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![Kirill Smelkov](/assets/img/avatar_default.png)
A FUSE filesystem server queues /dev/fuse sys_read calls to get filesystem requests to handle. It does not know in advance what would be that request as it can be anything that client issues - LOOKUP, READ, WRITE, ... Many requests are short and retrieve data from the filesystem. However WRITE and NOTIFY_REPLY write data into filesystem. Before getting into operation phase, FUSE filesystem server and kernel client negotiate what should be the maximum write size the client will ever issue. After negotiation the contract in between server/client is that the filesystem server then should queue /dev/fuse sys_read calls with enough buffer capacity to receive any client request - WRITE in particular, while FUSE client should not, in particular, send WRITE requests with > negotiated max_write payload. FUSE client in kernel and libfuse historically reserve 4K for request header. This way the contract is that filesystem server should queue sys_reads with 4K+max_write buffer. If the filesystem server does not follow this contract, what can happen is that fuse_dev_do_read will see that request size is > buffer size, and then it will return EIO to client who issued the request but won't indicate in any way that there is a problem to filesystem server. This can be hard to diagnose because for some requests, e.g. for NOTIFY_REPLY which mimics WRITE, there is no client thread that is waiting for request completion and that EIO goes nowhere, while on filesystem server side things look like the kernel is not replying back after successful NOTIFY_RETRIEVE request made by the server. We can make the problem easy to diagnose if we indicate via error return to filesystem server when it is violating the contract. This should not practically cause problems because if a filesystem server is using shorter buffer, writes to it were already very likely to cause EIO, and if the filesystem is read-only it should be too following FUSE_MIN_READ_BUFFER minimum buffer size. Please see [1] for context where the problem of stuck filesystem was hit for real (because kernel client was incorrectly sending more than max_write data with NOTIFY_REPLY; see also previous patch), how the situation was traced and for more involving patch that did not make it into the tree. [1] https://marc.info/?l=linux-fsdevel&m=155057023600853&w=2 Signed-off-by: Kirill Smelkov <kirr@nexedi.com> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Jakob Unterwurzacher <jakobunt@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2402 lines
55 KiB
C
2402 lines
55 KiB
C
/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU GPL.
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See the file COPYING.
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*/
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#include "fuse_i.h"
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/poll.h>
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#include <linux/sched/signal.h>
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#include <linux/uio.h>
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#include <linux/miscdevice.h>
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#include <linux/pagemap.h>
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#include <linux/file.h>
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#include <linux/slab.h>
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#include <linux/pipe_fs_i.h>
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#include <linux/swap.h>
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#include <linux/splice.h>
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#include <linux/sched.h>
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MODULE_ALIAS_MISCDEV(FUSE_MINOR);
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MODULE_ALIAS("devname:fuse");
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/* Ordinary requests have even IDs, while interrupts IDs are odd */
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#define FUSE_INT_REQ_BIT (1ULL << 0)
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#define FUSE_REQ_ID_STEP (1ULL << 1)
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static struct kmem_cache *fuse_req_cachep;
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static struct fuse_dev *fuse_get_dev(struct file *file)
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{
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/*
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* Lockless access is OK, because file->private data is set
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* once during mount and is valid until the file is released.
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*/
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return READ_ONCE(file->private_data);
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}
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static void fuse_request_init(struct fuse_req *req, struct page **pages,
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struct fuse_page_desc *page_descs,
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unsigned npages)
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{
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INIT_LIST_HEAD(&req->list);
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INIT_LIST_HEAD(&req->intr_entry);
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init_waitqueue_head(&req->waitq);
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refcount_set(&req->count, 1);
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req->pages = pages;
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req->page_descs = page_descs;
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req->max_pages = npages;
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__set_bit(FR_PENDING, &req->flags);
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}
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static struct page **fuse_req_pages_alloc(unsigned int npages, gfp_t flags,
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struct fuse_page_desc **desc)
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{
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struct page **pages;
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pages = kzalloc(npages * (sizeof(struct page *) +
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sizeof(struct fuse_page_desc)), flags);
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*desc = (void *) pages + npages * sizeof(struct page *);
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return pages;
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}
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static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
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{
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struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags);
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if (req) {
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struct page **pages = NULL;
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struct fuse_page_desc *page_descs = NULL;
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WARN_ON(npages > FUSE_MAX_MAX_PAGES);
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if (npages > FUSE_REQ_INLINE_PAGES) {
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pages = fuse_req_pages_alloc(npages, flags,
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&page_descs);
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if (!pages) {
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kmem_cache_free(fuse_req_cachep, req);
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return NULL;
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}
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} else if (npages) {
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pages = req->inline_pages;
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page_descs = req->inline_page_descs;
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}
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fuse_request_init(req, pages, page_descs, npages);
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}
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return req;
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}
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struct fuse_req *fuse_request_alloc(unsigned npages)
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{
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return __fuse_request_alloc(npages, GFP_KERNEL);
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}
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EXPORT_SYMBOL_GPL(fuse_request_alloc);
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struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
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{
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return __fuse_request_alloc(npages, GFP_NOFS);
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}
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static void fuse_req_pages_free(struct fuse_req *req)
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{
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if (req->pages != req->inline_pages)
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kfree(req->pages);
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}
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bool fuse_req_realloc_pages(struct fuse_conn *fc, struct fuse_req *req,
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gfp_t flags)
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{
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struct page **pages;
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struct fuse_page_desc *page_descs;
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unsigned int npages = min_t(unsigned int,
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max_t(unsigned int, req->max_pages * 2,
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FUSE_DEFAULT_MAX_PAGES_PER_REQ),
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fc->max_pages);
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WARN_ON(npages <= req->max_pages);
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pages = fuse_req_pages_alloc(npages, flags, &page_descs);
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if (!pages)
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return false;
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memcpy(pages, req->pages, sizeof(struct page *) * req->max_pages);
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memcpy(page_descs, req->page_descs,
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sizeof(struct fuse_page_desc) * req->max_pages);
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fuse_req_pages_free(req);
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req->pages = pages;
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req->page_descs = page_descs;
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req->max_pages = npages;
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return true;
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}
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void fuse_request_free(struct fuse_req *req)
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{
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fuse_req_pages_free(req);
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kmem_cache_free(fuse_req_cachep, req);
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}
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void __fuse_get_request(struct fuse_req *req)
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{
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refcount_inc(&req->count);
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}
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/* Must be called with > 1 refcount */
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static void __fuse_put_request(struct fuse_req *req)
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{
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refcount_dec(&req->count);
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}
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void fuse_set_initialized(struct fuse_conn *fc)
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{
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/* Make sure stores before this are seen on another CPU */
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smp_wmb();
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fc->initialized = 1;
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}
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static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
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{
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return !fc->initialized || (for_background && fc->blocked);
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}
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static void fuse_drop_waiting(struct fuse_conn *fc)
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{
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/*
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* lockess check of fc->connected is okay, because atomic_dec_and_test()
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* provides a memory barrier mached with the one in fuse_wait_aborted()
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* to ensure no wake-up is missed.
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*/
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if (atomic_dec_and_test(&fc->num_waiting) &&
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!READ_ONCE(fc->connected)) {
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/* wake up aborters */
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wake_up_all(&fc->blocked_waitq);
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}
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}
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static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
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bool for_background)
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{
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struct fuse_req *req;
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int err;
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atomic_inc(&fc->num_waiting);
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if (fuse_block_alloc(fc, for_background)) {
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err = -EINTR;
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if (wait_event_killable_exclusive(fc->blocked_waitq,
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!fuse_block_alloc(fc, for_background)))
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goto out;
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}
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/* Matches smp_wmb() in fuse_set_initialized() */
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smp_rmb();
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err = -ENOTCONN;
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if (!fc->connected)
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goto out;
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err = -ECONNREFUSED;
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if (fc->conn_error)
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goto out;
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req = fuse_request_alloc(npages);
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err = -ENOMEM;
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if (!req) {
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if (for_background)
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wake_up(&fc->blocked_waitq);
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goto out;
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}
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req->in.h.uid = from_kuid(fc->user_ns, current_fsuid());
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req->in.h.gid = from_kgid(fc->user_ns, current_fsgid());
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req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
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__set_bit(FR_WAITING, &req->flags);
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if (for_background)
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__set_bit(FR_BACKGROUND, &req->flags);
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if (unlikely(req->in.h.uid == ((uid_t)-1) ||
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req->in.h.gid == ((gid_t)-1))) {
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fuse_put_request(fc, req);
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return ERR_PTR(-EOVERFLOW);
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}
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return req;
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out:
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fuse_drop_waiting(fc);
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return ERR_PTR(err);
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}
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struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
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{
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return __fuse_get_req(fc, npages, false);
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}
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EXPORT_SYMBOL_GPL(fuse_get_req);
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struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
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unsigned npages)
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{
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return __fuse_get_req(fc, npages, true);
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}
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EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
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/*
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* Return request in fuse_file->reserved_req. However that may
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* currently be in use. If that is the case, wait for it to become
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* available.
