| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Miklos Szeredi | 9014 | 79.22% | 141 | 58.26% |
| John Muir | 541 | 4.75% | 2 | 0.83% |
| Kirill V Tkhai | 323 | 2.84% | 15 | 6.20% |
| Maxim Patlasov | 232 | 2.04% | 8 | 3.31% |
| Max Reitz | 167 | 1.47% | 3 | 1.24% |
| Tejun Heo | 164 | 1.44% | 4 | 1.65% |
| Al Viro | 147 | 1.29% | 9 | 3.72% |
| Stefan Hajnoczi | 122 | 1.07% | 4 | 1.65% |
| Eric W. Biedermann | 73 | 0.64% | 3 | 1.24% |
| Jeff Dike | 71 | 0.62% | 2 | 0.83% |
| David Howells | 68 | 0.60% | 4 | 1.65% |
| Vishal Moola (Oracle) | 64 | 0.56% | 2 | 0.83% |
| Bryan Green | 38 | 0.33% | 1 | 0.41% |
| Eric Biggers | 36 | 0.32% | 1 | 0.41% |
| Fang Wenqi | 36 | 0.32% | 1 | 0.41% |
| Kirill Smelkov | 34 | 0.30% | 2 | 0.83% |
| Alessio Balsini | 26 | 0.23% | 1 | 0.41% |
| Jann Horn | 22 | 0.19% | 2 | 0.83% |
| Szymon Lukasz | 21 | 0.18% | 1 | 0.41% |
| Tom Van Braeckel | 19 | 0.17% | 1 | 0.41% |
| Andrey Ryabinin | 16 | 0.14% | 2 | 0.83% |
| Sahitya Tummala | 15 | 0.13% | 1 | 0.41% |
| Vivek Goyal | 12 | 0.11% | 2 | 0.83% |
| Matthew Wilcox | 10 | 0.09% | 1 | 0.41% |
| Tahsin Erdogan | 9 | 0.08% | 1 | 0.41% |
| Vasily Averin | 9 | 0.08% | 1 | 0.41% |
| Seth Forshee | 9 | 0.08% | 1 | 0.41% |
| Csaba Henk | 9 | 0.08% | 1 | 0.41% |
| Kirill A. Shutemov | 9 | 0.08% | 1 | 0.41% |
| Badari Pulavarty | 7 | 0.06% | 1 | 0.41% |
| Linus Torvalds | 6 | 0.05% | 1 | 0.41% |
| Kay Sievers | 5 | 0.04% | 1 | 0.41% |
| Hao Peng | 4 | 0.04% | 1 | 0.41% |
| Elena Reshetova | 4 | 0.04% | 1 | 0.41% |
| Constantine Shulyupin | 4 | 0.04% | 1 | 0.41% |
| Dong Fang | 4 | 0.04% | 1 | 0.41% |
| Yu Zhao | 4 | 0.04% | 1 | 0.41% |
| Ingo Molnar | 3 | 0.03% | 1 | 0.41% |
| Linus Torvalds (pre-git) | 3 | 0.03% | 2 | 0.83% |
| Kees Cook | 2 | 0.02% | 1 | 0.41% |
| Eric Wong | 2 | 0.02% | 1 | 0.41% |
| Geert Uytterhoeven | 2 | 0.02% | 1 | 0.41% |
| Christoph Hellwig | 2 | 0.02% | 1 | 0.41% |
| Josh Triplett | 2 | 0.02% | 1 | 0.41% |
| Christoph Lameter | 2 | 0.02% | 1 | 0.41% |
| Zheng Yongjun | 1 | 0.01% | 1 | 0.41% |
| Mauro Carvalho Chehab | 1 | 0.01% | 1 | 0.41% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.41% |
| Randy Dunlap | 1 | 0.01% | 1 | 0.41% |
| Arnd Bergmann | 1 | 0.01% | 1 | 0.41% |
| Yue haibing | 1 | 0.01% | 1 | 0.41% |
| Mark Rutland | 1 | 0.01% | 1 | 0.41% |
| Total | 11379 | 242 |
/* FUSE: Filesystem in Userspace Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu> This program can be distributed under the terms of the GNU GPL. See the file COPYING. */ #include "fuse_i.h" #include <linux/init.h> #include <linux/module.h> #include <linux/poll.h> #include <linux/sched/signal.h> #include <linux/uio.h> #include <linux/miscdevice.h> #include <linux/pagemap.h> #include <linux/file.h> #include <linux/slab.h> #include <linux/pipe_fs_i.h> #include <linux/swap.h> #include <linux/splice.h> #include <linux/sched.h> MODULE_ALIAS_MISCDEV(FUSE_MINOR); MODULE_ALIAS("devname:fuse"); /* Ordinary requests have even IDs, while interrupts IDs are odd */ #define FUSE_INT_REQ_BIT (1ULL << 0) #define FUSE_REQ_ID_STEP (1ULL << 1) static struct kmem_cache *fuse_req_cachep; static struct fuse_dev *fuse_get_dev(struct file *file) { /* * Lockless access is OK, because file->private data is set * once during mount and is valid until the file is released. */ return READ_ONCE(file->private_data); } static void fuse_request_init(struct fuse_mount *fm, struct fuse_req *req) { INIT_LIST_HEAD(&req->list); INIT_LIST_HEAD(&req->intr_entry); init_waitqueue_head(&req->waitq); refcount_set(&req->count, 1); __set_bit(FR_PENDING, &req->flags); req->fm = fm; } static struct fuse_req *fuse_request_alloc(struct fuse_mount *fm, gfp_t flags) { struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags); if (req) fuse_request_init(fm, req); return req; } static void fuse_request_free(struct fuse_req *req) { kmem_cache_free(fuse_req_cachep, req); } static void __fuse_get_request(struct fuse_req *req) { refcount_inc(&req->count); } /* Must be called with > 1 refcount */ static void __fuse_put_request(struct fuse_req *req) { refcount_dec(&req->count); } void fuse_set_initialized(struct fuse_conn *fc) { /* Make sure stores before this are seen on another CPU */ smp_wmb(); fc->initialized = 1; } static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background) { return !fc->initialized || (for_background && fc->blocked); } static void fuse_drop_waiting(struct fuse_conn *fc) { /* * lockess check of fc->connected is okay, because atomic_dec_and_test() * provides a memory barrier matched with the one in fuse_wait_aborted() * to ensure no wake-up is missed. */ if (atomic_dec_and_test(&fc->num_waiting) && !READ_ONCE(fc->connected)) { /* wake up aborters */ wake_up_all(&fc->blocked_waitq); } } static void fuse_put_request(struct fuse_req *req); static struct fuse_req *fuse_get_req(struct fuse_mount *fm, bool for_background) { struct fuse_conn *fc = fm->fc; struct fuse_req *req; int err; atomic_inc(&fc->num_waiting); if (fuse_block_alloc(fc, for_background)) { err = -EINTR; if (wait_event_killable_exclusive(fc->blocked_waitq, !fuse_block_alloc(fc, for_background))) goto out; } /* Matches smp_wmb() in fuse_set_initialized() */ smp_rmb(); err = -ENOTCONN; if (!fc->connected) goto out; err = -ECONNREFUSED; if (fc->conn_error) goto out; req = fuse_request_alloc(fm, GFP_KERNEL); err = -ENOMEM; if (!req) { if (for_background) wake_up(&fc->blocked_waitq); goto out; } req->in.h.uid = from_kuid(fc->user_ns, current_fsuid()); req->in.h.gid = from_kgid(fc->user_ns, current_fsgid()); req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); __set_bit(FR_WAITING, &req->flags); if (for_background) __set_bit(FR_BACKGROUND, &req->flags); if (unlikely(req->in.h.uid == ((uid_t)-1) || req->in.h.gid == ((gid_t)-1))) { fuse_put_request(req); return ERR_PTR(-EOVERFLOW); } return req; out: fuse_drop_waiting(fc); return ERR_PTR(err); } static void fuse_put_request(struct fuse_req *req) { struct fuse_conn *fc = req->fm->fc; if (refcount_dec_and_test(&req->count)) { if (test_bit(FR_BACKGROUND, &req->flags)) { /* * We get here in the unlikely case that a background * request was allocated but not sent */ spin_lock(&fc->bg_lock); if (!fc->blocked) wake_up(&fc->blocked_waitq); spin_unlock(&fc->bg_lock); } if (test_bit(FR_WAITING, &req->flags)) { __clear_bit(FR_WAITING, &req->flags); fuse_drop_waiting(fc); } fuse_request_free(req); } } unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args) { unsigned nbytes = 0; unsigned i; for (i = 0; i < numargs; i++) nbytes += args[i].size; return nbytes; } EXPORT_SYMBOL_GPL(fuse_len_args); u64 fuse_get_unique(struct fuse_iqueue *fiq) { fiq->reqctr += FUSE_REQ_ID_STEP; return fiq->reqctr; } EXPORT_SYMBOL_GPL(fuse_get_unique); static unsigned int fuse_req_hash(u64 unique) { return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS); } /* * A new request is available, wake fiq->waitq */ static void fuse_dev_wake_and_unlock(struct fuse_iqueue *fiq) __releases(fiq->lock) { wake_up(&fiq->waitq); kill_fasync(&fiq->fasync, SIGIO, POLL_IN); spin_unlock(&fiq->lock); } const struct fuse_iqueue_ops fuse_dev_fiq_ops = { .wake_forget_and_unlock = fuse_dev_wake_and_unlock, .wake_interrupt_and_unlock = fuse_dev_wake_and_unlock, .wake_pending_and_unlock = fuse_dev_wake_and_unlock, }; EXPORT_SYMBOL_GPL(fuse_dev_fiq_ops); static void queue_request_and_unlock(struct fuse_iqueue *fiq, struct fuse_req *req) __releases(fiq->lock) { req->in.h.len = sizeof(struct fuse_in_header) + fuse_len_args(req->args->in_numargs, (struct fuse_arg *) req->args->in_args); list_add_tail(&req->list, &fiq->pending); fiq->ops->wake_pending_and_unlock(fiq); } void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget, u64 nodeid, u64 nlookup) { struct fuse_iqueue *fiq = &fc->iq; forget->forget_one.nodeid = nodeid; forget->forget_one.nlookup = nlookup; spin_lock(&fiq->lock); if (fiq->connected) { fiq->forget_list_tail->next = forget; fiq->forget_list_tail = forget; fiq->ops->wake_forget_and_unlock(fiq); } else { kfree(forget); spin_unlock(&fiq->lock); } } static void flush_bg_queue(struct fuse_conn *fc) { struct fuse_iqueue *fiq = &fc->iq; while (fc->active_background < fc->max_background && !list_empty(&fc->bg_queue)) { struct fuse_req *req; req = list_first_entry(&fc->bg_queue, struct fuse_req, list); list_del(&req->list); fc->active_background++; spin_lock(&fiq->lock); req->in.h.unique = fuse_get_unique(fiq); queue_request_and_unlock(fiq, req); } } /* * This function is called when a request is finished. Either a reply * has arrived or it was aborted (and not yet sent) or some error * occurred during communication with userspace, or the device file * was closed. The requester thread is woken up (if still waiting), * the 'end' callback is called if given, else the reference to the * request is released */ void fuse_request_end(struct fuse_req *req) { struct fuse_mount *fm = req->fm; struct fuse_conn *fc = fm->fc; struct fuse_iqueue *fiq = &fc->iq; if (test_and_set_bit(FR_FINISHED, &req->flags)) goto put_request; /* * test_and_set_bit() implies smp_mb() between bit * changing and below FR_INTERRUPTED check. Pairs with * smp_mb() from queue_interrupt(). */ if (test_bit(FR_INTERRUPTED, &req->flags)) { spin_lock(&fiq->lock); list_del_init(&req->intr_entry); spin_unlock(&fiq->lock); } WARN_ON(test_bit(FR_PENDING, &req->flags)); WARN_ON(test_bit(FR_SENT, &req->flags)); if (test_bit(FR_BACKGROUND, &req->flags)) { spin_lock(&fc->bg_lock); clear_bit(FR_BACKGROUND, &req->flags); if (fc->num_background == fc->max_background) { fc->blocked = 0; wake_up(&fc->blocked_waitq); } else if (!fc->blocked) { /* * Wake up next waiter, if any. It's okay to use * waitqueue_active(), as we've already synced up * fc->blocked with waiters with the wake_up() call * above. */ if (waitqueue_active(&fc->blocked_waitq)) wake_up(&fc->blocked_waitq); } 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 (test_bit(FR_ASYNC, &req->flags)) req->args->end(fm, req->args, req->out.h.error); put_request: fuse_put_request(req); } EXPORT_SYMBOL_GPL(fuse_request_end); static int queue_interrupt(struct fuse_req *req) { struct fuse_iqueue *fiq = &req->fm->fc->iq; spin_lock(&fiq->lock); /* Check for we've sent request to interrupt this req */ if (unlikely(!test_bit(FR_INTERRUPTED, &req->flags))) { spin_unlock(&fiq->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 fuse_request_end(). */ smp_mb(); if (test_bit(FR_FINISHED, &req->flags)) { list_del_init(&req->intr_entry); spin_unlock(&fiq->lock); return 0; } fiq->ops->wake_interrupt_and_unlock(fiq); } else { spin_unlock(&fiq->lock); } return 0; } static void request_wait_answer(struct fuse_req *req) { struct fuse_conn *fc = req->fm->fc; 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(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->lock); /* Request is not yet in userspace, bail out */ if (test_bit(FR_PENDING, &req->flags)) { list_del(&req->list); spin_unlock(&fiq->lock); __fuse_put_request(req); req->out.h.error = -EINTR; return; } spin_unlock(&fiq->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_req *req) { struct fuse_iqueue *fiq = &req->fm->fc->iq; BUG_ON(test_bit(FR_BACKGROUND, &req->flags)); spin_lock(&fiq->lock); if (!fiq->connected) { spin_unlock(&fiq->lock); req->out.h.error = -ENOTCONN; } else { req->in.h.unique = fuse_get_unique(fiq); /* acquire extra reference, since request is still needed after fuse_request_end() */ __fuse_get_request(req); queue_request_and_unlock(fiq, req); request_wait_answer(req); /* Pairs with smp_wmb() in fuse_request_end() */ smp_rmb(); } } static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) { if (fc->minor < 4 && args->opcode == FUSE_STATFS) args->out_args[0].size = FUSE_COMPAT_STATFS_SIZE; if (fc->minor < 9) { switch (args->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->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; } } } static