin_unlock_irq(&head->lock);
|
|
|
|
if (skb) {
|
|
fput(file);
|
|
return 0;
|
|
}
|
|
|
|
return __io_sqe_files_scm(ctx, 1, index);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static int io_queue_file_removal(struct fixed_file_data *data,
|
|
struct file *file)
|
|
{
|
|
struct io_file_put *pfile;
|
|
struct fixed_file_ref_node *ref_node = data->node;
|
|
|
|
pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
|
|
if (!pfile)
|
|
return -ENOMEM;
|
|
|
|
pfile->file = file;
|
|
list_add(&pfile->list, &ref_node->file_list);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __io_sqe_files_update(struct io_ring_ctx *ctx,
|
|
struct io_uring_files_update *up,
|
|
unsigned nr_args)
|
|
{
|
|
struct fixed_file_data *data = ctx->file_data;
|
|
struct fixed_file_ref_node *ref_node;
|
|
struct file *file;
|
|
__s32 __user *fds;
|
|
int fd, i, err;
|
|
__u32 done;
|
|
bool needs_switch = false;
|
|
|
|
if (check_add_overflow(up->offset, nr_args, &done))
|
|
return -EOVERFLOW;
|
|
if (done > ctx->nr_user_files)
|
|
return -EINVAL;
|
|
|
|
ref_node = alloc_fixed_file_ref_node(ctx);
|
|
if (IS_ERR(ref_node))
|
|
return PTR_ERR(ref_node);
|
|
|
|
done = 0;
|
|
fds = u64_to_user_ptr(up->fds);
|
|
while (nr_args) {
|
|
struct fixed_file_table *table;
|
|
unsigned index;
|
|
|
|
err = 0;
|
|
if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
|
|
err = -EFAULT;
|
|
break;
|
|
}
|
|
i = array_index_nospec(up->offset, ctx->nr_user_files);
|
|
table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
|
|
index = i & IORING_FILE_TABLE_MASK;
|
|
if (table->files[index]) {
|
|
file = table->files[index];
|
|
err = io_queue_file_removal(data, file);
|
|
if (err)
|
|
break;
|
|
table->files[index] = NULL;
|
|
needs_switch = true;
|
|
}
|
|
if (fd != -1) {
|
|
file = fget(fd);
|
|
if (!file) {
|
|
err = -EBADF;
|
|
break;
|
|
}
|
|
/*
|
|
* Don't allow io_uring instances to be registered. If
|
|
* UNIX isn't enabled, then this causes a reference
|
|
* cycle and this instance can never get freed. If UNIX
|
|
* is enabled we'll handle it just fine, but there's
|
|
* still no point in allowing a ring fd as it doesn't
|
|
* support regular read/write anyway.
|
|
*/
|
|
if (file->f_op == &io_uring_fops) {
|
|
fput(file);
|
|
err = -EBADF;
|
|
break;
|
|
}
|
|
table->files[index] = file;
|
|
err = io_sqe_file_register(ctx, file, i);
|
|
if (err) {
|
|
table->files[index] = NULL;
|
|
fput(file);
|
|
break;
|
|
}
|
|
}
|
|
nr_args--;
|
|
done++;
|
|
up->offset++;
|
|
}
|
|
|
|
if (needs_switch) {
|
|
percpu_ref_kill(&data->node->refs);
|
|
spin_lock(&data->lock);
|
|
list_add(&ref_node->node, &data->ref_list);
|
|
data->node = ref_node;
|
|
spin_unlock(&data->lock);
|
|
percpu_ref_get(&ctx->file_data->refs);
|
|
} else
|
|
destroy_fixed_file_ref_node(ref_node);
|
|
|
|
return done ? done : err;
|
|
}
|
|
|
|
static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
|
|
unsigned nr_args)
|
|
{
|
|
struct io_uring_files_update up;
|
|
|
|
if (!ctx->file_data)
|
|
return -ENXIO;
|
|
if (!nr_args)
|
|
return -EINVAL;
|
|
if (copy_from_user(&up, arg, sizeof(up)))
|
|
return -EFAULT;
|
|
if (up.resv)
|
|
return -EINVAL;
|
|
|
|
return __io_sqe_files_update(ctx, &up, nr_args);
|
|
}
|
|
|
|
static void io_free_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
|
|
/* Consider that io_steal_work() relies on this ref */
|
|
io_put_req(req);
|
|
}
|
|
|
|
static int io_init_wq_offload(struct io_ring_ctx *ctx,
|
|
struct io_uring_params *p)
|
|
{
|
|
struct io_wq_data data;
|
|
struct fd f;
|
|
struct io_ring_ctx *ctx_attach;
|
|
unsigned int concurrency;
|
|
int ret = 0;
|
|
|
|
data.user = ctx->user;
|
|
data.free_work = io_free_work;
|
|
data.do_work = io_wq_submit_work;
|
|
|
|
if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
|
|
/* Do QD, or 4 * CPUS, whatever is smallest */
|
|
concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
|
|
|
|
ctx->io_wq = io_wq_create(concurrency, &data);
|
|
if (IS_ERR(ctx->io_wq)) {
|
|
ret = PTR_ERR(ctx->io_wq);
|
|
ctx->io_wq = NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
f = fdget(p->wq_fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
|
|
if (f.file->f_op != &io_uring_fops) {
|
|
ret = -EINVAL;
|
|
goto out_fput;
|
|
}
|
|
|
|
ctx_attach = f.file->private_data;
|
|
/* @io_wq is protected by holding the fd */
|
|
if (!io_wq_get(ctx_attach->io_wq, &data)) {
|
|
ret = -EINVAL;
|
|
goto out_fput;
|
|
}
|
|
|
|
ctx->io_wq = ctx_attach->io_wq;
|
|
out_fput:
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
static int io_uring_alloc_task_context(struct task_struct *task)
|
|
{
|
|
struct io_uring_task *tctx;
|
|
int ret;
|
|
|
|
tctx = kmalloc(sizeof(*tctx), GFP_KERNEL);
|
|
if (unlikely(!tctx))
|
|
return -ENOMEM;
|
|
|
|
ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
|
|
if (unlikely(ret)) {
|
|
kfree(tctx);
|
|
return ret;
|
|
}
|
|
|
|
xa_init(&tctx->xa);
|
|
init_waitqueue_head(&tctx->wait);
|
|
tctx->last = NULL;
|
|
atomic_set(&tctx->in_idle, 0);
|
|
tctx->sqpoll = false;
|
|
io_init_identity(&tctx->__identity);
|
|
tctx->identity = &tctx->__identity;
|
|
task->io_uring = tctx;
|
|
return 0;
|
|
}
|
|
|
|
void __io_uring_free(struct task_struct *tsk)
|
|
{
|
|
struct io_uring_task *tctx = tsk->io_uring;
|
|
|
|
WARN_ON_ONCE(!xa_empty(&tctx->xa));
|
|
WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1);
|
|
if (tctx->identity != &tctx->__identity)
|
|
kfree(tctx->identity);
|
|
percpu_counter_destroy(&tctx->inflight);
|
|
kfree(tctx);
|
|
tsk->io_uring = NULL;
|
|
}
|
|
|
|
static int io_sq_offload_create(struct io_ring_ctx *ctx,
|
|
struct io_uring_params *p)
|
|
{
|
|
int ret;
|
|
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
struct io_sq_data *sqd;
|
|
|
|
ret = -EPERM;
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
goto err;
|
|
|
|
sqd = io_get_sq_data(p);
|
|
if (IS_ERR(sqd)) {
|
|
ret = PTR_ERR(sqd);
|
|
goto err;
|
|
}
|
|
|
|
ctx->sq_data = sqd;
|
|
io_sq_thread_park(sqd);
|
|
mutex_lock(&sqd->ctx_lock);
|
|
list_add(&ctx->sqd_list, &sqd->ctx_new_list);
|
|
mutex_unlock(&sqd->ctx_lock);
|
|
io_sq_thread_unpark(sqd);
|
|
|
|
ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
|
|
if (!ctx->sq_thread_idle)
|
|
ctx->sq_thread_idle = HZ;
|
|
|
|
if (sqd->thread)
|
|
goto done;
|
|
|
|
if (p->flags & IORING_SETUP_SQ_AFF) {
|
|
int cpu = p->sq_thread_cpu;
|
|
|
|
ret = -EINVAL;
|
|
if (cpu >= nr_cpu_ids)
|
|
goto err;
|
|
if (!cpu_online(cpu))
|
|
goto err;
|
|
|
|
sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd,
|
|
cpu, "io_uring-sq");
|
|
} else {
|
|
sqd->thread = kthread_create(io_sq_thread, sqd,
|
|
"io_uring-sq");
|
|
}
|
|
if (IS_ERR(sqd->thread)) {
|
|
ret = PTR_ERR(sqd->thread);
|
|
sqd->thread = NULL;
|
|
goto err;
|
|
}
|
|
ret = io_uring_alloc_task_context(sqd->thread);
|
|
if (ret)
|
|
goto err;
|
|
} else if (p->flags & IORING_SETUP_SQ_AFF) {
|
|
/* Can't have SQ_AFF without SQPOLL */
|
|
ret = -EINVAL;
|
|
goto err;
|
|
}
|
|
|
|
done:
|
|
