From 385a17bfc3cb035333c8a91eddc78a6e04c4625e Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 10 Apr 2006 22:54:52 -0700 Subject: [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 Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/inode.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/fuse/inode.c') 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); -- cgit v1.2.3-55-g7522