Commit bef53b01 authored Sep 20, 2012 by Tao Ma Committed by Theodore Ts'o Sep 20, 2012

ext4: remove erroneous ext4_superblock_csum_set() in update_backups()



The update_backups() function is used to backup all the metadata
blocks, so we should not take it for granted that 'data' is pointed to
a super block and use ext4_superblock_csum_set to calculate the
checksum there.  In case where the data is a group descriptor block,
it will corrupt the last group descriptor, and then e2fsck will
complain about it it.

As all the metadata checksums should already be OK when we do the
backup, remove the wrong ext4_superblock_csum_set and it should be
just fine.

Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

parent 00d4e736

fs/ext4/resize.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1049,8 +1049,6 @@ static void update_backups(struct super_block sb, int blk_off, char data,
		goto exit_err;
		}

		ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);

		if (meta_bg == 0) {
		group = ext4_list_backups(sb, &three, &five, &seven);
		last = sbi->s_groups_count;

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