From a5ab5da03870a832211e3c9c9d088e3347337026 Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Sun, 27 Aug 2023 01:47:00 +0800 Subject: [PATCH] ext4: correct offset of gdb backup in non meta_bg group to update_backups commit 31f13421c004a420c0e9d288859c9ea9259ea0cc upstream. Commit 0aeaa2559d6d5 ("ext4: fix corruption when online resizing a 1K bigalloc fs") found that primary superblock's offset in its group is not equal to offset of backup superblock in its group when block size is 1K and bigalloc is enabled. As group descriptor blocks are right after superblock, we can't pass block number of gdb to update_backups for the same reason. The root casue of the issue above is that leading 1K padding block is count as data block offset for primary block while backup block has no padding block offset in its group. Remove padding data block count to fix the issue for gdb backups. For meta_bg case, update_backups treat blk_off as block number, do no conversion in this case. Signed-off-by: Kemeng Shi Reviewed-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230826174712.4059355-2-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/resize.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 0361c20..87cd5b0 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1601,6 +1601,8 @@ exit_journal: int gdb_num_end = ((group + flex_gd->count - 1) / EXT4_DESC_PER_BLOCK(sb)); int meta_bg = ext4_has_feature_meta_bg(sb); + sector_t padding_blocks = meta_bg ? 0 : sbi->s_sbh->b_blocknr - + ext4_group_first_block_no(sb, 0); sector_t old_gdb = 0; update_backups(sb, ext4_group_first_block_no(sb, 0), @@ -1612,8 +1614,8 @@ exit_journal: gdb_num); if (old_gdb == gdb_bh->b_blocknr) continue; - update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, - gdb_bh->b_size, meta_bg); + update_backups(sb, gdb_bh->b_blocknr - padding_blocks, + gdb_bh->b_data, gdb_bh->b_size, meta_bg); old_gdb = gdb_bh->b_blocknr; } } -- 2.7.4