kernel/git/stable/linux-stable.git/fs/ext4/mballoc.c, branch master

ext4: get ext4_group_desc in ext4_mb_prefetch only when necessary

2026-07-21T15:26:39+00:00

Getting ext4_group_desc structure can contribute to the cost of ext4_mb_prefetch() without any need, as most groups fail the !EXT4_MB_GRP_TEST_AND_SET_READ check. Optimize ext4_mb_prefetch by getting the group description only when necessary. The result is further increase in performance of fallocate() system call path that triggers ext4_mb_prefetch() via a linear group scan. Signed-off-by: Bohdan Trach Reviewed-by: Jan Kara Reviewed-by: Andreas Dilger Link: https://patch.msgid.link/20260615100331.163997-3-bohdan.trach@huaweicloud.com Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linux-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2026-04-18T00:08:31+00:00

Pull ext4 updates from Ted Ts'o: - Refactor code paths involved with partial block zero-out in prearation for converting ext4 to use iomap for buffered writes - Remove use of d_alloc() from ext4 in preparation for the deprecation of this interface - Replace some J_ASSERTS with a journal abort so we can avoid a kernel panic for a localized file system error - Simplify various code paths in mballoc, move_extent, and fast commit - Fix rare deadlock in jbd2_journal_cancel_revoke() that can be triggered by generic/013 when blocksize < pagesize - Fix memory leak when releasing an extended attribute when its value is stored in an ea_inode - Fix various potential kunit test bugs in fs/ext4/extents.c - Fix potential out-of-bounds access in check_xattr() with a corrupted file system - Make the jbd2_inode dirty range tracking safe for lockless reads - Avoid a WARN_ON when writeback files due to a corrupted file system; we already print an ext4 warning indicatign that data will be lost, so the WARN_ON is not necessary and doesn't add any new information * tag 'ext4_for_linux-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (37 commits) jbd2: fix deadlock in jbd2_journal_cancel_revoke() ext4: fix missing brelse() in ext4_xattr_inode_dec_ref_all() ext4: fix possible null-ptr-deref in mbt_kunit_exit() ext4: fix possible null-ptr-deref in extents_kunit_exit() ext4: fix the error handling process in extents_kunit_init). ext4: call deactivate_super() in extents_kunit_exit() ext4: fix miss unlock 'sb->s_umount' in extents_kunit_init() ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access ext4: zero post-EOF partial block before appending write ext4: move pagecache_isize_extended() out of active handle ext4: remove ctime/mtime update from ext4_alloc_file_blocks() ext4: unify SYNC mode checks in fallocate paths ext4: ensure zeroed partial blocks are persisted in SYNC mode ext4: move zero partial block range functions out of active handle ext4: pass allocate range as loff_t to ext4_alloc_file_blocks() ext4: remove handle parameters from zero partial block functions ext4: move ordered data handling out of ext4_block_do_zero_range() ext4: rename ext4_block_zero_page_range() to ext4_block_zero_range() ext4: factor out journalled block zeroing range ext4: rename and extend ext4_block_truncate_page() ...

