kernel/linux.git/fs/jbd2/commit.c, branch v7.2-rc1

Merge tag 'ext4_for_linus-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2026-06-18T16:42:02+00:00

Pull ext4 updates from Ted Ts'o: - A major rework of the fast commit mechanism to avoid lock contention and deadlocks. We also export snapshot statistics in /proc/fs/ext4/*/fc_info - Performance optimization for directory hash computation by processing input in 4-byte chunks and removing function pointers, along with new KUnit tests for directory hash - Cleanups in JBD2 to remove special slabs and use kmalloc() instead - Various bug fixes, including: - Early validation of donor superblock in EXT4_IOC_MOVE_EXT to avoid cross-fs deadlock - Fix for a kernel BUG in ext4_write_inline_data_end under data=journal - Fix for a NULL dereference in jbd2_journal_dirty_metadata when handle is aborted - Fix for an underflow in JBD2 fast commit block initialization check - Fix for LOGFLUSH shutdown ordering to ensure ordered data writeback - Miscellaneous fixes for error path return values and KUnit assertions * tag 'ext4_for_linus-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: validate donor file superblock early in EXT4_IOC_MOVE_EXT ext4: fix kernel BUG in ext4_write_inline_data_end ext4: fix ERR_PTR(0) in ext4_mkdir() jbd2: remove special jbd2 slabs ext4: remove mention of PageWriteback ext4: improve str2hashbuf by processing 4-byte chunks and removing function pointers ext4: add Kunit coverage for directory hash computation ext4: fast commit: export snapshot stats in fc_info ext4: fast commit: add lock_updates tracepoint ext4: fast commit: avoid i_data_sem by dropping ext4_map_blocks() in snapshots ext4: fast commit: avoid self-deadlock in inode snapshotting ext4: fast commit: avoid waiting for FC_COMMITTING ext4: lockdep: handle i_data_sem subclassing for special inodes ext4: fast commit: snapshot inode state before writing log jbd2: fix integer underflow in jbd2_journal_initialize_fast_commit() ext4: fix fast commit wait/wake bit mapping on 64-bit jbd2: check for aborted handle in jbd2_journal_dirty_metadata() ext4: Use %pe to print PTR_ERR() ext4: fix LOGFLUSH shutdown ordering to allow ordered-mode data writeback ext4: replace KUnit tests for memcmp() with KUNIT_ASSERT_MEMEQ()

Merge tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-06-14T22:29:45+00:00

