tree 6be71e265e503888b87c99f7211cc4279a9c5c89
parent 569fda5c0183f36ea86185ca505fdf91dfcf4def
author Miklos Szeredi <mszeredi@redhat.com> 1538145802 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1542788354 +0100

fuse: fix blocked_waitq wakeup

commit 908a572b80f6e9577b45e81b3dfe2e22111286b8 upstream.

Using waitqueue_active() is racy.  Make sure we issue a wake_up()
unconditionally after storing into fc->blocked.  After that it's okay to
optimize with waitqueue_active() since the first wake up provides the
necessary barrier for all waiters, not the just the woken one.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 3c18ef8117f0 ("fuse: optimize wake_up")
Cc: <stable@vger.kernel.org> # v3.10
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>