mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 11:19:37 +00:00
![Stefan Metzmacher](/assets/img/avatar_default.png)
Signed-off-by: Stefan Metzmacher <metze@samba.org> Link: https://lore.kernel.org/r/ffcaf8dc4778db4af673822df60dbda6efdd3065.1660201408.git.metze@samba.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
3966 lines
101 KiB
C
3966 lines
101 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_cqe (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 <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/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/highmem.h>
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#include <linux/fsnotify.h>
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#include <linux/fadvise.h>
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#include <linux/task_work.h>
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#include <linux/io_uring.h>
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#include <linux/audit.h>
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#include <linux/security.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 "io-wq.h"
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#include "io_uring.h"
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#include "opdef.h"
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#include "refs.h"
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#include "tctx.h"
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#include "sqpoll.h"
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#include "fdinfo.h"
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#include "kbuf.h"
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#include "rsrc.h"
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#include "cancel.h"
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#include "net.h"
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#include "notif.h"
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#include "timeout.h"
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#include "poll.h"
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#include "alloc_cache.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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#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
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IORING_REGISTER_LAST + IORING_OP_LAST)
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#define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
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IOSQE_IO_HARDLINK | IOSQE_ASYNC)
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#define SQE_VALID_FLAGS (SQE_COMMON_FLAGS | IOSQE_BUFFER_SELECT | \
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IOSQE_IO_DRAIN | IOSQE_CQE_SKIP_SUCCESS)
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#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
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REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS | \
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REQ_F_ASYNC_DATA)
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#define IO_REQ_CLEAN_SLOW_FLAGS (REQ_F_REFCOUNT | REQ_F_LINK | REQ_F_HARDLINK |\
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IO_REQ_CLEAN_FLAGS)
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#define IO_TCTX_REFS_CACHE_NR (1U << 10)
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#define IO_COMPL_BATCH 32
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#define IO_REQ_ALLOC_BATCH 8
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enum {
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IO_CHECK_CQ_OVERFLOW_BIT,
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IO_CHECK_CQ_DROPPED_BIT,
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};
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struct io_defer_entry {
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struct list_head list;
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struct io_kiocb *req;
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u32 seq;
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};
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/* requests with any of those set should undergo io_disarm_next() */
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#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
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#define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK)
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static bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
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struct task_struct *task,
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bool cancel_all);
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static void io_dismantle_req(struct io_kiocb *req);
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static void io_clean_op(struct io_kiocb *req);
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static void io_queue_sqe(struct io_kiocb *req);
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static void __io_submit_flush_completions(struct io_ring_ctx *ctx);
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static struct kmem_cache *req_cachep;
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struct sock *io_uring_get_socket(struct file *file)
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{
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#if defined(CONFIG_UNIX)
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if (io_is_uring_fops(file)) {
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struct io_ring_ctx *ctx = file->private_data;
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return ctx->ring_sock->sk;
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}
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#endif
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return NULL;
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}
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EXPORT_SYMBOL(io_uring_get_socket);
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static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
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{
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if (!wq_list_empty(&ctx->submit_state.compl_reqs))
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__io_submit_flush_completions(ctx);
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}
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static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
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{
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return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
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}
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static bool io_match_linked(struct io_kiocb *head)
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{
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struct io_kiocb *req;
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io_for_each_link(req, head) {
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if (req->flags & REQ_F_INFLIGHT)
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return true;
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}
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return false;
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}
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/*
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* As io_match_task() but protected against racing with linked timeouts.
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* User must not hold timeout_lock.
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*/
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bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
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bool cancel_all)
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{
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bool matched;
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if (task && head->task != task)
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return false;
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if (cancel_all)
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return true;
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if (head->flags & REQ_F_LINK_TIMEOUT) {
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struct io_ring_ctx *ctx = head->ctx;
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/* protect against races with linked timeouts */
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spin_lock_irq(&ctx->timeout_lock);
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matched = io_match_linked(head);
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spin_unlock_irq(&ctx->timeout_lock);
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} else {
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matched = io_match_linked(head);
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}
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return matched;
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}
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static inline void req_fail_link_node(struct io_kiocb *req, int res)
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{
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req_set_fail(req);
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io_req_set_res(req, res, 0);
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}
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static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx *ctx)
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{
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wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list);
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}
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static __cold void io_ring_ctx_ref_free(struct percpu_ref *ref)
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{
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struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
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complete(&ctx->ref_comp);
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}
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static __cold void io_fallback_req_func(struct work_struct *work)
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{
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struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
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fallback_work.work);
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struct llist_node *node = llist_del_all(&ctx->fallback_llist);
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struct io_kiocb *req, *tmp;
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bool locked = false;
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percpu_ref_get(&ctx->refs);
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llist_for_each_entry_safe(req, tmp, node, io_task_work.node)
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req->io_task_work.func(req, &locked);
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if (locked) {
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io_submit_flush_completions(ctx);
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mutex_unlock(&ctx->uring_lock);
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}
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percpu_ref_put(&ctx->refs);
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}
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static int io_alloc_hash_table(struct io_hash_table *table, unsigned bits)
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{
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unsigned hash_buckets = 1U << bits;
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size_t hash_size = hash_buckets * sizeof(table->hbs[0]);
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table->hbs = kmalloc(hash_size, GFP_KERNEL);
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if (!table->hbs)
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return -ENOMEM;
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table->hash_bits = bits;
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init_hash_table(table, hash_buckets);
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return 0;
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}
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static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
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{
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struct io_ring_ctx *ctx;
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int hash_bits;
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ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return NULL;
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xa_init(&ctx->io_bl_xa);
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/*
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* Use 5 bits less than the max cq entries, that should give us around
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* 32 entries per hash list if totally full and uniformly spread, but
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* don't keep too many buckets to not overconsume memory.
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*/
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hash_bits = ilog2(p->cq_entries) - 5;
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hash_bits = clamp(hash_bits, 1, 8);
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if (io_alloc_hash_table(&ctx->cancel_table, hash_bits))
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goto err;
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if (io_alloc_hash_table(&ctx->cancel_table_locked, hash_bits))
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goto err;
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ctx->dummy_ubuf = kzalloc(sizeof(*ctx->dummy_ubuf), GFP_KERNEL);
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if (!ctx->dummy_ubuf)
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goto err;
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/* set invalid range, so io_import_fixed() fails meeting it */
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ctx->dummy_ubuf->ubuf = -1UL;
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if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
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0, GFP_KERNEL))
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goto err;
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ctx->flags = p->flags;
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init_waitqueue_head(&ctx->sqo_sq_wait);
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INIT_LIST_HEAD(&ctx->sqd_list);
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INIT_LIST_HEAD(&ctx->cq_overflow_list);
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INIT_LIST_HEAD(&ctx->io_buffers_cache);
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io_alloc_cache_init(&ctx->apoll_cache);
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io_alloc_cache_init(&ctx->netmsg_cache);
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init_completion(&ctx->ref_comp);
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xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
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mutex_init(&ctx->uring_lock);
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init_waitqueue_head(&ctx->cq_wait);
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spin_lock_init(&ctx->completion_lock);
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spin_lock_init(&ctx->timeout_lock);
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INIT_WQ_LIST(&ctx->iopoll_list);
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INIT_LIST_HEAD(&ctx->io_buffers_pages);
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INIT_LIST_HEAD(&ctx->io_buffers_comp);
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INIT_LIST_HEAD(&ctx->defer_list);
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INIT_LIST_HEAD(&ctx->timeout_list);
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INIT_LIST_HEAD(&ctx->ltimeout_list);
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spin_lock_init(&ctx->rsrc_ref_lock);
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INIT_LIST_HEAD(&ctx->rsrc_ref_list);
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INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
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init_llist_head(&ctx->rsrc_put_llist);
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INIT_LIST_HEAD(&ctx->tctx_list);
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ctx->submit_state.free_list.next = NULL;
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INIT_WQ_LIST(&ctx->locked_free_list);
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INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
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INIT_WQ_LIST(&ctx->submit_state.compl_reqs);
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return ctx;
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err:
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kfree(ctx->dummy_ubuf);
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kfree(ctx->cancel_table.hbs);
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kfree(ctx->cancel_table_locked.hbs);
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kfree(ctx->io_bl);
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xa_destroy(&ctx->io_bl_xa);
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kfree(ctx);
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return NULL;
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}
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static void io_account_cq_overflow(struct io_ring_ctx *ctx)
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{
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struct io_rings *r = ctx->rings;
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WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1);
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ctx->cq_extra--;
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}
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static bool req_need_defer(struct io_kiocb *req, u32 seq)
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{
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if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
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struct io_ring_ctx *ctx = req->ctx;
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return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail;
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}
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return false;
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}
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static inline void io_req_track_inflight(struct io_kiocb *req)
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{
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if (!(req->flags & REQ_F_INFLIGHT)) {
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req->flags |= REQ_F_INFLIGHT;
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atomic_inc(&req->task->io_uring->inflight_tracked);
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}
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}
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static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
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{
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if (WARN_ON_ONCE(!req->link))
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return NULL;
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req->flags &= ~REQ_F_ARM_LTIMEOUT;
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req->flags |= REQ_F_LINK_TIMEOUT;
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/* linked timeouts should have two refs once prep'ed */
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io_req_set_refcount(req);
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__io_req_set_refcount(req->link, 2);
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return req->link;
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}
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static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
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{
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if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
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return NULL;
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return __io_prep_linked_timeout(req);
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}
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static noinline void __io_arm_ltimeout(struct io_kiocb *req)
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{
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io_queue_linked_timeout(__io_prep_linked_timeout(req));
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}
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static inline void io_arm_ltimeout(struct io_kiocb *req)
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{
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if (unlikely(req->flags & REQ_F_ARM_LTIMEOUT))
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__io_arm_ltimeout(req);
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}
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static void io_prep_async_work(struct io_kiocb *req)
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{
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const struct io_op_def *def = &io_op_defs[req->opcode];
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struct io_ring_ctx *ctx = req->ctx;
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if (!(req->flags & REQ_F_CREDS)) {
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req->flags |= REQ_F_CREDS;
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req->creds = get_current_cred();
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}
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req->work.list.next = NULL;
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req->work.flags = 0;
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req->work.cancel_seq = atomic_read(&ctx->cancel_seq);
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if (req->flags & REQ_F_FORCE_ASYNC)
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req->work.flags |= IO_WQ_WORK_CONCURRENT;
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if (req->file && !io_req_ffs_set(req))
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req->flags |= io_file_get_flags(req->file) << REQ_F_SUPPORT_NOWAIT_BIT;
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|
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if (req->flags & REQ_F_ISREG) {
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if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
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io_wq_hash_work(&req->work, file_inode(req->file));
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} else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
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if (def->unbound_nonreg_file)
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req->work.flags |= IO_WQ_WORK_UNBOUND;
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}
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}
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|
|
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static void io_prep_async_link(struct io_kiocb *req)
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{
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struct io_kiocb *cur;
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|
|
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if (req->flags & REQ_F_LINK_TIMEOUT) {
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struct io_ring_ctx *ctx = req->ctx;
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spin_lock_irq(&ctx->timeout_lock);
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io_for_each_link(cur, req)
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io_prep_async_work(cur);
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spin_unlock_irq(&ctx->timeout_lock);
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} else {
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io_for_each_link(cur, req)
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io_prep_async_work(cur);
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}
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}
|
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|
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void io_queue_iowq(struct io_kiocb *req, bool *dont_use)
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|
{
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struct io_kiocb *link = io_prep_linked_timeout(req);
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struct io_uring_task *tctx = req->task->io_uring;
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BUG_ON(!tctx);
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BUG_ON(!tctx->io_wq);
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|
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/* init ->work of the whole link before punting */
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io_prep_async_link(req);
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|
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/*
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* Not expected to happen, but if we do have a bug where this _can_
|
|
* happen, catch it here and ensure the request is marked as
|
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* canceled. That will make io-wq go through the usual work cancel
|
|
* procedure rather than attempt to run this request (or create a new
|
|
* worker for it).
|
|
*/
|
|
if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
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req->work.flags |= IO_WQ_WORK_CANCEL;
|
|
|
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trace_io_uring_queue_async_work(req, io_wq_is_hashed(&req->work));
|
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io_wq_enqueue(tctx->io_wq, &req->work);
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|
if (link)
|
|
io_queue_linked_timeout(link);
|
|
}
|
|
|
|
static __cold void io_queue_deferred(struct io_ring_ctx *ctx)
|
|
{
|
|
while (!list_empty(&ctx->defer_list)) {
|
|
struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
|
|
struct io_defer_entry, list);
|
|
|
|
if (req_need_defer(de->req, de->seq))
|
|
break;
|
|
list_del_init(&de->list);
|
|
io_req_task_queue(de->req);
|
|
kfree(de);
|
|
}
|
|
}
|
|
|
|
static void io_eventfd_signal(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_ev_fd *ev_fd;
|
|
bool skip;
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
/*
|
|
* Eventfd should only get triggered when at least one event has been
|
|
* posted. Some applications rely on the eventfd notification count only
|
|
* changing IFF a new CQE has been added to the CQ ring. There's no
|
|
* depedency on 1:1 relationship between how many times this function is
|
|
* called (and hence the eventfd count) and number of CQEs posted to the
|
|
* CQ ring.