Pull misc vfs updates from Christian Brauner: "Features: - Reduce pipe->mutex contention by pre-allocating pages outside the lock in anon_pipe_write(). anon_pipe_write() called alloc_page() once per page while holding pipe->mutex. The allocation can sleep doing direct reclaim and runs memcg charging, which extends the critical section and stalls any concurrent reader on the same mutex. Now up to 8 pages are pre-allocated before the mutex is taken, leftovers are recycled into the per-pipe tmp_page[] cache before unlock, and any remainder is released after unlock, keeping the allocator out of the critical section on both sides. On a writers x readers sweep with 64KB writes against a 1 MB pipe throughput improves 6-28% and average write latency drops 5-22%; under memory pressure - when the cost of holding the mutex across reclaim is highest - throughput improves 21-48% and latency drops 17-33%. The microbenchmark is added to selftests. - uaccess/sockptr: fix the ignored_trailing logic in copy_struct_to_user() to behave as documented and the usize check in copy_struct_from_sockptr() for user pointers, and add copy_struct_{from,to}_bounce_buffer() and copy_struct_to_sockptr() helpers for upcoming users (IPPROTO_SMBDIRECT, IPPROTO_QUIC). - bpf: add a sleepable bpf_real_inode() kfunc that resolves the real inode backing a dentry via d_real_inode(). On overlayfs the inode attached to the dentry doesn't carry the underlying device information; this is used by the filesystem restriction BPF program that was merged into systemd. - docs: add guidelines for submitting new filesystems, motivated by the maintenance burden abandoned and untestable filesystems impose on VFS developers, blocking infrastructure work like folio conversions and iomap migration. Fixes: - libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() and drop the now-redundant assignments in callers. This began as a one-line dma-buf fix for a path_noexec() warning; a pseudo filesystem has no reason not to set SB_I_NOEXEC. All init_pseudo() callers were audited: the only visible effect is on dma-buf where SB_I_NOEXEC silences the warning. - Handle set_blocksize() failures in legacy filesystems (bfs, hpfs, qnx4, jfs, befs, affs, isofs, minix, ntfs3, omfs). Mounting a device with a sector size > PAGE_SIZE crashed roughly half of them; the rest had the same missing error handling pattern. Plus a follow-up releasing the superblock buffer_head when setting the minix v3 block size fails. - mount: honour SB_NOUSER in the new mount API. - fs/fcntl: fix a SOFTIRQ-unsafe lock order in fasync signaling by switching the process-group paths of send_sigio() and send_sigurg() from read_lock(&tasklist_lock) to RCU, matching the single-PID path. - vfs: add an FS_USERNS_DELEGATABLE flag and set it for NFS, fixing delegated NFS mounts (fsopen() in a container with the mount performed by a privileged daemon) that broke when non-init s_user_ns was tied to FS_USERNS_MOUNT. - selftests/namespaces: fix a hang in nsid_test where an unreaped grandchild kept the TAP pipe write-end open, a waitpid(-1) race in listns_efault_test, and a false FAIL on kernels without listns() where the tests should SKIP. - filelock: fix the break_lease() stub signature for CONFIG_FILE_LOCKING=n. - init/initramfs_test: wait for the async initramfs unpacking before running; the test and do_populate_rootfs() share the parser state. - fs/coredump: reduce redundant log noise in validate_coredump_safety(). - iomap: pass the correct length to fserror_report_io() in __iomap_write_begin(). - backing-file: fix the backing_file_open() kerneldoc. Cleanups: - initramfs: refactor the cpio hex header parsing to use hex2bin() instead of the hand-rolled simple_strntoul() which is reverted, and extend the initramfs KUnit tests to cover header fields with 0x prefixes. - Replace __get_free_pages() and friends with kmalloc()/kzalloc() across quota, proc, ocfs2/dlm, nilfs2, nfs, nfsd, libfs, jfs, jbd2, isofs, fuse, select, namespace, configfs, binfmt_misc, bfs, and the do_mounts init code - part of the larger work of replacing page allocator calls with kmalloc(). - Use clear_and_wake_up_bit() in unlock_buffer() and journal_end_buffer_io_sync() instead of open-coding the sequence. - Drop unused VFS exports: unexport drop_super_exclusive(), remove start_removing_user_path_at(), and fold __start_removing_path() into start_removing_path(). - fs/read_write: narrow the __kernel_write() export with EXPORT_SYMBOL_FOR_MODULES(). - vfs: uapi: retire octal and hex constants in favor of (1 << n) for the O_ flags. Finding a free bit for a new flag across the architectures was needlessly hard with the mixed bases. - dcache: add extra sanity checks of dead dentries in dentry_free() via a new DENTRY_WARN_ONCE() that also prints d_flags. - iov_iter: use kmemdup_array() in dup_iter() to harden the allocation against multiplication overflow. - fs/pipe: write to ->poll_usage only once. - vfs: remove an always-taken if-branch in find_next_fd(). - dcache: use kmalloc_flex() for struct external_name in __d_alloc(). - namei: use QSTR() instead of QSTR_INIT() in path_pts(). - sync_file_range: delete dead S_ISLNK code. - Comment fixes: retire a stale comment in fget_task_next() and fix assorted spelling mistakes" * tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (73 commits) backing-file: fix backing_file_open() kerneldoc parameter iomap: pass the correct len to fserror_report_io in __iomap_write_begin vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS filelock: fix break_lease() stub signature for CONFIG_FILE_LOCKING=n vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags bpf: add bpf_real_inode() kfunc fs/read_write: Do not export __kernel_write() to the entire world libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callers libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() mount: honour SB_NOUSER in the new mount API fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling selftests/pipe: add pipe_bench microbenchmark fs/pipe: pre-allocate pages outside pipe->mutex in anon_pipe_write fs: retire stale comment in fget_task_next() fs: fix spelling mistakes in comment bfs: replace get_zeroed_page() with kzalloc() binfmt_misc: replace __get_free_page() with kmalloc() configfs: replace __get_free_pages() with kzalloc() fs/namespace: use __getname() to allocate mntpath buffer fs/select: replace __get_free_page() with kmalloc() ...

jbd2: remove special jbd2 slabs

2026-06-10T14:42:55+00:00

When jbd2 was originally written, kmalloc() would not guarantee memory alignment for the requested objects. Since commit 59bb47985c1d in 2019, kmalloc has guaranteed natural alignment for power-of-two allocations. We can now remove the jbd2 special slabs and just use kmalloc() directly. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jan Kara Acked-by: Mike Rapoport (Microsoft) Acked-by: Vlastimil Babka (SUSE) Reviewed-by: Tal Zussman Link: https://patch.msgid.link/20260528171413.1088143-1-willy@infradead.org Signed-off-by: Theodore Ts'o

jbd2: Convert journal commit to bh_submit()

