kernel/linux.git/fs/namei.c, branch v7.0.10

vfs: fix docstring of hash_name()

2026-03-19T10:18:01+00:00

The docstring of hash_name() is falsely reporting that it returns the component length, whereas it returns a pointer to the terminating '/' or NUL character in the pathname being resolved. Signed-off-by: Jori Koolstra Link: https://patch.msgid.link/20260318203953.5770-1-jkoolstra@xs4all.nl Signed-off-by: Christian Brauner

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

Merge tag 'vfs-7.0-rc1.misc.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-16T21:00:36+00:00

Pull more misc vfs updates from Christian Brauner: "Features: - Optimize close_range() from O(range size) to O(active FDs) by using find_next_bit() on the open_fds bitmap instead of linearly scanning the entire requested range. This is a significant improvement for large-range close operations on sparse file descriptor tables. - Add FS_XFLAG_VERITY file attribute for fs-verity files, retrievable via FS_IOC_FSGETXATTR and file_getattr(). The flag is read-only. Add tracepoints for fs-verity enable and verify operations, replacing the previously removed debug printk's. - Prevent nfsd from exporting special kernel filesystems like pidfs and nsfs. These filesystems have custom ->open() and ->permission() export methods that are designed for open_by_handle_at(2) only and are incompatible with nfsd. Update the exportfs documentation accordingly. Fixes: - Fix KMSAN uninit-value in ovl_fill_real() where strcmp() was used on a non-null-terminated decrypted directory entry name from fscrypt. This triggered on encrypted lower layers when the decrypted name buffer contained uninitialized tail data. The fix also adds VFS-level name_is_dot(), name_is_dotdot(), and name_is_dot_dotdot() helpers, replacing various open-coded "." and ".." checks across the tree. - Fix read-only fsflags not being reset together with xflags in vfs_fileattr_set(). Currently harmless since no read-only xflags overlap with flags, but this would cause inconsistencies for any future shared read-only flag - Return -EREMOTE instead of -ESRCH from PIDFD_GET_INFO when the target process is in a different pid namespace. This lets userspace distinguish "process exited" from "process in another namespace", matching glibc's pidfd_getpid() behavior Cleanups: - Use C-string literals in the Rust seq_file bindings, replacing the kernel::c_str!() macro (available since Rust 1.77) - Fix typo in d_walk_ret enum comment, add porting notes for the readlink_copy() calling convention change" * tag 'vfs-7.0-rc1.misc.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: add porting notes about readlink_copy() pidfs: return -EREMOTE when PIDFD_GET_INFO is called on another ns nfsd: do not allow exporting of special kernel filesystems exportfs: clarify the documentation of open()/permission() expotrfs ops fsverity: add tracepoints fs: add FS_XFLAG_VERITY for fs-verity files rust: seq_file: replace `kernel::c_str!` with C-Strings fs: dcache: fix typo in enum d_walk_ret comment ovl: use name_is_dot* helpers in readdir code fs: add helpers name_is_dot{,dot,_dotdot} ovl: Fix uninit-value in ovl_fill_real fs: reset read-only fsflags together with xflags fs/file: optimize close_range() complexity from O(N) to O(Sparse)

Merge tag 'pull-filename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2026-02-10T00:58:28+00:00

Pull vfs 'struct filename' updates from Al Viro: "[Mostly] sanitize struct filename handling" * tag 'pull-filename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (68 commits) sysfs(2): fs_index() argument is _not_ a pathname alpha: switch osf_mount() to strndup_user() ksmbd: use CLASS(filename_kernel) mqueue: switch to CLASS(filename) user_statfs(): switch to CLASS(filename) statx: switch to CLASS(filename_maybe_null) quotactl_block(): switch to CLASS(filename) chroot(2): switch to CLASS(filename) move_mount(2): switch to CLASS(filename_maybe_null) namei.c: switch user pathname imports to CLASS(filename{,_flags}) namei.c: convert getname_kernel() callers to CLASS(filename_kernel) do_f{chmod,chown,access}at(): use CLASS(filename_uflags) do_readlinkat(): switch to CLASS(filename_flags) do_sys_truncate(): switch to CLASS(filename) do_utimes_path(): switch to CLASS(filename_uflags) chdir(2): unspaghettify a bit... do_fchownat(): unspaghettify a bit... fspick(2): use CLASS(filename_flags) name_to_handle_at(): use CLASS(filename_uflags) vfs_open_tree(): use CLASS(filename_uflags) ...

