ext4: modify the logic of ext4_mb_new_blocks_simple

stable inclusion
from stable-v5.10.99
commit 6c5bd55e36d3bdcbd723902b29bcf083e5592c6f
bugzilla: https://gitee.com/openeuler/kernel/issues/I55O7H

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6c5bd55e36d3bdcbd723902b29bcf083e5592c6f

--------------------------------

commit 31a074a0 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: NXin Yin <yinxin.x@bytedance.com>
Reviewed-by: NHarshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20220110035141.1980-3-yinxin.x@bytedance.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/ext4/mballoc.c

@@ -5173,7 +5173,8 @@ 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;
 
@@ -5195,19 +5196,26 @@ 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);