kernel/fs/ext4, branch linux-6.1.y

ext4: mark group extend fast-commit ineligible

2026-03-04T12:20:26Z

[ Upstream commit 1f8dd813a1c771b13c303f73d876164bc9b327cc ] Fast commits only log operations that have dedicated replay support. EXT4_IOC_GROUP_EXTEND grows the filesystem to the end of the last block group and updates the same on-disk metadata without going through the fast commit tracking paths. In practice these operations are rare and usually followed by further updates, but mixing them into a fast commit makes the overall semantics harder to reason about and risks replay gaps if new call sites appear. Teach ext4 to mark the filesystem fast-commit ineligible when EXT4_IOC_GROUP_EXTEND grows the filesystem. This forces those transactions to fall back to a full commit, ensuring that the group extension changes are captured by the normal journal rather than partially encoded in fast commit TLVs. This change should not affect common workloads but makes online resize via GROUP_EXTEND safer and easier to reason about under fast commit. Testing: 1. prepare: dd if=/dev/zero of=/root/fc_resize.img bs=1M count=0 seek=256 mkfs.ext4 -O fast_commit -F /root/fc_resize.img mkdir -p /mnt/fc_resize && mount -t ext4 -o loop /root/fc_resize.img /mnt/fc_resize 2. Extended the filesystem to the end of the last block group using a helper that calls EXT4_IOC_GROUP_EXTEND on the mounted filesystem and checked fc_info: ./group_extend_helper /mnt/fc_resize cat /proc/fs/ext4/loop0/fc_info shows the "Resize" ineligible reason increased. 3. Fsynced a file on the resized filesystem and confirmed that the fast commit ineligible counter incremented for the resize transaction: touch /mnt/fc_resize/file /root/fsync_file /mnt/fc_resize/file sync cat /proc/fs/ext4/loop0/fc_info Signed-off-by: Li Chen Link: https://patch.msgid.link/20251211115146.897420-6-me@linux.beauty Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: mark group add fast-commit ineligible

2026-03-04T12:20:26Z

[ Upstream commit 89b4336fd5ec78f51f9d3a1d100f3ffa3228e604 ] Fast commits only log operations that have dedicated replay support. Online resize via EXT4_IOC_GROUP_ADD updates the superblock and group descriptor metadata without going through the fast commit tracking paths. In practice these operations are rare and usually followed by further updates, but mixing them into a fast commit makes the overall semantics harder to reason about and risks replay gaps if new call sites appear. Teach ext4 to mark the filesystem fast-commit ineligible when ext4_ioctl_group_add() adds new block groups. This forces those transactions to fall back to a full commit, ensuring that the filesystem geometry updates are captured by the normal journal rather than partially encoded in fast commit TLVs. This change should not affect common workloads but makes online resize via GROUP_ADD safer and easier to reason about under fast commit. Testing: 1. prepare: dd if=/dev/zero of=/root/fc_resize.img bs=1M count=0 seek=256 mkfs.ext4 -O fast_commit -F /root/fc_resize.img mkdir -p /mnt/fc_resize && mount -t ext4 -o loop /root/fc_resize.img /mnt/fc_resize 2. Ran a helper that issues EXT4_IOC_GROUP_ADD on the mounted filesystem and checked the resize ineligible reason: ./group_add_helper /mnt/fc_resize cat /proc/fs/ext4/loop0/fc_info shows "Resize": > 0. 3. Fsynced a file on the resized filesystem and verified that the fast commit stats report at least one ineligible commit: touch /mnt/fc_resize/file /root/fsync_file /mnt/fc_resize/file sync cat /proc/fs/ext4/loop0/fc_info shows fc stats ineligible > 0. Signed-off-by: Li Chen Link: https://patch.msgid.link/20251211115146.897420-5-me@linux.beauty Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin

ext4: use optimized mballoc scanning regardless of inode format

2026-03-04T12:19:55Z

commit 3574c322b1d0eb32dbd76b469cb08f9a67641599 upstream. Currently we don't used mballoc optimized scanning (using max free extent order and avg free extent order group lists) for inodes with indirect block based format. This is confusing for users and I don't see a good reason for that. Even with indirect block based inode format we can spend big amount of time searching for free blocks for large filesystems with fragmented free space. To add to the confusion before commit 077d0c2c78df ("ext4: make mb_optimize_scan performance mount option work with extents") optimized scanning was applied *only* to indirect block based inodes so that commit appears as a performance regression to some users. Just use optimized scanning whenever it is enabled by mount options. Reviewed-by: Baokun Li Reviewed-by: Zhang Yi Signed-off-by: Jan Kara Cc: stable@kernel.org Link: https://patch.msgid.link/20260114182836.14120-4-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix memory leak in ext4_ext_shift_extents()

2026-03-04T12:19:55Z

commit ca81109d4a8f192dc1cbad4a1ee25246363c2833 upstream. In ext4_ext_shift_extents(), if the extent is NULL in the while loop, the function returns immediately without releasing the path obtained via ext4_find_extent(), leading to a memory leak. Fix this by jumping to the out label to ensure the path is properly released. Fixes: a18ed359bdddc ("ext4: always check ext4_ext_find_extent result") Signed-off-by: Zilin Guan Reviewed-by: Zhang Yi Reviewed-by: Baokun Li Link: https://patch.msgid.link/20251225084800.905701-1-zilin@seu.edu.cn Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: don't cache extent during splitting extent