ret = io_init_wq_offload(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
return 0;
|
|
err:
|
|
io_finish_async(ctx);
|
|
return ret;
|
|
}
|
|
|
|
static void io_sq_offload_start(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd->thread)
|
|
wake_up_process(sqd->thread);
|
|
}
|
|
|
|
static inline void __io_unaccount_mem(struct user_struct *user,
|
|
unsigned long nr_pages)
|
|
{
|
|
atomic_long_sub(nr_pages, &user->locked_vm);
|
|
}
|
|
|
|
static inline int __io_account_mem(struct user_struct *user,
|
|
unsigned long nr_pages)
|
|
{
|
|
unsigned long page_limit, cur_pages, new_pages;
|
|
|
|
/* Don't allow more pages than we can safely lock */
|
|
page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
|
|
|
do {
|
|
cur_pages = atomic_long_read(&user->locked_vm);
|
|
new_pages = cur_pages + nr_pages;
|
|
if (new_pages > page_limit)
|
|
return -ENOMEM;
|
|
} while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
|
|
new_pages) != cur_pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
|
|
enum io_mem_account acct)
|
|
{
|
|
if (ctx->limit_mem)
|
|
__io_unaccount_mem(ctx->user, nr_pages);
|
|
|
|
if (ctx->mm_account) {
|
|
if (acct == ACCT_LOCKED)
|
|
ctx->mm_account->locked_vm -= nr_pages;
|
|
else if (acct == ACCT_PINNED)
|
|
atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
|
|
}
|
|
}
|
|
|
|
static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
|
|
enum io_mem_account acct)
|
|
{
|
|
int ret;
|
|
|
|
if (ctx->limit_mem) {
|
|
ret = __io_account_mem(ctx->user, nr_pages);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (ctx->mm_account) {
|
|
if (acct == ACCT_LOCKED)
|
|
ctx->mm_account->locked_vm += nr_pages;
|
|
else if (acct == ACCT_PINNED)
|
|
atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void io_mem_free(void *ptr)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!ptr)
|
|
return;
|
|
|
|
page = virt_to_head_page(ptr);
|
|
if (put_page_testzero(page))
|
|
free_compound_page(page);
|
|
}
|
|
|
|
static void *io_mem_alloc(size_t size)
|
|
{
|
|
gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
|
|
__GFP_NORETRY;
|
|
|
|
return (void *) __get_free_pages(gfp_flags, get_order(size));
|
|
}
|
|
|
|
static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
|
|
size_t *sq_offset)
|
|
{
|
|
struct io_rings *rings;
|
|
size_t off, sq_array_size;
|
|
|
|
off = struct_size(rings, cqes, cq_entries);
|
|
if (off == SIZE_MAX)
|
|
return SIZE_MAX;
|
|
|
|
#ifdef CONFIG_SMP
|
|
off = ALIGN(off, SMP_CACHE_BYTES);
|
|
if (off == 0)
|
|
return SIZE_MAX;
|
|
#endif
|
|
|
|
if (sq_offset)
|
|
*sq_offset = off;
|
|
|
|
sq_array_size = array_size(sizeof(u32), sq_entries);
|
|
if (sq_array_size == SIZE_MAX)
|
|
return SIZE_MAX;
|
|
|
|
if (check_add_overflow(off, sq_array_size, &off))
|
|
return SIZE_MAX;
|
|
|
|
return off;
|
|
}
|
|
|
|
static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
|
|
{
|
|
size_t pages;
|
|
|
|
pages = (size_t)1 << get_order(
|
|
rings_size(sq_entries, cq_entries, NULL));
|
|
pages += (size_t)1 << get_order(
|
|
array_size(sizeof(struct io_uring_sqe), sq_entries));
|
|
|
|
return pages;
|
|
}
|
|
|
|
static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
|
|
{
|
|
int i, j;
|
|
|
|
if (!ctx->user_bufs)
|
|
return -ENXIO;
|
|
|
|
for (i = 0; i < ctx->nr_user_bufs; i++) {
|
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
|
|
|
|
for (j = 0; j < imu->nr_bvecs; j++)
|
|
unpin_user_page(imu->bvec[j].bv_page);
|
|
|
|
if (imu->acct_pages)
|
|
io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
|
|
kvfree(imu->bvec);
|
|
imu->nr_bvecs = 0;
|
|
}
|
|
|
|
kfree(ctx->user_bufs);
|
|
ctx->user_bufs = NULL;
|
|
ctx->nr_user_bufs = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
|
|
void __user *arg, unsigned index)
|
|
{
|
|
struct iovec __user *src;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (ctx->compat) {
|
|
struct compat_iovec __user *ciovs;
|
|
struct compat_iovec ciov;
|
|
|
|
ciovs = (struct compat_iovec __user *) arg;
|
|
if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
|
|
return -EFAULT;
|
|
|
|
dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
|
|
dst->iov_len = ciov.iov_len;
|
|
return 0;
|
|
}
|
|
#endif
|
|
src = (struct iovec __user *) arg;
|
|
if (copy_from_user(dst, &src[index], sizeof(*dst)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Not super efficient, but this is just a registration time. And we do cache
|
|
* the last compound head, so generally we'll only do a full search if we don't
|
|
* match that one.
|
|
*
|
|
* We check if the given compound head page has already been accounted, to
|
|
* avoid double accounting it. This allows us to account the full size of the
|
|
* page, not just the constituent pages of a huge page.
|
|
*/
|
|
static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
|
|
int nr_pages, struct page *hpage)
|
|
{
|
|
int i, j;
|
|
|
|
/* check current page array */
|
|
for (i = 0; i < nr_pages; i++) {
|
|
if (!PageCompound(pages[i]))
|
|
continue;
|
|
if (compound_head(pages[i]) == hpage)
|
|
return true;
|
|
}
|
|
|
|
/* check previously registered pages */
|
|
for (i = 0; i < ctx->nr_user_bufs; i++) {
|
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
|
|
|
|
for (j = 0; j < imu->nr_bvecs; j++) {
|
|
if (!PageCompound(imu->bvec[j].bv_page))
|
|
continue;
|
|
if (compound_head(imu->bvec[j].bv_page) == hpage)
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
|
|
int nr_pages, struct io_mapped_ubuf *imu,
|
|
struct page **last_hpage)
|
|
{
|
|
int i, ret;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
if (!PageCompound(pages[i])) {
|
|
imu->acct_pages++;
|
|
} else {
|
|
struct page *hpage;
|
|
|
|
hpage = compound_head(pages[i]);
|
|
if (hpage == *last_hpage)
|
|
continue;
|
|
*last_hpage = hpage;
|
|
if (headpage_already_acct(ctx, pages, i, hpage))
|
|
continue;
|
|
imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
|
|
}
|
|
}
|
|
|
|
if (!imu->acct_pages)
|
|
return 0;
|
|
|
|
ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED);
|
|
if (ret)
|
|
imu->acct_pages = 0;
|
|
return ret;
|
|
}
|
|
|
|
static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
|
|
unsigned nr_args)
|
|
{
|
|
struct vm_area_struct **vmas = NULL;
|
|
struct page **pages = NULL;
|
|
struct page *last_hpage = NULL;
|
|
int i, j, got_pages = 0;
|
|
int ret = -EINVAL;
|
|
|
|
if (ctx->user_bufs)
|
|
return -EBUSY;
|
|
if (!nr_args || nr_args > UIO_MAXIOV)
|
|
return -EINVAL;
|
|
|
|
ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
|
|
GFP_KERNEL);
|
|
if (!ctx->user_bufs)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < nr_args; i++) {
|
|
struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
|
|
unsigned long off, start, end, ubuf;
|
|
int pret, nr_pages;
|
|
struct iovec iov;
|
|
size_t size;
|
|
|
|
ret = io_copy_iov(ctx, &iov, arg, i);
|
|
if (ret)
|
|
goto err;
|
|
|
|
/*
|
|
* Don't impose further limits on the size and buffer
|
|
* constraints here, we'll -EINVAL later when IO is
|
|
* submitted if they are wrong.
