diff options
author | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
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committer | Dmitry Torokhov <dtor_core@ameritech.net> | 2006-04-29 01:11:23 -0400 |
commit | 7b7e394185014e0f3bd8989cac937003f20ef9ce (patch) | |
tree | 3beda5f979bba0aa9822534e239cf1b45f3be69c /fs/fuse/dev.c | |
parent | ddc5d3414593e4d7ad7fbd33e7f7517fcc234544 (diff) | |
parent | 693f7d362055261882659475d2ef022e32edbff1 (diff) | |
download | linux-stable-7b7e394185014e0f3bd8989cac937003f20ef9ce.tar.gz linux-stable-7b7e394185014e0f3bd8989cac937003f20ef9ce.tar.bz2 linux-stable-7b7e394185014e0f3bd8989cac937003f20ef9ce.zip |
Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'fs/fuse/dev.c')
-rw-r--r-- | fs/fuse/dev.c | 279 |
1 files changed, 138 insertions, 141 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 23d1f52eb1b8..104a62dadb94 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1,6 +1,6 @@ /* FUSE: Filesystem in Userspace - Copyright (C) 2001-2005 Miklos Szeredi <miklos@szeredi.hu> + Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> This program can be distributed under the terms of the GNU GPL. See the file COPYING. @@ -23,13 +23,11 @@ static kmem_cache_t *fuse_req_cachep; static struct fuse_conn *fuse_get_conn(struct file *file) { - struct fuse_conn *fc; - spin_lock(&fuse_lock); - fc = file->private_data; - if (fc && !fc->connected) - fc = NULL; - spin_unlock(&fuse_lock); - return fc; + /* + * Lockless access is OK, because file->private data is set + * once during mount and is valid until the file is released. + */ + return file->private_data; } static void fuse_request_init(struct fuse_req *req) @@ -74,10 +72,8 @@ static void restore_sigs(sigset_t *oldset) */ void fuse_reset_request(struct fuse_req *req) { - int preallocated = req->preallocated; BUG_ON(atomic_read(&req->count) != 1); fuse_request_init(req); - req->preallocated = preallocated; } static void __fuse_get_request(struct fuse_req *req) @@ -92,80 +88,64 @@ static void __fuse_put_request(struct fuse_req *req) atomic_dec(&req->count); } -static struct fuse_req *do_get_request(struct fuse_conn *fc) +struct fuse_req *fuse_get_req(struct fuse_conn *fc) { struct fuse_req *req; - - spin_lock(&fuse_lock); - BUG_ON(list_empty(&fc->unused_list)); - req = list_entry(fc->unused_list.next, struct fuse_req, list); - list_del_init(&req->list); - spin_unlock(&fuse_lock); - fuse_request_init(req); - req->preallocated = 1; - req->in.h.uid = current->fsuid; - req->in.h.gid = current->fsgid; - req->in.h.pid = current->pid; - return req; -} - -/* This can return NULL, but only in case it's interrupted by a SIGKILL */ -struct fuse_req *fuse_get_request(struct fuse_conn *fc) -{ - int intr; sigset_t oldset; + int intr; + int err; atomic_inc(&fc->num_waiting); block_sigs(&oldset); - intr = down_interruptible(&fc->outstanding_sem); + intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked); restore_sigs(&oldset); - if (intr) { - atomic_dec(&fc->num_waiting); - return NULL; - } - return do_get_request(fc); -} + err = -EINTR; + if (intr) + goto out; -/* Must be called with fuse_lock held */ -static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req) -{ - if (req->preallocated) { - atomic_dec(&fc->num_waiting); - list_add(&req->list, &fc->unused_list); - } else - fuse_request_free(req); + req = fuse_request_alloc(); + err = -ENOMEM; + if (!req) + goto out; - /* If we are in debt decrease that first */ - if (fc->outstanding_debt) - fc->outstanding_debt--; - else - up(&fc->outstanding_sem); + req->in.h.uid = current->fsuid; + req->in.h.gid = current->fsgid; + req->in.h.pid = current->pid; + req->waiting = 1; + return req; + + out: + atomic_dec(&fc->num_waiting); + return ERR_PTR(err); } void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) { if (atomic_dec_and_test(&req->count)) { - spin_lock(&fuse_lock); - fuse_putback_request(fc, req); - spin_unlock(&fuse_lock); + if (req->waiting) + atomic_dec(&fc->num_waiting); + fuse_request_free(req); } } -static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req) -{ - if (atomic_dec_and_test(&req->count)) - fuse_putback_request(fc, req); -} - -void fuse_release_background(struct fuse_req *req) +/* + * Called with sbput_sem held for read (request_end) or