diff options
| author | Jeff Dike <jdike@addtoit.com> | 2006-04-10 22:54:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-11 06:18:48 -0700 |
| commit | 385a17bfc3cb035333c8a91eddc78a6e04c4625e (patch) | |
| tree | 7a9fde77c95f0e4cc86f31e8b1f5d23b6d815634 /fs/fuse/dev.c | |
| parent | 7025d9ad10a38dadef8b286e0092731c2d3cdc53 (diff) | |
[PATCH] fuse: add O_ASYNC support to FUSE device
This adds asynchronous notification to FUSE - a FUSE server can request
O_ASYNC on a /dev/fuse file descriptor and receive SIGIO when there is input
available.
One subtlety - fuse_dev_fasync, which is called when O_ASYNC is requested,
does no locking, unlink the other methods. I think it's unnecessary, as the
fuse_conn.fasync list is manipulated only by fasync_helper and kill_fasync,
which provide their own locking. It would also be wrong to use the fuse_lock,
as it's a spin lock and fasync_helper can sleep. My one concern with this is
the fuse_conn going away underneath fuse_dev_fasync - sys_fcntl takes a
reference on the file struct, so this seems not to be a problem.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/fuse/dev.c')
| -rw-r--r-- | fs/fuse/dev.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index b2e8613a26d8..438770f8867f 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -317,6 +317,7 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req) list_add_tail(&req->list, &fc->pending); req->state = FUSE_REQ_PENDING; wake_up(&fc->waitq); + kill_fasync(&fc->fasync, SIGIO, POLL_IN); } /* @@ -901,6 +902,7 @@ void fuse_abort_conn(struct fuse_conn *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); } @@ -917,12 +919,24 @@ static int fuse_dev_release(struct inode *inode, struct file *file) end_requests(fc, &fc->processing); } spin_unlock(&fuse_lock); - if (fc) + if (fc) { + 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 -ENODEV; + + /* 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, @@ -932,6 +946,7 @@ 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 = { |