block: add a queue_limits_commit_update_frozen helper

JIRA: https://issues.redhat.com/browse/RHEL-71345
Upstream Status: for-6.4/block

commit aa427d7
Author: Christoph Hellwig <hch@lst.de>
Date:   Fri Jan 10 06:47:10 2025 +0100

    block: add a queue_limits_commit_update_frozen helper

    Add a helper that freezes the queue, updates the queue limits and
    unfreezes the queue and convert all open coded versions of that to the
    new helper.

    Signed-off-by: Christoph Hellwig <hch@lst.de>
    Reviewed-by: John Garry <john.g.garry@oracle.com>
    Reviewed-by: Ming Lei <ming.lei@redhat.com>
    Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
    Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
    Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
    Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
    Link: https://lore.kernel.org/r/20250110054726.1499538-3-hch@lst.de
    Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Ming Lei <ming.lei@redhat.com>

Author: Ming Lei

block/blk-integrity.c

@@ -218,9 +218,7 @@ static ssize_t flag_store(struct device *dev, const char *page, size_t count,
 	else
 		lim.integrity.flags |= flag;
 
-	blk_mq_freeze_queue(q);
-	err = queue_limits_commit_update(q, &lim);
-	blk_mq_unfreeze_queue(q);
+	err = queue_limits_commit_update_frozen(q, &lim);
 	if (err)
 		return err;
 	return count;

block/blk-settings.c

@@ -420,6 +420,30 @@ int queue_limits_commit_update(struct request_queue *q,
 }
 EXPORT_SYMBOL_GPL(queue_limits_commit_update);
 
+/**
+ * queue_limits_commit_update_frozen - commit an atomic update of queue limits
+ * @q:		queue to update
+ * @lim:	limits to apply
+ *
+ * Apply the limits in @lim that were obtained from queue_limits_start_update()
+ * and updated with the new values by the caller to @q.  Freezes the queue
+ * before the update and unfreezes it after.
+ *
+ * Returns 0 if successful, else a negative error code.
+ */
+int queue_limits_commit_update_frozen(struct request_queue *q,
+		struct queue_limits *lim)
+{
+	int ret;
+
+	blk_mq_freeze_queue(q);
+	ret = queue_limits_commit_update(q, lim);
+	blk_mq_unfreeze_queue(q);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(queue_limits_commit_update_frozen);
+
 /**
  * queue_limits_commit_set - apply queue limits to queue
  * @q:		queue to update

block/blk-zoned.c

@@ -1446,7 +1446,6 @@ static int disk_update_zone_resources(struct gendisk *disk,
 	unsigned int nr_seq_zones, nr_conv_zones;
 	unsigned int pool_size;
 	struct queue_limits lim;
-	int ret;
 
 	disk->nr_zones = args->nr_zones;
 	disk->zone_capacity = args->zone_capacity;
@@ -1497,11 +1496,7 @@ static int disk_update_zone_resources(struct gendisk *disk,
 	}
 
 commit:
-	blk_mq_freeze_queue(q);
-	ret = queue_limits_commit_update(q, &lim);
-	blk_mq_unfreeze_queue(q);
-
-	return ret;
+	return queue_limits_commit_update_frozen(q, &lim);
 }
 
 static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx,

drivers/block/virtio_blk.c

@@ -1115,9 +1115,7 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 		lim.features |= BLK_FEAT_WRITE_CACHE;
 	else
 		lim.features &= ~BLK_FEAT_WRITE_CACHE;
-	blk_mq_freeze_queue(disk->queue);
-	i = queue_limits_commit_update(disk->queue, &lim);
-	blk_mq_unfreeze_queue(disk->queue);
+	i = queue_limits_commit_update_frozen(disk->queue, &lim);
 	if (i)
 		return i;
 	return count;

drivers/scsi/sd.c

@@ -183,9 +183,8 @@ cache_type_store(struct device *dev, struct device_attribute *attr,
 
 		lim = queue_limits_start_update(sdkp->disk->queue);
 		sd_set_flush_flag(sdkp, &lim);
-		blk_mq_freeze_queue(sdkp->disk->queue);
-		ret = queue_limits_commit_update(sdkp->disk->queue, &lim);
-		blk_mq_unfreeze_queue(sdkp->disk->queue);
+		ret = queue_limits_commit_update_frozen(sdkp->disk->queue,
+				&lim);
 		if (ret)
 			return ret;
 		return count;
@@ -489,9 +488,7 @@ provisioning_mode_store(struct device *dev, struct device_attribute *attr,
 
 	lim = queue_limits_start_update(sdkp->disk->queue);
 	sd_config_discard(sdkp, &lim, mode);
-	blk_mq_freeze_queue(sdkp->disk->queue);
-	err = queue_limits_commit_update(sdkp->disk->queue, &lim);
-	blk_mq_unfreeze_queue(sdkp->disk->queue);
+	err = queue_limits_commit_update_frozen(sdkp->disk->queue, &lim);
 	if (err)
 		return err;
 	return count;
@@ -600,9 +597,7 @@ max_write_same_blocks_store(struct device *dev, struct device_attribute *attr,
 
 	lim = queue_limits_start_update(sdkp->disk->queue);
 	sd_config_write_same(sdkp, &lim);
-	blk_mq_freeze_queue(sdkp->disk->queue);
-	err = queue_limits_commit_update(sdkp->disk->queue, &lim);
-	blk_mq_unfreeze_queue(sdkp->disk->queue);
+	err = queue_limits_commit_update_frozen(sdkp->disk->queue, &lim);
 	if (err)
 		return err;
 	return count;
@@ -3714,9 +3709,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
 	sd_config_write_same(sdkp, &lim);
 	kfree(buffer);
 
-	blk_mq_freeze_queue(sdkp->disk->queue);
-	err = queue_limits_commit_update(sdkp->disk->queue, &lim);
-	blk_mq_unfreeze_queue(sdkp->disk->queue);
+	err = queue_limits_commit_update_frozen(sdkp->disk->queue, &lim);
 	if (err)
 		return err;
 

drivers/scsi/sr.c

@@ -797,10 +797,7 @@ static int get_sectorsize(struct scsi_cd *cd)
 
 	lim = queue_limits_start_update(q);
 	lim.logical_block_size = sector_size;
-	blk_mq_freeze_queue(q);
-	err = queue_limits_commit_update(q, &lim);
-	blk_mq_unfreeze_queue(q);
-	return err;
+	return queue_limits_commit_update_frozen(q, &lim);
 }
 
 static int get_capabilities(struct scsi_cd *cd)

include/linux/blkdev.h

@@ -919,6 +919,8 @@ queue_limits_start_update(struct request_queue *q)
 	mutex_lock(&q->limits_lock);
 	return q->limits;
 }
+int queue_limits_commit_update_frozen(struct request_queue *q,
+		struct queue_limits *lim);
 int queue_limits_commit_update(struct request_queue *q,
 		struct queue_limits *lim);
 int queue_limits_set(struct request_queue *q, struct queue_limits *lim);