|
|
*/
|
|
ret = -EFAULT;
|
|
if (!iov.iov_base || !iov.iov_len)
|
|
goto err;
|
|
|
|
/* arbitrary limit, but we need something */
|
|
if (iov.iov_len > SZ_1G)
|
|
goto err;
|
|
|
|
ubuf = (unsigned long) iov.iov_base;
|
|
end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
start = ubuf >> PAGE_SHIFT;
|
|
nr_pages = end - start;
|
|
|
|
ret = 0;
|
|
if (!pages || nr_pages > got_pages) {
|
|
kvfree(vmas);
|
|
kvfree(pages);
|
|
pages = kvmalloc_array(nr_pages, sizeof(struct page *),
|
|
GFP_KERNEL);
|
|
vmas = kvmalloc_array(nr_pages,
|
|
sizeof(struct vm_area_struct *),
|
|
GFP_KERNEL);
|
|
if (!pages || !vmas) {
|
|
ret = -ENOMEM;
|
|
goto err;
|
|
}
|
|
got_pages = nr_pages;
|
|
}
|
|
|
|
imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
|
|
GFP_KERNEL);
|
|
ret = -ENOMEM;
|
|
if (!imu->bvec)
|
|
goto err;
|
|
|
|
ret = 0;
|
|
mmap_read_lock(current->mm);
|
|
pret = pin_user_pages(ubuf, nr_pages,
|
|
FOLL_WRITE | FOLL_LONGTERM,
|
|
pages, vmas);
|
|
if (pret == nr_pages) {
|
|
/* don't support file backed memory */
|
|
for (j = 0; j < nr_pages; j++) {
|
|
struct vm_area_struct *vma = vmas[j];
|
|
|
|
if (vma->vm_file &&
|
|
!is_file_hugepages(vma->vm_file)) {
|
|
ret = -EOPNOTSUPP;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
ret = pret < 0 ? pret : -EFAULT;
|
|
}
|
|
mmap_read_unlock(current->mm);
|
|
if (ret) {
|
|
/*
|
|
* if we did partial map, or found file backed vmas,
|
|
* release any pages we did get
|
|
*/
|
|
if (pret > 0)
|
|
unpin_user_pages(pages, pret);
|
|
kvfree(imu->bvec);
|
|
goto err;
|
|
}
|
|
|
|
ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage);
|
|
if (ret) {
|
|
unpin_user_pages(pages, pret);
|
|
kvfree(imu->bvec);
|
|
goto err;
|
|
}
|
|
|
|
off = ubuf & ~PAGE_MASK;
|
|
size = iov.iov_len;
|
|
for (j = 0; j < nr_pages; j++) {
|
|
size_t vec_len;
|
|
|
|
vec_len = min_t(size_t, size, PAGE_SIZE - off);
|
|
imu->bvec[j].bv_page = pages[j];
|
|
imu->bvec[j].bv_len = vec_len;
|
|
imu->bvec[j].bv_offset = off;
|
|
off = 0;
|
|
size -= vec_len;
|
|
}
|
|
/* store original address for later verification */
|
|
imu->ubuf = ubuf;
|
|
imu->len = iov.iov_len;
|
|
imu->nr_bvecs = nr_pages;
|
|
|
|
ctx->nr_user_bufs++;
|
|
}
|
|
kvfree(pages);
|
|
kvfree(vmas);
|
|
return 0;
|
|
err:
|
|
kvfree(pages);
|
|
kvfree(vmas);
|
|
io_sqe_buffer_unregister(ctx);
|
|
return ret;
|
|
}
|
|
|
|
static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
|
|
{
|
|
__s32 __user *fds = arg;
|
|
int fd;
|
|
|
|
if (ctx->cq_ev_fd)
|
|
return -EBUSY;
|
|
|
|
if (copy_from_user(&fd, fds, sizeof(*fds)))
|
|
return -EFAULT;
|
|
|
|
ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
|
|
if (IS_ERR(ctx->cq_ev_fd)) {
|
|
int ret = PTR_ERR(ctx->cq_ev_fd);
|
|
ctx->cq_ev_fd = NULL;
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int io_eventfd_unregister(struct io_ring_ctx *ctx)
|
|
{
|
|
if (ctx->cq_ev_fd) {
|
|
eventfd_ctx_put(ctx->cq_ev_fd);
|
|
ctx->cq_ev_fd = NULL;
|
|
return 0;
|
|
}
|
|
|
|
return -ENXIO;
|
|
}
|
|
|
|
static int __io_destroy_buffers(int id, void *p, void *data)
|
|
{
|
|
struct io_ring_ctx *ctx = data;
|
|
struct io_buffer *buf = p;
|
|
|
|
__io_remove_buffers(ctx, buf, id, -1U);
|
|
return 0;
|
|
}
|
|
|
|
static void io_destroy_buffers(struct io_ring_ctx *ctx)
|
|
{
|
|
idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx);
|
|
idr_destroy(&ctx->io_buffer_idr);
|
|
}
|
|
|
|
static void io_ring_ctx_free(struct io_ring_ctx *ctx)
|
|
{
|
|
io_finish_async(ctx);
|
|
io_sqe_buffer_unregister(ctx);
|
|
|
|
if (ctx->sqo_task) {
|
|
put_task_struct(ctx->sqo_task);
|
|
ctx->sqo_task = NULL;
|
|
mmdrop(ctx->mm_account);
|
|
ctx->mm_account = NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
if (ctx->sqo_blkcg_css)
|
|
css_put(ctx->sqo_blkcg_css);
|
|
#endif
|
|
|
|
io_sqe_files_unregister(ctx);
|
|
io_eventfd_unregister(ctx);
|
|
io_destroy_buffers(ctx);
|
|
idr_destroy(&ctx->personality_idr);
|
|
|
|
#if defined(CONFIG_UNIX)
|
|
if (ctx->ring_sock) {
|
|
ctx->ring_sock->file = NULL; /* so that iput() is called */
|
|
sock_release(ctx->ring_sock);
|
|
}
|
|
#endif
|
|
|
|
io_mem_free(ctx->rings);
|
|
io_mem_free(ctx->sq_sqes);
|
|
|
|
percpu_ref_exit(&ctx->refs);
|
|
free_uid(ctx->user);
|
|
put_cred(ctx->creds);
|
|
kfree(ctx->cancel_hash);
|
|
kmem_cache_free(req_cachep, ctx->fallback_req);
|
|
kfree(ctx);
|
|
}
|
|
|
|
static __poll_t io_uring_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
__poll_t mask = 0;
|
|
|
|
poll_wait(file, &ctx->cq_wait, wait);
|
|
/*
|
|
* synchronizes with barrier from wq_has_sleeper call in
|
|
* io_commit_cqring
|
|
*/
|
|
smp_rmb();
|
|
if (!io_sqring_full(ctx))
|
|
mask |= EPOLLOUT | EPOLLWRNORM;
|
|
if (io_cqring_events(ctx, false))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static int io_uring_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
return fasync_helper(fd, file, on, &ctx->cq_fasync);
|
|
}
|
|
|
|
static int io_remove_personalities(int id, void *p, void *data)
|
|
{
|
|
struct io_ring_ctx *ctx = data;
|
|
struct io_identity *iod;
|
|
|
|
iod = idr_remove(&ctx->personality_idr, id);
|
|
if (iod) {
|
|
put_cred(iod->creds);
|
|
if (refcount_dec_and_test(&iod->count))
|
|
kfree(iod);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void io_ring_exit_work(struct work_struct *work)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
|
|
exit_work);
|
|
|
|
/*
|
|
* If we're doing polled IO and end up having requests being
|
|
* submitted async (out-of-line), then completions can come in while
|
|
* we're waiting for refs to drop. We need to reap these manually,
|
|
* as nobody else will be looking for them.
|
|
*/
|
|
do {
|
|
if (ctx->rings)
|
|
io_cqring_overflow_flush(ctx, true, NULL, NULL);
|
|
io_iopoll_try_reap_events(ctx);
|
|
} while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
|
|
io_ring_ctx_free(ctx);
|
|
}
|
|
|
|
static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
|
|
{
|
|
mutex_lock(&ctx->uring_lock);
|
|
percpu_ref_kill(&ctx->refs);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
io_kill_timeouts(ctx, NULL);
|
|
io_poll_remove_all(ctx, NULL);
|
|
|
|
if (ctx->io_wq)
|
|
io_wq_cancel_all(ctx->io_wq);
|
|
|
|
/* if we failed setting up the ctx, we might not have any rings */
|
|
if (ctx->rings)
|
|
io_cqring_overflow_flush(ctx, true, NULL, NULL);
|
|
io_iopoll_try_reap_events(ctx);
|
|
idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
|
|
|
|
/*
|
|
* Do this upfront, so we won't have a grace period where the ring
|
|
* is closed but resources aren't reaped yet. This can cause
|
|
* spurious failure in setting up a new ring.
|
|
*/
|
|
io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
|
|
ACCT_LOCKED);
|
|
|
|
INIT_WORK(&ctx->exit_work, io_ring_exit_work);
|
|
/*
|
|
* Use system_unbound_wq to avoid spawning tons of event kworkers
|
|
* if we're exiting a ton of rings at the same time. It just adds
|
|
* noise and overhead, there's no discernable change in runtime
|
|
* over using system_wq.
|
|
*/
|
|
queue_work(system_unbound_wq, &ctx->exit_work);
|
|
}
|
|
|
|
static int io_uring_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
file->private_data = NULL;
|
|
io_ring_ctx_wait_and_kill(ctx);
|
|
return 0;
|
|
}
|
|
|
|
static bool io_wq_files_match(struct io_wq_work *work, void *data)
|
|
{
|
|
struct files_struct *files = data;
|
|
|
|
return !files || ((work->flags & IO_WQ_WORK_FILES) &&
|
|
work->identity->files == files);
|
|
}
|
|
|
|
/*
|
|
* Returns true if 'preq' is the link parent of 'req'
|
|
*/
|
|
static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *link;
|
|
|
|
if (!(preq->flags & REQ_F_LINK_HEAD))
|
|
return false;
|
|
|
|
list_for_each_entry(link, &preq->link_list, link_list) {
|
|
if (link == req)
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* We're looking to cancel 'req' because it's holding on to our files, but
|
|
* 'req' could be a link to another request. See if it is, and cancel that
|
|
* parent request if so.
|
|
*/
|
|
static bool io_poll_remove_link(struct io_ring_ctx *ctx, struct io_kiocb *req)
|
|
{
|
|
struct hlist_node *tmp;
|
|
struct io_kiocb *preq;
|
|
bool found = false;
|
|
int i;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
|
|
struct hlist_head *list;
|
|
|
|
list = &ctx->cancel_hash[i];
|
|
hlist_for_each_entry_safe(preq, tmp, list, hash_node) {
|
|
found = io_match_link(preq, req);
|
|
if (found) {
|
|
io_poll_remove_one(preq);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
return found;
|
|
}
|
|
|
|
static bool io_timeout_remove_link(struct io_ring_ctx *ctx,
|
|
struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *preq;
|
|
bool found = false;
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
list_for_each_entry(preq, &ctx->timeout_list, timeout.list) {
|
|
found = io_match_link(preq, req);
|
|
if (found) {
|
|
__io_timeout_cancel(preq);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
return found;
|
|
}
|
|
|
|
static bool io_cancel_link_cb(struct io_wq_work *work, void *data)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
bool ret;
|
|
|
|
if (req->flags & REQ_F_LINK_TIMEOUT) {
|
|
unsigned long flags;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
/* protect against races with linked timeouts */
|
|
spin_lock_irqsave(&ctx->completion_lock, flags);
|
|
ret = io_match_link(req, data);
|
|
spin_unlock_irqrestore(&ctx->completion_lock, flags);
|
|
} else {
|
|
ret = io_match_link(req, data);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
|
|
{
|
|
enum io_wq_cancel cret;
|
|
|
|
/* cancel this particular work, if it's running */
|
|
cret = io_wq_cancel_work(ctx->io_wq, &req->work);
|
|
if (cret != IO_WQ_CANCEL_NOTFOUND)
|
|
return;
|
|
|
|
/* find links that hold this pending, cancel those */
|
|
cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_link_cb, req, true);
|
|
if (cret != IO_WQ_CANCEL_NOTFOUND)
|
|
return;
|
|
|
|
/* if we have a poll link holding this pending, cancel that */
|
|
if (io_poll_remove_link(ctx, req))
|
|
return;
|
|
|
|
/* final option, timeout link is holding this req pending */
|
|
io_timeout_remove_link(ctx, req);
|
|
}
|
|
|
|
static void io_cancel_defer_files(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
struct files_struct *files)
|
|
{
|
|
struct io_defer_entry *de = NULL;
|
|
LIST_HEAD(list);
|
|
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
list_for_each_entry_reverse(de, &ctx->defer_list, list) {
|
|
if (io_task_match(de->req, task) &&
|
|
io_match_files(de->req, files)) {
|
|
list_cut_position(&list, &ctx->defer_list, &de->list);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
|
|
while (!list_empty(&list)) {
|
|
de = list_first_entry(&list, struct io_defer_entry, list);
|
|
list_del_init(&de->list);
|
|
req_set_fail_links(de->req);
|
|
io_put_req(de->req);
|
|
io_req_complete(de->req, -ECANCELED);
|
|
kfree(de);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if we found and killed one or more files pinning requests
|
|
*/
|
|
static bool io_uring_cancel_files(struct io_ring_ctx *ctx,
|
|
struct files_struct *files)
|
|
{
|
|
if (list_empty_careful(&ctx->inflight_list))
|
|
return false;
|
|
|
|
/* cancel all at once, should be faster than doing it one by one*/
|
|
io_wq_cancel_cb(ctx->io_wq, io_wq_files_match, files, true);
|
|
|
|
while (!list_empty_careful(&ctx->inflight_list)) {
|
|
struct io_kiocb *cancel_req = NULL, *req;
|
|
DEFINE_WAIT(wait);
|
|
|
|
spin_lock_irq(&ctx->inflight_lock);
|
|
list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
|
|
if (files && (req->work.flags & IO_WQ_WORK_FILES) &&
|
|
req->work.identity->files != files)
|
|
continue;
|
|
/* req is being completed, ignore */
|
|
if (!refcount_inc_not_zero(&req->refs))
|
|
continue;
|
|
cancel_req = req;
|
|
break;
|
|
}
|
|
if (cancel_req)
|
|
prepare_to_wait(&ctx->inflight_wait, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
spin_unlock_irq(&ctx->inflight_lock);
|
|
|
|
/* We need to keep going until we don't find a matching req */
|
|
if (!cancel_req)
|
|
break;
|
|
/* cancel this request, or head link requests */
|
|
io_attempt_cancel(ctx, cancel_req);
|
|
io_put_req(cancel_req);
|
|
/* cancellations _may_ trigger task work */
|
|
io_run_task_work();
|
|
schedule();
|
|
finish_wait(&ctx->inflight_wait, &wait);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
struct task_struct *task = data;
|
|
|
|
return io_task_match(req, task);
|
|
}
|
|
|
|
static bool __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
struct files_struct *files)
|
|
{
|
|
bool ret;
|
|
|
|
ret = io_uring_cancel_files(ctx, files);
|
|
if (!files) {
|
|
enum io_wq_cancel cret;
|
|
|
|
cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, task, true);
|
|
if (cret != IO_WQ_CANCEL_NOTFOUND)
|
|
ret = true;
|
|
|
|
/* SQPOLL thread does its own polling */
|
|
if (!(ctx->flags & IORING_SETUP_SQPOLL)) {
|
|
while (!list_empty_careful(&ctx->iopoll_list)) {
|
|
io_iopoll_try_reap_events(ctx);
|
|
ret = true;
|
|
}
|
|
}
|
|
|
|
ret |= io_poll_remove_all(ctx, task);
|
|
ret |= io_kill_timeouts(ctx, task);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We need to iteratively cancel requests, in case a request has dependent
|
|
* hard links. These persist even for failure of cancelations, hence keep
|
|
* looping until none are found.
