Commit b8a9ae77 authored Sep 11, 2009 by Jens Axboe

block: don't assume device has a request list backing in nr_requests store



Stacked devices do not. For now, just error out with -EINVAL. Later
we could make the limit apply on stacked devices too, for throttling
reasons.

This fixes

5a54cd13353bb3b88887604e2c980aa01e314309

and should go into 2.6.31 stable as well.

Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

parent 3c5820c7

block/blk-sysfs.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -40,7 +40,12 @@ queue_requests_store(struct request_queue q, const char page, size_t count)
		{
		struct request_list *rl = &q->rq;
		unsigned long nr;
		int ret = queue_var_store(&nr, page, count);
		int ret;

		if (!q->request_fn)
		return -EINVAL;

		ret = queue_var_store(&nr, page, count);
		if (nr < BLKDEV_MIN_RQ)
		nr = BLKDEV_MIN_RQ;