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List:       linux-ext4
Subject:    [PATCH v2 5/8] ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt
From:       Baokun Li <libaokun1 () huawei ! com>
Date:       2023-12-21 15:05:55
Message-ID: 20231221150558.2740823-6-libaokun1 () huawei ! com
[Download RAW message or body]

Determine if bb_fragments is 0 instead of determining bb_free to eliminate
the risk of dividing by zero when the block bitmap is corrupted.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
---
 fs/ext4/mballoc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1f15774971d7..03500aec43ac 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -842,7 +842,7 @@ mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	int new_order;
 
-	if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0)
+	if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0)
 		return;
 
 	new_order = mb_avg_fragment_size_order(sb,
-- 
2.31.1


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