Merge tag 'vfs-7.0-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-09T23:13:05+00:00

Pull misc vfs updates from Christian Brauner: "This contains a mix of VFS cleanups, performance improvements, API fixes, documentation, and a deprecation notice. Scalability and performance: - Rework pid allocation to only take pidmap_lock once instead of twice during alloc_pid(), improving thread creation/teardown throughput by 10-16% depending on false-sharing luck. Pad the namespace refcount to reduce false-sharing - Track file lock presence via a flag in ->i_opflags instead of reading ->i_flctx, avoiding false-sharing with ->i_readcount on open/close hot paths. Measured 4-16% improvement on 24-core open-in-a-loop benchmarks - Use a consume fence in locks_inode_context() to match the store-release/load-consume idiom, eliminating a hardware fence on some architectures - Annotate cdev_lock with __cacheline_aligned_in_smp to prevent false-sharing - Remove a redundant DCACHE_MANAGED_DENTRY check in __follow_mount_rcu() that never fires since the caller already verifies it, eliminating a 100% mispredicted branch - Fix a 100% mispredicted likely() in devcgroup_inode_permission() that became wrong after a prior code reorder Bug fixes and correctness: - Make insert_inode_locked() wait for inode destruction instead of skipping, fixing a corner case where two matching inodes could exist in the hash - Move f_mode initialization before file_ref_init() in alloc_file() to respect the SLAB_TYPESAFE_BY_RCU ordering contract - Add a WARN_ON_ONCE guard in try_to_free_buffers() for folios with no buffers attached, preventing a null pointer dereference when AS_RELEASE_ALWAYS is set but no release_folio op exists - Fix select restart_block to store end_time as timespec64, avoiding truncation of tv_sec on 32-bit architectures - Make dump_inode() use get_kernel_nofault() to safely access inode and superblock fields, matching the dump_mapping() pattern API modernization: - Make posix_acl_to_xattr() allocate the buffer internally since every single caller was doing it anyway. Reduces boilerplate and unnecessary error checking across ~15 filesystems - Replace deprecated simple_strtoul() with kstrtoul() for the ihash_entries, dhash_entries, mhash_entries, and mphash_entries boot parameters, adding proper error handling - Convert chardev code to use guard(mutex) and __free(kfree) cleanup patterns - Replace min_t() with min() or umin() in VFS code to avoid silently truncating unsigned long to unsigned int - Gate LOOKUP_RCU assertions behind CONFIG_DEBUG_VFS since callers already check the flag Deprecation: - Begin deprecating legacy BSD process accounting (acct(2)). The interface has numerous footguns and better alternatives exist (eBPF) Documentation: - Fix and complete kernel-doc for struct export_operations, removing duplicated documentation between ReST and source - Fix kernel-doc warnings for __start_dirop() and ilookup5_nowait() Testing: - Add a kunit test for initramfs cpio handling of entries with filesize > PATH_MAX Misc: - Add missing include in fs_struct.c" * tag 'vfs-7.0-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits) posix_acl: make posix_acl_to_xattr() alloc the buffer fs: make insert_inode_locked() wait for inode destruction initramfs_test: kunit test for cpio.filesize > PATH_MAX fs: improve dump_inode() to safely access inode fields fs: add for 'init_fs' docs: exportfs: Use source code struct documentation fs: move initializing f_mode before file_ref_init() exportfs: Complete kernel-doc for struct export_operations exportfs: Mark struct export_operations functions at kernel-doc exportfs: Fix kernel-doc output for get_name() acct(2): begin the deprecation of legacy BSD process accounting device_cgroup: remove branch hint after code refactor VFS: fix __start_dirop() kernel-doc warnings fs: Describe @isnew parameter in ilookup5_nowait() fs/namei: Remove redundant DCACHE_MANAGED_DENTRY check in __follow_mount_rcu fs: only assert on LOOKUP_RCU when built with CONFIG_DEBUG_VFS select: store end_time as timespec64 in restart block chardev: Switch to guard(mutex) and __free(kfree) namespace: Replace simple_strtoul with kstrtoul to parse boot params dcache: Replace simple_strtoul with kstrtoul in set_dhash_entries ...

