[PATCH] btrfs: zoned: fix missing chunk metadata reservation

[Guanghui Yang]

reserve_chunk_space() stores the return value of
btrfs_zoned_activate_one_bg() in ret. The helper can return 1 after
successfully activating a block group, but ret is later used to decide
whether to reserve metadata for chunk tree updates.

As a result, successful activation skips btrfs_block_rsv_add() and leaves
trans->chunk_bytes_reserved unchanged. Use a separate variable for the
activation result so positive success does not affect the later
reservation.

Fixes: b6a98021e401 ("btrfs: zoned: activate necessary block group")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guanghui Yang <3497809730@xxxxxx>
---
 fs/btrfs/block-group.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index ab76a5173272..00540b96c163 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -4532,12 +4532,14 @@ static void reserve_chunk_space(struct btrfs_trans_handle *trans,
 		if (IS_ERR(bg)) {
 			ret = PTR_ERR(bg);
 		} else {
+			int activate_ret;
+
 			/*
 			 * We have a new chunk. We also need to activate it for
 			 * zoned filesystem.
 			 */
-			ret = btrfs_zoned_activate_one_bg(info, true);
-			if (ret < 0)
+			activate_ret = btrfs_zoned_activate_one_bg(info, true);
+			if (activate_ret < 0)
 				return;
 
 			/*

base-commit: a13c140cc289c0b7b3770bce5b3ad42ab35074aa
-- 
2.52.0.windows.1