2026-06-04T08:28:08+00:00

Avoid an extra indirect function call by using bh_submit() instead of submit_bh() in journal_submit_commit_record() and jbd2_journal_commit_transaction(). These both use journal_end_buffer_io_sync(), so it's more straightforward to do them both at once. Signed-off-by: Matthew Wilcox (Oracle) Link: https://patch.msgid.link/20260528173150.1093780-17-willy@infradead.org Acked-by: Theodore Ts'o Reviewed-by: Jan Kara Cc: linux-ext4@vger.kernel.org Signed-off-by: Christian Brauner (Amutable)

fs: jbd2: use clear_and_wake_up_bit() in journal_end_buffer_io_sync()

2026-05-27T13:11:02+00:00

Use `clear_and_wake_up_bit()` in `journal_end_buffer_io_sync()`, since the helper was introduced in 'commit 8236b0ae31c83 ("bdi: wake up concurrent wb_shutdown() callers.")' as a generic way of doing the same sequence of operations: clear_bit_unlock(); smp_mb__after_atomic(); wake_up_bit(); The helper was first implemented to avoid bugs caused by forgetting to call `wake_up_bit()` after `clear_bit_unlock()`. Since `journal_end_buffer_io_sync()` was first introduced by 'commit 470decc613ab2 ("jbd2: initial copy of files from jbd")' and last modified in this operation by 'commit 4e857c58efeb9 ("arch: Mass conversion of smp_mb__*()")', years before `clear_and_wake_up_bit()`, it still uses the open-coded sequence. Replace the open-coded sequence with the helper to avoid duplicate code and reduce code paths to maintain. Suggested-by: shuo chen <1289151713@qq.com> Link: https://lore.kernel.org/kernelnewbies/agzoqV835-co4kAN@guidai/T/#t Signed-off-by: Agatha Isabelle Moreira Link: https://patch.msgid.link/ag4SrrOl7R2DcLLi@guidai Signed-off-by: Christian Brauner (Amutable)

jbd2: store jinode dirty range in PAGE_SIZE units

2026-04-09T14:52:35+00:00

jbd2_inode fields are updated under journal->j_list_lock, but some paths read them without holding the lock (e.g. fast commit helpers and ordered truncate helpers). READ_ONCE() alone is not sufficient for the dirty range fields when they are stored as loff_t because 32-bit platforms can observe torn loads. Store the dirty range in PAGE_SIZE units as pgoff_t instead. Represent the dirty range end as an exclusive end page. This avoids a special sentinel value and keeps MAX_LFS_FILESIZE on 32-bit representable. Publish a new dirty range by updating end_page before start_page, and treat start_page >= end_page as empty in the accessor for robustness. Use READ_ONCE() on the read side and WRITE_ONCE() on the write side for the dirty range and i_flags to match the existing lockless access pattern. Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Li Chen Link: https://patch.msgid.link/20260306085643.465275-5-me@linux.beauty Signed-off-by: Theodore Ts'o

jbd2: remove journal_t argument from jbd2_chksum()

2025-05-20T14:31:12+00:00

Since jbd2_chksum() no longer uses its journal_t argument, remove it. Signed-off-by: Eric Biggers Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250513053809.699974-4-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

jbd2: Correct stale comment of release_buffer_page

2025-03-13T14:41:21+00:00

Update stale lock info in comment of release_buffer_page. Signed-off-by: Kemeng Shi Reviewed-by: Jan Kara Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250123155014.2097920-7-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o

jbd2: drop JBD2_ABORT_ON_SYNCDATA_ERR

2025-03-13T14:08:09+00:00

Since ext4's data_err=abort mode doesn't depend on JBD2_ABORT_ON_SYNCDATA_ERR anymore, and nobody else uses it, we can drop it and only warn in jbd2 as it used to be long ago. Suggested-by: Jan Kara Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Link: https://patch.msgid.link/20250122110533.4116662-7-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o

jbd2: flush filesystem device before updating tail sequence

2024-12-04T11:00:05+00:00

When committing transaction in jbd2_journal_commit_transaction(), the disk caches for the filesystem device should be flushed before updating the journal tail sequence. However, this step is missed if the journal is not located on the filesystem device. As a result, the filesystem may become inconsistent following a power failure or system crash. Fix it by ensuring that the filesystem device is flushed appropriately. Fixes: 3339578f0578 ("jbd2: cleanup journal tail after transaction commit") Signed-off-by: Zhang Yi Link: https://lore.kernel.org/r/20241203014407.805916-3-yi.zhang@huaweicloud.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner