When bb_free is not 0 but bb_fragments is 0, return directly to avoid
system crash due to division by zero.
Fixes: 83e80a6e3543 ("ext4: use buckets for cr 1 block scan instead of rbtree")
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
fs/ext4/mballoc.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 2fbee0f0f5c3..e2a167240335 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -845,6 +845,9 @@ mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0)
return;
+ if (unlikely(grp->bb_fragments == 0))
+ return;
+
new_order = mb_avg_fragment_size_order(sb,
grp->bb_free / grp->bb_fragments);
if (new_order == grp->bb_avg_fragment_size_order)
--
2.31.1
