Commit 31a074a0 authored by Xin Yin's avatar Xin Yin Committed by Theodore Ts'o
Browse files

ext4: modify the logic of ext4_mb_new_blocks_simple 



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: default avatarXin Yin <yinxin.x@bytedance.com>
Reviewed-by: default avatarHarshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20220110035141.1980-3-yinxin.x@bytedance.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent 599ea31d

fs/ext4/mballoc.c

+17 −9
Original line number Diff line number Diff line
@@ -5753,7 +5753,8 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, 
	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_simple(handle_t *handle, 
		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);

		brelse(bitmap_bh);

		if (i >= sb->s_blocksize)

			continue;

			if (i >= max)

				break;

			if (ext4_fc_replay_check_excluded(sb,

			ext4_group_first_block_no(sb, group) + i))

			continue;

				ext4_group_first_block_no(sb, group) + i)) {

				blkoff = i + 1;

			} else

				break;

		}

		brelse(bitmap_bh);

		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);