From 8f6665afff79f98e63561fe7629cb35764d132a0 Mon Sep 17 00:00:00 2001
From: Mark Lord <kernel@teksavvy.com>
Date: Fri, 24 Sep 2010 09:51:13 -0400
Subject: [PATCH] --- yaml --- r: 213055 b: refs/heads/master c:
 4b1977698ceb4c4caa800d475127139da49966f9 h: refs/heads/master i:   213053:
 90ffc571f5c2980a14f9533e1eee395529284629   213051:
 471c905253184a7419615faa5e70d97b13ed4630   213047:
 b11b30985e611923fae4a5d492f8efc4fa78afa8   213039:
 ddd966a09cc968c25c6e9b4298f8503efe2c8be2   213023:
 4dc5572978494c37a8a84ba7276f0e41ee26e66f   212991:
 0c478d4f5473aabada2e4f738739d42a1a13a2eb v: v3

---
 [refs]                 | 2 +-
 trunk/block/blk-exec.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 76212b399f53..7ea941981907 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 749ef9f8423054e326f3a246327ed2db4b6d395f
+refs/heads/master: 4b1977698ceb4c4caa800d475127139da49966f9
diff --git a/trunk/block/blk-exec.c b/trunk/block/blk-exec.c
index e1672f14840e..cf1456a02acd 100644
--- a/trunk/block/blk-exec.c
+++ b/trunk/block/blk-exec.c
@@ -80,6 +80,7 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	char sense[SCSI_SENSE_BUFFERSIZE];
 	int err = 0;
+	unsigned long hang_check;
 
 	/*
 	 * we need an extra reference to the request, so we can look at
@@ -95,7 +96,13 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 
 	rq->end_io_data = &wait;
 	blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
-	wait_for_completion(&wait);
+
+	/* Prevent hang_check timer from firing at us during very long I/O */
+	hang_check = sysctl_hung_task_timeout_secs;
+	if (hang_check)
+		while (!wait_for_completion_timeout(&wait, hang_check * (HZ/2)));
+	else
+		wait_for_completion(&wait);
 
 	if (rq->errors)
 		err = -EIO;