kernel/linux.git/fs/overlayfs/super.c, branch linux-7.1.y

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

2026-04-13T17:24:33+00:00

Pull vfs directory updates from Christian Brauner: "Recently 'start_creating', 'start_removing', 'start_renaming' and related interfaces were added which combine the locking and the lookup. At that time many callers were changed to use the new interfaces. However there are still an assortment of places out side of the core vfs where the directory is locked explictly, whether with inode_lock() or lock_rename() or similar. These were missed in the first pass for an assortment of uninteresting reasons. This addresses the remaining places where explicit locking is used, and changes them to use the new interfaces, or otherwise removes the explicit locking. The biggest changes are in overlayfs. The other changes are quite simple, though maybe the cachefiles changes is the least simple of those" * tag 'vfs-7.1-rc1.directory' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: VFS: unexport lock_rename(), lock_rename_child(), unlock_rename() ovl: remove ovl_lock_rename_workdir() ovl: use is_subdir() for testing if one thing is a subdir of another ovl: change ovl_create_real() to get a new lock when re-opening created file. ovl: pass name buffer to ovl_start_creating_temp() cachefiles: change cachefiles_bury_object to use start_renaming_dentry() ovl: Simplify ovl_lookup_real_one() VFS: make lookup_one_qstr_excl() static. nfsd: switch purge_old() to use start_removing_noperm() selinux: Use simple_start_creating() / simple_done_creating() Apparmor: Use simple_start_creating() / simple_done_creating() libfs: change simple_done_creating() to use end_creating() VFS: move the start_dirop() kerndoc comment to before start_dirop() fs/proc: Don't lock root inode when creating "self" and "thread-self" VFS: note error returns in documentation for various lookup functions

ovl: make fsync after metadata copy-up opt-in mount option

2026-03-27T11:48:10+00:00

Commit 7d6899fb69d25 ("ovl: fsync after metadata copy-up") was done to fix durability of overlayfs copy up on an upper filesystem which does not enforce ordering on storing of metadata changes (e.g. ubifs). In an earlier revision of the regressing commit by Lei Lv, the metadata fsync behavior was opt-in via a new "fsync=strict" mount option. We were hoping that the opt-in mount option could be avoided, so the change was only made to depend on metacopy=off, in the hope of not hurting performance of metadata heavy workloads, which are more likely to be using metacopy=on. This hope was proven wrong by a performance regression report from Google COS workload after upgrade to kernel 6.12. This is an adaptation of Lei's original "fsync=strict" mount option to the existing upstream code. The new mount option is mutually exclusive with the "volatile" mount option, so the latter is now an alias to the "fsync=volatile" mount option. Reported-by: Chenglong Tang Closes: https://lore.kernel.org/linux-unionfs/CAOdxtTadAFH01Vui1FvWfcmQ8jH1O45owTzUcpYbNvBxnLeM7Q@mail.gmail.com/ Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxgKC1SgjMWre=fUb00v8rxtd6sQi-S+dxR8oDzAuiGu8g@mail.gmail.com/ Fixes: 7d6899fb69d25 ("ovl: fsync after metadata copy-up") Depends: 50e638beb67e0 ("ovl: Use str_on_off() helper in ovl_show_options()") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Fei Lv Signed-off-by: Amir Goldstein

ovl: use is_subdir() for testing if one thing is a subdir of another

2026-03-09T08:43:03+00:00

Rather than using lock_rename(), use the more obvious is_subdir() for ensuring that neither upper nor workdir contain the other. Also be explicit in the comment that the two directories cannot be the same. As this is a point-it-time sanity check and does not provide any on-going guarantees, the removal of locking does not introduce any interesting races. Reviewed-by: Amir Goldstein Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20260224222542.3458677-14-neilb@ownmail.net Signed-off-by: Christian Brauner

ovl: change ovl_create_real() to get a new lock when re-opening created file.

2026-03-09T08:43:03+00:00

When ovl_create_real() is used to create a file on the upper filesystem it needs to return the resulting dentry - positive and hashed. It is usually the case the that dentry passed to the create function (e.g. vfs_create()) will be suitable but this is not guaranteed. The filesystem may unhash that dentry forcing a repeat lookup next time the name is wanted. So ovl_create_real() must be (and is) aware of this and prepared to perform that lookup to get a hash positive dentry. This is currently done under that same directory lock that provided exclusion for the create. Proposed changes to locking will make this not possible - as the name, rather than the directory, will be locked. The new APIs provided for lookup and locking do not and cannot support this pattern. The lock isn't needed. ovl_create_real() can drop the lock and then get a new lock for the lookup - then check that the lookup returned the correct inode. In a well-behaved configuration where the upper filesystem is not being modified by a third party, this will always work reliably, and if there are separate modification it will fail cleanly. So change ovl_create_real() to drop the lock and call ovl_start_creating_upper() to find the correct dentry. Note that start_creating doesn't fail if the name already exists. The lookup previously used the name from newdentry which was guaranteed to be stable because the parent directory was locked. As we now drop the lock we lose that guarantee. As newdentry is unhashed it is unlikely for the name to change, but safest not to depend on that. So the expected name is now passed in to ovl_create_real() and that is used. This removes the only remaining use of ovl_lookup_upper, so it is removed. Reviewed-by: Amir Goldstein Signed-off-by: NeilBrown Link: https://patch.msgid.link/20260224222542.3458677-13-neilb@ownmail.net Signed-off-by: Christian Brauner

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

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

ovl: relax requirement for uuid=off,index=on

2026-02-06T12:48:23+00:00

uuid=off,index=on required that all upper/lower directories are on the same filesystem. Relax the requirement so that only all the lower directories need to be on the same filesystem. Reported-by: André Almeida Link: https://lore.kernel.org/r/20260114-tonyk-get_disk_uuid-v1-3-e6a319e25d57@igalia.com/ Signed-off-by: Amir Goldstein

Merge tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2025-12-05T23:25:13+00:00

Pull fuse updates from Miklos Szeredi: - Add mechanism for cleaning out unused, stale dentries; controlled via a module option (Luis Henriques) - Fix various bugs - Cleanups * tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: Uninitialized variable in fuse_epoch_work() fuse: fix io-uring list corruption for terminated non-committed requests fuse: signal that a fuse inode should exhibit local fs behaviors fuse: Always flush the page cache before FOPEN_DIRECT_IO write fuse: Invalidate the page cache after FOPEN_DIRECT_IO write fuse: rename 'namelen' to 'namesize' fuse: use strscpy instead of strcpy fuse: refactor fuse_conn_put() to remove negative logic. fuse: new work queue to invalidate dentries from old epochs fuse: new work queue to periodically invalidate expired dentries dcache: export shrink_dentry_list() and add new helper d_dispose_if_unused() fuse: add WARN_ON and comment for RCU revalidate fuse: Fix whitespace for fuse_uring_args_to_ring() comment fuse: missing copy_finish in fuse-over-io-uring argument copies fuse: fix readahead reclaim deadlock

ovl: port ovl_fill_super() to cred guard

2025-11-19T20:58:25+00:00

Use the scoped ovl cred guard. Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-41-b31603935724@kernel.org Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner

ovl: refactor ovl_fill_super()

2025-11-19T20:58:25+00:00

Split the core into a separate helper in preparation of converting the caller to the scoped ovl cred guard. Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-40-b31603935724@kernel.org Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner