[PATCH 5.15 381/570] ext4: make recently_deleted() properly work with lazy itable initialization

Greg Kroah-Hartman
2026-04-13T16:34:26Z

From: Jan Kara <jack@suse.cz>

commit bd060afa7cc3e0ad30afa9ecc544a78638498555 upstream.

recently_deleted() checks whether inode has been used in the near past.
However this can give false positive result when inode table is not
initialized yet and we are in fact comparing to random garbage (or stale
itable block of a filesystem before mkfs). Ultimately this results in
uninitialized inodes being skipped during inode allocation and possibly
they are never initialized and thus e2fsck complains. Verify if the
inode has been initialized before checking for dtime.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260216164848.3074-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ext4/ialloc.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -688,6 +688,12 @@ static int recently_deleted(struct super
if (unlikely(!gdp))
return 0;

+ /* Inode was never used in this filesystem? */
+ if (ext4_has_group_desc_csum(sb) &&
+ (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT) ||
+ ino >= EXT4_INODES_PER_GROUP(sb) - ext4_itable_unused_count(sb, gdp)))
+ return 0;
+
bh = sb_find_get_block(sb, ext4_inode_table(sb, gdp) +
(ino / inodes_per_block));
if (!bh || !buffer_uptodate(bh))