2026-03-04T12:19:54Z

commit 8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79 upstream. Caching extents during the splitting process is risky, as it may result in stale extents remaining in the status tree. Moreover, in most cases, the corresponding extent block entries are likely already cached before the split happens, making caching here not particularly useful. Assume we have an unwritten extent, and then DIO writes the first half. [UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUUUUUU] extent status tree |<- ->| ----> dio write this range First, when ext4_split_extent_at() splits this extent, it truncates the existing extent and then inserts a new one. During this process, this extent status entry may be shrunk, and calls to ext4_find_extent() and ext4_cache_extents() may occur, which could potentially insert the truncated range as a hole into the extent status tree. After the split is completed, this hole is not replaced with the correct status. [UUUUUUU|UUUUUUUU] on-disk extent U: unwritten extent [UUUUUUU|HHHHHHHH] extent status tree H: hole Then, the outer calling functions will not correct this remaining hole extent either. Finally, if we perform a delayed buffer write on this latter part, it will re-insert the delayed extent and cause an error in space accounting. In adition, if the unwritten extent cache is not shrunk during the splitting, ext4_cache_extents() also conflicts with existing extents when caching extents. In the future, we will add checks when caching extents, which will trigger a warning. Therefore, Do not cache extents that are being split. Signed-off-by: Zhang Yi Reviewed-by: Ojaswin Mujoo Reviewed-by: Baokun Li Cc: stable@kernel.org Message-ID: <20251129103247.686136-6-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix iloc.bh leak in ext4_xattr_inode_update_ref

2026-02-06T15:43:59Z

commit d250bdf531d9cd4096fedbb9f172bb2ca660c868 upstream. The error branch for ext4_xattr_inode_update_ref forget to release the refcount for iloc.bh. Find this when review code. Fixes: 57295e835408 ("ext4: guard against EA inode refcount underflow in xattr update") Signed-off-by: Yang Erkun Reviewed-by: Baokun Li Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20251213055706.3417529-1-yangerkun@huawei.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: fix out-of-bound read in ext4_xattr_inode_dec_ref_all()

2026-01-17T15:39:28Z

[ Upstream commit 5701875f9609b000d91351eaa6bfd97fe2f157f4 ] There's issue as follows: BUG: KASAN: use-after-free in ext4_xattr_inode_dec_ref_all+0x6ff/0x790 Read of size 4 at addr ffff88807b003000 by task syz-executor.0/15172 CPU: 3 PID: 15172 Comm: syz-executor.0 Call Trace: __dump_stack lib/dump_stack.c:82 [inline] dump_stack+0xbe/0xfd lib/dump_stack.c:123 print_address_description.constprop.0+0x1e/0x280 mm/kasan/report.c:400 __kasan_report.cold+0x6c/0x84 mm/kasan/report.c:560 kasan_report+0x3a/0x50 mm/kasan/report.c:585 ext4_xattr_inode_dec_ref_all+0x6ff/0x790 fs/ext4/xattr.c:1137 ext4_xattr_delete_inode+0x4c7/0xda0 fs/ext4/xattr.c:2896 ext4_evict_inode+0xb3b/0x1670 fs/ext4/inode.c:323 evict+0x39f/0x880 fs/inode.c:622 iput_final fs/inode.c:1746 [inline] iput fs/inode.c:1772 [inline] iput+0x525/0x6c0 fs/inode.c:1758 ext4_orphan_cleanup fs/ext4/super.c:3298 [inline] ext4_fill_super+0x8c57/0xba40 fs/ext4/super.c:5300 mount_bdev+0x355/0x410 fs/super.c:1446 legacy_get_tree+0xfe/0x220 fs/fs_context.c:611 vfs_get_tree+0x8d/0x2f0 fs/super.c:1576 do_new_mount fs/namespace.c:2983 [inline] path_mount+0x119a/0x1ad0 fs/namespace.c:3316 do_mount+0xfc/0x110 fs/namespace.c:3329 __do_sys_mount fs/namespace.c:3540 [inline] __se_sys_mount+0x219/0x2e0 fs/namespace.c:3514 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Memory state around the buggy address: ffff88807b002f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807b002f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807b003000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88807b003080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88807b003100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Above issue happens as ext4_xattr_delete_inode() isn't check xattr is valid if xattr is in inode. To solve above issue call xattr_check_inode() check if xattr if valid in inode. In fact, we can directly verify in ext4_iget_extra_inode(), so that there is no divergent verification. Fixes: e50e5129f384 ("ext4: xattr-in-inode support") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://patch.msgid.link/20250208063141.1539283-3-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: David Nyström Signed-off-by: Greg Kroah-Hartman

ext4: introduce ITAIL helper

2026-01-17T15:39:27Z

[ Upstream commit 69f3a3039b0d0003de008659cafd5a1eaaa0a7a4 ] Introduce ITAIL helper to get the bound of xattr in inode. Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://patch.msgid.link/20250208063141.1539283-2-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: David Nyström Signed-off-by: Greg Kroah-Hartman

ext4: fix error message when rejecting the default hash

2026-01-11T14:19:26Z

commit a2187431c395cdfbf144e3536f25468c64fc7cfa upstream. Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") properly rejects volumes where s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the error message should not look into casefold setup - a filesystem should never have DX_HASH_SIPHASH as the default hash. Fix it and, since we are there, move the check to ext4_hash_info_init. Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") Signed-off-by: Gabriel Krisman Bertazi Link: https://patch.msgid.link/87jzg1en6j.fsf_-_@mailhost.krisman.be Signed-off-by: Theodore Ts'o Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

ext4: factor out ext4_hash_info_init()

2026-01-11T14:19:26Z

commit db9345d9e6f075e1ec26afadf744078ead935fec upstream. Factor out ext4_hash_info_init() to simplify __ext4_fill_super(). No functional change. Signed-off-by: Jason Yan Link: https://lore.kernel.org/r/20230323140517.1070239-2-yanaijie@huawei.com Signed-off-by: Theodore Ts'o Stable-dep-of: a2187431c395 ("ext4: fix error message when rejecting the default hash") Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman