From: Jens Axboe <jens.axboe@oracle.com>
Date: Thu, 18 Sep 2008 16:22:54 +0000 (-0700)
Subject: block: blk_cleanup_queue() should call blk_sync_queue()
X-Git-Tag: v2.6.28-rc1~733^2~31
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=e3335de94067dbebe22e3962632ead34e832cb60

block: blk_cleanup_queue() should call blk_sync_queue()

When a driver calls blk_cleanup_queue(), the device should be fully idle.
However, the block layer may have pending plugging timers and the IO
schedulers may have pending work in the work queues. So quisce the device
by waiting for the timer and flushing the work queues.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/block/blk-core.c b/block/blk-core.c
index d768a8ddc173..37fba001bdcf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -436,6 +436,14 @@ void blk_put_queue(struct request_queue *q)
 
 void blk_cleanup_queue(struct request_queue *q)
 {
+	/*
+	 * We know we have process context here, so we can be a little
+	 * cautious and ensure that pending block actions on this device
+	 * are done before moving on. Going into this function, we should
+	 * not have processes doing IO to this device.
+	 */
+	blk_sync_queue(q);
+
 	mutex_lock(&q->sysfs_lock);
 	queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
 	mutex_unlock(&q->sysfs_lock);