|
|
*/
|
|
skip = ctx->cached_cq_tail == ctx->evfd_last_cq_tail;
|
|
ctx->evfd_last_cq_tail = ctx->cached_cq_tail;
|
|
spin_unlock(&ctx->completion_lock);
|
|
if (skip)
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
/*
|
|
* rcu_dereference ctx->io_ev_fd once and use it for both for checking
|
|
* and eventfd_signal
|
|
*/
|
|
ev_fd = rcu_dereference(ctx->io_ev_fd);
|
|
|
|
/*
|
|
* Check again if ev_fd exists incase an io_eventfd_unregister call
|
|
* completed between the NULL check of ctx->io_ev_fd at the start of
|
|
* the function and rcu_read_lock.
|
|
*/
|
|
if (unlikely(!ev_fd))
|
|
goto out;
|
|
if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
|
|
goto out;
|
|
|
|
if (!ev_fd->eventfd_async || io_wq_current_is_worker())
|
|
eventfd_signal(ev_fd->cq_ev_fd, 1);
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
|
|
{
|
|
if (ctx->off_timeout_used || ctx->drain_active) {
|
|
spin_lock(&ctx->completion_lock);
|
|
if (ctx->off_timeout_used)
|
|
io_flush_timeouts(ctx);
|
|
if (ctx->drain_active)
|
|
io_queue_deferred(ctx);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
if (ctx->has_evfd)
|
|
io_eventfd_signal(ctx);
|
|
}
|
|
|
|
static inline void io_cqring_ev_posted(struct io_ring_ctx *ctx)
|
|
{
|
|
io_commit_cqring_flush(ctx);
|
|
io_cqring_wake(ctx);
|
|
}
|
|
|
|
static inline void __io_cq_unlock_post(struct io_ring_ctx *ctx)
|
|
__releases(ctx->completion_lock)
|
|
{
|
|
io_commit_cqring(ctx);
|
|
spin_unlock(&ctx->completion_lock);
|
|
io_cqring_ev_posted(ctx);
|
|
}
|
|
|
|
void io_cq_unlock_post(struct io_ring_ctx *ctx)
|
|
{
|
|
__io_cq_unlock_post(ctx);
|
|
}
|
|
|
|
/* Returns true if there are no backlogged entries after the flush */
|
|
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
|
|
{
|
|
bool all_flushed;
|
|
size_t cqe_size = sizeof(struct io_uring_cqe);
|
|
|
|
if (!force && __io_cqring_events(ctx) == ctx->cq_entries)
|
|
return false;
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32)
|
|
cqe_size <<= 1;
|
|
|
|
io_cq_lock(ctx);
|
|
while (!list_empty(&ctx->cq_overflow_list)) {
|
|
struct io_uring_cqe *cqe = io_get_cqe(ctx);
|
|
struct io_overflow_cqe *ocqe;
|
|
|
|
if (!cqe && !force)
|
|
break;
|
|
ocqe = list_first_entry(&ctx->cq_overflow_list,
|
|
struct io_overflow_cqe, list);
|
|
if (cqe)
|
|
memcpy(cqe, &ocqe->cqe, cqe_size);
|
|
else
|
|
io_account_cq_overflow(ctx);
|
|
|
|
list_del(&ocqe->list);
|
|
kfree(ocqe);
|
|
}
|
|
|
|
all_flushed = list_empty(&ctx->cq_overflow_list);
|
|
if (all_flushed) {
|
|
clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq);
|
|
atomic_andnot(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags);
|
|
}
|
|
|
|
io_cq_unlock_post(ctx);
|
|
return all_flushed;
|
|
}
|
|
|
|
static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx)
|
|
{
|
|
bool ret = true;
|
|
|
|
if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) {
|
|
/* iopoll syncs against uring_lock, not completion_lock */
|
|
if (ctx->flags & IORING_SETUP_IOPOLL)
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = __io_cqring_overflow_flush(ctx, false);
|
|
if (ctx->flags & IORING_SETUP_IOPOLL)
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
void __io_put_task(struct task_struct *task, int nr)
|
|
{
|
|
struct io_uring_task *tctx = task->io_uring;
|
|
|
|
percpu_counter_sub(&tctx->inflight, nr);
|
|
if (unlikely(atomic_read(&tctx->in_idle)))
|
|
wake_up(&tctx->wait);
|
|
put_task_struct_many(task, nr);
|
|
}
|
|
|
|
void io_task_refs_refill(struct io_uring_task *tctx)
|
|
{
|
|
unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
|
|
|
|
percpu_counter_add(&tctx->inflight, refill);
|
|
refcount_add(refill, ¤t->usage);
|
|
tctx->cached_refs += refill;
|
|
}
|
|
|
|
static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
|
|
{
|
|
struct io_uring_task *tctx = task->io_uring;
|
|
unsigned int refs = tctx->cached_refs;
|
|
|
|
if (refs) {
|
|
tctx->cached_refs = 0;
|
|
percpu_counter_sub(&tctx->inflight, refs);
|
|
put_task_struct_many(task, refs);
|
|
}
|
|
}
|
|
|
|
static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
|
|
s32 res, u32 cflags, u64 extra1, u64 extra2)
|
|
{
|
|
struct io_overflow_cqe *ocqe;
|
|
size_t ocq_size = sizeof(struct io_overflow_cqe);
|
|
bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32);
|
|
|
|
if (is_cqe32)
|
|
ocq_size += sizeof(struct io_uring_cqe);
|
|
|
|
ocqe = kmalloc(ocq_size, GFP_ATOMIC | __GFP_ACCOUNT);
|
|
trace_io_uring_cqe_overflow(ctx, user_data, res, cflags, ocqe);
|
|
if (!ocqe) {
|
|
/*
|
|
* If we're in ring overflow flush mode, or in task cancel mode,
|
|
* or cannot allocate an overflow entry, then we need to drop it
|
|
* on the floor.
|
|
*/
|
|
io_account_cq_overflow(ctx);
|
|
set_bit(IO_CHECK_CQ_DROPPED_BIT, &ctx->check_cq);
|
|
return false;
|
|
}
|
|
if (list_empty(&ctx->cq_overflow_list)) {
|
|
set_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq);
|
|
atomic_or(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags);
|
|
|
|
}
|
|
ocqe->cqe.user_data = user_data;
|
|
ocqe->cqe.res = res;
|
|
ocqe->cqe.flags = cflags;
|
|
if (is_cqe32) {
|
|
ocqe->cqe.big_cqe[0] = extra1;
|
|
ocqe->cqe.big_cqe[1] = extra2;
|
|
}
|
|
list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
|
|
return true;
|
|
}
|
|
|
|
bool io_req_cqe_overflow(struct io_kiocb *req)
|
|
{
|
|
if (!(req->flags & REQ_F_CQE32_INIT)) {
|
|
req->extra1 = 0;
|
|
req->extra2 = 0;
|
|
}
|
|
return io_cqring_event_overflow(req->ctx, req->cqe.user_data,
|
|
req->cqe.res, req->cqe.flags,
|
|
req->extra1, req->extra2);
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*/
|
|
struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1);
|
|
unsigned int free, queued, len;
|
|
|
|
|
|
/* userspace may cheat modifying the tail, be safe and do min */
|
|
queued = min(__io_cqring_events(ctx), ctx->cq_entries);
|
|
free = ctx->cq_entries - queued;
|
|
/* we need a contiguous range, limit based on the current array offset */
|
|
len = min(free, ctx->cq_entries - off);
|
|
if (!len)
|
|
return NULL;
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
off <<= 1;
|
|
len <<= 1;
|
|
}
|
|
|
|
ctx->cqe_cached = &rings->cqes[off];
|
|
ctx->cqe_sentinel = ctx->cqe_cached + len;
|
|
|
|
ctx->cached_cq_tail++;
|
|
ctx->cqe_cached++;
|
|
if (ctx->flags & IORING_SETUP_CQE32)
|
|
ctx->cqe_cached++;
|
|
return &rings->cqes[off];
|
|
}
|
|
|
|
bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags,
|
|
bool allow_overflow)
|
|
{
|
|
struct io_uring_cqe *cqe;
|
|
|
|
ctx->cq_extra++;
|
|
|
|
/*
|
|
* 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_cqe(ctx);
|
|
if (likely(cqe)) {
|
|
trace_io_uring_complete(ctx, NULL, user_data, res, cflags, 0, 0);
|
|
|
|
WRITE_ONCE(cqe->user_data, user_data);
|
|
WRITE_ONCE(cqe->res, res);
|
|
WRITE_ONCE(cqe->flags, cflags);
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
WRITE_ONCE(cqe->big_cqe[0], 0);
|
|
WRITE_ONCE(cqe->big_cqe[1], 0);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
if (allow_overflow)
|
|
return io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0);
|
|
|
|
return false;
|
|
}
|
|
|
|
bool io_post_aux_cqe(struct io_ring_ctx *ctx,
|
|
u64 user_data, s32 res, u32 cflags,
|
|
bool allow_overflow)
|
|
{
|
|
bool filled;
|
|
|
|
io_cq_lock(ctx);
|
|
filled = io_fill_cqe_aux(ctx, user_data, res, cflags, allow_overflow);
|
|
io_cq_unlock_post(ctx);
|
|
return filled;
|
|
}
|
|
|
|
static void __io_req_complete_put(struct io_kiocb *req)
|
|
{
|
|
/*
|
|
* If we're the last reference to this request, add to our locked
|
|
* free_list cache.
|
|
*/
|
|
if (req_ref_put_and_test(req)) {
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (req->flags & IO_REQ_LINK_FLAGS) {
|
|
if (req->flags & IO_DISARM_MASK)
|
|
io_disarm_next(req);
|
|
if (req->link) {
|
|
io_req_task_queue(req->link);
|
|
req->link = NULL;
|
|
}
|
|
}
|
|
io_req_put_rsrc(req);
|
|
/*
|
|
* Selected buffer deallocation in io_clean_op() assumes that
|
|
* we don't hold ->completion_lock. Clean them here to avoid
|
|
* deadlocks.
|
|
*/
|
|
io_put_kbuf_comp(req);
|
|
io_dismantle_req(req);
|
|
io_put_task(req->task, 1);
|
|
wq_list_add_head(&req->comp_list, &ctx->locked_free_list);
|
|
ctx->locked_free_nr++;
|
|
}
|
|
}
|
|
|
|
void __io_req_complete_post(struct io_kiocb *req)
|
|
{
|
|
if (!(req->flags & REQ_F_CQE_SKIP))
|
|
__io_fill_cqe_req(req->ctx, req);
|
|
__io_req_complete_put(req);
|
|
}
|
|
|
|
void io_req_complete_post(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_cq_lock(ctx);
|
|
__io_req_complete_post(req);
|
|
io_cq_unlock_post(ctx);
|
|
}
|
|
|
|
inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags)
|
|
{
|
|
io_req_complete_post(req);
|
|
}
|
|
|
|
void io_req_complete_failed(struct io_kiocb *req, s32 res)
|
|
{
|
|
req_set_fail(req);
|
|
io_req_set_res(req, res, io_put_kbuf(req, IO_URING_F_UNLOCKED));
|
|
io_req_complete_post(req);
|
|
}
|
|
|
|
/*
|
|
* Don't initialise the fields below on every allocation, but do that in
|
|
* advance and keep them valid across allocations.
|
|
*/
|
|
static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
|
|
{
|
|
req->ctx = ctx;
|
|
req->link = NULL;
|
|
req->async_data = NULL;
|
|
/* not necessary, but safer to zero */
|
|
req->cqe.res = 0;
|
|
}
|
|
|
|
static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
|
|
struct io_submit_state *state)
|
|
{
|
|
spin_lock(&ctx->completion_lock);
|
|
wq_list_splice(&ctx->locked_free_list, &state->free_list);
|
|
ctx->locked_free_nr = 0;
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
/*
|
|
* A request might get retired back into the request caches even before opcode
|
|
* handlers and io_issue_sqe() are done with it, e.g. inline completion path.
|
|
* Because of that, io_alloc_req() should be called only under ->uring_lock
|
|
* and with extra caution to not get a request that is still worked on.
|
|
*/
|
|
__cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
|
|
void *reqs[IO_REQ_ALLOC_BATCH];
|
|
int ret, i;
|
|
|
|
/*
|
|
* If we have more than a batch's worth of requests in our IRQ side
|
|
* locked cache, grab the lock and move them over to our submission
|
|
* side cache.
