Commit e0c60d01 authored by Shin'ichiro Kawasaki's avatar Shin'ichiro Kawasaki Committed by Jens Axboe
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block: Fix partition check for host-aware zoned block devices 



Commit a33df75c ("block: use an xarray for disk->part_tbl") modified
the method to check partition existence in host-aware zoned block
devices from disk_has_partitions() helper function call to empty check
of xarray disk->part_tbl. However, disk->part_tbl always has single
entry for disk->part0 and never becomes empty. This resulted in the
host-aware zoned devices always judged to have partitions, and it made
the sysfs queue/zoned attribute to be "none" instead of "host-aware"
regardless of partition existence in the devices.

This also caused DEBUG_LOCKS_WARN_ON(lock->magic != lock) for
sdkp->rev_mutex in scsi layer when the kernel detects host-aware zoned
device. Since block layer handled the host-aware zoned devices as non-
zoned devices, scsi layer did not have chance to initialize the mutex
for zone revalidation. Therefore, the warning was triggered.

To fix the issues, call the helper function disk_has_partitions() in
place of disk->part_tbl empty check. Since the function was removed with
the commit a33df75c, reimplement it to walk through entries in the
xarray disk->part_tbl.

Fixes: a33df75c ("block: use an xarray for disk->part_tbl")
Signed-off-by: default avatarShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Cc: stable@vger.kernel.org # v5.14+
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211026060115.753746-1-shinichiro.kawasaki@wdc.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9586e67b

block/blk-settings.c

+19 −1
Original line number Diff line number Diff line
@@ -842,6 +842,24 @@ bool blk_queue_can_use_dma_map_merging(struct request_queue *q, 
}

EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);



static bool disk_has_partitions(struct gendisk *disk)

{

	unsigned long idx;

	struct block_device *part;

	bool ret = false;



	rcu_read_lock();

	xa_for_each(&disk->part_tbl, idx, part) {

		if (bdev_is_partition(part)) {

			ret = true;

			break;

		}

	}

	rcu_read_unlock();



	return ret;

}



/**

 * blk_queue_set_zoned - configure a disk queue zoned model.

 * @disk:	the gendisk of the queue to configure
@@ -876,7 +894,7 @@ void blk_queue_set_zoned(struct gendisk *disk, enum blk_zoned_model model) 
		 * we do nothing special as far as the block layer is concerned.

		 */

		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) ||

		    !xa_empty(&disk->part_tbl))

		    disk_has_partitions(disk))

			model = BLK_ZONED_NONE;

		break;

	case BLK_ZONED_NONE: