[PATCH 5/5] fuse: fix synchronous case of fuse_file_put()

[Maxim Patlasov <MPatlasov@parallels.com>]

If fuse_file_put() is called with sync==true, the user may be blocked for
a while, until userspace ACKs our FUSE_RELEASE request. This blocking must be
uninterruptible. Otherwise request could be interrupted, but file association
in user space remains.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
---
 fs/fuse/file.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 783cb52..9f38568 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -136,6 +136,10 @@ static void fuse_file_put(struct fuse_file *ff, bool sync)
 			path_put(&req->misc.release.path);
 			fuse_put_request(ff->fc, req);
 		} else if (sync) {
+			/* Must force. Otherwise request could be interrupted,
+			 * but file association in user space remains.
+			 */
+			req->force = 1;
 			req->background = 0;
 			fuse_request_send(ff->fc, req);
 			path_put(&req->misc.release.path);