From: Xin Yin yinxin.x@bytedance.com
commit 31a074a0c62dc0d2bfb9b543142db4fe27f9e5eb upstream.
For now in ext4_mb_new_blocks_simple, if we found a block which should be excluded then will switch to next group, this may probably cause 'group' run out of range.
Change to check next block in the same group when get a block should be excluded. Also change the search range to EXT4_CLUSTERS_PER_GROUP and add error checking.
Signed-off-by: Xin Yin yinxin.x@bytedance.com Reviewed-by: Harshad Shirwadkar harshadshirwadkar@gmail.com Link: https://lore.kernel.org/r/20220110035141.1980-3-yinxin.x@bytedance.com Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/mballoc.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
--- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5753,7 +5753,8 @@ static ext4_fsblk_t ext4_mb_new_blocks_s struct super_block *sb = ar->inode->i_sb; ext4_group_t group; ext4_grpblk_t blkoff; - int i = sb->s_blocksize; + ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); + ext4_grpblk_t i = 0; ext4_fsblk_t goal, block; struct ext4_super_block *es = EXT4_SB(sb)->s_es;
@@ -5775,19 +5776,26 @@ static ext4_fsblk_t ext4_mb_new_blocks_s ext4_get_group_no_and_offset(sb, max(ext4_group_first_block_no(sb, group), goal), NULL, &blkoff); - i = mb_find_next_zero_bit(bitmap_bh->b_data, sb->s_blocksize, + while (1) { + i = mb_find_next_zero_bit(bitmap_bh->b_data, max, blkoff); + if (i >= max) + break; + if (ext4_fc_replay_check_excluded(sb, + ext4_group_first_block_no(sb, group) + i)) { + blkoff = i + 1; + } else + break; + } brelse(bitmap_bh); - if (i >= sb->s_blocksize) - continue; - if (ext4_fc_replay_check_excluded(sb, - ext4_group_first_block_no(sb, group) + i)) - continue; - break; + if (i < max) + break; }
- if (group >= ext4_get_groups_count(sb) && i >= sb->s_blocksize) + if (group >= ext4_get_groups_count(sb) || i >= max) { + *errp = -ENOSPC; return 0; + }
block = ext4_group_first_block_no(sb, group) + i; ext4_mb_mark_bb(sb, block, 1, 1);