6.1-stable review patch. If anyone has any objections, please let me know.
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From: Kemeng Shi shikemeng@huaweicloud.com
[ 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 shikemeng@huaweicloud.com Suggested-by: Theodore Ts'o tytso@mit.edu Reviewed-by: Ojaswin Mujoo ojaswin@linux.ibm.com Link: https://lore.kernel.org/r/20230603150327.3596033-8-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o tytso@mit.edu Stable-dep-of: 3f4830abd236 ("ext4: fix potential unnitialized variable") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 a809a80589857..a7801d2a7d1b4 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5875,7 +5875,7 @@ 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; @@ -5889,7 +5889,7 @@ 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); @@ -5913,10 +5913,13 @@ 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; }