diff options
| author | Jeff Dike <jdike@addtoit.com> | 2006-04-11 07:54:52 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-11 15:18:48 +0200 |
| commit | 385a17bfc3cb035333c8a91eddc78a6e04c4625e (patch) | |
| tree | 7a9fde77c95f0e4cc86f31e8b1f5d23b6d815634 | |
| parent | [PATCH] fuse: fix fuse_dev_poll() return value (diff) | |
| download | linux-385a17bfc3cb035333c8a91eddc78a6e04c4625e.tar.xz linux-385a17bfc3cb035333c8a91eddc78a6e04c4625e.zip | |
[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>
| -rw-r--r-- | fs/fuse/dev.c | 17 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 3 | ||||
| -rw-r--r-- | fs/fuse/inode.c | 1 |
3 files changed, 20 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 = { diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index a16a04fcf41e..e5cb46b78437 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -318,6 +318,9 @@ struct fuse_conn { /** kobject */ struct kobject kobj; + + /** O_ASYNC requests */ + struct fasync_struct *fasync; }; static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 879e6fba9480..78700cbb9cdf 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -216,6 +216,7 @@ static void fuse_put_super(struct super_block *sb) spin_unlock(&fuse_lock); up_write(&fc->sbput_sem); /* Flush all readers on this fs */ + kill_fasync(&fc->fasync, SIGIO, POLL_IN); wake_up_all(&fc->waitq); kobject_del(&fc->kobj); kobject_put(&fc->kobj); |