kernel/linux.git/fs/iomap, branch v7.2-rc2

iomap: submit read bio after each extent

2026-07-01T13:26:47+00:00

Currently the iomap buffered read path tries to build up read context (i.e. bios for the typical block based case) over multiple iomaps as long as the sector matches. This does not take into account files that can map to multiple different devices. While this could be fixed by a bdev check in iomap_bio_read_folio_range, the building up of I/O over iomaps actually was a problem for the not yet merged ext2 iomap port, as that does want to send out I/O at the end of an indirect block mapped range. So instead of adding more checks move over to a model where a bio only spans a single iomap. Change ->submit_read to be called after each iteration so that the bio based users submit the bio after each iomap. Fuse is unchanged because the previous commit stopped using ->submit_read for it. Fixes: dfeab2e95a75 ("erofs: add multiple device support") Reported-by: Kelu Ye Reported-by: Yifan Zhao Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260629121750.3392300-4-hch@lst.de Tested-by: Yifan Zhao Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner (Amutable)

iomap: consolidate bio submission

2026-07-01T13:26:47+00:00

Add a iomap_bio_submit_read_endio helper factored out of iomap_bio_submit_read to that all ->submit_read implementations for iomap_read_ops that use iomap_bio_read_folio_range can shared the logic. Right now that logic is mostly trivial, but already has a bug for XFS because the XFS version is too trivial: file system integrity validation needs a workqueue context and thus can't happen from the default iomap bi_end_io I/O handler. Unfortunately the iomap refactoring just before fs integrity landed moved code around here and the call go misplaced, meaning it never got called. The PI information still is verified by the block layer, but the offloading is less efficient (and the future userspace interface can't get at it). Fixes: 0b10a370529c ("iomap: support T10 protection information") Cc: stable@vger.kernel.org # v7.1 Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260629121750.3392300-2-hch@lst.de Acked-by: Namjae Jeon Reviewed-by: "Darrick J. Wong" Reviewed-by: Joanne Koong Signed-off-by: Christian Brauner (Amutable)

iomap: guard io_size EOF trim against concurrent truncate underflow

2026-07-01T13:26:27+00:00

iomap: fix zero padding data issue in concurrent append writes changed ioend accounting so that io_size tracks only valid data within EOF. This trims io_size when a writeback range extends past end_pos: ioend->io_size += map_len; if (ioend->io_offset + ioend->io_size > end_pos) ioend->io_size = end_pos - ioend->io_offset; However, if end_pos ends up below ioend->io_offset, the subtraction becomes negative and is stored in size_t io_size, causing an unsigned wrap to a huge value. This can happen when writeback continues past byte-level EOF up to a block-aligned range, or when a concurrent truncate shrinks the file after end_pos was sampled in iomap_writeback_handle_eof(). A wrapped io_size can mislead append detection and corrupt completion-time size handling, since filesystem end_io paths consume io_size for decisions such as on-disk EOF updates and unwritten/COW completion ranges. Fix this by clamping io_size to zero when EOF has moved to or before the ioend start offset. This preserves the original intent of trimming io_size to valid in-EOF data while avoiding the underflow. Fixes: 51d20d1dacbe ("iomap: fix zero padding data issue in concurrent append writes") Suggested-by: Christoph Hellwig Signed-off-by: Morduan Zang Link: https://patch.msgid.link/9E38E2659B47DC2A+20260624062622.337469-1-zhangdandan@uniontech.com Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Amutable)

iomap: release pages on atomic dio size mismatch

2026-07-01T13:26:24+00:00

If bio_iov_iter_get_pages() or the bounce helper succeeds but builds a short bio, the REQ_ATOMIC size check rejects it before submission. The old error path only dropped the bio reference, leaving any pages already attached to the bio unreleased. Release or unbounce the pages before falling through to out_put_bio on this error path. This bug was reported by sashiko: https://sashiko.dev/#/patchset/20260608073134.95964-1-changfengnan%40bytedance.com Fixes: 9e0933c21c12 ("fs: iomap: Atomic write support") Signed-off-by: Fengnan Chang Link: https://patch.msgid.link/20260612044041.10677-1-changfengnan@bytedance.com Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Amutable)

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() ...

