From 869cb287d89344e2520cd53f1f04b76833e91698 Mon Sep 17 00:00:00 2001 From: Xin Yin Date: Mon, 10 Jan 2022 11:51:41 +0800 Subject: [PATCH] ext4: modify the logic of ext4_mb_new_blocks_simple 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 Reviewed-by: Harshad Shirwadkar Link: https://lore.kernel.org/r/20220110035141.1980-3-yinxin.x@bytedance.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b05a83b..74e3286 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -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); + 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); -- 2.7.4