[patch 67/67] block layer: elv_iosched_show should get elv_list_lock

Greg KH
2006-10-11T21:10:59Z

[-- Attachment #1: block-layer-elv_iosched_show-should-get-elv_list_lock.patch --]
[-- Type: text/plain, Size: 1172 bytes --]

-stable review patch. If anyone has any objections, please let us know.

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From: Vasily Tarasov <vtaras@openvz.org>

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>

---
block/elevator.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-2.6.18.orig/block/elevator.c
+++ linux-2.6.18/block/elevator.c
@@ -892,7 +892,7 @@ ssize_t elv_iosched_show(request_queue_t
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
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;

--