From 778b1ac4d6728fb709f927aebaac61f7eb672fba Mon Sep 17 00:00:00 2001 From: Kemeng Shi Date: Sat, 3 Jun 2023 23:03:15 +0800 Subject: [PATCH] ext4: try all groups in ext4_mb_new_blocks_simple [ Upstream commit 19a043bb1fd1b5cb2652ca33536c55e6c0a70df0 ] 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: Kemeng Shi Suggested-by: Theodore Ts'o Reviewed-by: Ojaswin Mujoo Link: https://lore.kernel.org/r/20230603150327.3596033-8-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 3f4830abd236 ("ext4: fix potential unnitialized variable") Signed-off-by: Sasha Levin --- fs/ext4/mballoc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 383703e20ea3..a346ab8f3e5f 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5887,7 +5887,7 @@ 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; @@ -5901,7 +5901,7 @@ 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); @@ -5925,10 +5925,13 @@ 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; }