Merge tag 'vfs-7.0-rc1.atomic_open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-09T22:25:37+00:00

Pull vfs atomic_open updates from Christian Brauner: "Allow knfsd to use atomic_open() While knfsd offers combined exclusive create and open results to clients, on some filesystems those results are not atomic. The separate vfs_create() + vfs_open() sequence in dentry_create() can produce races and unexpected errors. For example, open O_CREAT with mode 0 will succeed in creating the file but return -EACCES from vfs_open(). Additionally, network filesystems benefit from reducing remote round-trip operations by using a single atomic_open() call. Teach dentry_create() -- whose sole caller is knfsd -- to use atomic_open() for filesystems that support it" * tag 'vfs-7.0-rc1.atomic_open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs/namei: fix kernel-doc markup for dentry_create VFS/knfsd: Teach dentry_create() to use atomic_open() VFS: Prepare atomic_open() for dentry_create() VFS: move dentry_create() from fs/open.c to fs/namei.c

Merge tag 'vfs-7.0-rc1.btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-02-09T21:05:35+00:00

Pull vfs updates for btrfs from Christian Brauner: "This contains some changes for btrfs that are taken to the vfs tree to stop duplicating VFS code for subvolume/snapshot dentry Btrfs has carried private copies of the VFS may_delete() and may_create() functions in fs/btrfs/ioctl.c for permission checks during subvolume creation and snapshot destruction. These copies have drifted out of sync with the VFS originals — btrfs_may_delete() is missing the uid/gid validity check and btrfs_may_create() is missing the audit_inode_child() call. Export the VFS functions as may_{create,delete}_dentry() and switch btrfs to use them, removing ~70 lines of duplicated code" * tag 'vfs-7.0-rc1.btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: btrfs: use may_create_dentry() in btrfs_mksubvol() btrfs: use may_delete_dentry() in btrfs_ioctl_snap_destroy() fs: export may_create() as may_create_dentry() fs: export may_delete() as may_delete_dentry()

fs: add helpers name_is_dot{,dot,_dotdot}

2026-01-29T09:06:59+00:00

Rename the helper is_dot_dotdot() into the name_ namespace and add complementary helpers to check for dot and dotdot names individually. Signed-off-by: Amir Goldstein Link: https://patch.msgid.link/20260128132406.23768-3-amir73il@gmail.com Reviewed-by: Eric Biggers Signed-off-by: Christian Brauner

fs/namei: fix kernel-doc markup for dentry_create

2026-01-20T13:54:01+00:00

O_ is interpreted as a broken hyperlink target. Escape _ with a backslash. The asterisk in "struct file *" is interpreted as an opening emphasis string that never closes. Replace double quotes with rST backticks. Change "a ERR_PTR" to "an ERR_PTR". Signed-off-by: Jay Winston Link: https://patch.msgid.link/20260118110401.2651-1-jaybenjaminwinston@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

namei.c: switch user pathname imports to CLASS(filename{,_flags})

2026-01-16T17:52:03+00:00

filename_flags is used by user_path_at(). I suspect that mixing LOOKUP_EMPTY with real lookup flags had been a mistake all along; the former belongs to pathname import, the latter - to pathwalk. Right now none of the remaining in-tree callers of user_path_at() are getting LOOKUP_EMPTY in flags, so user_path_at() could probably be switched to CLASS(filename)... Signed-off-by: Al Viro