write + * (fuse_put_super). By the time fuse_put_super() is finished, all + * inodes belonging to background requests must be released, so the + * iputs have to be done within the locked region. + */ +void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req) { iput(req->inode); iput(req->inode2); - if (req->file) - fput(req->file); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); list_del(&req->bg_entry); - spin_unlock(&fuse_lock); + if (fc->num_background == FUSE_MAX_BACKGROUND) { + fc->blocked = 0; + wake_up_all(&fc->blocked_waitq); + } + fc->num_background--; + spin_unlock(&fc->lock); } /* @@ -184,24 +164,29 @@ void fuse_release_background(struct fuse_req *req) * interrupted and put in the background, it will return with an error * and hence never be reset and reused. * - * Called with fuse_lock, unlocks it + * Called with fc->lock, unlocks it */ static void request_end(struct fuse_conn *fc, struct fuse_req *req) { list_del(&req->list); req->state = FUSE_REQ_FINISHED; if (!req->background) { + spin_unlock(&fc->lock); wake_up(&req->waitq); - fuse_put_request_locked(fc, req); - spin_unlock(&fuse_lock); + fuse_put_request(fc, req); } else { void (*end) (struct fuse_conn *, struct fuse_req *) = req->end; req->end = NULL; - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); down_read(&fc->sbput_sem); if (fc->mounted) - fuse_release_background(req); + fuse_release_background(fc, req); up_read(&fc->sbput_sem); + + /* fput must go outside sbput_sem, otherwise it can deadlock */ + if (req->file) + fput(req->file); + if (end) end(fc, req); else @@ -242,6 +227,9 @@ static void background_request(struct fuse_conn *fc, struct fuse_req *req) { req->background = 1; list_add(&req->bg_entry, &fc->background); + fc->num_background++; + if (fc->num_background == FUSE_MAX_BACKGROUND) + fc->blocked = 1; if (req->inode) req->inode = igrab(req->inode); if (req->inode2) @@ -250,16 +238,16 @@ static void background_request(struct fuse_conn *fc, struct fuse_req *req) get_file(req->file); } -/* Called with fuse_lock held. Releases, and then reacquires it. */ +/* Called with fc->lock held. Releases, and then reacquires it. */ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req) { sigset_t oldset; - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); block_sigs(&oldset); wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED); restore_sigs(&oldset); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); if (req->state == FUSE_REQ_FINISHED && !req->interrupted) return; @@ -273,9 +261,9 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req) locked state, there mustn't be any filesystem operation (e.g. page fault), since that could lead to deadlock */ - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); wait_event(req->waitq, !req->locked); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); } if (req->state == FUSE_REQ_PENDING) { list_del(&req->list); @@ -304,19 +292,14 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req) req->in.h.unique = fc->reqctr; req->in.h.len = sizeof(struct fuse_in_header) + len_args(req->in.numargs, (struct fuse_arg *) req->in.args); - if (!req->preallocated) { - /* If request is not preallocated (either FORGET or - RELEASE), then still decrease outstanding_sem, so - user can't open infinite number of files while not - processing the RELEASE requests. However for - efficiency do it without blocking, so if down() - would block, just increase the debt instead */ - if (down_trylock(&fc->outstanding_sem)) - fc->outstanding_debt++; - } list_add_tail(&req->list, &fc->pending); req->state = FUSE_REQ_PENDING; + if (!req->waiting) { + req->waiting = 1; + atomic_inc(&fc->num_waiting); + } wake_up(&fc->waitq); + kill_fasync(&fc->fasync, SIGIO, POLL_IN); } /* @@ -325,7 +308,7 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req) void request_send(struct fuse_conn *fc, struct fuse_req *req) { req->isreply = 1; - spin_lock(&fuse_lock); + spin_lock(&fc->lock); if (!fc->connected) req->out.h.error = -ENOTCONN; else if (fc->conn_error) @@ -338,15 +321,16 @@ void request_send(struct fuse_conn *fc, struct fuse_req *req) request_wait_answer(fc, req); } - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req) { - spin_lock(&fuse_lock); + spin_lock(&fc->lock); + background_request(fc, req); if (fc->connected) { queue_request(fc, req); - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } else { req->out.h.error = -ENOTCONN; request_end(fc, req); @@ -362,9 +346,6 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req) void request_send_background(struct fuse_conn *fc, struct fuse_req *req) { req->isreply = 1; - spin_lock(&fuse_lock); - background_request(fc, req); - spin_unlock(&fuse_lock); request_send_nowait(fc, req); } @@ -373,16 +354,16 @@ void request_send_background(struct fuse_conn *fc, struct fuse_req *req) * anything that could cause a page-fault. If the request was already * interrupted bail out. */ -static int lock_request(struct fuse_req *req) +static int lock_request(struct fuse_conn *fc, struct fuse_req *req) { int err = 0; if (req) { - spin_lock(&fuse_lock); + spin_lock(&fc->lock); if (req->interrupted) err = -ENOENT; else req->locked = 1; - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } return err; } @@ -392,18 +373,19 @@ static int lock_request(struct fuse_req *req) * requester thread is currently waiting for it to be unlocked, so * wake it up. */ -static void unlock_request(struct fuse_req *req) +static void unlock_request(struct fuse_conn *fc, struct fuse_req *req) { if (req) { - spin_lock(&fuse_lock); + spin_lock(&fc->lock); req->locked = 0; if (req->interrupted) wake_up(&req->waitq); - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } } struct fuse_copy_state { + struct fuse_conn *fc; int write; struct fuse_req *req; const struct iovec *iov; @@ -416,11 +398,12 @@ struct fuse_copy_state { unsigned len; }; -static void fuse_copy_init(struct fuse_copy_state *cs, int write, - struct fuse_req *req, const struct iovec *iov, - unsigned long nr_segs) +static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc, + int write, struct fuse_req *req, + const struct iovec *iov, unsigned long nr_segs) { memset(cs, 0, sizeof(*cs)); + cs->fc = fc; cs->write = write; cs->req = req; cs->iov = iov; @@ -450,7 +433,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs) unsigned long offset; int err; - unlock_request(cs->req); + unlock_request(cs->fc, cs->req); fuse_copy_finish(cs); if (!cs->seglen) { BUG_ON(!cs->nr_segs); @@ -473,7 +456,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs) cs->seglen -= cs->len; cs->addr += cs->len; - return lock_request(cs->req); + return lock_request(cs->fc, cs->req); } /* Do as much copy to/from userspace buffer as we can */ @@ -585,9 +568,9 @@ static void request_wait(struct fuse_conn *fc) if (signal_pending(current)) break; - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); schedule(); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); } set_current_state(TASK_RUNNING); remove_wait_queue(&fc->waitq, &wait); @@ -606,18 +589,21 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, unsigned long nr_segs, loff_t *off) { int err; - struct fuse_conn *fc; struct fuse_req *req; struct fuse_in *in; struct fuse_copy_state cs; unsigned reqsize; + struct fuse_conn *fc = fuse_get_conn(file); + if (!fc) + return -EPERM; restart: - spin_lock(&fuse_lock); - fc = file->private_data; - err = -EPERM; - if (!fc) + spin_lock(&fc->lock); + err = -EAGAIN; + if ((file->f_flags & O_NONBLOCK) && fc->connected && + list_empty(&fc->pending)) goto err_unlock; + request_wait(fc); err = -ENODEV; if (!fc->connected) @@ -641,14 +627,14 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, request_end(fc, req); goto restart; } - spin_unlock(&fuse_lock); - fuse_copy_init(&cs, 1, req, iov, nr_segs); + spin_unlock(&fc->lock); + fuse_copy_init(&cs, fc, 1, req, iov, nr_segs); 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(&fuse_lock); + spin_lock(&fc->lock); req->locked = 0; if (!err && req->interrupted) err = -ENOENT; @@ -663,12 +649,12 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, else { req->state = FUSE_REQ_SENT; list_move_tail(&req->list, &fc->processing); - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } return reqsize; err_unlock: - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); return err; } @@ -735,9 +721,9 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, struct fuse_copy_state cs; struct fuse_conn *fc = fuse_get_conn(file); if (!fc) - return -ENODEV; + return -EPERM; - fuse_copy_init(&cs, 