|
|
*/
|
|
if (data_race(ctx->locked_free_nr) > IO_COMPL_BATCH) {
|
|
io_flush_cached_locked_reqs(ctx, &ctx->submit_state);
|
|
if (!io_req_cache_empty(ctx))
|
|
return true;
|
|
}
|
|
|
|
ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), 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)) {
|
|
reqs[0] = kmem_cache_alloc(req_cachep, gfp);
|
|
if (!reqs[0])
|
|
return false;
|
|
ret = 1;
|
|
}
|
|
|
|
percpu_ref_get_many(&ctx->refs, ret);
|
|
for (i = 0; i < ret; i++) {
|
|
struct io_kiocb *req = reqs[i];
|
|
|
|
io_preinit_req(req, ctx);
|
|
io_req_add_to_cache(req, ctx);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static inline void io_dismantle_req(struct io_kiocb *req)
|
|
{
|
|
unsigned int flags = req->flags;
|
|
|
|
if (unlikely(flags & IO_REQ_CLEAN_FLAGS))
|
|
io_clean_op(req);
|
|
if (!(flags & REQ_F_FIXED_FILE))
|
|
io_put_file(req->file);
|
|
}
|
|
|
|
__cold void io_free_req(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_req_put_rsrc(req);
|
|
io_dismantle_req(req);
|
|
io_put_task(req->task, 1);
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
wq_list_add_head(&req->comp_list, &ctx->locked_free_list);
|
|
ctx->locked_free_nr++;
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
static void __io_req_find_next_prep(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
io_cq_lock(ctx);
|
|
io_disarm_next(req);
|
|
io_cq_unlock_post(ctx);
|
|
}
|
|
|
|
static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt;
|
|
|
|
/*
|
|
* 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 (unlikely(req->flags & IO_DISARM_MASK))
|
|
__io_req_find_next_prep(req);
|
|
nxt = req->link;
|
|
req->link = NULL;
|
|
return nxt;
|
|
}
|
|
|
|
static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
|
|
{
|
|
if (!ctx)
|
|
return;
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
if (*locked) {
|
|
io_submit_flush_completions(ctx);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
*locked = false;
|
|
}
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
static unsigned int handle_tw_list(struct llist_node *node,
|
|
struct io_ring_ctx **ctx, bool *locked,
|
|
struct llist_node *last)
|
|
{
|
|
unsigned int count = 0;
|
|
|
|
while (node != last) {
|
|
struct llist_node *next = node->next;
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
io_task_work.node);
|
|
|
|
prefetch(container_of(next, struct io_kiocb, io_task_work.node));
|
|
|
|
if (req->ctx != *ctx) {
|
|
ctx_flush_and_put(*ctx, locked);
|
|
*ctx = req->ctx;
|
|
/* if not contended, grab and improve batching */
|
|
*locked = mutex_trylock(&(*ctx)->uring_lock);
|
|
percpu_ref_get(&(*ctx)->refs);
|
|
}
|
|
req->io_task_work.func(req, locked);
|
|
node = next;
|
|
count++;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* io_llist_xchg - swap all entries in a lock-less list
|
|
* @head: the head of lock-less list to delete all entries
|
|
* @new: new entry as the head of the list
|
|
*
|
|
* If list is empty, return NULL, otherwise, return the pointer to the first entry.
|
|
* The order of entries returned is from the newest to the oldest added one.
|
|
*/
|
|
static inline struct llist_node *io_llist_xchg(struct llist_head *head,
|
|
struct llist_node *new)
|
|
{
|
|
return xchg(&head->first, new);
|
|
}
|
|
|
|
/**
|
|
* io_llist_cmpxchg - possibly swap all entries in a lock-less list
|
|
* @head: the head of lock-less list to delete all entries
|
|
* @old: expected old value of the first entry of the list
|
|
* @new: new entry as the head of the list
|
|
*
|
|
* perform a cmpxchg on the first entry of the list.
|
|
*/
|
|
|
|
static inline struct llist_node *io_llist_cmpxchg(struct llist_head *head,
|
|
struct llist_node *old,
|
|
struct llist_node *new)
|
|
{
|
|
return cmpxchg(&head->first, old, new);
|
|
}
|
|
|
|
void tctx_task_work(struct callback_head *cb)
|
|
{
|
|
bool uring_locked = false;
|
|
struct io_ring_ctx *ctx = NULL;
|
|
struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
|
|
task_work);
|
|
struct llist_node fake = {};
|
|
struct llist_node *node = io_llist_xchg(&tctx->task_list, &fake);
|
|
unsigned int loops = 1;
|
|
unsigned int count = handle_tw_list(node, &ctx, &uring_locked, NULL);
|
|
|
|
node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL);
|
|
while (node != &fake) {
|
|
loops++;
|
|
node = io_llist_xchg(&tctx->task_list, &fake);
|
|
count += handle_tw_list(node, &ctx, &uring_locked, &fake);
|
|
node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL);
|
|
}
|
|
|
|
ctx_flush_and_put(ctx, &uring_locked);
|
|
|
|
/* relaxed read is enough as only the task itself sets ->in_idle */
|
|
if (unlikely(atomic_read(&tctx->in_idle)))
|
|
io_uring_drop_tctx_refs(current);
|
|
|
|
trace_io_uring_task_work_run(tctx, count, loops);
|
|
}
|
|
|
|
void io_req_task_work_add(struct io_kiocb *req)
|
|
{
|
|
struct io_uring_task *tctx = req->task->io_uring;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct llist_node *node;
|
|
bool running;
|
|
|
|
running = !llist_add(&req->io_task_work.node, &tctx->task_list);
|
|
|
|
/* task_work already pending, we're done */
|
|
if (running)
|
|
return;
|
|
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
|
|
if (likely(!task_work_add(req->task, &tctx->task_work, ctx->notify_method)))
|
|
return;
|
|
|
|
node = llist_del_all(&tctx->task_list);
|
|
|
|
while (node) {
|
|
req = container_of(node, struct io_kiocb, io_task_work.node);
|
|
node = node->next;
|
|
if (llist_add(&req->io_task_work.node,
|
|
&req->ctx->fallback_llist))
|
|
schedule_delayed_work(&req->ctx->fallback_work, 1);
|
|
}
|
|
}
|
|
|
|
static void io_req_tw_post(struct io_kiocb *req, bool *locked)
|
|
{
|
|
io_req_complete_post(req);
|
|
}
|
|
|
|
void io_req_tw_post_queue(struct io_kiocb *req, s32 res, u32 cflags)
|
|
{
|
|
io_req_set_res(req, res, cflags);
|
|
req->io_task_work.func = io_req_tw_post;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
static void io_req_task_cancel(struct io_kiocb *req, bool *locked)
|
|
{
|
|
/* not needed for normal modes, but SQPOLL depends on it */
|
|
io_tw_lock(req->ctx, locked);
|
|
io_req_complete_failed(req, req->cqe.res);
|
|
}
|
|
|
|
void io_req_task_submit(struct io_kiocb *req, bool *locked)
|
|
{
|
|
io_tw_lock(req->ctx, locked);
|
|
/* req->task == current here, checking PF_EXITING is safe */
|
|
if (likely(!(req->task->flags & PF_EXITING)))
|
|
io_queue_sqe(req);
|
|
else
|
|
io_req_complete_failed(req, -EFAULT);
|
|
}
|
|
|
|
void io_req_task_queue_fail(struct io_kiocb *req, int ret)
|
|
{
|
|
io_req_set_res(req, ret, 0);
|
|
req->io_task_work.func = io_req_task_cancel;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
void io_req_task_queue(struct io_kiocb *req)
|
|
{
|
|
req->io_task_work.func = io_req_task_submit;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
void io_queue_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt = io_req_find_next(req);
|
|
|
|
if (nxt)
|
|
io_req_task_queue(nxt);
|
|
}
|
|
|
|
void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct task_struct *task = NULL;
|
|
int task_refs = 0;
|
|
|
|
do {
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
comp_list);
|
|
|
|
if (unlikely(req->flags & IO_REQ_CLEAN_SLOW_FLAGS)) {
|
|
if (req->flags & REQ_F_REFCOUNT) {
|
|
node = req->comp_list.next;
|
|
if (!req_ref_put_and_test(req))
|
|
continue;
|
|
}
|
|
if ((req->flags & REQ_F_POLLED) && req->apoll) {
|
|
struct async_poll *apoll = req->apoll;
|
|
|
|
if (apoll->double_poll)
|
|
kfree(apoll->double_poll);
|
|
if (!io_alloc_cache_put(&ctx->apoll_cache, &apoll->cache))
|
|
kfree(apoll);
|
|
req->flags &= ~REQ_F_POLLED;
|
|
}
|
|
if (req->flags & IO_REQ_LINK_FLAGS)
|
|
io_queue_next(req);
|
|
if (unlikely(req->flags & IO_REQ_CLEAN_FLAGS))
|
|
io_clean_op(req);
|
|
}
|
|
if (!(req->flags & REQ_F_FIXED_FILE))
|
|
io_put_file(req->file);
|
|
|
|
io_req_put_rsrc_locked(req, ctx);
|
|
|
|
if (req->task != task) {
|
|
if (task)
|
|
io_put_task(task, task_refs);
|
|
task = req->task;
|
|
task_refs = 0;
|
|
}
|
|
task_refs++;
|
|
node = req->comp_list.next;
|
|
io_req_add_to_cache(req, ctx);
|
|
} while (node);
|
|
|
|
if (task)
|
|
io_put_task(task, task_refs);
|
|
}
|
|
|
|
static void __io_submit_flush_completions(struct io_ring_ctx *ctx)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_wq_work_node *node, *prev;
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
wq_list_for_each(node, prev, &state->compl_reqs) {
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
comp_list);
|
|
|
|
if (!(req->flags & REQ_F_CQE_SKIP))
|
|
__io_fill_cqe_req(ctx, req);
|
|
}
|
|
__io_cq_unlock_post(ctx);
|
|
|
|
io_free_batch_list(ctx, state->compl_reqs.first);
|
|
INIT_WQ_LIST(&state->compl_reqs);
|
|
}
|
|
|
|
/*
|
|
* Drop reference to request, return next in chain (if there is one) if this
|
|
* was the last reference to this request.
|
|
*/
|
|
static inline struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt = NULL;
|
|
|
|
if (req_ref_put_and_test(req)) {
|
|
if (unlikely(req->flags & IO_REQ_LINK_FLAGS))
|
|
nxt = io_req_find_next(req);
|
|
io_free_req(req);
|
|
}
|
|
return nxt;
|
|
}
|
|
|
|
static unsigned io_cqring_events(struct io_ring_ctx *ctx)
|
|
{
|
|
/* See comment at the top of this file */
|
|
smp_rmb();
|
|
return __io_cqring_events(ctx);
|
|
}
|
|
|
|
/*
|
|
* We can't just wait for polled events to come to us, we have to actively
|
|
* find and complete them.
|
|
*/
|
|
static __cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
while (!wq_list_empty(&ctx->iopoll_list)) {
|
|
/* let it sleep and repeat later if can't complete a request */
|
|
if (io_do_iopoll(ctx, true) == 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 ret = 0;
|
|
unsigned long check_cq;
|
|
|
|
check_cq = READ_ONCE(ctx->check_cq);
|
|
if (unlikely(check_cq)) {
|
|
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
|
|
__io_cqring_overflow_flush(ctx, false);
|
|
/*
|
|
* Similarly do not spin if we have not informed the user of any
|
|
* dropped CQE.
|
|
*/
|
|
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
|
|
return -EBADR;
|
|
}
|
|
/*
|
|
* 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))
|
|
return 0;
|
|
|
|
do {
|
|
/*
|
|
* 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 (wq_list_empty(&ctx->iopoll_list)) {
|
|
u32 tail = ctx->cached_cq_tail;
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
io_run_task_work();
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
/* some requests don't go through iopoll_list */
|
|
if (tail != ctx->cached_cq_tail ||
|
|
wq_list_empty(&ctx->iopoll_list))
|
|
break;
|
|
}
|
|
ret = io_do_iopoll(ctx, !min);
|
|
if (ret < 0)
|
|
break;
|
|
nr_events += ret;
|
|
ret = 0;
|
|
} while (nr_events < min && !need_resched());
|
|
|
|
return ret;
|
|
}
|
|
|
|
void io_req_task_complete(struct io_kiocb *req, bool *locked)
|
|
{
|
|
if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) {
|
|
unsigned issue_flags = *locked ? 0 : IO_URING_F_UNLOCKED;
|
|
|
|
req->cqe.flags |= io_put_kbuf(req, issue_flags);
|
|
}
|
|
|
|
if (*locked)
|
|
io_req_complete_defer(req);
|
|
else
|
|
io_req_complete_post(req);
|
|
}
|
|
|
|
/*
|
|
* 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_do_iopoll() thread before the issuer is done
|
|
* accessing the kiocb cookie.
|
|
*/
|
|
static void io_iopoll_req_issued(struct io_kiocb *req, unsigned int issue_flags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
const bool needs_lock = issue_flags & IO_URING_F_UNLOCKED;
|
|
|
|
/* workqueue context doesn't hold uring_lock, grab it now */
|
|
if (unlikely(needs_lock))
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
/*
|
|
* 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 (wq_list_empty(&ctx->iopoll_list)) {
|
|
ctx->poll_multi_queue = false;
|
|
} else if (!ctx->poll_multi_queue) {
|
|
struct io_kiocb *list_req;
|
|
|
|
list_req = container_of(ctx->iopoll_list.first, struct io_kiocb,
|
|
comp_list);
|
|
if (list_req->file != req->file)
|
|
ctx->poll_multi_queue = 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))
|
|
wq_list_add_head(&req->comp_list, &ctx->iopoll_list);
|
|
else
|
|
wq_list_add_tail(&req->comp_list, &ctx->iopoll_list);
|
|
|
|
if (unlikely(needs_lock)) {
|
|
/*
|
|
* If IORING_SETUP_SQPOLL is enabled, sqes are either handle
|
|
* in sq thread task context or in io worker task context. If
|
|
* current task context is sq thread, we don't need to check
|
|
* whether should wake up sq thread.
|
|
*/
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) &&
|
|
wq_has_sleeper(&ctx->sq_data->wait))
|
|
wake_up(&ctx->sq_data->wait);
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
}
|
|
|
|
static bool io_bdev_nowait(struct block_device *bdev)
|
|
{
|
|
return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
|
|
}
|
|
|
|
/*
|
|
* 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_nowait(struct file *file, umode_t mode)
|
|
{
|
|
if (S_ISBLK(mode)) {
|
|
if (IS_ENABLED(CONFIG_BLOCK) &&
|
|
io_bdev_nowait(I_BDEV(file->f_mapping->host)))
|
|
return true;
|
|
return false;
|
|
}
|
|
if (S_ISSOCK(mode))
|
|
return true;
|
|
if (S_ISREG(mode)) {
|
|
if (IS_ENABLED(CONFIG_BLOCK) &&
|
|
io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
|
|
!io_is_uring_fops(file))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/* any ->read/write should understand O_NONBLOCK */
|
|
if (file->f_flags & O_NONBLOCK)
|
|
return true;
|
|
return file->f_mode & FMODE_NOWAIT;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
unsigned int io_file_get_flags(struct file *file)
|
|
{
|
|
umode_t mode = file_inode(file)->i_mode;
|
|
unsigned int res = 0;
|
|
|
|
if (S_ISREG(mode))
|
|
res |= FFS_ISREG;
|
|
if (__io_file_supports_nowait(file, mode))
|
|
res |= FFS_NOWAIT;
|
|
if (io_file_need_scm(file))
|
|
res |= FFS_SCM;
|
|
return res;
|
|
}
|
|
|
|
bool 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);
|
|
if (req->async_data) {
|
|
req->flags |= REQ_F_ASYNC_DATA;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
int io_req_prep_async(struct io_kiocb *req)
|
|
{
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
|
|
/* assign early for deferred execution for non-fixed file */
|
|
if (def->needs_file && !(req->flags & REQ_F_FIXED_FILE))
|
|
req->file = io_file_get_normal(req, req->cqe.fd);
|
|
if (!def->prep_async)
|
|
return 0;
|
|
if (WARN_ON_ONCE(req_has_async_data(req)))
|
|
return -EFAULT;
|
|
if (io_alloc_async_data(req))
|
|
return -EAGAIN;
|
|
|
|
return def->prep_async(req);
|
|
}
|
|
|
|
static u32 io_get_sequence(struct io_kiocb *req)
|
|
{
|
|
u32 seq = req->ctx->cached_sq_head;
|
|
struct io_kiocb *cur;
|
|
|
|
/* need original cached_sq_head, but it was increased for each req */
|
|
io_for_each_link(cur, req)
|
|
seq--;
|
|
return seq;
|
|
}
|
|
|
|
static __cold void io_drain_req(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_defer_entry *de;
|
|
int ret;
|
|
u32 seq = io_get_sequence(req);
|
|
|
|
/* Still need defer if there is pending req in defer list. */
|
|
spin_lock(&ctx->completion_lock);
|
|
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) {
|
|
spin_unlock(&ctx->completion_lock);
|
|
queue:
|
|
ctx->drain_active = false;
|
|
io_req_task_queue(req);
|
|
return;
|
|
}
|
|
spin_unlock(&ctx->completion_lock);
|
|
|
|
ret = io_req_prep_async(req);
|
|
if (ret) {
|
|
fail:
|
|
io_req_complete_failed(req, ret);
|
|
return;
|
|
}
|
|
io_prep_async_link(req);
|
|
de = kmalloc(sizeof(*de), GFP_KERNEL);
|
|
if (!de) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
|
|
spin_unlock(&ctx->completion_lock);
|
|
kfree(de);
|
|
goto queue;
|
|
}
|
|
|
|
trace_io_uring_defer(req);
|
|
de->req = req;
|
|
de->seq = seq;
|
|
list_add_tail(&de->list, &ctx->defer_list);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
static void io_clean_op(struct io_kiocb *req)
|
|
{
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) {
|
|
spin_lock(&req->ctx->completion_lock);
|
|
io_put_kbuf_comp(req);
|
|
spin_unlock(&req->ctx->completion_lock);
|
|
}
|
|
|
|
if (req->flags & REQ_F_NEED_CLEANUP) {
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
|
|
if (def->cleanup)
|
|
def->cleanup(req);
|
|
}
|
|
if ((req->flags & REQ_F_POLLED) && req->apoll) {
|
|
kfree(req->apoll->double_poll);
|
|
kfree(req->apoll);
|
|
req->apoll = NULL;
|
|
}
|
|
if (req->flags & REQ_F_INFLIGHT) {
|
|
struct io_uring_task *tctx = req->task->io_uring;
|
|
|
|
atomic_dec(&tctx->inflight_tracked);
|
|
}
|
|
if (req->flags & REQ_F_CREDS)
|
|
put_cred(req->creds);
|
|
if (req->flags & REQ_F_ASYNC_DATA) {
|
|
kfree(req->async_data);
|
|
req->async_data = NULL;
|
|
}
|
|
req->flags &= ~IO_REQ_CLEAN_FLAGS;
|
|
}
|
|
|
|
static bool io_assign_file(struct io_kiocb *req, unsigned int issue_flags)
|
|
{
|
|
if (req->file || !io_op_defs[req->opcode].needs_file)
|
|
return true;
|
|
|
|
if (req->flags & REQ_F_FIXED_FILE)
|
|
req->file = io_file_get_fixed(req, req->cqe.fd, issue_flags);
|
|
else
|
|
req->file = io_file_get_normal(req, req->cqe.fd);
|
|
|
|
return !!req->file;
|
|
}
|
|
|
|
static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
|
|
{
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
const struct cred *creds = NULL;
|
|
int ret;
|
|
|
|
if (unlikely(!io_assign_file(req, issue_flags)))
|
|
return -EBADF;
|
|
|
|
if (unlikely((req->flags & REQ_F_CREDS) && req->creds != current_cred()))
|
|
creds = override_creds(req->creds);
|
|
|
|
if (!def->audit_skip)
|
|
audit_uring_entry(req->opcode);
|
|
|
|
ret = def->issue(req, issue_flags);
|
|
|
|
if (!def->audit_skip)
|
|
audit_uring_exit(!ret, ret);
|
|
|
|
if (creds)
|
|
revert_creds(creds);
|
|
|
|
if (ret == IOU_OK) {
|
|
if (issue_flags & IO_URING_F_COMPLETE_DEFER)
|
|
io_req_complete_defer(req);
|
|
else
|
|
io_req_complete_post(req);
|
|
} else if (ret != IOU_ISSUE_SKIP_COMPLETE)
|
|
return ret;
|
|
|
|
/* If the op doesn't have a file, we're not polling for it */
|
|
if ((req->ctx->flags & IORING_SETUP_IOPOLL) && req->file)
|
|
io_iopoll_req_issued(req, issue_flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int io_poll_issue(struct io_kiocb *req, bool *locked)
|
|
{
|
|
io_tw_lock(req->ctx, locked);
|
|
if (unlikely(req->task->flags & PF_EXITING))
|
|
return -EFAULT;
|
|
return io_issue_sqe(req, IO_URING_F_NONBLOCK);
|
|
}
|
|
|
|
struct io_wq_work *io_wq_free_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
|
|
req = io_put_req_find_next(req);
|
|
return req ? &req->work : NULL;
|
|
}
|
|
|
|
void io_wq_submit_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
const struct io_op_def *def = &io_op_defs[req->opcode];
|
|
unsigned int issue_flags = IO_URING_F_UNLOCKED;
|
|
bool needs_poll = false;
|
|
int ret = 0, err = -ECANCELED;
|
|
|
|
/* one will be dropped by ->io_free_work() after returning to io-wq */
|
|
if (!(req->flags & REQ_F_REFCOUNT))
|
|
__io_req_set_refcount(req, 2);
|
|
else
|
|
req_ref_get(req);
|
|
|
|
io_arm_ltimeout(req);
|
|
|
|
/* either cancelled or io-wq is dying, so don't touch tctx->iowq */
|
|
if (work->flags & IO_WQ_WORK_CANCEL) {
|
|
fail:
|
|
io_req_task_queue_fail(req, err);
|
|
return;
|
|
}
|
|
if (!io_assign_file(req, issue_flags)) {
|
|
err = -EBADF;
|
|
work->flags |= IO_WQ_WORK_CANCEL;
|
|
goto fail;
|
|
}
|
|
|
|
if (req->flags & REQ_F_FORCE_ASYNC) {
|
|
bool opcode_poll = def->pollin || def->pollout;
|
|
|
|
if (opcode_poll && file_can_poll(req->file)) {
|
|
needs_poll = true;
|
|
issue_flags |= IO_URING_F_NONBLOCK;
|
|
}
|
|
}
|
|
|
|
do {
|
|
ret = io_issue_sqe(req, issue_flags);
|
|
if (ret != -EAGAIN)
|
|
break;
|
|
/*
|
|
* We can get EAGAIN for iopolled IO even though we're
|
|
* forcing a sync submission from here, since we can't
|
|
* wait for request slots on the block side.
|
|
*/
|
|
if (!needs_poll) {
|
|
if (!(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
break;
|
|
cond_resched();
|
|
continue;
|
|
}
|
|
|
|
if (io_arm_poll_handler(req, issue_flags) == IO_APOLL_OK)
|
|
return;
|
|
/* aborted or ready, in either case retry blocking */
|
|
needs_poll = false;
|
|
issue_flags &= ~IO_URING_F_NONBLOCK;
|
|
} while (1);
|
|
|
|
/* avoid locking problems by failing it from a clean context */
|
|
if (ret < 0)
|
|
io_req_task_queue_fail(req, ret);
|
|
}
|
|
|
|
inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
|
|
unsigned int issue_flags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct file *file = NULL;
|
|
unsigned long file_ptr;
|
|
|
|
io_ring_submit_lock(ctx, issue_flags);
|
|
|
|
if (unlikely((unsigned int)fd >= ctx->nr_user_files))
|
|
goto out;
|
|
fd = array_index_nospec(fd, ctx->nr_user_files);
|
|
file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr;
|
|
file = (struct file *) (file_ptr & FFS_MASK);
|
|
file_ptr &= ~FFS_MASK;
|
|
/* mask in overlapping REQ_F and FFS bits */
|
|
req->flags |= (file_ptr << REQ_F_SUPPORT_NOWAIT_BIT);
|
|
io_req_set_rsrc_node(req, ctx, 0);
|
|
WARN_ON_ONCE(file && !test_bit(fd, ctx->file_table.bitmap));
|
|
out:
|
|
io_ring_submit_unlock(ctx, issue_flags);
|
|
return file;
|
|
}
|
|
|
|
struct file *io_file_get_normal(struct io_kiocb *req, int fd)
|
|
{
|
|
struct file *file = fget(fd);
|
|
|
|
trace_io_uring_file_get(req, fd);
|
|
|
|
/* we don't allow fixed io_uring files */
|
|
if (file && io_is_uring_fops(file))
|
|
io_req_track_inflight(req);
|
|
return file;
|
|
}
|
|
|
|
static void io_queue_async(struct io_kiocb *req, int ret)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
struct io_kiocb *linked_timeout;
|
|
|
|
if (ret != -EAGAIN || (req->flags & REQ_F_NOWAIT)) {
|
|
io_req_complete_failed(req, ret);
|
|
return;
|
|
}
|
|
|
|
linked_timeout = io_prep_linked_timeout(req);
|
|
|
|
switch (io_arm_poll_handler(req, 0)) {
|
|
case IO_APOLL_READY:
|
|
io_req_task_queue(req);
|
|
break;
|
|
case IO_APOLL_ABORTED:
|
|
/*
|
|
* Queued up for async execution, worker will release
|
|
* submit reference when the iocb is actually submitted.
|
|
*/
|
|
io_kbuf_recycle(req, 0);
|
|
io_queue_iowq(req, NULL);
|
|
break;
|
|
case IO_APOLL_OK:
|
|
break;
|
|
}
|
|
|
|
if (linked_timeout)
|
|
io_queue_linked_timeout(linked_timeout);
|
|
}
|
|
|
|
static inline void io_queue_sqe(struct io_kiocb *req)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
int ret;
|
|
|
|
ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
|
|
|
|
/*
|
|
* We async punt it if the file wasn't marked NOWAIT, or if the file
|
|
* doesn't support non-blocking read/write attempts
|
|
*/
|
|
if (likely(!ret))
|
|
io_arm_ltimeout(req);
|
|
else
|
|
io_queue_async(req, ret);
|
|
}
|
|
|
|
static void io_queue_sqe_fallback(struct io_kiocb *req)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_FAIL)) {
|
|
/*
|
|
* We don't submit, fail them all, for that replace hardlinks
|
|
* with normal links. Extra REQ_F_LINK is tolerated.
|
|
*/
|
|
req->flags &= ~REQ_F_HARDLINK;
|
|
req->flags |= REQ_F_LINK;
|
|
io_req_complete_failed(req, req->cqe.res);
|
|
} else if (unlikely(req->ctx->drain_active)) {
|
|
io_drain_req(req);
|
|
} else {
|
|
int ret = io_req_prep_async(req);
|
|
|
|
if (unlikely(ret))
|
|
io_req_complete_failed(req, ret);
|
|
else
|
|
io_queue_iowq(req, NULL);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 (!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;
|
|
}
|
|
|
|
static void io_init_req_drain(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *head = ctx->submit_state.link.head;
|
|
|
|
ctx->drain_active = true;
|
|
if (head) {
|
|
/*
|
|
* If we need to drain a request in the middle of a link, drain
|
|
* the head request and the next request/link after the current
|
|
* link. Considering sequential execution of links,
|
|
* REQ_F_IO_DRAIN will be maintained for every request of our
|
|
* link.
|
|
*/
|
|
head->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
|
|
ctx->drain_next = true;
|
|
}
|
|
}
|
|
|
|
static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
const struct io_op_def *def;
|
|
unsigned int sqe_flags;
|
|
int personality;
|
|
u8 opcode;
|
|
|
|
/* req is partially pre-initialised, see io_preinit_req() */
|
|
req->opcode = opcode = READ_ONCE(sqe->opcode);
|
|
/* same numerical values with corresponding REQ_F_*, safe to copy */
|
|
req->flags = sqe_flags = READ_ONCE(sqe->flags);
|
|
req->cqe.user_data = READ_ONCE(sqe->user_data);
|
|
req->file = NULL;
|
|
req->rsrc_node = NULL;
|
|
req->task = current;
|
|
|
|
if (unlikely(opcode >= IORING_OP_LAST)) {
|
|
req->opcode = 0;
|
|
return -EINVAL;
|
|
}
|
|
def = &io_op_defs[opcode];
|
|
if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) {
|
|
/* enforce forwards compatibility on users */
|
|
if (sqe_flags & ~SQE_VALID_FLAGS)
|
|
return -EINVAL;
|
|
if (sqe_flags & IOSQE_BUFFER_SELECT) {
|
|
if (!def->buffer_select)
|
|
return -EOPNOTSUPP;
|
|
req->buf_index = READ_ONCE(sqe->buf_group);
|
|
}
|
|
if (sqe_flags & IOSQE_CQE_SKIP_SUCCESS)
|
|
ctx->drain_disabled = true;
|
|
if (sqe_flags & IOSQE_IO_DRAIN) {
|
|
if (ctx->drain_disabled)
|
|
return -EOPNOTSUPP;
|
|
io_init_req_drain(req);
|
|
}
|
|
}
|
|
if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) {
|
|
if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags))
|
|
return -EACCES;
|
|
/* knock it to the slow queue path, will be drained there */
|
|
if (ctx->drain_active)
|
|
req->flags |= REQ_F_FORCE_ASYNC;
|
|
/* if there is no link, we're at "next" request and need to drain */
|
|
if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) {
|
|
ctx->drain_next = false;
|
|
ctx->drain_active = true;
|
|
req->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
|
|
}
|
|
}
|
|
|
|
if (!def->ioprio && sqe->ioprio)
|
|
return -EINVAL;
|
|
if (!def->iopoll && (ctx->flags & IORING_SETUP_IOPOLL))
|
|
return -EINVAL;
|
|
|
|
if (def->needs_file) {
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
|
|
req->cqe.fd = READ_ONCE(sqe->fd);
|
|
|
|
/*
|
|
* Plug now if we have more than 2 IO left after this, and the
|
|
* target is potentially a read/write to block based storage.
|
|
*/
|
|
if (state->need_plug && def->plug) {
|
|
state->plug_started = true;
|
|
state->need_plug = false;
|
|
blk_start_plug_nr_ios(&state->plug, state->submit_nr);
|
|
}
|
|
}
|
|
|
|
personality = READ_ONCE(sqe->personality);
|
|
if (personality) {
|
|
int ret;
|
|
|
|
req->creds = xa_load(&ctx->personalities, personality);
|
|
if (!req->creds)
|
|
return -EINVAL;
|
|
get_cred(req->creds);
|
|
ret = security_uring_override_creds(req->creds);
|
|
if (ret) {
|
|
put_cred(req->creds);
|
|
return ret;
|
|
}
|
|
req->flags |= REQ_F_CREDS;
|
|
}
|
|
|
|
return def->prep(req, sqe);
|
|
}
|
|
|
|
static __cold int io_submit_fail_init(const struct io_uring_sqe *sqe,
|
|
struct io_kiocb *req, int ret)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_submit_link *link = &ctx->submit_state.link;
|
|
struct io_kiocb *head = link->head;
|
|
|
|
trace_io_uring_req_failed(sqe, req, ret);
|
|
|
|
/*
|
|
* Avoid breaking links in the middle as it renders links with SQPOLL
|
|
* unusable. Instead of failing eagerly, continue assembling the link if
|
|
* applicable and mark the head with REQ_F_FAIL. The link flushing code
|
|
* should find the flag and handle the rest.
|
|
*/
|
|
req_fail_link_node(req, ret);
|
|
if (head && !(head->flags & REQ_F_FAIL))
|
|
req_fail_link_node(head, -ECANCELED);
|
|
|
|
if (!(req->flags & IO_REQ_LINK_FLAGS)) {
|
|
if (head) {
|
|
link->last->link = req;
|
|
link->head = NULL;
|
|
req = head;
|
|
}
|
|
io_queue_sqe_fallback(req);
|
|
return ret;
|
|
}
|
|
|
|
if (head)
|
|
link->last->link = req;
|
|
else
|
|
link->head = req;
|
|
link->last = req;
|
|
return 0;
|
|
}
|
|
|
|
static inline int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_submit_link *link = &ctx->submit_state.link;
|
|
int ret;
|
|
|
|
ret = io_init_req(ctx, req, sqe);
|
|
if (unlikely(ret))
|
|
return io_submit_fail_init(sqe, req, ret);
|
|
|
|
/* don't need @sqe from now on */
|
|
trace_io_uring_submit_sqe(req, true);
|
|
|
|
/*
|
|
* 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 (unlikely(link->head)) {
|
|
ret = io_req_prep_async(req);
|
|
if (unlikely(ret))
|
|
return io_submit_fail_init(sqe, req, ret);
|
|
|
|
trace_io_uring_link(req, link->head);
|
|
link->last->link = req;
|
|
link->last = req;
|
|
|
|
if (req->flags & IO_REQ_LINK_FLAGS)
|
|
return 0;
|
|
/* last request of the link, flush it */
|
|
req = link->head;
|
|
link->head = NULL;
|
|
if (req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL))
|
|
goto fallback;
|
|
|
|
} else if (unlikely(req->flags & (IO_REQ_LINK_FLAGS |
|
|
REQ_F_FORCE_ASYNC | REQ_F_FAIL))) {
|
|
if (req->flags & IO_REQ_LINK_FLAGS) {
|
|
link->head = req;
|
|
link->last = req;
|
|
} else {
|
|
fallback:
|
|
io_queue_sqe_fallback(req);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
io_queue_sqe(req);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Batched submission is done, ensure local IO is flushed out.
|
|
*/
|
|
static void io_submit_state_end(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
|
|
if (unlikely(state->link.head))
|
|
io_queue_sqe_fallback(state->link.head);
|
|
/* flush only after queuing links as they can generate completions */
|
|
io_submit_flush_completions(ctx);
|
|
if (state->plug_started)
|
|
blk_finish_plug(&state->plug);
|
|
}
|
|
|
|
/*
|
|
* Start submission side cache.
|
|
*/
|
|
static void io_submit_state_start(struct io_submit_state *state,
|
|
unsigned int max_ios)
|
|
{
|
|
state->plug_started = false;
|
|
state->need_plug = max_ios > 2;
|
|
state->submit_nr = max_ios;
|
|
/* set only head, no need to init link_last in advance */
|
|
state->link.head = NULL;
|
|
}
|
|
|
|
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 this returns a pointer 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)
|
|
{
|
|
unsigned head, mask = ctx->sq_entries - 1;
|
|
unsigned sq_idx = ctx->cached_sq_head++ & mask;
|
|
|
|
/*
|
|
* 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(ctx->sq_array[sq_idx]);
|
|
if (likely(head < ctx->sq_entries)) {
|
|
/* double index for 128-byte SQEs, twice as long */
|
|
if (ctx->flags & IORING_SETUP_SQE128)
|
|
head <<= 1;
|
|
return &ctx->sq_sqes[head];
|
|
}
|
|
|
|
/* drop invalid entries */
|
|
ctx->cq_extra--;
|
|
WRITE_ONCE(ctx->rings->sq_dropped,
|
|
READ_ONCE(ctx->rings->sq_dropped) + 1);
|
|
return NULL;
|
|
}
|
|
|
|
int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
unsigned int entries = io_sqring_entries(ctx);
|
|
unsigned int left;
|
|
int ret;
|
|
|
|
if (unlikely(!entries))
|
|
return 0;
|
|
/* make sure SQ entry isn't read before tail */
|
|
ret = left = min3(nr, ctx->sq_entries, entries);
|
|
io_get_task_refs(left);
|
|
io_submit_state_start(&ctx->submit_state, left);
|
|
|
|
do {
|
|
const struct io_uring_sqe *sqe;
|
|
struct io_kiocb *req;
|
|
|
|
if (unlikely(!io_alloc_req_refill(ctx)))
|
|
break;
|
|
req = io_alloc_req(ctx);
|
|
sqe = io_get_sqe(ctx);
|
|
if (unlikely(!sqe)) {
|
|
io_req_add_to_cache(req, ctx);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Continue submitting even for sqe failure if the
|
|
* ring was setup with IORING_SETUP_SUBMIT_ALL
|
|
*/
|
|
if (unlikely(io_submit_sqe(ctx, req, sqe)) &&
|
|
!(ctx->flags & IORING_SETUP_SUBMIT_ALL)) {
|
|
left--;
|
|
break;
|
|
}
|
|
} while (--left);
|
|
|
|
if (unlikely(left)) {
|
|
ret -= left;
|
|
/* try again if it submitted nothing and can't allocate a req */
|
|
if (!ret && io_req_cache_empty(ctx))
|
|
ret = -EAGAIN;
|
|
current->io_uring->cached_refs += left;
|
|
}
|
|
|
|
io_submit_state_end(ctx);
|
|
/* Commit SQ ring head once we've consumed and submitted all SQEs */
|
|
io_commit_sqring(ctx);
|
|
return ret;
|
|
}
|
|
|
|
struct io_wait_queue {
|
|
struct wait_queue_entry wq;
|
|
struct io_ring_ctx *ctx;
|
|
unsigned cq_tail;
|
|
unsigned nr_timeouts;
|
|
};
|
|
|
|
static inline bool io_should_wake(struct io_wait_queue *iowq)
|
|
{
|
|
struct io_ring_ctx *ctx = iowq->ctx;
|
|
int dist = ctx->cached_cq_tail - (int) iowq->cq_tail;
|
|
|
|
/*
|
|
* 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 dist >= 0 || 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);
|
|
|
|
/*
|
|
* Cannot safely flush overflowed CQEs from here, ensure we wake up
|
|
* the task, and the next invocation will do it.
