Commit 58367c8a authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: sanitize the elevator name before passing it to __elevator_change 



The stripped name should also be used for the none check.  To do so
strip it in the caller and pass in the sanitized name.  Drop the pointless
__ prefix in the function name while we're at it.

Based on a patch from Jinlong Chen <nickyc975@zju.edu.cn>.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221020064819.1469928-3-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dd6f7f17

block/elevator.c

+7 −8
Original line number Diff line number Diff line
@@ -734,9 +734,8 @@ int elevator_switch(struct request_queue *q, struct elevator_type *new_e) 
/*

 * Switch this queue to the given IO scheduler.

 */

static int __elevator_change(struct request_queue *q, const char *name)

static int elevator_change(struct request_queue *q, const char *elevator_name)

{

	char elevator_name[ELV_NAME_MAX];

	struct elevator_type *e;



	/* Make sure queue is not in the middle of being removed */
@@ -746,14 +745,13 @@ static int __elevator_change(struct request_queue *q, const char *name) 
	/*

	 * Special case for mq, turn off scheduling

	 */

	if (!strncmp(name, "none", 4)) {

	if (!strncmp(elevator_name, "none", 4)) {

		if (!q->elevator)

			return 0;

		return elevator_switch(q, NULL);

	}



	strlcpy(elevator_name, name, sizeof(elevator_name));

	e = elevator_get(q, strstrip(elevator_name), true);

	e = elevator_get(q, elevator_name, true);

	if (!e)

		return -EINVAL;
@@ -766,18 +764,19 @@ static int __elevator_change(struct request_queue *q, const char *name) 
	return elevator_switch(q, e);

}



ssize_t elv_iosched_store(struct request_queue *q, const char *name,

ssize_t elv_iosched_store(struct request_queue *q, const char *buf,

			  size_t count)

{

	char elevator_name[ELV_NAME_MAX];

	int ret;



	if (!elv_support_iosched(q))

		return count;



	ret = __elevator_change(q, name);

	strlcpy(elevator_name, buf, sizeof(elevator_name));

	ret = elevator_change(q, strstrip(elevator_name));

	if (!ret)

		return count;



	return ret;

}