From: Vasily Tarasov <vtaras@openvz.org>
Date: Wed, 11 Oct 2006 11:23:48 +0000 (+0200)
Subject: block layer: elv_iosched_show should get elv_list_lock
X-Git-Tag: v2.6.18.1~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=116191c17c2c8e7e7d4fa9d5ed4a3218ff8d2055;p=thirdparty%2Fkernel%2Fstable.git

block layer: elv_iosched_show should get elv_list_lock

elv_iosched_show function iterates other elv_list,
hence elv_list_lock should be got.

Also the question is: in elv_iosched_show, elv_iosched_store
q->elevator->elevator_type construction is used without locking q->queue_lock.
Is it expected?..

Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/block/elevator.c b/block/elevator.c
index 9b72dc7c8a5c9..8ed284691c0bc 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -892,7 +892,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 	struct list_head *entry;
 	int len = 0;
 
-	spin_lock_irq(q->queue_lock);
+	spin_lock_irq(&elv_list_lock);
 	list_for_each(entry, &elv_list) {
 		struct elevator_type *__e;
 
@@ -902,7 +902,7 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 		else
 			len += sprintf(name+len, "%s ", __e->elevator_name);
 	}
-	spin_unlock_irq(q->queue_lock);
+	spin_unlock_irq(&elv_list_lock);
 
 	len += sprintf(len+name, "\n");
 	return len;