|
|
*/
|
|
if (io_should_wake(iowq) ||
|
|
test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &iowq->ctx->check_cq))
|
|
return autoremove_wake_function(curr, mode, wake_flags, key);
|
|
return -1;
|
|
}
|
|
|
|
int io_run_task_work_sig(void)
|
|
{
|
|
if (io_run_task_work())
|
|
return 1;
|
|
if (task_sigpending(current))
|
|
return -EINTR;
|
|
return 0;
|
|
}
|
|
|
|
/* when returns >0, the caller should retry */
|
|
static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
|
|
struct io_wait_queue *iowq,
|
|
ktime_t timeout)
|
|
{
|
|
int ret;
|
|
unsigned long check_cq;
|
|
|
|
/* make sure we run task_work before checking for signals */
|
|
ret = io_run_task_work_sig();
|
|
if (ret || io_should_wake(iowq))
|
|
return ret;
|
|
|
|
check_cq = READ_ONCE(ctx->check_cq);
|
|
if (unlikely(check_cq)) {
|
|
/* let the caller flush overflows, retry */
|
|
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
|
|
return 1;
|
|
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
|
|
return -EBADR;
|
|
}
|
|
if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS))
|
|
return -ETIME;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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 __kernel_timespec __user *uts)
|
|
{
|
|
struct io_wait_queue iowq;
|
|
struct io_rings *rings = ctx->rings;
|
|
ktime_t timeout = KTIME_MAX;
|
|
int ret;
|
|
|
|
do {
|
|
io_cqring_overflow_flush(ctx);
|
|
if (io_cqring_events(ctx) >= 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;
|
|
}
|
|
|
|
if (uts) {
|
|
struct timespec64 ts;
|
|
|
|
if (get_timespec64(&ts, uts))
|
|
return -EFAULT;
|
|
timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
|
|
}
|
|
|
|
init_waitqueue_func_entry(&iowq.wq, io_wake_function);
|
|
iowq.wq.private = current;
|
|
INIT_LIST_HEAD(&iowq.wq.entry);
|
|
iowq.ctx = ctx;
|
|
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
|
|
iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
|
|
|
|
trace_io_uring_cqring_wait(ctx, min_events);
|
|
do {
|
|
/* if we can't even flush overflow, don't wait for more */
|
|
if (!io_cqring_overflow_flush(ctx)) {
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
|
|
TASK_INTERRUPTIBLE);
|
|
ret = io_cqring_wait_schedule(ctx, &iowq, timeout);
|
|
cond_resched();
|
|
} while (ret > 0);
|
|
|
|
finish_wait(&ctx->cq_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_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 = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
|
|
|
|
return (void *) __get_free_pages(gfp, get_order(size));
|
|
}
|
|
|
|
static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries,
|
|
unsigned int 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;
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
if (check_shl_overflow(off, 1, &off))
|
|
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 int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg,
|
|
unsigned int eventfd_async)
|
|
{
|
|
struct io_ev_fd *ev_fd;
|
|
__s32 __user *fds = arg;
|
|
int fd;
|
|
|
|
ev_fd = rcu_dereference_protected(ctx->io_ev_fd,
|
|
lockdep_is_held(&ctx->uring_lock));
|
|
if (ev_fd)
|
|
return -EBUSY;
|
|
|
|
if (copy_from_user(&fd, fds, sizeof(*fds)))
|
|
return -EFAULT;
|
|
|
|
ev_fd = kmalloc(sizeof(*ev_fd), GFP_KERNEL);
|
|
if (!ev_fd)
|
|
return -ENOMEM;
|
|
|
|
ev_fd->cq_ev_fd = eventfd_ctx_fdget(fd);
|
|
if (IS_ERR(ev_fd->cq_ev_fd)) {
|
|
int ret = PTR_ERR(ev_fd->cq_ev_fd);
|
|
kfree(ev_fd);
|
|
return ret;
|
|
}
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
ctx->evfd_last_cq_tail = ctx->cached_cq_tail;
|
|
spin_unlock(&ctx->completion_lock);
|
|
|
|
ev_fd->eventfd_async = eventfd_async;
|
|
ctx->has_evfd = true;
|
|
rcu_assign_pointer(ctx->io_ev_fd, ev_fd);
|
|
return 0;
|
|
}
|
|
|
|
static void io_eventfd_put(struct rcu_head *rcu)
|
|
{
|
|
struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu);
|
|
|
|
eventfd_ctx_put(ev_fd->cq_ev_fd);
|
|
kfree(ev_fd);
|
|
}
|
|
|
|
static int io_eventfd_unregister(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_ev_fd *ev_fd;
|
|
|
|
ev_fd = rcu_dereference_protected(ctx->io_ev_fd,
|
|
lockdep_is_held(&ctx->uring_lock));
|
|
if (ev_fd) {
|
|
ctx->has_evfd = false;
|
|
rcu_assign_pointer(ctx->io_ev_fd, NULL);
|
|
call_rcu(&ev_fd->rcu, io_eventfd_put);
|
|
return 0;
|
|
}
|
|
|
|
return -ENXIO;
|
|
}
|
|
|
|
static void io_req_caches_free(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
int nr = 0;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
io_flush_cached_locked_reqs(ctx, state);
|
|
|
|
while (!io_req_cache_empty(ctx)) {
|
|
struct io_wq_work_node *node;
|
|
struct io_kiocb *req;
|
|
|
|
node = wq_stack_extract(&state->free_list);
|
|
req = container_of(node, struct io_kiocb, comp_list);
|
|
kmem_cache_free(req_cachep, req);
|
|
nr++;
|
|
}
|
|
if (nr)
|
|
percpu_ref_put_many(&ctx->refs, nr);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
|
|
{
|
|
io_sq_thread_finish(ctx);
|
|
|
|
if (ctx->mm_account) {
|
|
mmdrop(ctx->mm_account);
|
|
ctx->mm_account = NULL;
|
|
}
|
|
|
|
io_rsrc_refs_drop(ctx);
|
|
/* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
|
|
io_wait_rsrc_data(ctx->buf_data);
|
|
io_wait_rsrc_data(ctx->file_data);
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
if (ctx->buf_data)
|
|
__io_sqe_buffers_unregister(ctx);
|
|
if (ctx->file_data)
|
|
__io_sqe_files_unregister(ctx);
|
|
if (ctx->rings)
|
|
__io_cqring_overflow_flush(ctx, true);
|
|
io_eventfd_unregister(ctx);
|
|
io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free);
|
|
io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
io_destroy_buffers(ctx);
|
|
if (ctx->sq_creds)
|
|
put_cred(ctx->sq_creds);
|
|
if (ctx->submitter_task)
|
|
put_task_struct(ctx->submitter_task);
|
|
|
|
/* there are no registered resources left, nobody uses it */
|
|
if (ctx->rsrc_node)
|
|
io_rsrc_node_destroy(ctx->rsrc_node);
|
|
if (ctx->rsrc_backup_node)
|
|
io_rsrc_node_destroy(ctx->rsrc_backup_node);
|
|
flush_delayed_work(&ctx->rsrc_put_work);
|
|
flush_delayed_work(&ctx->fallback_work);
|
|
|
|
WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
|
|
WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
|
|
|
|
#if defined(CONFIG_UNIX)
|
|
if (ctx->ring_sock) {
|
|
ctx->ring_sock->file = NULL; /* so that iput() is called */
|
|
sock_release(ctx->ring_sock);
|
|
}
|
|
#endif
|
|
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
|
|
WARN_ON_ONCE(ctx->notif_slots || ctx->nr_notif_slots);
|
|
|
|
io_mem_free(ctx->rings);
|
|
io_mem_free(ctx->sq_sqes);
|
|
|
|
percpu_ref_exit(&ctx->refs);
|
|
free_uid(ctx->user);
|
|
io_req_caches_free(ctx);
|
|
if (ctx->hash_map)
|
|
io_wq_put_hash(ctx->hash_map);
|
|
kfree(ctx->cancel_table.hbs);
|
|
kfree(ctx->cancel_table_locked.hbs);
|
|
kfree(ctx->dummy_ubuf);
|
|
kfree(ctx->io_bl);
|
|
xa_destroy(&ctx->io_bl_xa);
|
|
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;
|
|
|
|
/*
|
|
* Don't flush cqring overflow list here, just do a simple check.
|
|
* Otherwise there could possible be ABBA deadlock:
|
|
* CPU0 CPU1
|
|
* ---- ----
|
|
* lock(&ctx->uring_lock);
|
|
* lock(&ep->mtx);
|
|
* lock(&ctx->uring_lock);
|
|
* lock(&ep->mtx);
|
|
*
|
|
* Users may get EPOLLIN meanwhile seeing nothing in cqring, this
|
|
* pushs them to do the flush.
|
|
*/
|
|
if (io_cqring_events(ctx) ||
|
|
test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
|
|
{
|
|
const struct cred *creds;
|
|
|
|
creds = xa_erase(&ctx->personalities, id);
|
|
if (creds) {
|
|
put_cred(creds);
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
struct io_tctx_exit {
|
|
struct callback_head task_work;
|
|
struct completion completion;
|
|
struct io_ring_ctx *ctx;
|
|
};
|
|
|
|
static __cold void io_tctx_exit_cb(struct callback_head *cb)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
struct io_tctx_exit *work;
|
|
|
|
work = container_of(cb, struct io_tctx_exit, task_work);
|
|
/*
|
|
* When @in_idle, we're in cancellation and it's racy to remove the
|
|
* node. It'll be removed by the end of cancellation, just ignore it.
|
|
*/
|
|
if (!atomic_read(&tctx->in_idle))
|
|
io_uring_del_tctx_node((unsigned long)work->ctx);
|
|
complete(&work->completion);
|
|
}
|
|
|
|
static __cold bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
|
|
return req->ctx == data;
|
|
}
|
|
|
|
static __cold void io_ring_exit_work(struct work_struct *work)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
|
|
unsigned long timeout = jiffies + HZ * 60 * 5;
|
|
unsigned long interval = HZ / 20;
|
|
struct io_tctx_exit exit;
|
|
struct io_tctx_node *node;
|
|
int ret;
|
|
|
|
/*
|
|
* 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 {
|
|
while (io_uring_try_cancel_requests(ctx, NULL, true))
|
|
cond_resched();
|
|
|
|
if (ctx->sq_data) {
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
struct task_struct *tsk;
|
|
|
|
io_sq_thread_park(sqd);
|
|
tsk = sqd->thread;
|
|
if (tsk && tsk->io_uring && tsk->io_uring->io_wq)
|
|
io_wq_cancel_cb(tsk->io_uring->io_wq,
|
|
io_cancel_ctx_cb, ctx, true);
|
|
io_sq_thread_unpark(sqd);
|
|
}
|
|
|
|
io_req_caches_free(ctx);
|
|
|
|
if (WARN_ON_ONCE(time_after(jiffies, timeout))) {
|
|
/* there is little hope left, don't run it too often */
|
|
interval = HZ * 60;
|
|
}
|
|
} while (!wait_for_completion_timeout(&ctx->ref_comp, interval));
|
|
|
|
init_completion(&exit.completion);
|
|
init_task_work(&exit.task_work, io_tctx_exit_cb);
|
|
exit.ctx = ctx;
|
|
/*
|
|
* Some may use context even when all refs and requests have been put,
|
|
* and they are free to do so while still holding uring_lock or
|
|
* completion_lock, see io_req_task_submit(). Apart from other work,
|
|
* this lock/unlock section also waits them to finish.
|
|
*/
|
|
mutex_lock(&ctx->uring_lock);
|
|
while (!list_empty(&ctx->tctx_list)) {
|
|
WARN_ON_ONCE(time_after(jiffies, timeout));
|
|
|
|
node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
|
|
ctx_node);
|
|
/* don't spin on a single task if cancellation failed */
|
|
list_rotate_left(&ctx->tctx_list);
|
|
ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
|
|
if (WARN_ON_ONCE(ret))
|
|
continue;
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
wait_for_completion(&exit.completion);
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
spin_lock(&ctx->completion_lock);
|
|
spin_unlock(&ctx->completion_lock);
|
|
|
|
io_ring_ctx_free(ctx);
|
|
}
|
|
|
|
static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
|
|
{
|
|
unsigned long index;
|
|
struct creds *creds;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
percpu_ref_kill(&ctx->refs);
|
|
if (ctx->rings)
|
|
__io_cqring_overflow_flush(ctx, true);
|
|
xa_for_each(&ctx->personalities, index, creds)
|
|
io_unregister_personality(ctx, index);
|
|
if (ctx->rings)
|
|
io_poll_remove_all(ctx, NULL, true);
|
|
io_notif_unregister(ctx);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
/* failed during ring init, it couldn't have issued any requests */
|
|
if (ctx->rings) {
|
|
io_kill_timeouts(ctx, NULL, true);
|
|
/* if we failed setting up the ctx, we might not have any rings */
|
|
io_iopoll_try_reap_events(ctx);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
struct io_task_cancel {
|
|
struct task_struct *task;
|
|
bool all;
|
|
};
|
|
|
|
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 io_task_cancel *cancel = data;
|
|
|
|
return io_match_task_safe(req, cancel->task, cancel->all);
|
|
}
|
|
|
|
static __cold bool io_cancel_defer_files(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
bool cancel_all)
|
|
{
|
|
struct io_defer_entry *de;
|
|
LIST_HEAD(list);
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
list_for_each_entry_reverse(de, &ctx->defer_list, list) {
|
|
if (io_match_task_safe(de->req, task, cancel_all)) {
|
|
list_cut_position(&list, &ctx->defer_list, &de->list);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&ctx->completion_lock);
|
|
if (list_empty(&list))
|
|
return false;
|
|
|
|
while (!list_empty(&list)) {
|
|
de = list_first_entry(&list, struct io_defer_entry, list);
|
|
list_del_init(&de->list);
|
|
io_req_complete_failed(de->req, -ECANCELED);
|
|
kfree(de);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_tctx_node *node;
|
|
enum io_wq_cancel cret;
|
|
bool ret = false;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
|
|
struct io_uring_task *tctx = node->task->io_uring;
|
|
|
|
/*
|
|
* io_wq will stay alive while we hold uring_lock, because it's
|
|
* killed after ctx nodes, which requires to take the lock.
