[PATCH 4/6] fuse: enable close_wait synchronous release

[Maxim Patlasov <MPatlasov@parallels.com>]

The patch enables the feature by passing 'true' to fuse_file_put in
fuse_release_common.

Previously, this was safe only in special cases when we sure that
multi-threaded userspace won't deadlock if we'll synchronously send
FUSE_RELEASE in the context of read-ahead or write-back callback. Now, it's
always safe because callbacks don't send requests to userspace anymore.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
---
 fs/fuse/file.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 73bce1b..cd55488 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -333,7 +333,8 @@ void fuse_release_common(struct file *file, int opcode)
 	 * synchronous RELEASE is allowed (and desirable) in this case
 	 * because the server can be trusted not to screw up.
 	 */
-	fuse_file_put(ff, ff->fc->destroy_req != NULL);
+	fuse_file_put(ff, ff->fc->destroy_req != NULL ||
+			  must_release_synchronously(ff));
 }
 
 static int fuse_open(struct inode *inode, struct file *file)