|
|
*/
|
|
static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
|
|
struct files_struct *files)
|
|
{
|
|
struct task_struct *task = current;
|
|
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
|
|
task = ctx->sq_data->thread;
|
|
atomic_inc(&task->io_uring->in_idle);
|
|
io_sq_thread_park(ctx->sq_data);
|
|
}
|
|
|
|
if (files)
|
|
io_cancel_defer_files(ctx, NULL, files);
|
|
else
|
|
io_cancel_defer_files(ctx, task, NULL);
|
|
|
|
io_cqring_overflow_flush(ctx, true, task, files);
|
|
|
|
while (__io_uring_cancel_task_requests(ctx, task, files)) {
|
|
io_run_task_work();
|
|
cond_resched();
|
|
}
|
|
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
|
|
atomic_dec(&task->io_uring->in_idle);
|
|
/*
|
|
* If the files that are going away are the ones in the thread
|
|
* identity, clear them out.
|
|
*/
|
|
if (task->io_uring->identity->files == files)
|
|
task->io_uring->identity->files = NULL;
|
|
io_sq_thread_unpark(ctx->sq_data);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Note that this task has used io_uring. We use it for cancelation purposes.
|
|
*/
|
|
static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (unlikely(!tctx)) {
|
|
int ret;
|
|
|
|
ret = io_uring_alloc_task_context(current);
|
|
if (unlikely(ret))
|
|
return ret;
|
|
tctx = current->io_uring;
|
|
}
|
|
if (tctx->last != file) {
|
|
void *old = xa_load(&tctx->xa, (unsigned long)file);
|
|
|
|
if (!old) {
|
|
get_file(file);
|
|
xa_store(&tctx->xa, (unsigned long)file, file, GFP_KERNEL);
|
|
}
|
|
tctx->last = file;
|
|
}
|
|
|
|
/*
|
|
* This is race safe in that the task itself is doing this, hence it
|
|
* cannot be going through the exit/cancel paths at the same time.
|
|
* This cannot be modified while exit/cancel is running.
|
|
*/
|
|
if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL))
|
|
tctx->sqpoll = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Remove this io_uring_file -> task mapping.
|
|
*/
|
|
static void io_uring_del_task_file(struct file *file)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (tctx->last == file)
|
|
tctx->last = NULL;
|
|
file = xa_erase(&tctx->xa, (unsigned long)file);
|
|
if (file)
|
|
fput(file);
|
|
}
|
|
|
|
/*
|
|
* Drop task note for this file if we're the only ones that hold it after
|
|
* pending fput()
|
|
*/
|
|
static void io_uring_attempt_task_drop(struct file *file)
|
|
{
|
|
if (!current->io_uring)
|
|
return;
|
|
/*
|
|
* fput() is pending, will be 2 if the only other ref is our potential
|
|
* task file note. If the task is exiting, drop regardless of count.
|
|
*/
|
|
if (fatal_signal_pending(current) || (current->flags & PF_EXITING) ||
|
|
atomic_long_read(&file->f_count) == 2)
|
|
io_uring_del_task_file(file);
|
|
}
|
|
|
|
void __io_uring_files_cancel(struct files_struct *files)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
struct file *file;
|
|
unsigned long index;
|
|
|
|
/* make sure overflow events are dropped */
|
|
atomic_inc(&tctx->in_idle);
|
|
|
|
xa_for_each(&tctx->xa, index, file) {
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
io_uring_cancel_task_requests(ctx, files);
|
|
if (files)
|
|
io_uring_del_task_file(file);
|
|
}
|
|
|
|
atomic_dec(&tctx->in_idle);
|
|
}
|
|
|
|
static s64 tctx_inflight(struct io_uring_task *tctx)
|
|
{
|
|
unsigned long index;
|
|
struct file *file;
|
|
s64 inflight;
|
|
|
|
inflight = percpu_counter_sum(&tctx->inflight);
|
|
if (!tctx->sqpoll)
|
|
return inflight;
|
|
|
|
/*
|
|
* If we have SQPOLL rings, then we need to iterate and find them, and
|
|
* add the pending count for those.
|
|
*/
|
|
xa_for_each(&tctx->xa, index, file) {
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
struct io_uring_task *__tctx = ctx->sqo_task->io_uring;
|
|
|
|
inflight += percpu_counter_sum(&__tctx->inflight);
|
|
}
|
|
}
|
|
|
|
return inflight;
|
|
}
|
|
|
|
/*
|
|
* Find any io_uring fd that this task has registered or done IO on, and cancel
|
|
* requests.
|
|
*/
|
|
void __io_uring_task_cancel(void)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
DEFINE_WAIT(wait);
|
|
s64 inflight;
|
|
|
|
/* make sure overflow events are dropped */
|
|
atomic_inc(&tctx->in_idle);
|
|
|
|
do {
|
|
/* read completions before cancelations */
|
|
inflight = tctx_inflight(tctx);
|
|
if (!inflight)
|
|
break;
|
|
__io_uring_files_cancel(NULL);
|
|
|
|
prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
|
|
|
|
/*
|
|
* If we've seen completions, retry. This avoids a race where
|
|
* a completion comes in before we did prepare_to_wait().
|
|
*/
|
|
if (inflight != tctx_inflight(tctx))
|
|
continue;
|
|
schedule();
|
|
} while (1);
|
|
|
|
finish_wait(&tctx->wait, &wait);
|
|
atomic_dec(&tctx->in_idle);
|
|
}
|
|
|
|
static int io_uring_flush(struct file *file, void *data)
|
|
{
|
|
io_uring_attempt_task_drop(file);
|
|
return 0;
|
|
}
|
|
|
|
static void *io_uring_validate_mmap_request(struct file *file,
|
|
loff_t pgoff, size_t sz)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
loff_t offset = pgoff << PAGE_SHIFT;
|
|
struct page *page;
|
|
void *ptr;
|
|
|
|
switch (offset) {
|
|
case IORING_OFF_SQ_RING:
|
|
case IORING_OFF_CQ_RING:
|
|
ptr = ctx->rings;
|
|
break;
|
|
case IORING_OFF_SQES:
|
|
ptr = ctx->sq_sqes;
|
|
break;
|
|
default:
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
page = virt_to_head_page(ptr);
|
|
if (sz > page_size(page))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return ptr;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
size_t sz = vma->vm_end - vma->vm_start;
|
|
unsigned long pfn;
|
|
void *ptr;
|
|
|
|
ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
|
|
if (IS_ERR(ptr))
|
|
return PTR_ERR(ptr);
|
|
|
|
pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
|
|
return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
|
|
}
|
|
|
|
#else /* !CONFIG_MMU */
|
|
|
|
static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
|
|
}
|
|
|
|
static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
|
|
{
|
|
return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
|
|
}
|
|
|
|
static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
|
|
unsigned long addr, unsigned long len,
|
|
unsigned long pgoff, unsigned long flags)
|
|
{
|
|
void *ptr;
|
|
|
|
ptr = io_uring_validate_mmap_request(file, pgoff, len);
|
|
if (IS_ERR(ptr))
|
|
return PTR_ERR(ptr);
|
|
|
|
return (unsigned long) ptr;
|
|
}
|
|
|
|
#endif /* !CONFIG_MMU */
|
|
|
|
static void io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
|
|
do {
|
|
if (!io_sqring_full(ctx))
|
|
break;
|
|
|
|
prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
|
|
|
|
if (!io_sqring_full(ctx))
|
|
break;
|
|
|
|
schedule();
|
|
} while (!signal_pending(current));
|
|
|
|
finish_wait(&ctx->sqo_sq_wait, &wait);
|
|
}
|
|
|
|
SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
|
|
u32, min_complete, u32, flags, const sigset_t __user *, sig,
|
|
size_t, sigsz)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
long ret = -EBADF;
|
|
int submitted = 0;
|
|
struct fd f;
|
|
|
|
io_run_task_work();
|
|
|
|
if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
|
|
IORING_ENTER_SQ_WAIT))
|
|
return -EINVAL;
|
|
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
|
|
ret = -EOPNOTSUPP;
|
|
if (f.file->f_op != &io_uring_fops)
|
|
goto out_fput;
|
|
|
|
ret = -ENXIO;
|
|
ctx = f.file->private_data;
|
|
if (!percpu_ref_tryget(&ctx->refs))
|
|
goto out_fput;
|
|
|
|
ret = -EBADFD;
|
|
if (ctx->flags & IORING_SETUP_R_DISABLED)
|
|
goto out;
|
|
|
|
/*
|
|
* For SQ polling, the thread will do all submissions and completions.