0, NULL, iov, nr_segs); + fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs); if (nbytes < sizeof(struct fuse_out_header)) return -EINVAL; @@ -749,7 +735,7 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, oh.len != nbytes) goto err_finish; - spin_lock(&fuse_lock); + spin_lock(&fc->lock); err = -ENOENT; if (!fc->connected) goto err_unlock; @@ -760,9 +746,9 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, goto err_unlock; if (req->interrupted) { - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); fuse_copy_finish(&cs); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); request_end(fc, req); return -ENOENT; } @@ -770,12 +756,12 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, req->out.h = oh; req->locked = 1; cs.req = req; - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); err = copy_out_args(&cs, &req->out, nbytes); fuse_copy_finish(&cs); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); req->locked = 0; if (!err) { if (req->interrupted) @@ -787,7 +773,7 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov, return err ? err : nbytes; err_unlock: - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); err_finish: fuse_copy_finish(&cs); return err; @@ -804,18 +790,19 @@ static ssize_t fuse_dev_write(struct file *file, const char __user *buf, static unsigned fuse_dev_poll(struct file *file, poll_table *wait) { - struct fuse_conn *fc = fuse_get_conn(file); unsigned mask = POLLOUT | POLLWRNORM; - + struct fuse_conn *fc = fuse_get_conn(file); if (!fc) - return -ENODEV; + return POLLERR; poll_wait(file, &fc->waitq, wait); - spin_lock(&fuse_lock); - if (!list_empty(&fc->pending)) - mask |= POLLIN | POLLRDNORM; - spin_unlock(&fuse_lock); + spin_lock(&fc->lock); + if (!fc->connected) + mask = POLLERR; + else if (!list_empty(&fc->pending)) + mask |= POLLIN | POLLRDNORM; + spin_unlock(&fc->lock); return mask; } @@ -823,7 +810,7 @@ static unsigned fuse_dev_poll(struct file *file, poll_table *wait) /* * Abort all requests on the given list (pending or processing) * - * This function releases and reacquires fuse_lock + * This function releases and reacquires fc->lock */ static void end_requests(struct fuse_conn *fc, struct list_head *head) { @@ -832,7 +819,7 @@ static void end_requests(struct fuse_conn *fc, struct list_head *head) req = list_entry(head->next, struct fuse_req, list); req->out.h.error = -ECONNABORTED; request_end(fc, req); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); } } @@ -863,10 +850,10 @@ static void end_io_requests(struct fuse_conn *fc) req->end = NULL; /* The end function will consume this reference */ __fuse_get_request(req); - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); wait_event(req->waitq, !req->locked); end(fc, req); - spin_lock(&fuse_lock); + spin_lock(&fc->lock); } } } @@ -893,35 +880,44 @@ static void end_io_requests(struct fuse_conn *fc) */ void fuse_abort_conn(struct fuse_conn *fc) { - spin_lock(&fuse_lock); + spin_lock(&fc->lock); if (fc->connected) { fc->connected = 0; end_io_requests(fc); end_requests(fc, &fc->pending); end_requests(fc, &fc->processing); wake_up_all(&fc->waitq); + kill_fasync(&fc->fasync, SIGIO, POLL_IN); } - spin_unlock(&fuse_lock); + spin_unlock(&fc->lock); } static int fuse_dev_release(struct inode *inode, struct file *file) { - struct fuse_conn *fc; - - spin_lock(&fuse_lock); - fc = file->private_data; + struct fuse_conn *fc = fuse_get_conn(file); if (fc) { + spin_lock(&fc->lock); fc->connected = 0; end_requests(fc, &fc->pending); end_requests(fc, &fc->processing); - } - spin_unlock(&fuse_lock); - if (fc) + spin_unlock(&fc->lock); + fasync_helper(-1, file, 0, &fc->fasync); kobject_put(&fc->kobj); + } return 0; } +static int fuse_dev_fasync(int fd, struct file *file, int on) +{ + struct fuse_conn *fc = fuse_get_conn(file); + if (!fc) + return -EPERM; + + /* No locking - fasync_helper does its own locking */ + return fasync_helper(fd, file, on, &fc->fasync); +} + const struct file_operations fuse_dev_operations = { .owner = THIS_MODULE, .llseek = no_llseek, @@ -931,6 +927,7 @@ const struct file_operations fuse_dev_operations = { .writev = fuse_dev_writev, .poll = fuse_dev_poll, .release = fuse_dev_release, + .fasync = fuse_dev_fasync, }; static struct miscdevice fuse_miscdevice = { |