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*/
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static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
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struct file *file)
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{
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struct fuse_req *req = NULL;
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struct fuse_inode *fi = get_fuse_inode(file_inode(file));
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struct fuse_file *ff = file->private_data;
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do {
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wait_event(fc->reserved_req_waitq, ff->reserved_req);
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spin_lock(&fi->lock);
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if (ff->reserved_req) {
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req = ff->reserved_req;
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ff->reserved_req = NULL;
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req->stolen_file = get_file(file);
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}
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spin_unlock(&fi->lock);
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} while (!req);
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return req;
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}
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/*
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* Put stolen request back into fuse_file->reserved_req
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*/
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static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct file *file = req->stolen_file;
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struct fuse_inode *fi = get_fuse_inode(file_inode(file));
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struct fuse_file *ff = file->private_data;
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WARN_ON(req->max_pages);
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spin_lock(&fi->lock);
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memset(req, 0, sizeof(*req));
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fuse_request_init(req, NULL, NULL, 0);
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BUG_ON(ff->reserved_req);
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ff->reserved_req = req;
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wake_up_all(&fc->reserved_req_waitq);
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spin_unlock(&fi->lock);
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fput(file);
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}
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/*
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* Gets a requests for a file operation, always succeeds
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*
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* This is used for sending the FLUSH request, which must get to
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* userspace, due to POSIX locks which may need to be unlocked.
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*
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* If allocation fails due to OOM, use the reserved request in
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* fuse_file.
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*
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* This is very unlikely to deadlock accidentally, since the
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* filesystem should not have it's own file open. If deadlock is
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* intentional, it can still be broken by "aborting" the filesystem.
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*/
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struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
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struct file *file)
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{
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struct fuse_req *req;
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atomic_inc(&fc->num_waiting);
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wait_event(fc->blocked_waitq, fc->initialized);
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/* Matches smp_wmb() in fuse_set_initialized() */
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smp_rmb();
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req = fuse_request_alloc(0);
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if (!req)
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req = get_reserved_req(fc, file);
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req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());
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req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());
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req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
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__set_bit(FR_WAITING, &req->flags);
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__clear_bit(FR_BACKGROUND, &req->flags);
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return req;
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}
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void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
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{
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if (refcount_dec_and_test(&req->count)) {
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if (test_bit(FR_BACKGROUND, &req->flags)) {
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/*
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* We get here in the unlikely case that a background
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* request was allocated but not sent
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*/
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spin_lock(&fc->bg_lock);
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if (!fc->blocked)
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wake_up(&fc->blocked_waitq);
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spin_unlock(&fc->bg_lock);
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}
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if (test_bit(FR_WAITING, &req->flags)) {
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__clear_bit(FR_WAITING, &req->flags);
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fuse_drop_waiting(fc);
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}
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if (req->stolen_file)
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put_reserved_req(fc, req);
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else
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fuse_request_free(req);
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}
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}
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EXPORT_SYMBOL_GPL(fuse_put_request);
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static unsigned len_args(unsigned numargs, struct fuse_arg *args)
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{
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unsigned nbytes = 0;
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unsigned i;
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for (i = 0; i < numargs; i++)
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nbytes += args[i].size;
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return nbytes;
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}
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static u64 fuse_get_unique(struct fuse_iqueue *fiq)
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{
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fiq->reqctr += FUSE_REQ_ID_STEP;
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return fiq->reqctr;
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}
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static unsigned int fuse_req_hash(u64 unique)
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{
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return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS);
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}
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static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
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{
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req->in.h.len = sizeof(struct fuse_in_header) +
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len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
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list_add_tail(&req->list, &fiq->pending);
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wake_up_locked(&fiq->waitq);
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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}
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void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
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u64 nodeid, u64 nlookup)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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forget->forget_one.nodeid = nodeid;
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forget->forget_one.nlookup = nlookup;
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spin_lock(&fiq->waitq.lock);
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if (fiq->connected) {
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fiq->forget_list_tail->next = forget;
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fiq->forget_list_tail = forget;
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wake_up_locked(&fiq->waitq);
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kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
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} else {
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kfree(forget);
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}
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spin_unlock(&fiq->waitq.lock);
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}
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static void flush_bg_queue(struct fuse_conn *fc)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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while (fc->active_background < fc->max_background &&
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!list_empty(&fc->bg_queue)) {
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struct fuse_req *req;
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req = list_first_entry(&fc->bg_queue, struct fuse_req, list);
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list_del(&req->list);
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fc->active_background++;
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spin_lock(&fiq->waitq.lock);
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req->in.h.unique = fuse_get_unique(fiq);
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queue_request(fiq, req);
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spin_unlock(&fiq->waitq.lock);
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}
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}
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/*
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* This function is called when a request is finished. Either a reply
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* has arrived or it was aborted (and not yet sent) or some error
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* occurred during communication with userspace, or the device file
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* was closed. The requester thread is woken up (if still waiting),
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* the 'end' callback is called if given, else the reference to the
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* request is released
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*/
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static void request_end(struct fuse_conn *fc, struct fuse_req *req)
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{
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struct fuse_iqueue *fiq = &fc->iq;
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if (test_and_set_bit(FR_FINISHED, &req->flags))
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goto put_request;
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/*
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* test_and_set_bit() implies smp_mb() between bit
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* changing and below intr_entry check. Pairs with
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* smp_mb() from queue_interrupt().
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*/
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if (!list_empty(&req->intr_entry)) {
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spin_lock(&fiq->waitq.lock);
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list_del_init(&req->intr_entry);
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spin_unlock(&fiq->waitq.lock);
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}
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WARN_ON(test_bit(FR_PENDING, &req->flags));
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WARN_ON(test_bit(FR_SENT, &req->flags));
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if (test_bit(FR_BACKGROUND, &req->flags)) {
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spin_lock(&fc->bg_lock);
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clear_bit(FR_BACKGROUND, &req->flags);
|
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if (fc->num_background == fc->max_background) {
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fc->blocked = 0;
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wake_up(&fc->blocked_waitq);
|
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} else if (!fc->blocked) {
|
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/*
|
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* Wake up next waiter, if any. It's okay to use
|
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* waitqueue_active(), as we've already synced up
|
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* fc->blocked with waiters with the wake_up() call
|
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* above.
|
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*/
|
|
if (waitqueue_active(&fc->blocked_waitq))
|
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wake_up(&fc->blocked_waitq);
|
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}
|
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|
|
if (fc->num_background == fc->congestion_threshold && fc->sb) {
|
|
clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
|
|
clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
|
|
}
|
|
fc->num_background--;
|
|
fc->active_background--;
|
|
flush_bg_queue(fc);
|
|
spin_unlock(&fc->bg_lock);
|
|
} else {
|
|
/* Wake up waiter sleeping in request_wait_answer() */
|
|
wake_up(&req->waitq);
|
|
}
|
|
|
|
if (req->end)
|
|
req->end(fc, req);
|
|
put_request:
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
static int queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
|
|
{
|
|
spin_lock(&fiq->waitq.lock);
|
|
/* Check for we've sent request to interrupt this req */
|
|
if (unlikely(!test_bit(FR_INTERRUPTED, &req->flags))) {
|
|
spin_unlock(&fiq->waitq.lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (list_empty(&req->intr_entry)) {
|
|
list_add_tail(&req->intr_entry, &fiq->interrupts);
|
|
/*
|
|
* Pairs with smp_mb() implied by test_and_set_bit()
|
|
* from request_end().
|
|
*/
|
|
smp_mb();
|
|
if (test_bit(FR_FINISHED, &req->flags)) {
|
|
list_del_init(&req->intr_entry);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
return 0;
|
|
}
|
|
wake_up_locked(&fiq->waitq);
|
|
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
|
|
}
|
|
spin_unlock(&fiq->waitq.lock);
|
|
return 0;
|
|
}
|
|
|
|
static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
int err;
|
|
|
|
if (!fc->no_interrupt) {
|
|
/* Any signal may interrupt this */
|
|
err = wait_event_interruptible(req->waitq,
|
|
test_bit(FR_FINISHED, &req->flags));
|
|
if (!err)
|
|
return;
|
|
|
|
set_bit(FR_INTERRUPTED, &req->flags);
|
|
/* matches barrier in fuse_dev_do_read() */
|
|
smp_mb__after_atomic();
|
|
if (test_bit(FR_SENT, &req->flags))
|
|
queue_interrupt(fiq, req);
|
|
}
|
|
|
|
if (!test_bit(FR_FORCE, &req->flags)) {
|
|
/* Only fatal signals may interrupt this */
|
|
err = wait_event_killable(req->waitq,
|
|
test_bit(FR_FINISHED, &req->flags));
|
|
if (!err)
|
|
return;
|
|
|
|
spin_lock(&fiq->waitq.lock);
|
|
/* Request is not yet in userspace, bail out */
|
|
if (test_bit(FR_PENDING, &req->flags)) {
|
|
list_del(&req->list);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
__fuse_put_request(req);
|
|
req->out.h.error = -EINTR;
|
|
return;
|
|
}
|
|
spin_unlock(&fiq->waitq.lock);
|
|
}
|
|
|
|
/*
|
|
* Either request is already in userspace, or it was forced.
