[PATCH] btrfs: replace BUG_ON() with error return in cache_save_setup()
From: Teng Liu
Date: Sat Mar 28 2026 - 01:22:17 EST
In cache_save_setup(), if create_free_space_inode() succeeds but the
subsequent lookup_free_space_inode() still fails on retry, the
BUG_ON(retries) will crash the kernel. This can happen due to I/O
errors or transient failures, not just programming bugs.
Replace the BUG_ON with proper error handling that returns -EIO through
the existing cleanup path. The callers already handle this gracefully:
disk_cache_state defaults to BTRFS_DC_ERROR, so the space cache simply
won't be written for that block group.
Signed-off-by: Teng Liu <27rabbitlt@xxxxxxxxx>
---
fs/btrfs/block-group.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index ebf507909..9f71362ba 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -3343,7 +3343,13 @@ static int cache_save_setup(struct btrfs_block_group *block_group,
}
if (IS_ERR(inode)) {
- BUG_ON(retries);
+ if (retries) {
+ btrfs_debug(fs_info,
+ "free space inode not found after creation for block group %llu",
+ block_group->start);
+ ret = -EIO;
+ goto out_free;
+ }
retries++;
if (block_group->ro)
--
2.53.0