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~4090^2~788
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e584105db8de7ff57c8a4d6c8e2d2efa4827b7bb;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 1d55f9465400..0e16fc1cfcd3 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -20,6 +20,7 @@
 #include <linux/swap.h>
 #include <linux/splice.h>
 #include <linux/aio.h>
+#include <linux/freezer.h>
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 MODULE_ALIAS("devname:fuse");
@@ -464,7 +465,10 @@ __acquires(fc->lock)
 	 * Wait it out.
 	 */
 	spin_unlock(&fc->lock);
-	wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
+
+	while (req->state != FUSE_REQ_FINISHED)
+		wait_event_freezable(req->waitq,
+				     req->state == FUSE_REQ_FINISHED);
 	spin_lock(&fc->lock);
 
 	if (!req->aborted)