Commit 19a043bb authored by Kemeng Shi's avatar Kemeng Shi Committed by Theodore Ts'o
Browse files

ext4: try all groups in ext4_mb_new_blocks_simple 



ext4_mb_new_blocks_simple ignores the group before goal, so it will fail
if free blocks reside in group before goal. Try all groups to avoid
unexpected failure.
Search finishes either if any free block is found or if no available
blocks are found. Simpliy check "i >= max" to distinguish the above
cases.

Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Suggested-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarOjaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-8-shikemeng@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 95a4c3c7

fs/ext4/mballoc.c

+6 −3
Original line number Diff line number Diff line
@@ -6047,7 +6047,7 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, 
	struct buffer_head *bitmap_bh;

	struct super_block *sb = ar->inode->i_sb;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	ext4_group_t group;

	ext4_group_t group, nr;

	ext4_grpblk_t blkoff;

	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);

	ext4_grpblk_t i = 0;
@@ -6061,7 +6061,7 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, 


	ar->len = 0;

	ext4_get_group_no_and_offset(sb, goal, &group, &blkoff);

	for (; group < ext4_get_groups_count(sb); group++) {

	for (nr = ext4_get_groups_count(sb); nr > 0; nr--) {

		bitmap_bh = ext4_read_block_bitmap(sb, group);

		if (IS_ERR(bitmap_bh)) {

			*errp = PTR_ERR(bitmap_bh);
@@ -6085,10 +6085,13 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle, 
		if (i < max)

			break;



		if (++group >= ext4_get_groups_count(sb))

			group = 0;



		blkoff = 0;

	}



	if (group >= ext4_get_groups_count(sb) || i >= max) {

	if (i >= max) {

		*errp = -ENOSPC;

		return 0;

	}