Commit 9658b72e authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba
Browse files

btrfs: zoned: locate superblock position using zone capacity 



sb_write_pointer() returns the write position of next superblock. For READ,
we need a previous location. When the pointer is at the head, the previous
one is the last one of the other zone. Calculate the last one's position
from zone capacity.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 5daaf552

fs/btrfs/zoned.c

+13 −2
Original line number Diff line number Diff line
@@ -683,9 +683,20 @@ static int sb_log_location(struct block_device *bdev, struct blk_zone *zones, 
			reset->wp = reset->start;

		}

	} else if (ret != -ENOENT) {

		/* For READ, we want the precious one */

		/*

		 * For READ, we want the previous one. Move write pointer to

		 * the end of a zone, if it is at the head of a zone.

		 */

		u64 zone_end = 0;



		if (wp == zones[0].start << SECTOR_SHIFT)

			wp = (zones[1].start + zones[1].len) << SECTOR_SHIFT;

			zone_end = zones[1].start + zones[1].capacity;

		else if (wp == zones[1].start << SECTOR_SHIFT)

			zone_end = zones[0].start + zones[0].capacity;

		if (zone_end)

			wp = ALIGN_DOWN(zone_end << SECTOR_SHIFT,

					BTRFS_SUPER_INFO_SIZE);



		wp -= BTRFS_SUPER_INFO_SIZE;

	}