kernel/linux.git/fs/ext4/ialloc.c, branch v6.1.168

ext4: make recently_deleted() properly work with lazy itable initialization

2026-04-11T12:16:15+00:00

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 Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20260216164848.3074-3-jack@suse.cz Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: clear i_state_flags when alloc inode

2026-01-11T14:18:51+00:00

commit 4091c8206cfd2e3bb529ef260887296b90d9b6a2 upstream. i_state_flags used on 32-bit archs, need to clear this flag when alloc inode. Find this issue when umount ext4, sometimes track the inode as orphan accidently, cause ext4 mesg dump. Fixes: acf943e9768e ("ext4: fix checks for orphan inodes") Signed-off-by: Haibo Chen Reviewed-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Message-ID: <20251104-ext4-v1-1-73691a0800f9@nxp.com> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: avoid negative min_clusters in find_group_orlov()

2024-10-17T13:20:59+00:00

[ Upstream commit bb0a12c3439b10d88412fd3102df5b9a6e3cd6dc ] min_clusters is signed integer and will be converted to unsigned integer when compared with unsigned number stats.free_clusters. If min_clusters is negative, it will be converted to a huge unsigned value in which case all groups may not meet the actual desired free clusters. Set negative min_clusters to 0 to avoid unexpected behavior. Fixes: ac27a0ec112a ("[PATCH] ext4: initial copy of files from ext3") Signed-off-by: Kemeng Shi Link: https://patch.msgid.link/20240820132234.2759926-4-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: avoid potential buffer_head leak in __ext4_new_inode()

2024-10-17T13:20:59+00:00

[ Upstream commit 227d31b9214d1b9513383cf6c7180628d4b3b61f ] If a group is marked EXT4_GROUP_INFO_IBITMAP_CORRUPT after it's inode bitmap buffer_head was successfully verified, then __ext4_new_inode() will get a valid inode_bitmap_bh of a corrupted group from ext4_read_inode_bitmap() in which case inode_bitmap_bh misses a release. Hnadle "IS_ERR(inode_bitmap_bh)" and group corruption separately like how ext4_free_inode() does to avoid buffer_head leak. Fixes: 9008a58e5dce ("ext4: make the bitmap read routines return real error codes") Signed-off-by: Kemeng Shi Link: https://patch.msgid.link/20240820132234.2759926-3-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: avoid buffer_head leak in ext4_mark_inode_used()

2024-10-17T13:20:59+00:00

[ Upstream commit 5e5b2a56c57def1b41efd49596621504d7bcc61c ] Release inode_bitmap_bh from ext4_read_inode_bitmap() in ext4_mark_inode_used() to avoid buffer_head leak. By the way, remove unneeded goto for invalid ino when inode_bitmap_bh is NULL. Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Kemeng Shi Link: https://patch.msgid.link/20240820132234.2759926-2-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: allow ext4_get_group_info() to fail

2023-05-24T16:32:33+00:00

[ Upstream commit 5354b2af34064a4579be8bc0e2f15a7b70f14b5f ] Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara Signed-off-by: Sasha Levin

treewide: use get_random_u32() when possible

2022-10-11T23:42:58+00:00

The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: Jan Kara # for ext4 Acked-by: Toke Høiland-Jørgensen # for sch_cake Acked-by: Chuck Lever # for nfsd Acked-by: Jakub Kicinski Acked-by: Mika Westerberg # for thunderbolt Acked-by: Darrick J. Wong # for xfs Acked-by: Helge Deller # for parisc Acked-by: Heiko Carstens # for s390 Signed-off-by: Jason A. Donenfeld

treewide: use prandom_u32_max() when possible, part 2

2022-10-11T23:42:58+00:00

Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done by hand, covering things that coccinelle could not do on its own. Reviewed-by: Greg Kroah-Hartman Reviewed-by: Kees Cook Reviewed-by: Yury Norov Reviewed-by: Jan Kara # for ext2, ext4, and sbitmap Acked-by: Jakub Kicinski Signed-off-by: Jason A. Donenfeld

ext4: make directory inode spreading reflect flexbg size

2022-09-22T02:11:55+00:00

Currently the Orlov inode allocator searches for free inodes for a directory only in flex block groups with at most inodes_per_group/16 more directory inodes than average per flex block group. However with growing size of flex block group this becomes unnecessarily strict. Scale allowed difference from average directory count per flex block group with flex block group size as we do with other metrics. Tested-by: Stefan Wahren Tested-by: Ojaswin Mujoo Cc: stable@kernel.org Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/ Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20220908092136.11770-3-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: Support for checksumming from journal triggers

2021-08-31T03:36:50+00:00

JBD2 layer support triggers which are called when journaling layer moves buffer to a certain state. We can use the frozen trigger, which gets called when buffer data is frozen and about to be written out to the journal, to compute block checksums for some buffer types (similarly as does ocfs2). This avoids unnecessary repeated recomputation of the checksum (at the cost of larger window where memory corruption won't be caught by checksumming) and is even necessary when there are unsynchronized updaters of the checksummed data. So add superblock and journal trigger type arguments to ext4_journal_get_write_access() and ext4_journal_get_create_access() so that frozen triggers can be set accordingly. Also add inode argument to ext4_walk_page_buffers() and all the callbacks used with that function for the same purpose. This patch is mostly only a change of prototype of the above mentioned functions and a few small helpers. Real checksumming will come later. Reviewed-by: Theodore Ts'o Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz Signed-off-by: Theodore Ts'o