|
|
*/
|
|
if (!tctx || !tctx->io_wq)
|
|
continue;
|
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);
|
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
bool cancel_all)
|
|
{
|
|
struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
|
|
struct io_uring_task *tctx = task ? task->io_uring : NULL;
|
|
enum io_wq_cancel cret;
|
|
bool ret = false;
|
|
|
|
/* failed during ring init, it couldn't have issued any requests */
|
|
if (!ctx->rings)
|
|
return false;
|
|
|
|
if (!task) {
|
|
ret |= io_uring_try_cancel_iowq(ctx);
|
|
} else if (tctx && tctx->io_wq) {
|
|
/*
|
|
* Cancels requests of all rings, not only @ctx, but
|
|
* it's fine as the task is in exit/exec.
|
|
*/
|
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,
|
|
&cancel, true);
|
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
|
|
}
|
|
|
|
/* SQPOLL thread does its own polling */
|
|
if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) ||
|
|
(ctx->sq_data && ctx->sq_data->thread == current)) {
|
|
while (!wq_list_empty(&ctx->iopoll_list)) {
|
|
io_iopoll_try_reap_events(ctx);
|
|
ret = true;
|
|
}
|
|
}
|
|
|
|
ret |= io_cancel_defer_files(ctx, task, cancel_all);
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret |= io_poll_remove_all(ctx, task, cancel_all);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
ret |= io_kill_timeouts(ctx, task, cancel_all);
|
|
if (task)
|
|
ret |= io_run_task_work();
|
|
return ret;
|
|
}
|
|
|
|
static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
|
|
{
|
|
if (tracked)
|
|
return atomic_read(&tctx->inflight_tracked);
|
|
return percpu_counter_sum(&tctx->inflight);
|
|
}
|
|
|
|
/*
|
|
* Find any io_uring ctx that this task has registered or done IO on, and cancel
|
|
* requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
|
|
*/
|
|
__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
struct io_ring_ctx *ctx;
|
|
s64 inflight;
|
|
DEFINE_WAIT(wait);
|
|
|
|
WARN_ON_ONCE(sqd && sqd->thread != current);
|
|
|
|
if (!current->io_uring)
|
|
return;
|
|
if (tctx->io_wq)
|
|
io_wq_exit_start(tctx->io_wq);
|
|
|
|
atomic_inc(&tctx->in_idle);
|
|
do {
|
|
bool loop = false;
|
|
|
|
io_uring_drop_tctx_refs(current);
|
|
/* read completions before cancelations */
|
|
inflight = tctx_inflight(tctx, !cancel_all);
|
|
if (!inflight)
|
|
break;
|
|
|
|
if (!sqd) {
|
|
struct io_tctx_node *node;
|
|
unsigned long index;
|
|
|
|
xa_for_each(&tctx->xa, index, node) {
|
|
/* sqpoll task will cancel all its requests */
|
|
if (node->ctx->sq_data)
|
|
continue;
|
|
loop |= io_uring_try_cancel_requests(node->ctx,
|
|
current, cancel_all);
|
|
}
|
|
} else {
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
|
|
loop |= io_uring_try_cancel_requests(ctx,
|
|
current,
|
|
cancel_all);
|
|
}
|
|
|
|
if (loop) {
|
|
cond_resched();
|
|
continue;
|
|
}
|
|
|
|
prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
|
|
io_run_task_work();
|
|
io_uring_drop_tctx_refs(current);
|
|
|
|
/*
|
|
* If we've seen completions, retry without waiting. This
|
|
* avoids a race where a completion comes in before we did
|
|
* prepare_to_wait().
|
|
*/
|
|
if (inflight == tctx_inflight(tctx, !cancel_all))
|
|
schedule();
|
|
finish_wait(&tctx->wait, &wait);
|
|
} while (1);
|
|
|
|
io_uring_clean_tctx(tctx);
|
|
if (cancel_all) {
|
|
/*
|
|
* We shouldn't run task_works after cancel, so just leave
|
|
* ->in_idle set for normal exit.
|
|
*/
|
|
atomic_dec(&tctx->in_idle);
|
|
/* for exec all current's requests should be gone, kill tctx */
|
|
__io_uring_free(current);
|
|
}
|
|
}
|
|
|
|
void __io_uring_cancel(bool cancel_all)
|
|
{
|
|
io_uring_cancel_generic(cancel_all, NULL);
|
|
}
|
|
|
|
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 __cold 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 int io_validate_ext_arg(unsigned flags, const void __user *argp, size_t argsz)
|
|
{
|
|
if (flags & IORING_ENTER_EXT_ARG) {
|
|
struct io_uring_getevents_arg arg;
|
|
|
|
if (argsz != sizeof(arg))
|
|
return -EINVAL;
|
|
if (copy_from_user(&arg, argp, sizeof(arg)))
|
|
return -EFAULT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
|
|
struct __kernel_timespec __user **ts,
|
|
const sigset_t __user **sig)
|
|
{
|
|
struct io_uring_getevents_arg arg;
|
|
|
|
/*
|
|
* If EXT_ARG isn't set, then we have no timespec and the argp pointer
|
|
* is just a pointer to the sigset_t.
|
|
*/
|
|
if (!(flags & IORING_ENTER_EXT_ARG)) {
|
|
*sig = (const sigset_t __user *) argp;
|
|
*ts = NULL;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* EXT_ARG is set - ensure we agree on the size of it and copy in our
|
|
* timespec and sigset_t pointers if good.
|
|
*/
|
|
if (*argsz != sizeof(arg))
|
|
return -EINVAL;
|
|
if (copy_from_user(&arg, argp, sizeof(arg)))
|
|
return -EFAULT;
|
|
if (arg.pad)
|
|
return -EINVAL;
|
|
*sig = u64_to_user_ptr(arg.sigmask);
|
|
*argsz = arg.sigmask_sz;
|
|
*ts = u64_to_user_ptr(arg.ts);
|
|
return 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
|
|
u32, min_complete, u32, flags, const void __user *, argp,
|
|
size_t, argsz)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
struct fd f;
|
|
long ret;
|
|
|
|
io_run_task_work();
|
|
|
|
if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
|
|
IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG |
|
|
IORING_ENTER_REGISTERED_RING)))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Ring fd has been registered via IORING_REGISTER_RING_FDS, we
|
|
* need only dereference our task private array to find it.
|
|
*/
|
|
if (flags & IORING_ENTER_REGISTERED_RING) {
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX))
|
|
return -EINVAL;
|
|
fd = array_index_nospec(fd, IO_RINGFD_REG_MAX);
|
|
f.file = tctx->registered_rings[fd];
|
|
f.flags = 0;
|
|
if (unlikely(!f.file))
|
|
return -EBADF;
|
|
} else {
|
|
f = fdget(fd);
|
|
if (unlikely(!f.file))
|
|
return -EBADF;
|
|
ret = -EOPNOTSUPP;
|
|
if (unlikely(!io_is_uring_fops(f.file)))
|
|
goto out;
|
|
}
|
|
|
|
ctx = f.file->private_data;
|
|
ret = -EBADFD;
|
|
if (unlikely(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) {
|
|
io_cqring_overflow_flush(ctx);
|
|
|
|
if (unlikely(ctx->sq_data->thread == NULL)) {
|
|
ret = -EOWNERDEAD;
|
|
goto out;
|
|
}
|
|
if (flags & IORING_ENTER_SQ_WAKEUP)
|
|
wake_up(&ctx->sq_data->wait);
|
|
if (flags & IORING_ENTER_SQ_WAIT) {
|
|
ret = io_sqpoll_wait_sq(ctx);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
ret = to_submit;
|
|
} else if (to_submit) {
|
|
ret = io_uring_add_tctx_node(ctx);
|
|
if (unlikely(ret))
|
|
goto out;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = io_submit_sqes(ctx, to_submit);
|
|
if (ret != to_submit) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
goto out;
|
|
}
|
|
if ((flags & IORING_ENTER_GETEVENTS) && ctx->syscall_iopoll)
|
|
goto iopoll_locked;
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
if (flags & IORING_ENTER_GETEVENTS) {
|
|
int ret2;
|
|
if (ctx->syscall_iopoll) {
|
|
/*
|
|
* 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);
|
|
iopoll_locked:
|
|
ret2 = io_validate_ext_arg(flags, argp, argsz);
|
|
if (likely(!ret2)) {
|
|
min_complete = min(min_complete,
|
|
ctx->cq_entries);
|
|
ret2 = io_iopoll_check(ctx, min_complete);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
} else {
|
|
const sigset_t __user *sig;
|
|
struct __kernel_timespec __user *ts;
|
|
|
|
ret2 = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
|
|
if (likely(!ret2)) {
|
|
min_complete = min(min_complete,
|
|
ctx->cq_entries);
|
|
ret2 = io_cqring_wait(ctx, min_complete, sig,
|
|
argsz, ts);
|
|
}
|
|
}
|
|
|
|
if (!ret) {
|
|
ret = ret2;
|
|
|
|
/*
|
|
* EBADR indicates that one or more CQE were dropped.
|
|
* Once the user has been informed we can clear the bit
|
|
* as they are obviously ok with those drops.
|
|
*/
|
|
if (unlikely(ret2 == -EBADR))
|
|
clear_bit(IO_CHECK_CQ_DROPPED_BIT,
|
|
&ctx->check_cq);
|
|
}
|
|
}
|
|
out:
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations io_uring_fops = {
|
|
.release = io_uring_release,
|
|
.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,
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = io_uring_show_fdinfo,
|
|
#endif
|
|
};
|
|
|
|
bool io_is_uring_fops(struct file *file)
|
|
{
|
|
return file->f_op == &io_uring_fops;
|
|
}
|
|
|
|
static __cold 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(ctx, 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;
|
|
|
|
if (p->flags & IORING_SETUP_SQE128)
|
|
size = array_size(2 * sizeof(struct io_uring_sqe), p->sq_entries);
|
|
else
|
|
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;
|
|
}
|
|
|
|
static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
|
|
{
|
|
int ret, fd;
|
|
|
|
fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
|
|
if (fd < 0)
|
|
return fd;
|
|
|
|
ret = __io_uring_add_tctx_node(ctx, false);
|
|
if (ret) {
|
|
put_unused_fd(fd);
|
|
return ret;
|
|
}
|
|
fd_install(fd, file);
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* 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 struct file *io_uring_get_file(struct io_ring_ctx *ctx)
|
|
{
|
|
struct file *file;
|
|
#if defined(CONFIG_UNIX)
|
|
int ret;
|
|
|
|
ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
|
|
&ctx->ring_sock);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
#endif
|
|
|
|
file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
|
|
O_RDWR | O_CLOEXEC, NULL);
|
|
#if defined(CONFIG_UNIX)
|
|
if (IS_ERR(file)) {
|
|
sock_release(ctx->ring_sock);
|
|
ctx->ring_sock = NULL;
|
|
} else {
|
|
ctx->ring_sock->file = file;
|
|
}
|
|
#endif
|
|
return file;
|
|
}
|
|
|
|
static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
|
|
struct io_uring_params __user *params)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
struct file *file;
|
|
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)
|
|
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);
|
|
if (p->cq_entries < p->sq_entries)
|
|
return -EINVAL;
|
|
} else {
|
|
p->cq_entries = 2 * p->sq_entries;
|
|
}
|
|
|
|
ctx = io_ring_ctx_alloc(p);
|
|
if (!ctx)
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* 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))
|
|
ctx->syscall_iopoll = 1;
|
|
|
|
ctx->compat = in_compat_syscall();
|
|
if (!capable(CAP_IPC_LOCK))
|
|
ctx->user = get_uid(current_user());
|
|
|
|
/*
|
|
* For SQPOLL, we just need a wakeup, always. For !SQPOLL, if
|
|
* COOP_TASKRUN is set, then IPIs are never needed by the app.
