[PATCH] fuse: fix fuse_dev_poll() return value

fuse_dev_poll() returned an error value instead of a poll mask.  Luckily (or
unluckily) -ENODEV does contain the POLLERR bit.

There's also a race if filesystem is unmounted between fuse_get_conn() and
spin_lock(), in which case this event will be missed by poll().

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 23d1f52eb1b8..b2e8613a26d8 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -804,17 +804,18 @@ 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;
+        if (!fc->connected)
+                mask = POLLERR;
+        else if (!list_empty(&fc->pending))
+                mask |= POLLIN | POLLRDNORM;
         spin_unlock(&fuse_lock);
 
         return mask;