iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ext4: modify the logic of ext4_mb_new_blocks_simple

Browse Source 
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>
This commit is contained in:
Xin Yin 2022-01-10 11:51:41 +08:00 committed by Greg Kroah-Hartman
parent 0cb4480bc4
commit 869cb287d8
1 changed files with 17 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
fs/ext4/mballoc.c
View File

@ -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);