|
|
* Just return the requested submit count, and wake the thread if
|
|
* we were asked to.
|
|
*/
|
|
ret = 0;
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
if (!list_empty_careful(&ctx->cq_overflow_list))
|
|
io_cqring_overflow_flush(ctx, false, NULL, NULL);
|
|
if (flags & IORING_ENTER_SQ_WAKEUP)
|
|
wake_up(&ctx->sq_data->wait);
|
|
if (flags & IORING_ENTER_SQ_WAIT)
|
|
io_sqpoll_wait_sq(ctx);
|
|
submitted = to_submit;
|
|
} else if (to_submit) {
|
|
ret = io_uring_add_task_file(ctx, f.file);
|
|
if (unlikely(ret))
|
|
goto out;
|
|
mutex_lock(&ctx->uring_lock);
|
|
submitted = io_submit_sqes(ctx, to_submit);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
if (submitted != to_submit)
|
|
goto out;
|
|
}
|
|
if (flags & IORING_ENTER_GETEVENTS) {
|
|
min_complete = min(min_complete, ctx->cq_entries);
|
|
|
|
/*
|
|
* When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
|
|
* space applications don't need to do io completion events
|
|
* polling again, they can rely on io_sq_thread to do polling
|
|
* work, which can reduce cpu usage and uring_lock contention.
|
|
*/
|
|
if (ctx->flags & IORING_SETUP_IOPOLL &&
|
|
!(ctx->flags & IORING_SETUP_SQPOLL)) {
|
|
ret = io_iopoll_check(ctx, min_complete);
|
|
} else {
|
|
ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
|
|
}
|
|
}
|
|
|
|
out:
|
|
percpu_ref_put(&ctx->refs);
|
|
out_fput:
|
|
fdput(f);
|
|
return submitted ? submitted : ret;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static int io_uring_show_cred(int id, void *p, void *data)
|
|
{
|
|
struct io_identity *iod = p;
|
|
const struct cred *cred = iod->creds;
|
|
struct seq_file *m = data;
|
|
struct user_namespace *uns = seq_user_ns(m);
|
|
struct group_info *gi;
|
|
kernel_cap_t cap;
|
|
unsigned __capi;
|
|
int g;
|
|
|
|
seq_printf(m, "%5d\n", id);
|
|
seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
|
|
seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
|
|
seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
|
|
seq_puts(m, "\n\tGroups:\t");
|
|
gi = cred->group_info;
|
|
for (g = 0; g < gi->ngroups; g++) {
|
|
seq_put_decimal_ull(m, g ? " " : "",
|
|
from_kgid_munged(uns, gi->gid[g]));
|
|
}
|
|
seq_puts(m, "\n\tCapEff:\t");
|
|
cap = cred->cap_effective;
|
|
CAP_FOR_EACH_U32(__capi)
|
|
seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
|
|
seq_putc(m, '\n');
|
|
return 0;
|
|
}
|
|
|
|
static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
|
|
{
|
|
struct io_sq_data *sq = NULL;
|
|
bool has_lock;
|
|
int i;
|
|
|
|
/*
|
|
* Avoid ABBA deadlock between the seq lock and the io_uring mutex,
|
|
* since fdinfo case grabs it in the opposite direction of normal use
|
|
* cases. If we fail to get the lock, we just don't iterate any
|
|
* structures that could be going away outside the io_uring mutex.
|
|
*/
|
|
has_lock = mutex_trylock(&ctx->uring_lock);
|
|
|
|
if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL))
|
|
sq = ctx->sq_data;
|
|
|
|
seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
|
|
seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
|
|
seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
|
|
for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
|
|
struct fixed_file_table *table;
|
|
struct file *f;
|
|
|
|
table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
|
|
f = table->files[i & IORING_FILE_TABLE_MASK];
|
|
if (f)
|
|
seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
|
|
else
|
|
seq_printf(m, "%5u: <none>\n", i);
|
|
}
|
|
seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
|
|
for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
|
|
struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
|
|
|
|
seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
|
|
(unsigned int) buf->len);
|
|
}
|
|
if (has_lock && !idr_is_empty(&ctx->personality_idr)) {
|
|
seq_printf(m, "Personalities:\n");
|
|
idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
|
|
}
|
|
seq_printf(m, "PollList:\n");
|
|
spin_lock_irq(&ctx->completion_lock);
|
|
for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
|
|
struct hlist_head *list = &ctx->cancel_hash[i];
|
|
struct io_kiocb *req;
|
|
|
|
hlist_for_each_entry(req, list, hash_node)
|
|
seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
|
|
req->task->task_works != NULL);
|
|
}
|
|
spin_unlock_irq(&ctx->completion_lock);
|
|
if (has_lock)
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
|
|
{
|
|
struct io_ring_ctx *ctx = f->private_data;
|
|
|
|
if (percpu_ref_tryget(&ctx->refs)) {
|
|
__io_uring_show_fdinfo(ctx, m);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static const struct file_operations io_uring_fops = {
|
|
.release = io_uring_release,
|
|
.flush = io_uring_flush,
|
|
.mmap = io_uring_mmap,
|
|
#ifndef CONFIG_MMU
|
|
.get_unmapped_area = io_uring_nommu_get_unmapped_area,
|
|
.mmap_capabilities = io_uring_nommu_mmap_capabilities,
|
|
#endif
|
|
.poll = io_uring_poll,
|
|
.fasync = io_uring_fasync,
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = io_uring_show_fdinfo,
|
|
#endif
|
|
};
|
|
|
|
static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
|
|
struct io_uring_params *p)
|
|
{
|
|
struct io_rings *rings;
|
|
size_t size, sq_array_offset;
|
|
|
|
/* make sure these are sane, as we already accounted them */
|
|
ctx->sq_entries = p->sq_entries;
|
|
ctx->cq_entries = p->cq_entries;
|
|
|
|
size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
|
|
if (size == SIZE_MAX)
|
|
return -EOVERFLOW;
|
|
|
|
rings = io_mem_alloc(size);
|
|
if (!rings)
|
|
return -ENOMEM;
|
|
|
|
ctx->rings = rings;
|
|
ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
|
|
rings->sq_ring_mask = p->sq_entries - 1;
|
|
rings->cq_ring_mask = p->cq_entries - 1;
|
|
rings->sq_ring_entries = p->sq_entries;
|
|
rings->cq_ring_entries = p->cq_entries;
|
|
ctx->sq_mask = rings->sq_ring_mask;
|
|
ctx->cq_mask = rings->cq_ring_mask;
|
|
|
|
size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
|
|
if (size == SIZE_MAX) {
|
|
io_mem_free(ctx->rings);
|
|
ctx->rings = NULL;
|
|
return -EOVERFLOW;
|
|
}
|
|
|
|
ctx->sq_sqes = io_mem_alloc(size);
|
|
if (!ctx->sq_sqes) {
|
|
io_mem_free(ctx->rings);
|
|
ctx->rings = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Allocate an anonymous fd, this is what constitutes the application
|
|
* visible backing of an io_uring instance. The application mmaps this
|
|
* fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
|
|
* we have to tie this fd to a socket for file garbage collection purposes.
|
|
*/
|
|
static int io_uring_get_fd(struct io_ring_ctx *ctx)
|
|
{
|
|
struct file *file;
|
|
int ret;
|
|
|
|
#if defined(CONFIG_UNIX)
|
|
ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
|
|
&ctx->ring_sock);
|
|
if (ret)
|
|
return ret;
|
|
#endif
|
|
|
|
ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
|
|
if (ret < 0)
|
|
goto err;
|
|
|
|
file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
|
|
O_RDWR | O_CLOEXEC);
|
|
if (IS_ERR(file)) {
|
|
err_fd:
|
|
put_unused_fd(ret);
|
|
ret = PTR_ERR(file);
|
|
goto err;
|
|
}
|
|
|
|
#if defined(CONFIG_UNIX)
|
|
ctx->ring_sock->file = file;
|
|
#endif
|
|
if (unlikely(io_uring_add_task_file(ctx, file))) {
|
|
file = ERR_PTR(-ENOMEM);
|
|
goto err_fd;
|
|
}
|
|
fd_install(ret, file);
|
|
return ret;
|
|
err:
|
|
#if defined(CONFIG_UNIX)
|
|
sock_release(ctx->ring_sock);
|
|
ctx->ring_sock = NULL;
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
static int io_uring_create(unsigned entries, struct io_uring_params *p,
|
|
struct io_uring_params __user *params)
|
|
{
|
|
struct user_struct *user = NULL;
|
|
struct io_ring_ctx *ctx;
|
|
bool limit_mem;
|
|
int ret;
|
|
|
|
if (!entries)
|
|
return -EINVAL;
|
|
if (entries > IORING_MAX_ENTRIES) {
|
|
if (!(p->flags & IORING_SETUP_CLAMP))
|
|
return -EINVAL;
|
|
entries = IORING_MAX_ENTRIES;
|
|
}
|
|
|
|
/*
|
|
* Use twice as many entries for the CQ ring. It's possible for the
|
|
* application to drive a higher depth than the size of the SQ ring,
|
|
* since the sqes are only used at submission time. This allows for
|
|
* some flexibility in overcommitting a bit. If the application has
|
|
* set IORING_SETUP_CQSIZE, it will have passed in the desired number
|
|
* of CQ ring entries manually.
