linux-ext4 - [PATCH 2/8] ext4: remove redundant mb_regenerate

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1602820552-4082-2-git-send-email-brookxu@tencent.com>
Date:   Fri, 16 Oct 2020 11:55:46 +0800
From:   Chunguang Xu <brookxu.cn@...il.com>
To:     tytso@....edu, adilger.kernel@...ger.ca
Cc:     linux-ext4@...r.kernel.org
Subject: [PATCH 2/8] ext4: remove redundant mb_regenerate_buddy()

From: Chunguang Xu <brookxu@...cent.com>

After this patch (163a203), if an abnormal bitmap is detected, we
will mark the group as corrupt, and we will not use this group in
the future. Therefore, it should be meaningless to regenerate the
buddy bitmap of this group, It might be better to delete it.

Signed-off-by: Chunguang Xu <brookxu@...cent.com>
---
 fs/ext4/mballoc.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 2705a4c..5b8ce76 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -822,24 +822,6 @@ void ext4_mb_generate_buddy(struct super_block *sb,
 	spin_unlock(&sbi->s_bal_lock);
 }
 
-static void mb_regenerate_buddy(struct ext4_buddy *e4b)
-{
-	int count;
-	int order = 1;
-	void *buddy;
-
-	while ((buddy = mb_find_buddy(e4b, order++, &count))) {
-		ext4_set_bits(buddy, 0, count);
-	}
-	e4b->bd_info->bb_fragments = 0;
-	memset(e4b->bd_info->bb_counters, 0,
-		sizeof(*e4b->bd_info->bb_counters) *
-		(e4b->bd_sb->s_blocksize_bits + 2));
-
-	ext4_mb_generate_buddy(e4b->bd_sb, e4b->bd_buddy,
-		e4b->bd_bitmap, e4b->bd_group);
-}
-
 /* The buddy information is attached the buddy cache inode
  * for convenience. The information regarding each group
  * is loaded via ext4_mb_load_buddy. The information involve
@@ -1510,7 +1492,6 @@ static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
 				      block);
 		ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
 				EXT4_GROUP_INFO_BBITMAP_CORRUPT);
-		mb_regenerate_buddy(e4b);
 		goto done;
 	}
 
-- 
1.8.3.1