|
|
* Wait it out.
|
|
*/
|
|
wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
|
|
}
|
|
|
|
static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
|
|
BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
|
|
spin_lock(&fiq->waitq.lock);
|
|
if (!fiq->connected) {
|
|
spin_unlock(&fiq->waitq.lock);
|
|
req->out.h.error = -ENOTCONN;
|
|
} else {
|
|
req->in.h.unique = fuse_get_unique(fiq);
|
|
queue_request(fiq, req);
|
|
/* acquire extra reference, since request is still needed
|
|
after request_end() */
|
|
__fuse_get_request(req);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
|
|
request_wait_answer(fc, req);
|
|
/* Pairs with smp_wmb() in request_end() */
|
|
smp_rmb();
|
|
}
|
|
}
|
|
|
|
void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
__set_bit(FR_ISREPLY, &req->flags);
|
|
if (!test_bit(FR_WAITING, &req->flags)) {
|
|
__set_bit(FR_WAITING, &req->flags);
|
|
atomic_inc(&fc->num_waiting);
|
|
}
|
|
__fuse_request_send(fc, req);
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_request_send);
|
|
|
|
static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
|
|
{
|
|
if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
|
|
args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
|
|
|
|
if (fc->minor < 9) {
|
|
switch (args->in.h.opcode) {
|
|
case FUSE_LOOKUP:
|
|
case FUSE_CREATE:
|
|
case FUSE_MKNOD:
|
|
case FUSE_MKDIR:
|
|
case FUSE_SYMLINK:
|
|
case FUSE_LINK:
|
|
args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
|
|
break;
|
|
case FUSE_GETATTR:
|
|
case FUSE_SETATTR:
|
|
args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
|
|
break;
|
|
}
|
|
}
|
|
if (fc->minor < 12) {
|
|
switch (args->in.h.opcode) {
|
|
case FUSE_CREATE:
|
|
args->in.args[0].size = sizeof(struct fuse_open_in);
|
|
break;
|
|
case FUSE_MKNOD:
|
|
args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
|
|
{
|
|
struct fuse_req *req;
|
|
ssize_t ret;
|
|
|
|
req = fuse_get_req(fc, 0);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
/* Needs to be done after fuse_get_req() so that fc->minor is valid */
|
|
fuse_adjust_compat(fc, args);
|
|
|
|
req->in.h.opcode = args->in.h.opcode;
|
|
req->in.h.nodeid = args->in.h.nodeid;
|
|
req->in.numargs = args->in.numargs;
|
|
memcpy(req->in.args, args->in.args,
|
|
args->in.numargs * sizeof(struct fuse_in_arg));
|
|
req->out.argvar = args->out.argvar;
|
|
req->out.numargs = args->out.numargs;
|
|
memcpy(req->out.args, args->out.args,
|
|
args->out.numargs * sizeof(struct fuse_arg));
|
|
fuse_request_send(fc, req);
|
|
ret = req->out.h.error;
|
|
if (!ret && args->out.argvar) {
|
|
BUG_ON(args->out.numargs != 1);
|
|
ret = req->out.args[0].size;
|
|
}
|
|
fuse_put_request(fc, req);
|
|
|
|
return ret;
|
|
}
|
|
|
|
bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
bool queued = false;
|
|
|
|
WARN_ON(!test_bit(FR_BACKGROUND, &req->flags));
|
|
if (!test_bit(FR_WAITING, &req->flags)) {
|
|
__set_bit(FR_WAITING, &req->flags);
|
|
atomic_inc(&fc->num_waiting);
|
|
}
|
|
__set_bit(FR_ISREPLY, &req->flags);
|
|
spin_lock(&fc->bg_lock);
|
|
if (likely(fc->connected)) {
|
|
fc->num_background++;
|
|
if (fc->num_background == fc->max_background)
|
|
fc->blocked = 1;
|
|
if (fc->num_background == fc->congestion_threshold && fc->sb) {
|
|
set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
|
|
set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
|
|
}
|
|
list_add_tail(&req->list, &fc->bg_queue);
|
|
flush_bg_queue(fc);
|
|
queued = true;
|
|
}
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
return queued;
|
|
}
|
|
|
|
void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
WARN_ON(!req->end);
|
|
if (!fuse_request_queue_background(fc, req)) {
|
|
req->out.h.error = -ENOTCONN;
|
|
req->end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_request_send_background);
|
|
|
|
static int fuse_request_send_notify_reply(struct fuse_conn *fc,
|
|
struct fuse_req *req, u64 unique)
|
|
{
|
|
int err = -ENODEV;
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
|
|
__clear_bit(FR_ISREPLY, &req->flags);
|
|
req->in.h.unique = unique;
|
|
spin_lock(&fiq->waitq.lock);
|
|
if (fiq->connected) {
|
|
queue_request(fiq, req);
|
|
err = 0;
|
|
}
|
|
spin_unlock(&fiq->waitq.lock);
|
|
|
|
return err;
|
|
}
|
|
|
|
void fuse_force_forget(struct file *file, u64 nodeid)
|
|
{
|
|
struct inode *inode = file_inode(file);
|
|
struct fuse_conn *fc = get_fuse_conn(inode);
|
|
struct fuse_req *req;
|
|
struct fuse_forget_in inarg;
|
|
|
|
memset(&inarg, 0, sizeof(inarg));
|
|
inarg.nlookup = 1;
|
|
req = fuse_get_req_nofail_nopages(fc, file);
|
|
req->in.h.opcode = FUSE_FORGET;
|
|
req->in.h.nodeid = nodeid;
|
|
req->in.numargs = 1;
|
|
req->in.args[0].size = sizeof(inarg);
|
|
req->in.args[0].value = &inarg;
|
|
__clear_bit(FR_ISREPLY, &req->flags);
|
|
__fuse_request_send(fc, req);
|
|
/* ignore errors */
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
/*
|
|
* Lock the request. Up to the next unlock_request() there mustn't be
|
|
* anything that could cause a page-fault. If the request was already
|
|
* aborted bail out.
|
|
*/
|
|
static int lock_request(struct fuse_req *req)
|
|
{
|
|
int err = 0;
|
|
if (req) {
|
|
spin_lock(&req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
set_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Unlock request. If it was aborted while locked, caller is responsible
|
|
* for unlocking and ending the request.