void fuse_force_creds(struct fuse_req *req) { struct fuse_conn *fc = req->fm->fc; req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid()); req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid()); req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns); } static void fuse_args_to_req(struct fuse_req *req, struct fuse_args *args) { req->in.h.opcode = args->opcode; req->in.h.nodeid = args->nodeid; req->args = args; if (args->is_ext) req->in.h.total_extlen = args->in_args[args->ext_idx].size / 8; if (args->end) __set_bit(FR_ASYNC, &req->flags); } ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args) { struct fuse_conn *fc = fm->fc; struct fuse_req *req; ssize_t ret; if (args->force) { atomic_inc(&fc->num_waiting); req = fuse_request_alloc(fm, GFP_KERNEL | __GFP_NOFAIL); if (!args->nocreds) fuse_force_creds(req); __set_bit(FR_WAITING, &req->flags); __set_bit(FR_FORCE, &req->flags); } else { WARN_ON(args->nocreds); req = fuse_get_req(fm, false); 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); fuse_args_to_req(req, args); if (!args->noreply) __set_bit(FR_ISREPLY, &req->flags); __fuse_request_send(req); ret = req->out.h.error; if (!ret && args->out_argvar) { BUG_ON(args->out_numargs == 0); ret = args->out_args[args->out_numargs - 1].size; } fuse_put_request(req); return ret; } static bool fuse_request_queue_background(struct fuse_req *req) { struct fuse_mount *fm = req->fm; struct fuse_conn *fc = fm->fc; 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; list_add_tail(&req->list, &fc->bg_queue); flush_bg_queue(fc); queued = true; } spin_unlock(&fc->bg_lock); return queued; } int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args, gfp_t gfp_flags) { struct fuse_req *req; if (args->force) { WARN_ON(!args->nocreds); req = fuse_request_alloc(fm, gfp_flags); if (!req) return -ENOMEM; __set_bit(FR_BACKGROUND, &req->flags); } else { WARN_ON(args->nocreds); req = fuse_get_req(fm, true); if (IS_ERR(req)) return PTR_ERR(req); } fuse_args_to_req(req, args); if (!fuse_request_queue_background(req)) { fuse_put_request(req); return -ENOTCONN; } return 0; } EXPORT_SYMBOL_GPL(fuse_simple_background); static int fuse_simple_notify_reply(struct fuse_mount *fm, struct fuse_args *args, u64 unique) { struct fuse_req *req; struct fuse_iqueue *fiq = &fm->fc->iq; int err = 0; req = fuse_get_req(fm, false); if (IS_ERR(req)) return PTR_ERR(req); __clear_bit(FR_ISREPLY, &req->flags); req->in.h.unique = unique; fuse_args_to_req(req, args); spin_lock(&fiq->lock); if (fiq->connected) { queue_request_and_unlock(fiq, req); } else { err = -ENODEV; spin_unlock(&fiq->lock); fuse_put_request(req); } return err; } /* * 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->max_usage) 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_pages2(cs->iter, &page, PAGE_SIZE, 1, &off); if (err < 0) return err; BUG_ON(!err); cs->len = err; cs->offset = off; cs->pg = page; } 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_local_page(cs->pg); void *buf = pgaddr + cs->offset; if (cs->write) memcpy(buf, *val, ncpy); else memcpy(*val, buf, ncpy); kunmap_local(pgaddr); *val += ncpy; } *size -= ncpy; cs->len -= ncpy; cs->offset += ncpy; return ncpy; } static int fuse_check_folio(struct folio *folio) { if (folio_mapped(folio) || folio->mapping != NULL || (folio->flags & PAGE_FLAGS_CHECK_AT_PREP & ~(1 << PG_locked | 1 << PG_referenced | 1 << PG_uptodate | 1 << PG_lru | 1 << PG_active | 1 << PG_workingset | 1 << PG_reclaim | 1 << PG_waiters | LRU_GEN_MASK | LRU_REFS_MASK))) { dump_page(&folio->page, "fuse: trying to steal weird page"); return 1; } return 0; } static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) { int err; struct folio *oldfolio = page_folio(*pagep); struct folio *newfolio; struct pipe_buffer *buf = cs->pipebufs; folio_get(oldfolio); err = unlock_request(cs->req); if (err) goto out_put_old; fuse_copy_finish(cs); err = pipe_buf_confirm(cs->pipe, buf); if (err) goto out_put_old; 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_try_steal(cs->pipe, buf)) goto out_fallback; newfolio = page_folio(buf->page); if (!folio_test_uptodate(newfolio)) folio_mark_uptodate(newfolio); folio_clear_mappedtodisk(newfolio); if (fuse_check_folio(newfolio) != 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(folio_mapped(oldfolio))) goto out_fallback_unlock; if (WARN_ON(folio_has_private(oldfolio))) goto out_fallback_unlock; if (WARN_ON(folio_test_dirty(oldfolio) || folio_test_writeback(oldfolio))) goto out_fallback_unlock; if (WARN_ON(folio_test_mlocked(oldfolio))) goto out_fallback_unlock; replace_page_cache_folio(oldfolio, newfolio); folio_get(newfolio); if (!(buf->flags & PIPE_BUF_FLAG_LRU)) folio_add_lru(newfolio); /* * Release while we have extra ref on stolen page. Otherwise * anon_pipe_buf_release() might think the page can be reused. */ pipe_buf_release(cs->pipe, buf); err = 0; spin_lock(&cs->req->waitq.lock); if (test_bit(FR_ABORTED, &cs->req->flags)) err = -ENOENT; else *pagep = &newfolio->page; spin_unlock(&cs->req->waitq.lock); if (err) { folio_unlock(newfolio); folio_put(newfolio); goto out_put_old; } folio_unlock(oldfolio); /* Drop ref for ap->pages[] array */ folio_put(oldfolio); cs->len = 0; err = 0; out_put_old: /* Drop ref obtained in this function */ folio_put(oldfolio); return err; out_fallback_unlock: folio_unlock(newfolio); out_fallback: cs->pg = buf->page; cs->offset = buf->offset; err = lock_request(cs->req); if (!err) err = 1; goto out_put_old; } 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->max_usage) return -EIO; get_page(page); err = unlock_request(cs->req); if (err) { put_page(page); return err; } fuse_copy_finish(cs); buf = cs->pipebufs; 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) { /* * Can't control lifetime of pipe buffers, so always * copy user pages. */ if (cs->req->args->user_pages) { err = fuse_copy_fill(cs); if (err) return err; } else { 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_local_page(page); void *buf = mapaddr + offset; offset += fuse_copy_do(cs, &buf, &count); kunmap_local(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; struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args); for (i = 0; i < ap->num_pages && (nbytes || zeroing); i++) { int err; unsigned int offset = ap->descs[i].offset; unsigned int count = min(nbytes, ap->descs[i].length); err = fuse_copy_page(cs, &ap->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->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->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->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; } struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq, unsigned int max, unsigned int *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; } EXPORT_SYMBOL(fuse_dequeue_forget); static int fuse_read_single_forget(struct fuse_iqueue *fiq, struct fuse_copy_state *cs, size_t nbytes) __releases(fiq->lock) { int err; struct fuse_forget_link *forget = fuse_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->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->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->lock); return -EINVAL; } max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one); head = fuse_dequeue_forget(fiq, max_forgets, &count); spin_unlock(&fiq->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->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 * fuse_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_args *args; unsigned reqsize; unsigned int hash; /* * Require sane minimum read buffer - that has capacity for fixed part * of any request header + negotiated max_write room for data. * * Historically libfuse reserves 4K for fixed header room, but e.g. * GlusterFS reserves only 80 bytes * * = `sizeof(fuse_in_header) + sizeof(fuse_write_in)` * * which is the absolute minimum any sane filesystem should