[PATCH 06/17] btrfs: zoned: locate superblock position using zone capacity
From: Naohiro Aota <naohiro.aota@wdc.com>
Date: 2021-08-11 14:21:02
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
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. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> --- fs/btrfs/zoned.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index d20c97395a70..188a4ebefe59 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c@@ -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; }
--
2.32.0