|
|
*/
|
|
static int unlock_request(struct fuse_req *req)
|
|
{
|
|
int err = 0;
|
|
if (req) {
|
|
spin_lock(&req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
struct fuse_copy_state {
|
|
int write;
|
|
struct fuse_req *req;
|
|
struct iov_iter *iter;
|
|
struct pipe_buffer *pipebufs;
|
|
struct pipe_buffer *currbuf;
|
|
struct pipe_inode_info *pipe;
|
|
unsigned long nr_segs;
|
|
struct page *pg;
|
|
unsigned len;
|
|
unsigned offset;
|
|
unsigned move_pages:1;
|
|
};
|
|
|
|
static void fuse_copy_init(struct fuse_copy_state *cs, int write,
|
|
struct iov_iter *iter)
|
|
{
|
|
memset(cs, 0, sizeof(*cs));
|
|
cs->write = write;
|
|
cs->iter = iter;
|
|
}
|
|
|
|
/* Unmap and put previous page of userspace buffer */
|
|
static void fuse_copy_finish(struct fuse_copy_state *cs)
|
|
{
|
|
if (cs->currbuf) {
|
|
struct pipe_buffer *buf = cs->currbuf;
|
|
|
|
if (cs->write)
|
|
buf->len = PAGE_SIZE - cs->len;
|
|
cs->currbuf = NULL;
|
|
} else if (cs->pg) {
|
|
if (cs->write) {
|
|
flush_dcache_page(cs->pg);
|
|
set_page_dirty_lock(cs->pg);
|
|
}
|
|
put_page(cs->pg);
|
|
}
|
|
cs->pg = NULL;
|
|
}
|
|
|
|
/*
|
|
* Get another pagefull of userspace buffer, and map it to kernel
|
|
* address space, and lock request
|
|
*/
|
|
static int fuse_copy_fill(struct fuse_copy_state *cs)
|
|
{
|
|
struct page *page;
|
|
int err;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
if (cs->pipebufs) {
|
|
struct pipe_buffer *buf = cs->pipebufs;
|
|
|
|
if (!cs->write) {
|
|
err = pipe_buf_confirm(cs->pipe, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->currbuf = buf;
|
|
cs->pg = buf->page;
|
|
cs->offset = buf->offset;
|
|
cs->len = buf->len;
|
|
cs->pipebufs++;
|
|
cs->nr_segs--;
|
|
} else {
|
|
if (cs->nr_segs == cs->pipe->buffers)
|
|
return -EIO;
|
|
|
|
page = alloc_page(GFP_HIGHUSER);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
|
|
buf->page = page;
|
|
buf->offset = 0;
|
|
buf->len = 0;
|
|
|
|
cs->currbuf = buf;
|
|
cs->pg = page;
|
|
cs->offset = 0;
|
|
cs->len = PAGE_SIZE;
|
|
cs->pipebufs++;
|
|
cs->nr_segs++;
|
|
}
|
|
} else {
|
|
size_t off;
|
|
err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
|
|
if (err < 0)
|
|
return err;
|
|
BUG_ON(!err);
|
|
cs->len = err;
|
|
cs->offset = off;
|
|
cs->pg = page;
|
|
iov_iter_advance(cs->iter, err);
|
|
}
|
|
|
|
return lock_request(cs->req);
|
|
}
|
|
|
|
/* Do as much copy to/from userspace buffer as we can */
|
|
static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
|
|
{
|
|
unsigned ncpy = min(*size, cs->len);
|
|
if (val) {
|
|
void *pgaddr = kmap_atomic(cs->pg);
|
|
void *buf = pgaddr + cs->offset;
|
|
|
|
if (cs->write)
|
|
memcpy(buf, *val, ncpy);
|
|
else
|
|
memcpy(*val, buf, ncpy);
|
|
|
|
kunmap_atomic(pgaddr);
|
|
*val += ncpy;
|
|
}
|
|
*size -= ncpy;
|
|
cs->len -= ncpy;
|
|
cs->offset += ncpy;
|
|
return ncpy;
|
|
}
|
|
|
|
static int fuse_check_page(struct page *page)
|
|
{
|
|
if (page_mapcount(page) ||
|
|
page->mapping != NULL ||
|
|
page_count(page) != 1 ||
|
|
(page->flags & PAGE_FLAGS_CHECK_AT_PREP &
|
|
~(1 << PG_locked |
|
|
1 << PG_referenced |
|
|
1 << PG_uptodate |
|
|
1 << PG_lru |
|
|
1 << PG_active |
|
|
1 << PG_reclaim))) {
|
|
pr_warn("trying to steal weird page\n");
|
|
pr_warn(" page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
|
|
{
|
|
int err;
|
|
struct page *oldpage = *pagep;
|
|
struct page *newpage;
|
|
struct pipe_buffer *buf = cs->pipebufs;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
err = pipe_buf_confirm(cs->pipe, buf);
|
|
if (err)
|
|
return err;
|
|
|
|
BUG_ON(!cs->nr_segs);
|
|
cs->currbuf = buf;
|
|
cs->len = buf->len;
|
|
cs->pipebufs++;
|
|
cs->nr_segs--;
|
|
|
|
if (cs->len != PAGE_SIZE)
|
|
goto out_fallback;
|
|
|
|
if (pipe_buf_steal(cs->pipe, buf) != 0)
|
|
goto out_fallback;
|
|
|
|
newpage = buf->page;
|
|
|
|
if (!PageUptodate(newpage))
|
|
SetPageUptodate(newpage);
|
|
|
|
ClearPageMappedToDisk(newpage);
|
|
|
|
if (fuse_check_page(newpage) != 0)
|
|
goto out_fallback_unlock;
|
|
|
|
/*
|
|
* This is a new and locked page, it shouldn't be mapped or
|
|
* have any special flags on it
|
|
*/
|
|
if (WARN_ON(page_mapped(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(page_has_private(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
|
|
goto out_fallback_unlock;
|
|
if (WARN_ON(PageMlocked(oldpage)))
|
|
goto out_fallback_unlock;
|
|
|
|
err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
|
|
if (err) {
|
|
unlock_page(newpage);
|
|
return err;
|
|
}
|
|
|
|
get_page(newpage);
|
|
|
|
if (!(buf->flags & PIPE_BUF_FLAG_LRU))
|
|
lru_cache_add_file(newpage);
|
|
|
|
err = 0;
|
|
spin_lock(&cs->req->waitq.lock);
|
|
if (test_bit(FR_ABORTED, &cs->req->flags))
|
|
err = -ENOENT;
|
|
else
|
|
*pagep = newpage;
|
|
spin_unlock(&cs->req->waitq.lock);
|
|
|
|
if (err) {
|
|
unlock_page(newpage);
|
|
put_page(newpage);
|
|
return err;
|
|
}
|
|
|
|
unlock_page(oldpage);
|
|
put_page(oldpage);
|
|
cs->len = 0;
|
|
|
|
return 0;
|
|
|
|
out_fallback_unlock:
|
|
unlock_page(newpage);
|
|
out_fallback:
|
|
cs->pg = buf->page;
|
|
cs->offset = buf->offset;
|
|
|
|
err = lock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
|
|
unsigned offset, unsigned count)
|
|
{
|
|
struct pipe_buffer *buf;
|
|
int err;
|
|
|
|
if (cs->nr_segs == cs->pipe->buffers)
|
|
return -EIO;
|
|
|
|
err = unlock_request(cs->req);
|
|
if (err)
|
|
return err;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
buf = cs->pipebufs;
|
|
get_page(page);
|
|
buf->page = page;
|
|
buf->offset = offset;
|
|
buf->len = count;
|
|
|
|
cs->pipebufs++;
|
|
cs->nr_segs++;
|
|
cs->len = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy a page in the request to/from the userspace buffer. Must be
|
|
* done atomically
|
|
*/
|
|
static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
|
|
unsigned offset, unsigned count, int zeroing)
|
|
{
|
|
int err;
|
|
struct page *page = *pagep;
|
|
|
|
if (page && zeroing && count < PAGE_SIZE)
|
|
clear_highpage(page);
|
|
|
|
while (count) {
|
|
if (cs->write && cs->pipebufs && page) {
|
|
return fuse_ref_page(cs, page, offset, count);
|
|
} else if (!cs->len) {
|
|
if (cs->move_pages && page &&
|
|
offset == 0 && count == PAGE_SIZE) {
|
|
err = fuse_try_move_page(cs, pagep);
|
|
if (err <= 0)
|
|
return err;
|
|
} else {
|
|
err = fuse_copy_fill(cs);
|
|
if (err)
|
|
return err;
|
|
}
|
|
}
|
|
if (page) {
|
|
void *mapaddr = kmap_atomic(page);
|
|
void *buf = mapaddr + offset;
|
|
offset += fuse_copy_do(cs, &buf, &count);
|
|
kunmap_atomic(mapaddr);
|
|
} else
|
|
offset += fuse_copy_do(cs, NULL, &count);
|
|
}
|
|
if (page && !cs->write)
|
|
flush_dcache_page(page);
|
|
return 0;
|
|
}
|
|
|
|
/* Copy pages in the request to/from userspace buffer */
|
|
static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
|
|
int zeroing)
|
|
{
|
|
unsigned i;
|
|
struct fuse_req *req = cs->req;
|
|
|
|
for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
|
|
int err;
|
|
unsigned offset = req->page_descs[i].offset;
|
|
unsigned count = min(nbytes, req->page_descs[i].length);
|
|
|
|
err = fuse_copy_page(cs, &req->pages[i], offset, count,
|
|
zeroing);
|
|
if (err)
|
|
return err;
|
|
|
|
nbytes -= count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy a single argument in the request to/from userspace buffer */
|
|
static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
|
|
{
|
|
while (size) {
|
|
if (!cs->len) {
|
|
int err = fuse_copy_fill(cs);
|
|
if (err)
|
|
return err;
|
|
}
|
|
fuse_copy_do(cs, &val, &size);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Copy request arguments to/from userspace buffer */
|
|
static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
|
|
unsigned argpages, struct fuse_arg *args,
|
|
int zeroing)
|
|
{
|
|
int err = 0;
|
|
unsigned i;
|
|
|
|
for (i = 0; !err && i < numargs; i++) {
|
|
struct fuse_arg *arg = &args[i];
|
|
if (i == numargs - 1 && argpages)
|
|
err = fuse_copy_pages(cs, arg->size, zeroing);
|
|
else
|
|
err = fuse_copy_one(cs, arg->value, arg->size);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int forget_pending(struct fuse_iqueue *fiq)
|
|
{
|
|
return fiq->forget_list_head.next != NULL;
|
|
}
|
|
|
|
static int request_pending(struct fuse_iqueue *fiq)
|
|
{
|
|
return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
|
|
forget_pending(fiq);
|
|
}
|
|
|
|
/*
|
|
* Transfer an interrupt request to userspace
|
|
*
|
|
* Unlike other requests this is assembled on demand, without a need
|
|
* to allocate a separate fuse_req structure.
|
|
*
|
|
* Called with fiq->waitq.lock held, releases it
|
|
*/
|
|
static int fuse_read_interrupt(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes, struct fuse_req *req)
|
|
__releases(fiq->waitq.lock)
|
|
{
|
|
struct fuse_in_header ih;
|
|
struct fuse_interrupt_in arg;
|
|
unsigned reqsize = sizeof(ih) + sizeof(arg);
|
|
int err;
|
|
|
|
list_del_init(&req->intr_entry);
|
|
memset(&ih, 0, sizeof(ih));
|
|
memset(&arg, 0, sizeof(arg));
|
|
ih.len = reqsize;
|
|
ih.opcode = FUSE_INTERRUPT;
|
|
ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT);
|
|
arg.unique = req->in.h.unique;
|
|
|
|
spin_unlock(&fiq->waitq.lock);
|
|
if (nbytes < reqsize)
|
|
return -EINVAL;
|
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
fuse_copy_finish(cs);
|
|
|
|
return err ? err : reqsize;
|
|
}
|
|
|
|
static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
|
|
unsigned max,
|
|
unsigned *countp)
|
|
{
|
|
struct fuse_forget_link *head = fiq->forget_list_head.next;
|
|
struct fuse_forget_link **newhead = &head;
|
|
unsigned count;
|
|
|
|
for (count = 0; *newhead != NULL && count < max; count++)
|
|
newhead = &(*newhead)->next;
|
|
|
|
fiq->forget_list_head.next = *newhead;
|
|
*newhead = NULL;
|
|
if (fiq->forget_list_head.next == NULL)
|
|
fiq->forget_list_tail = &fiq->forget_list_head;
|
|
|
|
if (countp != NULL)
|
|
*countp = count;
|
|
|
|
return head;
|
|
}
|
|
|
|
static int fuse_read_single_forget(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes)
|
|
__releases(fiq->waitq.lock)
|
|
{
|
|
int err;
|
|
struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
|
|
struct fuse_forget_in arg = {
|
|
.nlookup = forget->forget_one.nlookup,
|
|
};
|
|
struct fuse_in_header ih = {
|
|
.opcode = FUSE_FORGET,
|
|
.nodeid = forget->forget_one.nodeid,
|
|
.unique = fuse_get_unique(fiq),
|
|
.len = sizeof(ih) + sizeof(arg),
|
|
};
|
|
|
|
spin_unlock(&fiq->waitq.lock);
|
|
kfree(forget);
|
|
if (nbytes < ih.len)
|
|
return -EINVAL;
|
|
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
fuse_copy_finish(cs);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
return ih.len;
|
|
}
|
|
|
|
static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
__releases(fiq->waitq.lock)
|
|
{
|
|
int err;
|
|
unsigned max_forgets;
|
|
unsigned count;
|
|
struct fuse_forget_link *head;
|
|
struct fuse_batch_forget_in arg = { .count = 0 };
|
|
struct fuse_in_header ih = {
|
|
.opcode = FUSE_BATCH_FORGET,
|
|
.unique = fuse_get_unique(fiq),
|
|
.len = sizeof(ih) + sizeof(arg),
|
|
};
|
|
|
|
if (nbytes < ih.len) {
|
|
spin_unlock(&fiq->waitq.lock);
|
|
return -EINVAL;
|
|
}
|
|
|
|
max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
|
|
head = dequeue_forget(fiq, max_forgets, &count);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
|
|
arg.count = count;
|
|
ih.len += count * sizeof(struct fuse_forget_one);
|
|
err = fuse_copy_one(cs, &ih, sizeof(ih));
|
|
if (!err)
|
|
err = fuse_copy_one(cs, &arg, sizeof(arg));
|
|
|
|
while (head) {
|
|
struct fuse_forget_link *forget = head;
|
|
|
|
if (!err) {
|
|
err = fuse_copy_one(cs, &forget->forget_one,
|
|
sizeof(forget->forget_one));
|
|
}
|
|
head = forget->next;
|
|
kfree(forget);
|
|
}
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
return ih.len;
|
|
}
|
|
|
|
static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
|
|
struct fuse_copy_state *cs,
|
|
size_t nbytes)
|
|
__releases(fiq->waitq.lock)
|
|
{
|
|
if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
|
|
return fuse_read_single_forget(fiq, cs, nbytes);
|
|
else
|
|
return fuse_read_batch_forget(fiq, cs, nbytes);
|
|
}
|
|
|
|
/*
|
|
* Read a single request into the userspace filesystem's buffer. This
|
|
* function waits until a request is available, then removes it from
|
|
* the pending list and copies request data to userspace buffer. If
|
|
* no reply is needed (FORGET) or request has been aborted or there
|
|
* was an error during the copying then it's finished by calling
|
|
* request_end(). Otherwise add it to the processing list, and set
|
|
* the 'sent' flag.
|
|
*/
|
|
static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
ssize_t err;
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
struct fuse_req *req;
|
|
struct fuse_in *in;
|
|
unsigned reqsize;
|
|
unsigned int hash;
|
|
|
|
/*
|
|
* Require sane minimum read buffer - that has capacity for fixed part
|
|
* of any request header + negotated max_write room for data. If the
|
|
* requirement is not satisfied return EINVAL to the filesystem server
|
|
* to indicate that it is not following FUSE server/client contract.
|
|
* Don't dequeue / abort any request.
|
|
*/
|
|
if (nbytes < max_t(size_t, FUSE_MIN_READ_BUFFER, 4096 + fc->max_write))
|
|
return -EINVAL;
|
|
|
|
restart:
|
|
spin_lock(&fiq->waitq.lock);
|
|
err = -EAGAIN;
|
|
if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
|
|
!request_pending(fiq))
|
|
goto err_unlock;
|
|
|
|
err = wait_event_interruptible_exclusive_locked(fiq->waitq,
|
|
!fiq->connected || request_pending(fiq));
|
|
if (err)
|
|
goto err_unlock;
|
|
|
|
if (!fiq->connected) {
|
|
err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
|
goto err_unlock;
|
|
}
|
|
|
|
if (!list_empty(&fiq->interrupts)) {
|
|
req = list_entry(fiq->interrupts.next, struct fuse_req,
|
|
intr_entry);
|
|
return fuse_read_interrupt(fiq, cs, nbytes, req);
|
|
}
|
|
|
|
if (forget_pending(fiq)) {
|
|
if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
|
|
return fuse_read_forget(fc, fiq, cs, nbytes);
|
|
|
|
if (fiq->forget_batch <= -8)
|
|
fiq->forget_batch = 16;
|
|
}
|
|
|
|
req = list_entry(fiq->pending.next, struct fuse_req, list);
|
|
clear_bit(FR_PENDING, &req->flags);
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
|
|
in = &req->in;
|
|
reqsize = in->h.len;
|
|
|
|
/* If request is too large, reply with an error and restart the read */
|
|
if (nbytes < reqsize) {
|
|
req->out.h.error = -EIO;
|
|
/* SETXATTR is special, since it may contain too large data */
|
|
if (in->h.opcode == FUSE_SETXATTR)
|
|
req->out.h.error = -E2BIG;
|
|
request_end(fc, req);
|
|
goto restart;
|
|
}
|
|
spin_lock(&fpq->lock);
|
|
list_add(&req->list, &fpq->io);
|
|
spin_unlock(&fpq->lock);
|
|
cs->req = req;
|
|
err = fuse_copy_one(cs, &in->h, sizeof(in->h));
|
|
if (!err)
|
|
err = fuse_copy_args(cs, in->numargs, in->argpages,
|
|
(struct fuse_arg *) in->args, 0);
|
|
fuse_copy_finish(cs);
|
|
spin_lock(&fpq->lock);
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
if (!fpq->connected) {
|
|
err = fc->aborted ? -ECONNABORTED : -ENODEV;
|
|
goto out_end;
|
|
}
|
|
if (err) {
|
|
req->out.h.error = -EIO;
|
|
goto out_end;
|
|
}
|
|
if (!test_bit(FR_ISREPLY, &req->flags)) {
|
|
err = reqsize;
|
|
goto out_end;
|
|
}
|
|
hash = fuse_req_hash(req->in.h.unique);
|
|
list_move_tail(&req->list, &fpq->processing[hash]);
|
|
__fuse_get_request(req);
|
|
set_bit(FR_SENT, &req->flags);
|
|
spin_unlock(&fpq->lock);
|
|
/* matches barrier in request_wait_answer() */
|
|
smp_mb__after_atomic();
|
|
if (test_bit(FR_INTERRUPTED, &req->flags))
|
|
queue_interrupt(fiq, req);
|
|
fuse_put_request(fc, req);
|
|
|
|
return reqsize;
|
|
|
|
out_end:
|
|
if (!test_bit(FR_PRIVATE, &req->flags))
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fpq->lock);
|
|
request_end(fc, req);
|
|
return err;
|
|
|
|
err_unlock:
|
|
spin_unlock(&fiq->waitq.lock);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_dev_open(struct inode *inode, struct file *file)
|
|
{
|
|
/*
|
|
* The fuse device's file's private_data is used to hold
|
|
* the fuse_conn(ection) when it is mounted, and is used to
|
|
* keep track of whether the file has been mounted already.