Merge tag 'for-7.1/block-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

2026-04-13T22:51:31+00:00

Pull block updates from Jens Axboe: - Add shared memory zero-copy I/O support for ublk, bypassing per-I/O copies between kernel and userspace by matching registered buffer PFNs at I/O time. Includes selftests. - Refactor bio integrity to support filesystem initiated integrity operations and arbitrary buffer alignment. - Clean up bio allocation, splitting bio_alloc_bioset() into clear fast and slow paths. Add bio_await() and bio_submit_or_kill() helpers, unify synchronous bi_end_io callbacks. - Fix zone write plug refcount handling and plug removal races. Add support for serializing zone writes at QD=1 for rotational zoned devices, yielding significant throughput improvements. - Add SED-OPAL ioctls for Single User Mode management and a STACK_RESET command. - Add io_uring passthrough (uring_cmd) support to the BSG layer. - Replace pp_buf in partition scanning with struct seq_buf. - zloop improvements and cleanups. - drbd genl cleanup, switching to pre_doit/post_doit. - NVMe pull request via Keith: - Fabrics authentication updates - Enhanced block queue limits support - Workqueue usage updates - A new write zeroes device quirk - Tagset cleanup fix for loop device - MD pull requests via Yu Kuai: - Fix raid5 soft lockup in retry_aligned_read() - Fix raid10 deadlock with check operation and nowait requests - Fix raid1 overlapping writes on writemostly disks - Fix sysfs deadlock on array_state=clear - Proactive RAID-5 parity building with llbitmap, with write_zeroes_unmap optimization for initial sync - Fix llbitmap barrier ordering, rdev skipping, and bitmap_ops version mismatch fallback - Fix bcache use-after-free and uninitialized closure - Validate raid5 journal metadata payload size - Various cleanups - Various other fixes, improvements, and cleanups * tag 'for-7.1/block-20260411' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (146 commits) ublk: fix tautological comparison warning in ublk_ctrl_reg_buf scsi: bsg: fix buffer overflow in scsi_bsg_uring_cmd() block: refactor blkdev_zone_mgmt_ioctl MAINTAINERS: update ublk driver maintainer email Documentation: ublk: address review comments for SHMEM_ZC docs ublk: allow buffer registration before device is started ublk: replace xarray with IDA for shmem buffer index allocation ublk: simplify PFN range loop in __ublk_ctrl_reg_buf ublk: verify all pages in multi-page bvec fall within registered range ublk: widen ublk_shmem_buf_reg.len to __u64 for 4GB buffer support xfs: use bio_await in xfs_zone_gc_reset_sync block: add a bio_submit_or_kill helper block: factor out a bio_await helper block: unify the synchronous bi_end_io callbacks xfs: fix number of GC bvecs selftests/ublk: add read-only buffer registration test selftests/ublk: add filesystem fio verify test for shmem_zc selftests/ublk: add hugetlbfs shmem_zc test for loop target selftests/ublk: add shared memory zero-copy test selftests/ublk: add UBLK_F_SHMEM_ZC support for loop target ...

Merge tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-04-13T19:19:01+00:00

Pull vfs i_ino updates from Christian Brauner: "For historical reasons, the inode->i_ino field is an unsigned long, which means that it's 32 bits on 32 bit architectures. This has caused a number of filesystems to implement hacks to hash a 64-bit identifier into a 32-bit field, and deprives us of a universal identifier field for an inode. This changes the inode->i_ino field from an unsigned long to a u64. This shouldn't make any material difference on 64-bit hosts, but 32-bit hosts will see struct inode grow by at least 4 bytes. This could have effects on slabcache sizes and field alignment. The bulk of the changes are to format strings and tracepoints, since the kernel itself doesn't care that much about the i_ino field. The first patch changes some vfs function arguments, so check that one out carefully. With this change, we may be able to shrink some inode structures. For instance, struct nfs_inode has a fileid field that holds the 64-bit inode number. With this set of changes, that field could be eliminated. I'd rather leave that sort of cleanups for later just to keep this simple" * tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nilfs2: fix 64-bit division operations in nilfs_bmap_find_target_in_group() EVM: add comment describing why ino field is still unsigned long vfs: remove externs from fs.h on functions modified by i_ino widening treewide: fix missed i_ino format specifier conversions ext4: fix signed format specifier in ext4_load_inode trace event treewide: change inode->i_ino from unsigned long to u64 nilfs2: widen trace event i_ino fields to u64 f2fs: widen trace event i_ino fields to u64 ext4: widen trace event i_ino fields to u64 zonefs: widen trace event i_ino fields to u64 hugetlbfs: widen trace event i_ino fields to u64 ext2: widen trace event i_ino fields to u64 cachefiles: widen trace event i_ino fields to u64 vfs: widen trace event i_ino fields to u64 net: change sock.sk_ino and sock_i_ino() to u64 audit: widen ino fields to u64 vfs: widen inode hash/lookup functions to u64

ext4: prefer IS_ERR_OR_NULL over manual NULL check

2026-04-10T01:27:24+00:00

Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL check. Change generated with coccinelle. To: "Theodore Ts'o" To: Andreas Dilger Cc: linux-ext4@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Philipp Hahn Link: https://patch.msgid.link/20260310-b4-is_err_or_null-v1-4-bd63b656022d@avm.de Signed-off-by: Theodore Ts'o

ext4: simplify mballoc preallocation size rounding for small files

2026-04-09T14:43:06+00:00

The if-else ladder in ext4_mb_normalize_request() manually rounds up the preallocation size to the next power of two for files up to 1MB, enumerating each step from 16KB to 1MB individually. Replace this with a single roundup_pow_of_two() call clamped to a 16KB minimum, which is functionally equivalent but much more concise. Also replace raw byte constants with SZ_1M and SZ_16K from for clarity, and remove the stale "XXX: should this table be tunable?" comment that has been there since the original mballoc code. No functional change. Reviewed-by: Andreas Dilger Signed-off-by: Weixie Cui Link: https://patch.msgid.link/tencent_E9C5F1B2E9939B3037501FD04A7E9CF0C407@qq.com Signed-off-by: Theodore Ts'o

ext4: always drain queued discard work in ext4_mb_release()

2026-03-28T03:39:10+00:00

While reviewing recent ext4 patch[1], Sashiko raised the following concern[2]: > If the filesystem is initially mounted with the discard option, > deleting files will populate sbi->s_discard_list and queue > s_discard_work. If it is then remounted with nodiscard, the > EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is > neither cancelled nor flushed. [1] https://lore.kernel.org/r/20260319094545.19291-1-qiang.zhang@linux.dev/ [2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev The concern was valid, but it had nothing to do with the patch[1]. One of the problems with Sashiko in its current (early) form is that it will detect pre-existing issues and report it as a problem with the patch that it is reviewing. In practice, it would be hard to hit deliberately (unless you are a malicious syzkaller fuzzer), since it would involve mounting the file system with -o discard, and then deleting a large number of files, remounting the file system with -o nodiscard, and then immediately unmounting the file system before the queued discard work has a change to drain on its own. Fix it because it's a real bug, and to avoid Sashiko from raising this concern when analyzing future patches to mballoc.c. Signed-off-by: Theodore Ts'o Fixes: 55cdd0af2bc5 ("ext4: get discard out of jbd2 commit kthread contex") Cc: stable@kernel.org

ext4: handle wraparound when searching for blocks for indirect mapped blocks

2026-03-28T03:39:02+00:00

Commit 4865c768b563 ("ext4: always allocate blocks only from groups inode can use") restricts what blocks will be allocated for indirect block based files to block numbers that fit within 32-bit block numbers. However, when using a review bot running on the latest Gemini LLM to check this commit when backporting into an LTS based kernel, it raised this concern: If ac->ac_g_ex.fe_group is >= ngroups (for instance, if the goal group was populated via stream allocation from s_mb_last_groups), then start will be >= ngroups. Does this allow allocating blocks beyond the 32-bit limit for indirect block mapped files? The commit message mentions that ext4_mb_scan_groups_linear() takes care to not select unsupported groups. However, its loop uses group = *start, and the very first iteration will call ext4_mb_scan_group() with this unsupported group because next_linear_group() is only called at the end of the iteration. After reviewing the code paths involved and considering the LLM review, I determined that this can happen when there is a file system where some files/directories are extent-mapped and others are indirect-block mapped. To address this, add a safety clamp in ext4_mb_scan_groups(). Fixes: 4865c768b563 ("ext4: always allocate blocks only from groups inode can use") Cc: Jan Kara Reviewed-by: Baokun Li Reviewed-by: Jan Kara Signed-off-by: Theodore Ts'o Link: https://patch.msgid.link/20260326045834.1175822-1-tytso@mit.edu Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

ext4: fix the might_sleep() warnings in kvfree()

