From: Todd Poynor <toddpoynor@google.com>
Date: Wed, 24 Aug 2011 22:01:30 +0000 (-0700)
Subject: fuse: Freeze client on suspend when request sent to userspace
X-Git-Tag: firefly_0821_release~2958^2~96
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d111876c7ea15f9041c792c141fcfab5de8cf379;p=firefly-linux-kernel-4.4.55.git

fuse: Freeze client on suspend when request sent to userspace

Suspend attempts can abort when the FUSE daemon is already frozen
and a client is waiting uninterruptibly for a response, causing
freezing of tasks to fail.

Use the freeze-friendly wait API, but disregard other signals.

Change-Id: Icefb7e4bbc718ccb76bf3c04daaa5eeea7e0e63c
Signed-off-by: Todd Poynor <toddpoynor@google.com>
---

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ebb5e37455a0..175fcdeabe4c 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -19,6 +19,7 @@
 #include <linux/pipe_fs_i.h>
 #include <linux/swap.h>
 #include <linux/splice.h>
+#include <linux/freezer.h>
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 MODULE_ALIAS("devname:fuse");
@@ -473,7 +474,9 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 	 * Either request is already in userspace, or it was forced.
 	 * Wait it out.
 	 */
-	wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
+	while (!test_bit(FR_FINISHED, &req->flags))
+		wait_event_freezable(req->waitq,
+				test_bit(FR_FINISHED, &req->flags));
 }
 
 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)