[PATCH 4.9 088/153] fuse: add missing FR_FORCE

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszeredi@xxxxxxxxxx>

commit 2e38bea99a80eab408adee27f873a188d57b76cb upstream.

fuse_file_put() was missing the "force" flag for the RELEASE request when
sending synchronously (fuseblk).

If this flag is not set, then a sync request may be interrupted before it
is dequeued by the userspace filesystem.  In this case the OPEN won't be
balanced with a RELEASE.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Fixes: 5a18ec176c93 ("fuse: fix hang of single threaded fuseblk filesystem")
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/fuse/file.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -100,6 +100,7 @@ static void fuse_file_put(struct fuse_fi
 			iput(req->misc.release.inode);
 			fuse_put_request(ff->fc, req);
 		} else if (sync) {
+			__set_bit(FR_FORCE, &req->flags);
 			__clear_bit(FR_BACKGROUND, &req->flags);
 			fuse_request_send(ff->fc, req);
 			iput(req->misc.release.inode);