2026-03-28T03:36:20+00:00

Use the kvfree() in the RCU read critical section can trigger the following warnings: EXT4-fs (vdb): unmounting filesystem cd983e5b-3c83-4f5a-a136-17b00eb9d018. WARNING: suspicious RCU usage ./include/linux/rcupdate.h:409 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 Call Trace: dump_stack_lvl+0xbb/0xd0 dump_stack+0x14/0x20 lockdep_rcu_suspicious+0x15a/0x1b0 __might_resched+0x375/0x4d0 ? put_object.part.0+0x2c/0x50 __might_sleep+0x108/0x160 vfree+0x58/0x910 ? ext4_group_desc_free+0x27/0x270 kvfree+0x23/0x40 ext4_group_desc_free+0x111/0x270 ext4_put_super+0x3c8/0xd40 generic_shutdown_super+0x14c/0x4a0 ? __pfx_shrinker_free+0x10/0x10 kill_block_super+0x40/0x90 ext4_kill_sb+0x6d/0xb0 deactivate_locked_super+0xb4/0x180 deactivate_super+0x7e/0xa0 cleanup_mnt+0x296/0x3e0 __cleanup_mnt+0x16/0x20 task_work_run+0x157/0x250 ? __pfx_task_work_run+0x10/0x10 ? exit_to_user_mode_loop+0x6a/0x550 exit_to_user_mode_loop+0x102/0x550 do_syscall_64+0x44a/0x500 entry_SYSCALL_64_after_hwframe+0x77/0x7f BUG: sleeping function called from invalid context at mm/vmalloc.c:3441 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 556, name: umount preempt_count: 1, expected: 0 CPU: 3 UID: 0 PID: 556 Comm: umount Call Trace: dump_stack_lvl+0xbb/0xd0 dump_stack+0x14/0x20 __might_resched+0x275/0x4d0 ? put_object.part.0+0x2c/0x50 __might_sleep+0x108/0x160 vfree+0x58/0x910 ? ext4_group_desc_free+0x27/0x270 kvfree+0x23/0x40 ext4_group_desc_free+0x111/0x270 ext4_put_super+0x3c8/0xd40 generic_shutdown_super+0x14c/0x4a0 ? __pfx_shrinker_free+0x10/0x10 kill_block_super+0x40/0x90 ext4_kill_sb+0x6d/0xb0 deactivate_locked_super+0xb4/0x180 deactivate_super+0x7e/0xa0 cleanup_mnt+0x296/0x3e0 __cleanup_mnt+0x16/0x20 task_work_run+0x157/0x250 ? __pfx_task_work_run+0x10/0x10 ? exit_to_user_mode_loop+0x6a/0x550 exit_to_user_mode_loop+0x102/0x550 do_syscall_64+0x44a/0x500 entry_SYSCALL_64_after_hwframe+0x77/0x7f The above scenarios occur in initialization failures and teardown paths, there are no parallel operations on the resources released by kvfree(), this commit therefore remove rcu_read_lock/unlock() and use rcu_access_pointer() instead of rcu_dereference() operations. Fixes: 7c990728b99e ("ext4: fix potential race between s_flex_groups online resizing and access") Fixes: df3da4ea5a0f ("ext4: fix potential race between s_group_info online resizing and access") Signed-off-by: Zqiang Reviewed-by: Baokun Li Link: https://patch.msgid.link/20260319094545.19291-1-qiang.zhang@linux.dev Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

ext4: fix mballoc-test.c is not compiled when EXT4_KUNIT_TESTS=M

2026-03-28T03:36:02+00:00

Now, only EXT4_KUNIT_TESTS=Y testcase will be compiled in 'mballoc.c'. To solve this issue, the ext4 test code needs to be decoupled. The ext4 test module is compiled into a separate module. Reported-by: ChenXiaoSong Closes: https://patchwork.kernel.org/project/cifs-client/patch/20260118091313.1988168-2-chenxiaosong.chenxiaosong@linux.dev/ Fixes: 7c9fa399a369 ("ext4: add first unit test for ext4_mb_new_blocks_simple in mballoc") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260314075258.1317579-3-yebin@huaweicloud.com Signed-off-by: Theodore Ts'o