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

2026-06-14T22:16:54+00:00

Pull iomap updates from Christian Brauner: - Add the vfs infrastructure required to implement fs-verity support for XFS with a post-EOF merkle tree: fsverity generates and stores a zero-block hash, and iomap learns to verify data on buffered reads, to handle fsverity during writeback via the new IOMAP_F_FSVERITY flag, and to write fsverity metadata through iomap_fsverity_write(). - Skip the memset of the iomap in iomap_iter() once the iteration is done. In high-IOPS scenarios (4k randread NVMe polling via io_uring) the pointless memset wasted memory write bandwidth; this improves IOPS by about 5% on ext4 and xfs. - Add balance_dirty_pages_ratelimited() to iomap_zero_iter(), aligning it with iomap_write_iter(). This prepares for the exFAT iomap conversion where zeroing beyond valid_size can trigger large-scale zeroing operations that caused memory pressure without throttling. - Remove the over-strict inline data boundary check. If a filesystem provides a valid inline_data pointer and length there is no reason to require that inline data must not cross a page boundary. - Don't make REQ_POLLED imply REQ_NOWAIT, matching the earlier equivalent block layer fix: there are valid cases to poll for I/O completion without REQ_NOWAIT, and REQ_NOWAIT for file system writes is currently not supported as writes aren't idempotent. - Introduce IOMAP_F_ZERO_TAIL for filesystems that maintain a separate valid data length (exFAT, NTFS). For a write starting at or beyond valid_size, __iomap_write_begin() now zeroes only the tail portion of the block while preserving valid data before it, instead of leaving stale data in the page cache. The flag is also added to the iomap trace event strings. * tag 'vfs-7.2-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iomap: Add IOMAP_F_ZERO_TAIL flag to trace event strings iomap: introduce iomap_fsverity_write() for writing fsverity metadata iomap: teach iomap to read files with fsverity iomap: introduce IOMAP_F_FSVERITY and teach writeback to handle fsverity fsverity: generate and store zero-block hash iomap: introduce IOMAP_F_ZERO_TAIL flag iomap: don't make REQ_POLLED imply REQ_NOWAIT iomap: remove over-strict inline data boundary check iomap: add dirty page control to iomap_zero_iter iomap: avoid memset iomap when iter is done

iomap: pass the correct len to fserror_report_io in __iomap_write_begin

2026-06-10T07:23:46+00:00

len is size of the (larger) write request, plen is the range for which the read failed here. Fixes: a9d573ee88af ("iomap: report file I/O errors to the VFS") Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260610050642.1906695-1-hch@lst.de Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner (Amutable)

Merge tag 'vfs-7.1-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-06-06T14:28:59+00:00

Pull vfs fixes from Christian Brauner: - Fix error handling in ovl_cache_get() - Tighten access checks for exited tasks in pidfd_getfd() - Fix selftests leak in __wait_for_test() - Limit FUSE_NOTIFY_RETRIEVE to uptodate folios - Reject fuse_notify() pagecache ops on directories - Clear JOBCTL_PENDING_MASK for caller in zap_other_threads() - Fix failure to unlock in nfsd4_create_file() - Fix pointer arithmetic in qnx6 directory iteration - Fix UAF due to unlocked ->mnt_ns read in may_decode_fh() - Avoid potential null folio->mapping deref during iomap error reporting * tag 'vfs-7.1-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iomap: avoid potential null folio->mapping deref during error reporting fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh() fs/qnx6: fix pointer arithmetic in directory iteration VFS: fix possible failure to unlock in nfsd4_create_file() signal: clear JOBCTL_PENDING_MASK for caller in zap_other_threads() fuse: reject fuse_notify() pagecache ops on directories fuse: limit FUSE_NOTIFY_RETRIEVE to uptodate folios selftests: harness: fix pidfd leak in __wait_for_test pidfd: refuse access to tasks that have started exiting harder ovl: keep err zero after successful ovl_cache_get()

iomap: Add IOMAP_F_ZERO_TAIL flag to trace event strings

2026-06-05T11:36:42+00:00

Add IOMAP_F_ZERO_TAIL to the flag string mapping in iomap trace events. This allows the new flag to be properly displayed in ftrace output when iomap operations use it. Signed-off-by: Namjae Jeon Link: https://patch.msgid.link/20260603144031.7370-1-linkinjeon@kernel.org Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner (Amutable)

iomap: introduce iomap_fsverity_write() for writing fsverity metadata

2026-06-05T11:36:22+00:00

This is just a wrapper around iomap_file_buffered_write() to create necessary iterator over metadata. Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Andrey Albershteyn Link: https://patch.msgid.link/20260520123722.405752-10-aalbersh@kernel.org Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner (Amutable)