block: use queue_limits_commit_update in queue_discard_max_store

Convert queue_discard_max_store to use queue_limits_commit_update to
check and update the max_discard_sectors limit and freeze the queue
before doing so to ensure we don't have requests in flight while
changing the limits.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

1 files changed, 10 insertions, 3 deletions

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index a1ec27f0ba41..8c8f69d8ba48 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -175,7 +175,9 @@ static ssize_t queue_discard_max_store(struct request_queue *q,
 				       const char *page, size_t count)
 {
 	unsigned long max_discard_bytes;
+	struct queue_limits lim;
 	ssize_t ret;
+	int err;
 
 	ret = queue_var_store(&max_discard_bytes, page, count);
 	if (ret < 0)
@@ -187,9 +189,14 @@ static ssize_t queue_discard_max_store(struct request_queue *q,
 	if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
 		return -EINVAL;
 
-	q->limits.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
-	q->limits.max_discard_sectors = min(q->limits.max_hw_discard_sectors,
-					    q->limits.max_user_discard_sectors);
+	blk_mq_freeze_queue(q);
+	lim = queue_limits_start_update(q);
+	lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
+	err = queue_limits_commit_update(q, &lim);
+	blk_mq_unfreeze_queue(q);
+
+	if (err)
+		return err;
 	return ret;
 }