[PATCH] btrfs: zoned: fix alloc offset calculation

[PATCH] btrfs: zoned: fix alloc offset calculation

[Naohiro Aota]

alloc_offset is offset from the start of a block group and @offset is
actually an address in logical space. Thus, we need to consider
block_group->start when calculating them.

Fixes: 011b41bffa3d ("btrfs: zoned: advance allocation pointer after tree log node")
Cc: stable@vger.kernel.org # 5.12+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/free-space-cache.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 8eeb65278ac0..e12f4d34e317 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2646,8 +2646,11 @@ int btrfs_remove_free_space(struct btrfs_block_group *block_group,
 		 * btrfs_pin_extent_for_log_replay() when replaying the log.
 		 * Advance the pointer not to overwrite the tree-log nodes.
 		 */
-		if (block_group->alloc_offset < offset + bytes)
-			block_group->alloc_offset = offset + bytes;
+		if (block_group->start + block_group->alloc_offset <
+		    offset + bytes) {
+			block_group->alloc_offset =
+				offset + bytes - block_group->start;
+		}
 		return 0;
 	}
 
-- 
2.32.0

Re: [PATCH] btrfs: zoned: fix alloc offset calculation

[David Sterba]

On Mon, Aug 09, 2021 at 01:13:44PM +0900, Naohiro Aota wrote:
> alloc_offset is offset from the start of a block group and @offset is
> actually an address in logical space. Thus, we need to consider
> block_group->start when calculating them.
> 
> Fixes: 011b41bffa3d ("btrfs: zoned: advance allocation pointer after tree log node")
> Cc: stable@vger.kernel.org # 5.12+
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>

Added to misc-next, thanks.