/* 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); } if (fc->num_background == fc->congestion_threshold && fm->sb) { clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); clear_bdi_congested(fm->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 (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->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);Lines 1–500 of 2335. 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/* 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); } if (fc->num_background == fc->congestion_threshold && fm->sb) { clear_bdi_congested(fm->sb->s_bdi, BLK_RW_SYNC); clear_bdi_congested(fm->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 (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->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);