Commit d1a987f3 authored by Jens Axboe's avatar Jens Axboe
Browse files

elevator: fix loading wrong elevator type for blk-mq devices 



The old elevator= boot parameter blindly attempts to load the
same scheduler for mq and !mq devices, leading to a crash if
we specify the wrong one.

Ensure that we only apply this boot parameter to old !mq devices.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent c5c9b26e

block/elevator.c

+5 −4
Original line number Diff line number Diff line
@@ -207,11 +207,12 @@ int elevator_init(struct request_queue *q, char *name) 
	}



	/*

	 * Use the default elevator specified by config boot param or

	 * config option.  Don't try to load modules as we could be running

	 * off async and request_module() isn't allowed from async.

	 * Use the default elevator specified by config boot param for

	 * non-mq devices, or by config option. Don't try to load modules

	 * as we could be running off async and request_module() isn't

	 * allowed from async.

	 */

	if (!e && *chosen_elevator) {

	if (!e && !q->mq_ops && *chosen_elevator) {

		e = elevator_get(chosen_elevator, false);

		if (!e)

			printk(KERN_ERR "I/O scheduler %s not found\n",

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