be using * for header room. */ if (nbytes < max_t(size_t, FUSE_MIN_READ_BUFFER, sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in) + fc->max_write)) return -EINVAL; restart: for (;;) { spin_lock(&fiq->lock); if (!fiq->connected || request_pending(fiq)) break; spin_unlock(&fiq->lock); if (file->f_flags & O_NONBLOCK) return -EAGAIN; err = wait_event_interruptible_exclusive(fiq->waitq, !fiq->connected || request_pending(fiq)); if (err) return err; } 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->lock); args = req->args; reqsize = req->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 (args->opcode == FUSE_SETXATTR) req->out.h.error = -E2BIG; fuse_request_end(req); goto restart; } spin_lock(&fpq->lock); /* * Must not put request on fpq->io queue after having been shut down by * fuse_abort_conn() */ if (!fpq->connected) { req->out.h.error = err = -ECONNABORTED; goto out_end; } list_add(&req->list, &fpq->io); spin_unlock(&fpq->lock); cs->req = req; err = fuse_copy_one(cs, &req->in.h, sizeof(req->in.h)); if (!err) err = fuse_copy_args(cs, args->in_numargs, args->in_pages, (struct fuse_arg *) args->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(req); fuse_put_request(req); return reqsize; out_end: if (!test_bit(FR_PRIVATE, &req->flags)) list_del_init(&req->list); spin_unlock(&fpq->lock); fuse_request_end(req); return err; err_unlock: spin_unlock(&fiq->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 (!user_backed_iter(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->max_usage, 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_occupancy(pipe->head, pipe->tail) + cs.nr_segs > pipe->max_usage) { 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 = fuse_reverse_inval_inode(fc, 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 = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags); 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 = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0); 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; inode = fuse_ilookup(fc, nodeid, NULL); 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_attr(inode, file_size, outarg.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; } struct fuse_retrieve_args { struct fuse_args_pages ap; struct fuse_notify_retrieve_in inarg; }; static void fuse_retrieve_end(struct fuse_mount *fm, struct fuse_args *args, int error) { struct fuse_retrieve_args *ra = container_of(args, typeof(*ra), ap.args); release_pages(ra->ap.pages, ra->ap.num_pages); kfree(ra); } static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode, struct fuse_notify_retrieve_out *outarg) { int err; struct address_space *mapping = inode->i_mapping; pgoff_t index; loff_t file_size; unsigned int num; unsigned int offset; size_t total_len = 0; unsigned int num_pages; struct fuse_conn *fc = fm->fc; struct fuse_retrieve_args *ra; size_t args_size = sizeof(*ra); struct fuse_args_pages *ap; struct fuse_args *args; 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); args_size += num_pages * (sizeof(ap->pages[0]) + sizeof(ap->descs[0])); ra = kzalloc(args_size, GFP_KERNEL); if (!ra) return -ENOMEM; ap = &ra->ap; ap->pages = (void *) (ra + 1); ap->descs = (void *) (ap->pages + num_pages); args = &ap->args; args->nodeid = outarg->nodeid; args->opcode = FUSE_NOTIFY_REPLY; args->in_numargs = 2; args->in_pages = true; args->end = fuse_retrieve_end; index = outarg->offset >> PAGE_SHIFT; while (num && ap->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); ap->pages[ap->num_pages] = page; ap->descs[ap->num_pages].offset = offset; ap->descs[ap->num_pages].length = this_num; ap->num_pages++; offset = 0; num -= this_num; total_len += this_num; index++; } ra->inarg.offset = outarg->offset; ra->inarg.size = total_len; args->in_args[0].size = sizeof(ra->inarg); args->in_args[0].value = &ra->inarg; args->in_args[1].size = total_len; err = fuse_simple_notify_reply(fm, args, outarg->notify_unique); if (err) fuse_retrieve_end(fm, args, err); 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 fuse_mount *fm; struct inode *inode; u64 nodeid; 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; nodeid = outarg.nodeid; inode = fuse_ilookup(fc, nodeid, &fm); if (inode) { err = fuse_retrieve(fm, 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_args *args, unsigned nbytes) { unsigned reqsize = sizeof(struct fuse_out_header); reqsize += fuse_len_args(args->out_numargs, args->out_args); if (reqsize < nbytes || (reqsize > nbytes && !args->out_argvar)) return -EINVAL; else if (reqsize > nbytes) { struct fuse_arg *lastarg = &args->out_args[args->out_numargs-1]; unsigned diffsize = reqsize - nbytes; if (diffsize > lastarg->size) return -EINVAL; lastarg->size -= diffsize; } return fuse_copy_args(cs, args->out_numargs, args->out_pages, args->out_args, args->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 fuse_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 <= -512 || 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(req); fuse_put_request(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->args->page_replace) cs->move_pages = 0; if (oh.error) err = nbytes != sizeof(oh) ? -EINVAL : 0; else err = copy_out_args(cs, req->args, 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); fuse_request_end(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 (!user_backed_iter(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 int head, tail, mask, count; 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); head = pipe->head; tail = pipe->tail; mask = pipe->ring_size - 1; count = head - tail; bufs = kvmalloc_array(count, sizeof(struct pipe_buffer), GFP_KERNEL); if (!bufs) { pipe_unlock(pipe); return -ENOMEM; } nbuf = 0; rem = 0; for (idx = tail; idx != head && rem < len; idx++) rem += pipe->bufs[idx & mask].len; ret = -EINVAL; if (rem < len) goto out_free; rem = len; while (rem) { struct pipe_buffer *ibuf; struct pipe_buffer *obuf; if (WARN_ON(nbuf >= count || tail == head)) goto out_free; ibuf = &pipe->bufs[tail & mask]; obuf = &bufs[nbuf]; if (rem >= ibuf->len) { *obuf = *ibuf; ibuf->ops = NULL; tail++; pipe->tail = tail; } 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++) { struct pipe_buffer *buf = &bufs[idx]; if (buf->ops) pipe_buf_release(pipe, buf); } 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->lock); if (!fiq->connected) mask = EPOLLERR; else if (request_pending(fiq)) mask |= EPOLLIN | EPOLLRDNORM; spin_unlock(&fiq->lock); return mask; } /* Abort all requests on the given list (pending or processing) */ static void end_requests(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); fuse_request_end(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.rst). * * 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->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(fuse_dequeue_forget(fiq, 1, NULL)); wake_up_all(&fiq->waitq); spin_unlock(&fiq->lock); kill_fasync(&fiq->fasync, SIGIO, POLL_IN); end_polls(fc); wake_up_all(&fc->blocked_waitq); spin_unlock(&fc->lock); end_requests(&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(&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_install(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 res; int oldfd; struct fuse_dev *fud = NULL; struct fd f; switch (cmd) { case FUSE_DEV_IOC_CLONE: if (get_user(oldfd, (__u32 __user *)arg)) return -EFAULT; f = fdget(oldfd); if (!f.file) return -EINVAL; /* * Check against file->f_op because CUSE * uses the same ioctl handler. */ if (f.file->f_op == file->f_op) fud = fuse_get_dev(f.file); res = -EINVAL; if (fud) { mutex_lock(&fuse_mutex); res = fuse_device_clone(fud->fc, file); mutex_unlock(&fuse_mutex); } fdput(f); break; default: res = -ENOTTY; break; } return res; } 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 = compat_ptr_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); }
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