|
|
*/
|
|
file->private_data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct file *file = iocb->ki_filp;
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
if (!iter_is_iovec(to))
|
|
return -EINVAL;
|
|
|
|
fuse_copy_init(&cs, 1, to);
|
|
|
|
return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
|
|
}
|
|
|
|
static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
|
|
struct pipe_inode_info *pipe,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
int total, ret;
|
|
int page_nr = 0;
|
|
struct pipe_buffer *bufs;
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud = fuse_get_dev(in);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
|
|
GFP_KERNEL);
|
|
if (!bufs)
|
|
return -ENOMEM;
|
|
|
|
fuse_copy_init(&cs, 1, NULL);
|
|
cs.pipebufs = bufs;
|
|
cs.pipe = pipe;
|
|
ret = fuse_dev_do_read(fud, in, &cs, len);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
|
|
/*
|
|
* Need to be careful about this. Having buf->ops in module
|
|
* code can Oops if the buffer persists after module unload.
|
|
*/
|
|
bufs[page_nr].ops = &nosteal_pipe_buf_ops;
|
|
bufs[page_nr].flags = 0;
|
|
ret = add_to_pipe(pipe, &bufs[page_nr++]);
|
|
if (unlikely(ret < 0))
|
|
break;
|
|
}
|
|
if (total)
|
|
ret = total;
|
|
out:
|
|
for (; page_nr < cs.nr_segs; page_nr++)
|
|
put_page(bufs[page_nr].page);
|
|
|
|
kvfree(bufs);
|
|
return ret;
|
|
}
|
|
|
|
static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_poll_wakeup_out outarg;
|
|
int err = -EINVAL;
|
|
|
|
if (size != sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
fuse_copy_finish(cs);
|
|
return fuse_notify_poll_wakeup(fc, &outarg);
|
|
|
|
err:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_inval_inode_out outarg;
|
|
int err = -EINVAL;
|
|
|
|
if (size != sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb) {
|
|
err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
|
|
outarg.off, outarg.len);
|
|
}
|
|
up_read(&fc->killsb);
|
|
return err;
|
|
|
|
err:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_inval_entry_out outarg;
|
|
int err = -ENOMEM;
|
|
char *buf;
|
|
struct qstr name;
|
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
|
if (!buf)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (outarg.namelen > FUSE_NAME_MAX)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg) + outarg.namelen + 1)
|
|
goto err;
|
|
|
|
name.name = buf;
|
|
name.len = outarg.namelen;
|
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
buf[outarg.namelen] = 0;
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb)
|
|
err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
|
|
up_read(&fc->killsb);
|
|
kfree(buf);
|
|
return err;
|
|
|
|
err:
|
|
kfree(buf);
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_delete_out outarg;
|
|
int err = -ENOMEM;
|
|
char *buf;
|
|
struct qstr name;
|
|
|
|
buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
|
|
if (!buf)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto err;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto err;
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (outarg.namelen > FUSE_NAME_MAX)
|
|
goto err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg) + outarg.namelen + 1)
|
|
goto err;
|
|
|
|
name.name = buf;
|
|
name.len = outarg.namelen;
|
|
err = fuse_copy_one(cs, buf, outarg.namelen + 1);
|
|
if (err)
|
|
goto err;
|
|
fuse_copy_finish(cs);
|
|
buf[outarg.namelen] = 0;
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb)
|
|
err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
|
|
outarg.child, &name);
|
|
up_read(&fc->killsb);
|
|
kfree(buf);
|
|
return err;
|
|
|
|
err:
|
|
kfree(buf);
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_store_out outarg;
|
|
struct inode *inode;
|
|
struct address_space *mapping;
|
|
u64 nodeid;
|
|
int err;
|
|
pgoff_t index;
|
|
unsigned int offset;
|
|
unsigned int num;
|
|
loff_t file_size;
|
|
loff_t end;
|
|
|
|
err = -EINVAL;
|
|
if (size < sizeof(outarg))
|
|
goto out_finish;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto out_finish;
|
|
|
|
err = -EINVAL;
|
|
if (size - sizeof(outarg) != outarg.size)
|
|
goto out_finish;
|
|
|
|
nodeid = outarg.nodeid;
|
|
|
|
down_read(&fc->killsb);
|
|
|
|
err = -ENOENT;
|
|
if (!fc->sb)
|
|
goto out_up_killsb;
|
|
|
|
inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
|
|
if (!inode)
|
|
goto out_up_killsb;
|
|
|
|
mapping = inode->i_mapping;
|
|
index = outarg.offset >> PAGE_SHIFT;
|
|
offset = outarg.offset & ~PAGE_MASK;
|
|
file_size = i_size_read(inode);
|
|
end = outarg.offset + outarg.size;
|
|
if (end > file_size) {
|
|
file_size = end;
|
|
fuse_write_update_size(inode, file_size);
|
|
}
|
|
|
|
num = outarg.size;
|
|
while (num) {
|
|
struct page *page;
|
|
unsigned int this_num;
|
|
|
|
err = -ENOMEM;
|
|
page = find_or_create_page(mapping, index,
|
|
mapping_gfp_mask(mapping));
|
|
if (!page)
|
|
goto out_iput;
|
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset);
|
|
err = fuse_copy_page(cs, &page, offset, this_num, 0);
|
|
if (!err && offset == 0 &&
|
|
(this_num == PAGE_SIZE || file_size == end))
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
put_page(page);
|
|
|
|
if (err)
|
|
goto out_iput;
|
|
|
|
num -= this_num;
|
|
offset = 0;
|
|
index++;
|
|
}
|
|
|
|
err = 0;
|
|
|
|
out_iput:
|
|
iput(inode);
|
|
out_up_killsb:
|
|
up_read(&fc->killsb);
|
|
out_finish:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
|
|
{
|
|
release_pages(req->pages, req->num_pages);
|
|
}
|
|
|
|
static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
|
|
struct fuse_notify_retrieve_out *outarg)
|
|
{
|
|
int err;
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct fuse_req *req;
|
|
pgoff_t index;
|
|
loff_t file_size;
|
|
unsigned int num;
|
|
unsigned int offset;
|
|
size_t total_len = 0;
|
|
unsigned int num_pages;
|
|
|
|
offset = outarg->offset & ~PAGE_MASK;
|
|
file_size = i_size_read(inode);
|
|
|
|
num = min(outarg->size, fc->max_write);
|
|
if (outarg->offset > file_size)
|
|
num = 0;
|
|
else if (outarg->offset + num > file_size)
|
|
num = file_size - outarg->offset;
|
|
|
|
num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
num_pages = min(num_pages, fc->max_pages);
|
|
|
|
req = fuse_get_req(fc, num_pages);
|
|
if (IS_ERR(req))
|
|
return PTR_ERR(req);
|
|
|
|
req->in.h.opcode = FUSE_NOTIFY_REPLY;
|
|
req->in.h.nodeid = outarg->nodeid;
|
|
req->in.numargs = 2;
|
|
req->in.argpages = 1;
|
|
req->end = fuse_retrieve_end;
|
|
|
|
index = outarg->offset >> PAGE_SHIFT;
|
|
|
|
while (num && req->num_pages < num_pages) {
|
|
struct page *page;
|
|
unsigned int this_num;
|
|
|
|
page = find_get_page(mapping, index);
|
|
if (!page)
|
|
break;
|
|
|
|
this_num = min_t(unsigned, num, PAGE_SIZE - offset);
|
|
req->pages[req->num_pages] = page;
|
|
req->page_descs[req->num_pages].offset = offset;
|
|
req->page_descs[req->num_pages].length = this_num;
|
|
req->num_pages++;
|
|
|
|
offset = 0;
|
|
num -= this_num;
|
|
total_len += this_num;
|
|
index++;
|
|
}
|
|
req->misc.retrieve_in.offset = outarg->offset;
|
|
req->misc.retrieve_in.size = total_len;
|
|
req->in.args[0].size = sizeof(req->misc.retrieve_in);
|
|
req->in.args[0].value = &req->misc.retrieve_in;
|
|
req->in.args[1].size = total_len;
|
|
|
|
err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
|
|
if (err) {
|
|
fuse_retrieve_end(fc, req);
|
|
fuse_put_request(fc, req);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
|
|
struct fuse_copy_state *cs)
|
|
{
|
|
struct fuse_notify_retrieve_out outarg;
|
|
struct inode *inode;
|
|
int err;
|
|
|
|
err = -EINVAL;
|
|
if (size != sizeof(outarg))
|
|
goto copy_finish;
|
|
|
|
err = fuse_copy_one(cs, &outarg, sizeof(outarg));
|
|
if (err)
|
|
goto copy_finish;
|
|
|
|
fuse_copy_finish(cs);
|
|
|
|
down_read(&fc->killsb);
|
|
err = -ENOENT;
|
|
if (fc->sb) {
|
|
u64 nodeid = outarg.nodeid;
|
|
|
|
inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
|
|
if (inode) {
|
|
err = fuse_retrieve(fc, inode, &outarg);
|
|
iput(inode);
|
|
}
|
|
}
|
|
up_read(&fc->killsb);
|
|
|
|
return err;
|
|
|
|
copy_finish:
|
|
fuse_copy_finish(cs);
|
|
return err;
|
|
}
|
|
|
|
static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
|
|
unsigned int size, struct fuse_copy_state *cs)
|
|
{
|
|
/* Don't try to move pages (yet) */
|
|
cs->move_pages = 0;
|
|
|
|
switch (code) {
|
|
case FUSE_NOTIFY_POLL:
|
|
return fuse_notify_poll(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_INVAL_INODE:
|
|
return fuse_notify_inval_inode(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_INVAL_ENTRY:
|
|
return fuse_notify_inval_entry(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_STORE:
|
|
return fuse_notify_store(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_RETRIEVE:
|
|
return fuse_notify_retrieve(fc, size, cs);
|
|
|
|
case FUSE_NOTIFY_DELETE:
|
|
return fuse_notify_delete(fc, size, cs);
|
|
|
|
default:
|
|
fuse_copy_finish(cs);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Look up request on processing list by unique ID */
|
|
static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
|
|
{
|
|
unsigned int hash = fuse_req_hash(unique);
|
|
struct fuse_req *req;
|
|
|
|
list_for_each_entry(req, &fpq->processing[hash], list) {
|
|
if (req->in.h.unique == unique)
|
|
return req;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
|
|
unsigned nbytes)
|
|
{
|
|
unsigned reqsize = sizeof(struct fuse_out_header);
|
|
|
|
if (out->h.error)
|
|
return nbytes != reqsize ? -EINVAL : 0;
|
|
|
|
reqsize += len_args(out->numargs, out->args);
|
|
|
|
if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
|
|
return -EINVAL;
|
|
else if (reqsize > nbytes) {
|
|
struct fuse_arg *lastarg = &out->args[out->numargs-1];
|
|
unsigned diffsize = reqsize - nbytes;
|
|
if (diffsize > lastarg->size)
|
|
return -EINVAL;
|
|
lastarg->size -= diffsize;
|
|
}
|
|
return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
|
|
out->page_zeroing);
|
|
}
|
|
|
|
/*
|
|
* Write a single reply to a request. First the header is copied from
|
|
* the write buffer. The request is then searched on the processing
|
|
* list by the unique ID found in the header. If found, then remove
|
|
* it from the list and copy the rest of the buffer to the request.
|
|
* The request is finished by calling request_end()
|
|
*/
|
|
static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
|
|
struct fuse_copy_state *cs, size_t nbytes)
|
|
{
|
|
int err;
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
struct fuse_req *req;
|
|
struct fuse_out_header oh;
|
|
|
|
err = -EINVAL;
|
|
if (nbytes < sizeof(struct fuse_out_header))
|
|
goto out;
|
|
|
|
err = fuse_copy_one(cs, &oh, sizeof(oh));
|
|
if (err)
|
|
goto copy_finish;
|
|
|
|
err = -EINVAL;
|
|
if (oh.len != nbytes)
|
|
goto copy_finish;
|
|
|
|
/*
|
|
* Zero oh.unique indicates unsolicited notification message
|
|
* and error contains notification code.
|
|
*/
|
|
if (!oh.unique) {
|
|
err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
|
|
goto out;
|
|
}
|
|
|
|
err = -EINVAL;
|
|
if (oh.error <= -1000 || oh.error > 0)
|
|
goto copy_finish;
|
|
|
|
spin_lock(&fpq->lock);
|
|
req = NULL;
|
|
if (fpq->connected)
|
|
req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT);
|
|
|
|
err = -ENOENT;
|
|
if (!req) {
|
|
spin_unlock(&fpq->lock);
|
|
goto copy_finish;
|
|
}
|
|
|
|
/* Is it an interrupt reply ID? */
|
|
if (oh.unique & FUSE_INT_REQ_BIT) {
|
|
__fuse_get_request(req);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
err = 0;
|
|
if (nbytes != sizeof(struct fuse_out_header))
|
|
err = -EINVAL;
|
|
else if (oh.error == -ENOSYS)
|
|
fc->no_interrupt = 1;
|
|
else if (oh.error == -EAGAIN)
|
|
err = queue_interrupt(&fc->iq, req);
|
|
|
|
fuse_put_request(fc, req);
|
|
|
|
goto copy_finish;
|
|
}
|
|
|
|
clear_bit(FR_SENT, &req->flags);
|
|
list_move(&req->list, &fpq->io);
|
|
req->out.h = oh;
|
|
set_bit(FR_LOCKED, &req->flags);
|
|
spin_unlock(&fpq->lock);
|
|
cs->req = req;
|
|
if (!req->out.page_replace)
|
|
cs->move_pages = 0;
|
|
|
|
err = copy_out_args(cs, &req->out, nbytes);
|
|
fuse_copy_finish(cs);
|
|
|
|
spin_lock(&fpq->lock);
|
|
clear_bit(FR_LOCKED, &req->flags);
|
|
if (!fpq->connected)
|
|
err = -ENOENT;
|
|
else if (err)
|
|
req->out.h.error = -EIO;
|
|
if (!test_bit(FR_PRIVATE, &req->flags))
|
|
list_del_init(&req->list);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
request_end(fc, req);
|
|
out:
|
|
return err ? err : nbytes;
|
|
|
|
copy_finish:
|
|
fuse_copy_finish(cs);
|
|
goto out;
|
|
}
|
|
|
|
static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
if (!iter_is_iovec(from))
|
|
return -EINVAL;
|
|
|
|
fuse_copy_init(&cs, 0, from);
|
|
|
|
return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
|
|
}
|
|
|
|
static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
|
|
struct file *out, loff_t *ppos,
|
|
size_t len, unsigned int flags)
|
|
{
|
|
unsigned nbuf;
|
|
unsigned idx;
|
|
struct pipe_buffer *bufs;
|
|
struct fuse_copy_state cs;
|
|
struct fuse_dev *fud;
|
|
size_t rem;
|
|
ssize_t ret;
|
|
|
|
fud = fuse_get_dev(out);
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
pipe_lock(pipe);
|
|
|
|
bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer),
|
|
GFP_KERNEL);
|
|
if (!bufs) {
|
|
pipe_unlock(pipe);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
nbuf = 0;
|
|
rem = 0;
|
|
for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
|
|
rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
|
|
|
|
ret = -EINVAL;
|
|
if (rem < len)
|
|
goto out_free;
|
|
|
|
rem = len;
|
|
while (rem) {
|
|
struct pipe_buffer *ibuf;
|
|
struct pipe_buffer *obuf;
|
|
|
|
BUG_ON(nbuf >= pipe->buffers);
|
|
BUG_ON(!pipe->nrbufs);
|
|
ibuf = &pipe->bufs[pipe->curbuf];
|
|
obuf = &bufs[nbuf];
|
|
|
|
if (rem >= ibuf->len) {
|
|
*obuf = *ibuf;
|
|
ibuf->ops = NULL;
|
|
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
|
|
pipe->nrbufs--;
|
|
} else {
|
|
if (!pipe_buf_get(pipe, ibuf))
|
|
goto out_free;
|
|
|
|
*obuf = *ibuf;
|
|
obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
|
|
obuf->len = rem;
|
|
ibuf->offset += obuf->len;
|
|
ibuf->len -= obuf->len;
|
|
}
|
|
nbuf++;
|
|
rem -= obuf->len;
|
|
}
|
|
pipe_unlock(pipe);
|
|
|
|
fuse_copy_init(&cs, 0, NULL);
|
|
cs.pipebufs = bufs;
|
|
cs.nr_segs = nbuf;
|
|
cs.pipe = pipe;
|
|
|
|
if (flags & SPLICE_F_MOVE)
|
|
cs.move_pages = 1;
|
|
|
|
ret = fuse_dev_do_write(fud, &cs, len);
|
|
|
|
pipe_lock(pipe);
|
|
out_free:
|
|
for (idx = 0; idx < nbuf; idx++)
|
|
pipe_buf_release(pipe, &bufs[idx]);
|
|
pipe_unlock(pipe);
|
|
|
|
kvfree(bufs);
|
|
return ret;
|
|
}
|
|
|
|
static __poll_t fuse_dev_poll(struct file *file, poll_table *wait)
|
|
{
|
|
__poll_t mask = EPOLLOUT | EPOLLWRNORM;
|
|
struct fuse_iqueue *fiq;
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return EPOLLERR;
|
|
|
|
fiq = &fud->fc->iq;
|
|
poll_wait(file, &fiq->waitq, wait);
|
|
|
|
spin_lock(&fiq->waitq.lock);
|
|
if (!fiq->connected)
|
|
mask = EPOLLERR;
|
|
else if (request_pending(fiq))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
spin_unlock(&fiq->waitq.lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
/* Abort all requests on the given list (pending or processing) */
|
|
static void end_requests(struct fuse_conn *fc, struct list_head *head)
|
|
{
|
|
while (!list_empty(head)) {
|
|
struct fuse_req *req;
|
|
req = list_entry(head->next, struct fuse_req, list);
|
|
req->out.h.error = -ECONNABORTED;
|
|
clear_bit(FR_SENT, &req->flags);
|
|
list_del_init(&req->list);
|
|
request_end(fc, req);
|
|
}
|
|
}
|
|
|
|
static void end_polls(struct fuse_conn *fc)
|
|
{
|
|
struct rb_node *p;
|
|
|
|
p = rb_first(&fc->polled_files);
|
|
|
|
while (p) {
|
|
struct fuse_file *ff;
|
|
ff = rb_entry(p, struct fuse_file, polled_node);
|
|
wake_up_interruptible_all(&ff->poll_wait);
|
|
|
|
p = rb_next(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Abort all requests.
|
|
*
|
|
* Emergency exit in case of a malicious or accidental deadlock, or just a hung
|
|
* filesystem.
|
|
*
|
|
* The same effect is usually achievable through killing the filesystem daemon
|
|
* and all users of the filesystem. The exception is the combination of an
|
|
* asynchronous request and the tricky deadlock (see
|
|
* Documentation/filesystems/fuse.txt).
|
|
*
|
|
* Aborting requests under I/O goes as follows: 1: Separate out unlocked
|
|
* requests, they should be finished off immediately. Locked requests will be
|
|
* finished after unlock; see unlock_request(). 2: Finish off the unlocked
|
|
* requests. It is possible that some request will finish before we can. This
|
|
* is OK, the request will in that case be removed from the list before we touch
|
|
* it.
|
|
*/
|
|
void fuse_abort_conn(struct fuse_conn *fc)
|
|
{
|
|
struct fuse_iqueue *fiq = &fc->iq;
|
|
|
|
spin_lock(&fc->lock);
|
|
if (fc->connected) {
|
|
struct fuse_dev *fud;
|
|
struct fuse_req *req, *next;
|
|
LIST_HEAD(to_end);
|
|
unsigned int i;
|
|
|
|
/* Background queuing checks fc->connected under bg_lock */
|
|
spin_lock(&fc->bg_lock);
|
|
fc->connected = 0;
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
fuse_set_initialized(fc);
|
|
list_for_each_entry(fud, &fc->devices, entry) {
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
|
|
spin_lock(&fpq->lock);
|
|
fpq->connected = 0;
|
|
list_for_each_entry_safe(req, next, &fpq->io, list) {
|
|
req->out.h.error = -ECONNABORTED;
|
|
spin_lock(&req->waitq.lock);
|
|
set_bit(FR_ABORTED, &req->flags);
|
|
if (!test_bit(FR_LOCKED, &req->flags)) {
|
|
set_bit(FR_PRIVATE, &req->flags);
|
|
__fuse_get_request(req);
|
|
list_move(&req->list, &to_end);
|
|
}
|
|
spin_unlock(&req->waitq.lock);
|
|
}
|
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
|
list_splice_tail_init(&fpq->processing[i],
|
|
&to_end);
|
|
spin_unlock(&fpq->lock);
|
|
}
|
|
spin_lock(&fc->bg_lock);
|
|
fc->blocked = 0;
|
|
fc->max_background = UINT_MAX;
|
|
flush_bg_queue(fc);
|
|
spin_unlock(&fc->bg_lock);
|
|
|
|
spin_lock(&fiq->waitq.lock);
|
|
fiq->connected = 0;
|
|
list_for_each_entry(req, &fiq->pending, list)
|
|
clear_bit(FR_PENDING, &req->flags);
|
|
list_splice_tail_init(&fiq->pending, &to_end);
|
|
while (forget_pending(fiq))
|
|
kfree(dequeue_forget(fiq, 1, NULL));
|
|
wake_up_all_locked(&fiq->waitq);
|
|
spin_unlock(&fiq->waitq.lock);
|
|
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
|
|
end_polls(fc);
|
|
wake_up_all(&fc->blocked_waitq);
|
|
spin_unlock(&fc->lock);
|
|
|
|
end_requests(fc, &to_end);
|
|
} else {
|
|
spin_unlock(&fc->lock);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_abort_conn);
|
|
|
|
void fuse_wait_aborted(struct fuse_conn *fc)
|
|
{
|
|
/* matches implicit memory barrier in fuse_drop_waiting() */
|
|
smp_mb();
|
|
wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
|
|
}
|
|
|
|
int fuse_dev_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (fud) {
|
|
struct fuse_conn *fc = fud->fc;
|
|
struct fuse_pqueue *fpq = &fud->pq;
|
|
LIST_HEAD(to_end);
|
|
unsigned int i;
|
|
|
|
spin_lock(&fpq->lock);
|
|
WARN_ON(!list_empty(&fpq->io));
|
|
for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
|
|
list_splice_init(&fpq->processing[i], &to_end);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
end_requests(fc, &to_end);
|
|
|
|
/* Are we the last open device? */
|
|
if (atomic_dec_and_test(&fc->dev_count)) {
|
|
WARN_ON(fc->iq.fasync != NULL);
|
|
fuse_abort_conn(fc);
|
|
}
|
|
fuse_dev_free(fud);
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fuse_dev_release);
|
|
|
|
static int fuse_dev_fasync(int fd, struct file *file, int on)
|
|
{
|
|
struct fuse_dev *fud = fuse_get_dev(file);
|
|
|
|
if (!fud)
|
|
return -EPERM;
|
|
|
|
/* No locking - fasync_helper does its own locking */
|
|
return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
|
|
}
|
|
|
|
static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
|
|
{
|
|
struct fuse_dev *fud;
|
|
|
|
if (new->private_data)
|
|
return -EINVAL;
|
|
|
|
fud = fuse_dev_alloc(fc);
|
|
if (!fud)
|
|
return -ENOMEM;
|
|
|
|
new->private_data = fud;
|
|
atomic_inc(&fc->dev_count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int err = -ENOTTY;
|
|
|
|
if (cmd == FUSE_DEV_IOC_CLONE) {
|
|
int oldfd;
|
|
|
|
err = -EFAULT;
|
|
if (!get_user(oldfd, (__u32 __user *) arg)) {
|
|
struct file *old = fget(oldfd);
|
|
|
|
err = -EINVAL;
|
|
if (old) {
|
|
struct fuse_dev *fud = NULL;
|
|
|
|
/*
|
|
* Check against file->f_op because CUSE
|
|
* uses the same ioctl handler.
|
|
*/
|
|
if (old->f_op == file->f_op &&
|
|
old->f_cred->user_ns == file->f_cred->user_ns)
|
|
fud = fuse_get_dev(old);
|
|
|
|
if (fud) {
|
|
mutex_lock(&fuse_mutex);
|
|
err = fuse_device_clone(fud->fc, file);
|
|
mutex_unlock(&fuse_mutex);
|
|
}
|
|
fput(old);
|
|
}
|
|
}
|
|
}
|
|
return err;
|
|
}
|
|
|
|
const struct file_operations fuse_dev_operations = {
|
|
.owner = THIS_MODULE,
|
|
.open = fuse_dev_open,
|
|
.llseek = no_llseek,
|
|
.read_iter = fuse_dev_read,
|
|
.splice_read = fuse_dev_splice_read,
|
|
.write_iter = fuse_dev_write,
|
|
.splice_write = fuse_dev_splice_write,
|
|
.poll = fuse_dev_poll,
|
|
.release = fuse_dev_release,
|
|
.fasync = fuse_dev_fasync,
|
|
.unlocked_ioctl = fuse_dev_ioctl,
|
|
.compat_ioctl = fuse_dev_ioctl,
|
|
};
|
|
EXPORT_SYMBOL_GPL(fuse_dev_operations);
|
|
|
|
static struct miscdevice fuse_miscdevice = {
|
|
.minor = FUSE_MINOR,
|
|
.name = "fuse",
|
|
.fops = &fuse_dev_operations,
|
|
};
|
|
|
|
int __init fuse_dev_init(void)
|
|
{
|
|
int err = -ENOMEM;
|
|
fuse_req_cachep = kmem_cache_create("fuse_request",
|
|
sizeof(struct fuse_req),
|
|
0, 0, NULL);
|
|
if (!fuse_req_cachep)
|
|
goto out;
|
|
|
|
err = misc_register(&fuse_miscdevice);
|
|
if (err)
|
|
goto out_cache_clean;
|
|
|
|
return 0;
|
|
|
|
out_cache_clean:
|
|
kmem_cache_destroy(fuse_req_cachep);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
void fuse_dev_cleanup(void)
|
|
{
|
|
misc_deregister(&fuse_miscdevice);
|
|
kmem_cache_destroy(fuse_req_cachep);
|
|
}
|