|
|
*/
|
|
ret = -EINVAL;
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
/* IPI related flags don't make sense with SQPOLL */
|
|
if (ctx->flags & (IORING_SETUP_COOP_TASKRUN |
|
|
IORING_SETUP_TASKRUN_FLAG))
|
|
goto err;
|
|
ctx->notify_method = TWA_SIGNAL_NO_IPI;
|
|
} else if (ctx->flags & IORING_SETUP_COOP_TASKRUN) {
|
|
ctx->notify_method = TWA_SIGNAL_NO_IPI;
|
|
} else {
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
goto err;
|
|
ctx->notify_method = TWA_SIGNAL;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
ret = io_allocate_scq_urings(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = io_sq_offload_create(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
/* always set a rsrc node */
|
|
ret = io_rsrc_node_switch_start(ctx);
|
|
if (ret)
|
|
goto err;
|
|
io_rsrc_node_switch(ctx, NULL);
|
|
|
|
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 | IORING_FEAT_SQPOLL_NONFIXED |
|
|
IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS |
|
|
IORING_FEAT_RSRC_TAGS | IORING_FEAT_CQE_SKIP |
|
|
IORING_FEAT_LINKED_FILE;
|
|
|
|
if (copy_to_user(params, p, sizeof(*p))) {
|
|
ret = -EFAULT;
|
|
goto err;
|
|
}
|
|
|
|
file = io_uring_get_file(ctx);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
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_install_fd(ctx, file);
|
|
if (ret < 0) {
|
|
/* fput will clean it up */
|
|
fput(file);
|
|
return ret;
|
|
}
|
|
|
|
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 | IORING_SETUP_SUBMIT_ALL |
|
|
IORING_SETUP_COOP_TASKRUN | IORING_SETUP_TASKRUN_FLAG |
|
|
IORING_SETUP_SQE128 | IORING_SETUP_CQE32 |
|
|
IORING_SETUP_SINGLE_ISSUER))
|
|
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 __cold 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)
|
|
{
|
|
const struct cred *creds;
|
|
u32 id;
|
|
int ret;
|
|
|
|
creds = get_current_cred();
|
|
|
|
ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds,
|
|
XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
|
|
if (ret < 0) {
|
|
put_cred(creds);
|
|
return ret;
|
|
}
|
|
return id;
|
|
}
|
|
|
|
static __cold 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;
|
|
if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait))
|
|
wake_up(&ctx->sq_data->wait);
|
|
return 0;
|
|
}
|
|
|
|
static __cold int io_register_iowq_aff(struct io_ring_ctx *ctx,
|
|
void __user *arg, unsigned len)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
cpumask_var_t new_mask;
|
|
int ret;
|
|
|
|
if (!tctx || !tctx->io_wq)
|
|
return -EINVAL;
|
|
|
|
if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
|
|
cpumask_clear(new_mask);
|
|
if (len > cpumask_size())
|
|
len = cpumask_size();
|
|
|
|
if (in_compat_syscall()) {
|
|
ret = compat_get_bitmap(cpumask_bits(new_mask),
|
|
(const compat_ulong_t __user *)arg,
|
|
len * 8 /* CHAR_BIT */);
|
|
} else {
|
|
ret = copy_from_user(new_mask, arg, len);
|
|
}
|
|
|
|
if (ret) {
|
|
free_cpumask_var(new_mask);
|
|
return -EFAULT;
|
|
}
|
|
|
|
ret = io_wq_cpu_affinity(tctx->io_wq, new_mask);
|
|
free_cpumask_var(new_mask);
|
|
return ret;
|
|
}
|
|
|
|
static __cold int io_unregister_iowq_aff(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (!tctx || !tctx->io_wq)
|
|
return -EINVAL;
|
|
|
|
return io_wq_cpu_affinity(tctx->io_wq, NULL);
|
|
}
|
|
|
|
static __cold int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
|
|
void __user *arg)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_tctx_node *node;
|
|
struct io_uring_task *tctx = NULL;
|
|
struct io_sq_data *sqd = NULL;
|
|
__u32 new_count[2];
|
|
int i, ret;
|
|
|
|
if (copy_from_user(new_count, arg, sizeof(new_count)))
|
|
return -EFAULT;
|
|
for (i = 0; i < ARRAY_SIZE(new_count); i++)
|
|
if (new_count[i] > INT_MAX)
|
|
return -EINVAL;
|
|
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
sqd = ctx->sq_data;
|
|
if (sqd) {
|
|
/*
|
|
* Observe the correct sqd->lock -> ctx->uring_lock
|
|
* ordering. Fine to drop uring_lock here, we hold
|
|
* a ref to the ctx.
|
|
*/
|
|
refcount_inc(&sqd->refs);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
mutex_lock(&sqd->lock);
|
|
mutex_lock(&ctx->uring_lock);
|
|
if (sqd->thread)
|
|
tctx = sqd->thread->io_uring;
|
|
}
|
|
} else {
|
|
tctx = current->io_uring;
|
|
}
|
|
|
|
BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits));
|
|
|
|
for (i = 0; i < ARRAY_SIZE(new_count); i++)
|
|
if (new_count[i])
|
|
ctx->iowq_limits[i] = new_count[i];
|
|
ctx->iowq_limits_set = true;
|
|
|
|
if (tctx && tctx->io_wq) {
|
|
ret = io_wq_max_workers(tctx->io_wq, new_count);
|
|
if (ret)
|
|
goto err;
|
|
} else {
|
|
memset(new_count, 0, sizeof(new_count));
|
|
}
|
|
|
|
if (sqd) {
|
|
mutex_unlock(&sqd->lock);
|
|
io_put_sq_data(sqd);
|
|
}
|
|
|
|
if (copy_to_user(arg, new_count, sizeof(new_count)))
|
|
return -EFAULT;
|
|
|
|
/* that's it for SQPOLL, only the SQPOLL task creates requests */
|
|
if (sqd)
|
|
return 0;
|
|
|
|
/* now propagate the restriction to all registered users */
|
|
list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
|
|
struct io_uring_task *tctx = node->task->io_uring;
|
|
|
|
if (WARN_ON_ONCE(!tctx->io_wq))
|
|
continue;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(new_count); i++)
|
|
new_count[i] = ctx->iowq_limits[i];
|
|
/* ignore errors, it always returns zero anyway */
|
|
(void)io_wq_max_workers(tctx->io_wq, new_count);
|
|
}
|
|
return 0;
|
|
err:
|
|
if (sqd) {
|
|
mutex_unlock(&sqd->lock);
|
|
io_put_sq_data(sqd);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
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 don't quiesce the refs for register anymore and so it can't be
|
|
* dying as we're holding a file ref here.
|
|
*/
|
|
if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx->refs)))
|
|
return -ENXIO;
|
|
|
|
if (ctx->restricted) {
|
|
if (opcode >= IORING_REGISTER_LAST)
|
|
return -EINVAL;
|
|
opcode = array_index_nospec(opcode, IORING_REGISTER_LAST);
|
|
if (!test_bit(opcode, ctx->restrictions.register_op))
|
|
return -EACCES;
|
|
}
|
|
|
|
switch (opcode) {
|
|
case IORING_REGISTER_BUFFERS:
|
|
ret = -EFAULT;
|
|
if (!arg)
|
|
break;
|
|
ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL);
|
|
break;
|
|
case IORING_UNREGISTER_BUFFERS:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_sqe_buffers_unregister(ctx);
|
|
break;
|
|
case IORING_REGISTER_FILES:
|
|
ret = -EFAULT;
|
|
if (!arg)
|
|
break;
|
|
ret = io_sqe_files_register(ctx, arg, nr_args, NULL);
|
|
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_register_files_update(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_REGISTER_EVENTFD:
|
|
ret = -EINVAL;
|
|
if (nr_args != 1)
|
|
break;
|
|
ret = io_eventfd_register(ctx, arg, 0);
|
|
break;
|
|
case IORING_REGISTER_EVENTFD_ASYNC:
|
|
ret = -EINVAL;
|
|
if (nr_args != 1)
|
|
break;
|
|
ret = io_eventfd_register(ctx, arg, 1);
|
|
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;
|
|
case IORING_REGISTER_FILES2:
|
|
ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE);
|
|
break;
|
|
case IORING_REGISTER_FILES_UPDATE2:
|
|
ret = io_register_rsrc_update(ctx, arg, nr_args,
|
|
IORING_RSRC_FILE);
|
|
break;
|
|
case IORING_REGISTER_BUFFERS2:
|
|
ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER);
|
|
break;
|
|
case IORING_REGISTER_BUFFERS_UPDATE:
|
|
ret = io_register_rsrc_update(ctx, arg, nr_args,
|
|
IORING_RSRC_BUFFER);
|
|
break;
|
|
case IORING_REGISTER_IOWQ_AFF:
|
|
ret = -EINVAL;
|
|
if (!arg || !nr_args)
|
|
break;
|
|
ret = io_register_iowq_aff(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_UNREGISTER_IOWQ_AFF:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_unregister_iowq_aff(ctx);
|
|
break;
|
|
case IORING_REGISTER_IOWQ_MAX_WORKERS:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args != 2)
|
|
break;
|
|
ret = io_register_iowq_max_workers(ctx, arg);
|
|
break;
|
|
case IORING_REGISTER_RING_FDS:
|
|
ret = io_ringfd_register(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_UNREGISTER_RING_FDS:
|
|
ret = io_ringfd_unregister(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_REGISTER_PBUF_RING:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args != 1)
|
|
break;
|
|
ret = io_register_pbuf_ring(ctx, arg);
|
|
break;
|
|
case IORING_UNREGISTER_PBUF_RING:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args != 1)
|
|
break;
|
|
ret = io_unregister_pbuf_ring(ctx, arg);
|
|
break;
|
|
case IORING_REGISTER_SYNC_CANCEL:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args != 1)
|
|
break;
|
|
ret = io_sync_cancel(ctx, arg);
|
|
break;
|
|
case IORING_REGISTER_FILE_ALLOC_RANGE:
|
|
ret = -EINVAL;
|
|
if (!arg || nr_args)
|
|
break;
|
|
ret = io_register_file_alloc_range(ctx, arg);
|
|
break;
|
|
case IORING_REGISTER_NOTIFIERS:
|
|
ret = io_notif_register(ctx, arg, nr_args);
|
|
break;
|
|
case IORING_UNREGISTER_NOTIFIERS:
|
|
ret = -EINVAL;
|
|
if (arg || nr_args)
|
|
break;
|
|
ret = io_notif_unregister(ctx);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
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 (!io_is_uring_fops(f.file))
|
|
goto out_fput;
|
|
|
|
ctx = f.file->private_data;
|
|
|
|
io_run_task_work();
|
|
|
|
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, ret);
|
|
out_fput:
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
static int __init io_uring_init(void)
|
|
{
|
|
#define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \
|
|
BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
|
|
BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \
|
|
} while (0)
|
|
|
|
#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
|
|
__BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, sizeof(etype), ename)
|
|
#define BUILD_BUG_SQE_ELEM_SIZE(eoffset, esize, ename) \
|
|
__BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, esize, 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(8, __u32, cmd_op);
|
|
BUILD_BUG_SQE_ELEM(12, __u32, __pad1);
|
|
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(28, __u32, rename_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, unlink_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, hardlink_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, xattr_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, msg_ring_flags);
|
|
BUILD_BUG_SQE_ELEM(32, __u64, user_data);
|
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
|
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_group);
|
|
BUILD_BUG_SQE_ELEM(42, __u16, personality);
|
|
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
|
|
BUILD_BUG_SQE_ELEM(44, __u32, file_index);
|
|
BUILD_BUG_SQE_ELEM(44, __u16, notification_idx);
|
|
BUILD_BUG_SQE_ELEM(46, __u16, addr_len);
|
|
BUILD_BUG_SQE_ELEM(48, __u64, addr3);
|
|
BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd);
|
|
BUILD_BUG_SQE_ELEM(56, __u64, __pad2);
|
|
|
|
BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
|
|
sizeof(struct io_uring_rsrc_update));
|
|
BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
|
|
sizeof(struct io_uring_rsrc_update2));
|
|
|
|
/* ->buf_index is u16 */
|
|
BUILD_BUG_ON(offsetof(struct io_uring_buf_ring, bufs) != 0);
|
|
BUILD_BUG_ON(offsetof(struct io_uring_buf, resv) !=
|
|
offsetof(struct io_uring_buf_ring, tail));
|
|
|
|
/* should fit into one byte */
|
|
BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
|
|
BUILD_BUG_ON(SQE_COMMON_FLAGS >= (1 << 8));
|
|
BUILD_BUG_ON((SQE_VALID_FLAGS | SQE_COMMON_FLAGS) != SQE_VALID_FLAGS);
|
|
|
|
BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));
|
|
|
|
BUILD_BUG_ON(sizeof(atomic_t) != sizeof(u32));
|
|
|
|
io_uring_optable_init();
|
|
|
|
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
|
|
SLAB_ACCOUNT);
|
|
return 0;
|
|
};
|
|
__initcall(io_uring_init);
|