tree bfe985113e15690714d8d099f454c5dc06c91a18
parent cc3200eac4c5eb11c3f34848a014d1f286316310
author Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> 1582249028 +0900
committer Jens Axboe <axboe@kernel.dk> 1584021279 -0600

block: Fix partition support for host aware zoned block devices

Commit b72053072c0b ("block: allow partitions on host aware zone
devices") introduced the helper function disk_has_partitions() to check
if a given disk has valid partitions. However, since this function result
directly depends on the disk partition table length rather than the
actual existence of valid partitions in the table, it returns true even
after all partitions are removed from the disk. For host aware zoned
block devices, this results in zone management support to be kept
disabled even after removing all partitions.

Fix this by changing disk_has_partitions() to walk through the partition
table entries and return true if and only if a valid non-zero size
partition is found.

Fixes: b72053072c0b ("block: allow partitions on host aware zone devices")
Cc: stable@vger.kernel.org # 5.5
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>