|
|
*/
|
|
p->sq_entries = roundup_pow_of_two(entries);
|
|
if (p->flags & IORING_SETUP_CQSIZE) {
|
|
/*
|
|
* If IORING_SETUP_CQSIZE is set, we do the same roundup
|
|
* to a power-of-two, if it isn't already. We do NOT impose
|
|
* any cq vs sq ring sizing.
|
|
*/
|
|
if (p->cq_entries < p->sq_entries)
|
|
return -EINVAL;
|
|
if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
|
|
if (!(p->flags & IORING_SETUP_CLAMP))
|
|
return -EINVAL;
|
|
p->cq_entries = IORING_MAX_CQ_ENTRIES;
|
|
}
|
|
p->cq_entries = roundup_pow_of_two(p->cq_entries);
|
|
} else {
|
|
p->cq_entries = 2 * p->sq_entries;
|
|
}
|
|
|
|
user = get_uid(current_user());
|
|
limit_mem = !capable(CAP_IPC_LOCK);
|
|
|
|
if (limit_mem) {
|
|
ret = __io_account_mem(user,
|
|
ring_pages(p->sq_entries, p->cq_entries));
|
|
if (ret) {
|
|
free_uid(user);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ctx = io_ring_ctx_alloc(p);
|
|
if (!ctx) {
|
|
if (limit_mem)
|
|
__io_unaccount_mem(user, ring_pages(p->sq_entries,
|
|
p->cq_entries));
|
|
free_uid(user);
|
|
return -ENOMEM;
|
|
}
|
|
ctx->compat = in_compat_syscall();
|
|
ctx->user = user;
|
|
ctx->creds = get_current_cred();
|
|
#ifdef CONFIG_AUDIT
|
|
ctx->loginuid = current->loginuid;
|
|
ctx->sessionid = current->sessionid;
|
|
#endif
|
|
ctx->sqo_task = get_task_struct(current);
|
|
|
|
/*
|
|
* This is just grabbed for accounting purposes. When a process exits,
|
|
* the mm is exited and dropped before the files, hence we need to hang
|
|
* on to this mm purely for the purposes of being able to unaccount
|
|
* memory (locked/pinned vm). It's not used for anything else.
|
|
*/
|
|
mmgrab(current->mm);
|
|
ctx->mm_account = current->mm;
|
|
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
/*
|
|
* The sq thread will belong to the original cgroup it was inited in.
|
|
* If the cgroup goes offline (e.g. disabling the io controller), then
|
|
* issued bios will be associated with the closest cgroup later in the
|
|
* block layer.
|
|
*/
|
|
rcu_read_lock();
|
|
ctx->sqo_blkcg_css = blkcg_css();
|
|
ret = css_tryget_online(ctx->sqo_blkcg_css);
|
|
rcu_read_unlock();
|
|
if (!ret) {
|
|
/* don't init against a dying cgroup, have the user try again */
|
|
ctx->sqo_blkcg_css = NULL;
|
|
ret = -ENODEV;
|
|
goto err;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Account memory _before_ installing the file descriptor. Once
|
|
* the descriptor is installed, it can get closed at any time. Also
|
|
* do this before hitting the general error path, as ring freeing
|
|
* will un-account as well.
|
|
*/
|
|
io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
|
|
ACCT_LOCKED);
|
|
ctx->limit_mem = limit_mem;
|
|
|
|
ret = io_allocate_scq_urings(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = io_sq_offload_create(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
if (!(p->flags & IORING_SETUP_R_DISABLED))
|
|
io_sq_offload_start(ctx);
|
|
|
|
memset(&p->sq_off, 0, sizeof(p->sq_off));
|
|
p->sq_off.head = offsetof(struct io_rings, sq.head);
|
|
p->sq_off.tail = offsetof(struct io_rings, sq.tail);
|
|
p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
|
|
p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
|
|
p->sq_off.flags = offsetof(struct io_rings, sq_flags);
|
|
p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
|
|
p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
|
|
|
|
memset(&p->cq_off, 0, sizeof(p->cq_off));
|
|
p->cq_off.head = offsetof(struct io_rings, cq.head);
|
|
p->cq_off.tail = offsetof(struct io_rings, cq.tail);
|
|
p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
|
|
p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
|
|
p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
|
|
p->cq_off.cqes = offsetof(struct io_rings, cqes);
|
|
p->cq_off.flags = offsetof(struct io_rings, cq_flags);
|
|
|
|
p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
|
|
IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
|
|
IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
|
|
IORING_FEAT_POLL_32BITS;
|
|
|
|
if (copy_to_user(params, p, sizeof(*p))) {
|
|
ret = -EFAULT;
|
|
goto err;
|
|
}
|
|
|
|
/*
|
|
* Install ring fd as the very last thing, so we don't risk someone
|
|
* having closed it before we finish setup
|
|
*/
|
|
ret = io_uring_get_fd(ctx);
|
|
if (ret < 0)
|
|
goto err;
|
|
|
|
trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
|
|
return ret;
|
|
err:
|
|
io_ring_ctx_wait_and_kill(ctx);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sets up an aio uring context, and returns the fd. Applications asks for a
|
|
* ring size, we return the actual sq/cq ring sizes (among other things) in the
|
|
* params structure passed in.
|
|
*/
|
|
static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
|
|
{
|
|
struct io_uring_params p;
|
|
int i;
|
|
|
|
if (copy_from_user(&p, params, sizeof(p)))
|
|
return -EFAULT;
|
|
for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
|
|
if (p.resv[i])
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
|
|
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
|
|
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
|
|
IORING_SETUP_R_DISABLED))
|
|
return -EINVAL;
|
|
|
|
return io_uring_create(entries, &p, params);
|
|
}
|
|
|
|
SYSCALL_DEFINE2(io_uring_setup, u32, entries,
|
|
struct io_uring_params __user *, params)
|
|
{
|
|
return io_uring_setup(entries, params);
|
|
}
|
|
|
|
static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
|
|
{
|
|
struct io_uring_probe *p;
|
|
size_t size;
|
|
int i, ret;
|
|
|
|
size = struct_size(p, ops, nr_args);
|
|
if (size == SIZE_MAX)
|
|
return -EOVERFLOW;
|
|
p = kzalloc(size, GFP_KERNEL);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
ret = -EFAULT;
|
|
if (copy_from_user(p, arg, size))
|
|
goto out;
|
|
ret = -EINVAL;
|
|
if (memchr_inv(p, 0, size))
|
|
goto out;
|
|
|
|
p->last_op = IORING_OP_LAST - 1;
|
|
if (nr_args > IORING_OP_LAST)
|
|
nr_args = IORING_OP_LAST;
|
|
|
|
for (i = 0; i < nr_args; i++) {
|
|
p->ops[i].op = i;
|
|
if (!io_op_defs[i].not_supported)
|
|
p->ops[i].flags = IO_URING_OP_SUPPORTED;
|
|
}
|
|
p->ops_len = i;
|
|
|
|
ret = 0;
|
|
if (copy_to_user(arg, p, size))
|
|
ret = -EFAULT;
|
|
out:
|
|
kfree(p);
|
|
return ret;
|
|
}
|
|
|
|
static int io_register_personality(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_identity *id;
|
|
int ret;
|
|
|
|
id = kmalloc(sizeof(*id), GFP_KERNEL);
|
|
if (unlikely(!id))
|
|
return -ENOMEM;
|
|
|
|
io_init_identity(id);
|
|
id->creds = get_current_cred();
|
|
|
|
ret = idr_alloc_cyclic(&ctx->personality_idr, id, 1, USHRT_MAX, GFP_KERNEL);
|
|
if (ret < 0) {
|
|
put_cred(id->creds);
|
|
kfree(id);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
|
|
{
|
|
struct io_identity *iod;
|
|
|
|
iod = idr_remove(&ctx->personality_idr, id);
|
|
if (iod) {
|
|
put_cred(iod->creds);
|
|
if (refcount_dec_and_test(&iod->count))
|
|
kfree(iod);
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
|
|
unsigned int nr_args)
|
|
{
|
|
struct io_uring_restriction *res;
|
|
size_t size;
|
|
int i, ret;
|
|
|
|
/* Restrictions allowed only if rings started disabled */
|
|
if (!(ctx->flags & IORING_SETUP_R_DISABLED))
|
|
return -EBADFD;
|
|
|
|
/* We allow only a single restrictions registration */
|
|
if (ctx->restrictions.registered)
|
|
return -EBUSY;
|
|
|
|
if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
|
|
return -EINVAL;
|
|
|
|
size = array_size(nr_args, sizeof(*res));
|
|
if (size == SIZE_MAX)
|
|
return -EOVERFLOW;
|
|
|
|
res = memdup_user(arg, size);
|
|
if (IS_ERR(res))
|
|
return PTR_ERR(res);
|
|
|
|
ret = 0;
|
|
|
|
for (i = 0; i < nr_args; i++) {
|
|
switch (res[i].opcode) {
|
|
case IORING_RESTRICTION_REGISTER_OP:
|
|
if (res[i].register_op >= IORING_REGISTER_LAST) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
__set_bit(res[i].register_op,
|
|
ctx->restrictions.register_op);
|
|
break;
|
|
case IORING_RESTRICTION_SQE_OP:
|
|
if (res[i].sqe_op >= IORING_OP_LAST) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
__set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
|
|
break;
|
|
case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
|
|
ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
|
|
break;
|
|
case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
|
|
ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
/* Reset all restrictions if an error happened */
|
|
if (ret != 0)
|
|
memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
|
|
else
|
|
ctx->restrictions.registered = true;
|
|
|
|
kfree(res);
|
|
return ret;
|
|
}
|
|
|
|
static int io_register_enable_rings(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!(ctx->flags & IORING_SETUP_R_DISABLED))
|
|
return -EBADFD;
|
|
|
|
if (ctx->restrictions.registered)
|
|
ctx->restricted = 1;
|
|
|
|
ctx->flags &= ~IORING_SETUP_R_DISABLED;
|
|
|
|
io_sq_offload_start(ctx);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool io_register_op_must_quiesce(int op)
|
|
{
|
|
switch (op) {
|
|
case IORING_UNREGISTER_FILES:
|
|
case IORING_REGISTER_FILES_UPDATE:
|
|
case IORING_REGISTER_PROBE:
|
|
case IORING_REGISTER_PERSONALITY:
|
|
case IORING_UNREGISTER_PERSONALITY:
|
|
return false;
|
|
default:
|
|
return true;
|
|
}
|
|
}
|
|
|
|
static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
|
|
void __user *arg, unsigned nr_args)
|
|
__releases(ctx->uring_lock)
|
|
__acquires(ctx->uring_lock)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* We're inside the ring mutex, if the ref is already dying, then
|
|
* someone else killed the ctx or is already going through
|
|
* io_uring_register().
|
|
*/
|
|
if (percpu_ref_is_dying(&ctx->refs))
|
|
return -ENXIO;
|
|
|
|
if (io_register_op_must_quiesce(opcode)) {
|
|
percpu_ref_kill(&ctx->refs);
|
|
|
|
/*
|
|
* Drop uring mutex before waiting for references to exit. If
|
|
* another thread is currently inside io_uring_enter() it might
|
|
* need to grab the uring_lock to make progress. If we hold it
|
|
* here across the drain wait, then we can deadlock. It's safe
|
|
* to drop the mutex here, since no new references will come in
|
|
* after we've killed the percpu ref.
|
|
*/
|
|
mutex_unlock(&ctx->uring_lock);
|
|
do {
|
|
ret = wait_for_completion_interruptible(&ctx->ref_comp);
|
|
if (!ret)
|
|
break;
|
|
ret = io_run_task_work_sig();
|
|
if (ret < 0)
|
|
break;
|
|
} while (1);
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
if (ret) {
|
|
percpu_ref_resurrect(&ctx->refs);
|
|
goto out_quiesce;
|
|
}
|
|
}
|
|
|
|
if (ctx->restricted) {
|
|
if (opcode >= IORING_REGISTER_LAST) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (!test_bit(opcode, ctx->restrictions.register_op)) {
|
|
ret = -EACCES;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
switch (opcode) {
|
|
case IORING_REGISTER_BUFFERS:
|
|
ret = io_sqe_buffer_register(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_UNREGISTER_BUFFERS:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_sqe_buffer_unregister(ctx);
|
|
break;
|
|
case IORING_REGISTER_FILES:
|
|
ret = io_sqe_files_register(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_UNREGISTER_FILES:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_sqe_files_unregister(ctx);
|
|
break;
|
|
case IORING_REGISTER_FILES_UPDATE:
|
|
ret = io_sqe_files_update(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_REGISTER_EVENTFD:
|
|
case IORING_REGISTER_EVENTFD_ASYNC:
|
|
ret = -EINVAL;
|
|
if (nr_args != 1)
|
|
break;
|
|
ret = io_eventfd_register(ctx, arg);
|
|
if (ret)
|
|
break;
|
|
if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
|
|
ctx->eventfd_async = 1;
|
|
else
|
|
ctx->eventfd_async = 0;
|
|
break;
|
|
case IORING_UNREGISTER_EVENTFD:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_eventfd_unregister(ctx);
|
|
break;
|
|
case IORING_REGISTER_PROBE:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args > 256)
|
|
break;
|
|
ret = io_probe(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_REGISTER_PERSONALITY:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_register_personality(ctx);
|
|
break;
|
|
case IORING_UNREGISTER_PERSONALITY:
|
|
ret = -EINVAL;
|
|
if (arg)
|
|
break;
|
|
ret = io_unregister_personality(ctx, nr_args);
|
|
break;
|
|
case IORING_REGISTER_ENABLE_RINGS:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_register_enable_rings(ctx);
|
|
break;
|
|
case IORING_REGISTER_RESTRICTIONS:
|
|
ret = io_register_restrictions(ctx, arg, nr_args);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
out:
|
|
if (io_register_op_must_quiesce(opcode)) {
|
|
/* bring the ctx back to life */
|
|
percpu_ref_reinit(&ctx->refs);
|
|
out_quiesce:
|
|
reinit_completion(&ctx->ref_comp);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
|
|
void __user *, arg, unsigned int, nr_args)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
long ret = -EBADF;
|
|
struct fd f;
|
|
|
|
f = fdget(fd);
|
|
if (!f.file)
|
|
return -EBADF;
|
|
|
|
ret = -EOPNOTSUPP;
|
|
if (f.file->f_op != &io_uring_fops)
|
|
goto out_fput;
|
|
|
|
ctx = f.file->private_data;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = __io_uring_register(ctx, opcode, arg, nr_args);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
|
|
ctx->cq_ev_fd != NULL, ret);
|
|
out_fput:
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
static int __init io_uring_init(void)
|
|
{
|
|
#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
|
|
BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
|
|
BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
|
|
} while (0)
|
|
|
|
#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
|
|
__BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
|
|
BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
|
|
BUILD_BUG_SQE_ELEM(0, __u8, opcode);
|
|
BUILD_BUG_SQE_ELEM(1, __u8, flags);
|
|
BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
|
|
BUILD_BUG_SQE_ELEM(4, __s32, fd);
|
|
BUILD_BUG_SQE_ELEM(8, __u64, off);
|
|
BUILD_BUG_SQE_ELEM(8, __u64, addr2);
|
|
BUILD_BUG_SQE_ELEM(16, __u64, addr);
|
|
BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
|
|
BUILD_BUG_SQE_ELEM(24, __u32, len);
|
|
BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
|
|
BUILD_BUG_SQE_ELEM(32, __u64, user_data);
|
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
|
|
BUILD_BUG_SQE_ELEM(42, __u16, personality);
|
|
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
|
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
|
|
BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
|
|
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
|
|
return 0;
|
|
};
|
|
__initcall(io_uring_init);
|