Pull vfs async directory updates from Christian Brauner:
"This contains further preparatory changes for the asynchronous directory
locking scheme:
- Add lookup_one_positive_killable() which allows overlayfs to
perform lookup that won't block on a fatal signal
- Unify the mount idmap handling in struct renamedata as a rename can
only happen within a single mount
- Introduce kern_path_parent() for audit which sets the path to the
parent and returns a dentry for the target without holding any
locks on return
- Rename kern_path_locked() as it is only used to prepare for the
removal of an object from the filesystem:
kern_path_locked() => start_removing_path()
kern_path_create() => start_creating_path()
user_path_create() => start_creating_user_path()
user_path_locked_at() => start_removing_user_path_at()
done_path_create() => end_creating_path()
NA => end_removing_path()"
* tag 'vfs-6.18-rc1.async' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
debugfs: rename start_creating() to debugfs_start_creating()
VFS: rename kern_path_locked() and related functions.
VFS/audit: introduce kern_path_parent() for audit
VFS: unify old_mnt_idmap and new_mnt_idmap in renamedata
VFS: discard err2 in filename_create()
VFS/ovl: add lookup_one_positive_killable()
start_creating() is a generic name which I would like to use for a
function similar to simple_start_creating(), only not quite so simple.
debugfs is using this name which, though static, will cause complaints
if then name is given a different signature in a header file.
So rename it to debugfs_start_creating().
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Mount options (uid, gid, mode) are silently ignored when debugfs is
mounted. This is a regression introduced during the conversion to the
new mount API.
When the mount API conversion was done, the parsed options were never
applied to the superblock when it was reused. As a result, the mount
options were ignored when debugfs was mounted.
Fix this by following the same pattern as the tracefs fix in commit
e4d32142d1 ("tracing: Fix tracefs mount options"). Call
debugfs_reconfigure() in debugfs_get_tree() to apply the mount options
to the superblock after it has been created or reused.
As an example, with the bug the "mode" mount option is ignored:
$ mount -o mode=0666 -t debugfs debugfs /tmp/debugfs_test
$ mount | grep debugfs_test
debugfs on /tmp/debugfs_test type debugfs (rw,relatime)
$ ls -ld /tmp/debugfs_test
drwx------ 25 root root 0 Aug 4 14:16 /tmp/debugfs_test
With the fix applied, it works as expected:
$ mount -o mode=0666 -t debugfs debugfs /tmp/debugfs_test
$ mount | grep debugfs_test
debugfs on /tmp/debugfs_test type debugfs (rw,relatime,mode=666)
$ ls -ld /tmp/debugfs_test
drw-rw-rw- 37 root root 0 Aug 2 17:28 /tmp/debugfs_test
Fixes: a20971c187 ("vfs: Convert debugfs to use the new mount API")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220406
Cc: stable <stable@kernel.org>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/r/20250816-debugfs-mount-opts-v3-1-d271dad57b5b@posteo.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core updates from Danilo Krummrich:
"debugfs:
- Remove unneeded debugfs_file_{get,put}() instances
- Remove last remnants of debugfs_real_fops()
- Allow storing non-const void * in struct debugfs_inode_info::aux
sysfs:
- Switch back to attribute_group::bin_attrs (treewide)
- Switch back to bin_attribute::read()/write() (treewide)
- Constify internal references to 'struct bin_attribute'
Support cache-ids for device-tree systems:
- Add arch hook arch_compact_of_hwid()
- Use arch_compact_of_hwid() to compact MPIDR values on arm64
Rust:
- Device:
- Introduce CoreInternal device context (for bus internal methods)
- Provide generic drvdata accessors for bus devices
- Provide Driver::unbind() callbacks
- Use the infrastructure above for auxiliary, PCI and platform
- Implement Device::as_bound()
- Rename Device::as_ref() to Device::from_raw() (treewide)
- Implement fwnode and device property abstractions
- Implement example usage in the Rust platform sample driver
- Devres:
- Remove the inner reference count (Arc) and use pin-init instead
- Replace Devres::new_foreign_owned() with devres::register()
- Require T to be Send in Devres<T>
- Initialize the data kept inside a Devres last
- Provide an accessor for the Devres associated Device
- Device ID:
- Add support for ACPI device IDs and driver match tables
- Split up generic device ID infrastructure
- Use generic device ID infrastructure in net::phy
- DMA:
- Implement the dma::Device trait
- Add DMA mask accessors to dma::Device
- Implement dma::Device for PCI and platform devices
- Use DMA masks from the DMA sample module
- I/O:
- Implement abstraction for resource regions (struct resource)
- Implement resource-based ioremap() abstractions
- Provide platform device accessors for I/O (remap) requests
- Misc:
- Support fallible PinInit types in Revocable
- Implement Wrapper<T> for Opaque<T>
- Merge pin-init blanket dependencies (for Devres)
Misc:
- Fix OF node leak in auxiliary_device_create()
- Use util macros in device property iterators
- Improve kobject sample code
- Add device_link_test() for testing device link flags
- Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
- Hint to prefer container_of_const() over container_of()"
* tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits)
rust: io: fix broken intra-doc links to `platform::Device`
rust: io: fix broken intra-doc link to missing `flags` module
rust: io: mem: enable IoRequest doc-tests
rust: platform: add resource accessors
rust: io: mem: add a generic iomem abstraction
rust: io: add resource abstraction
rust: samples: dma: set DMA mask
rust: platform: implement the `dma::Device` trait
rust: pci: implement the `dma::Device` trait
rust: dma: add DMA addressing capabilities
rust: dma: implement `dma::Device` trait
rust: net::phy Change module_phy_driver macro to use module_device_table macro
rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id
rust: device_id: split out index support into a separate trait
device: rust: rename Device::as_ref() to Device::from_raw()
arm64: cacheinfo: Provide helper to compress MPIDR value into u32
cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id
cacheinfo: Set cache 'id' based on DT data
container_of: Document container_of() is not to be used in new code
driver core: auxiliary bus: fix OF node leak
...
Pull rpc_pipefs updates from Al Viro:
"Massage rpc_pipefs to use saner primitives and clean up the APIs
provided to the rest of the kernel"
* tag 'pull-rpc_pipefs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
rpc_create_client_dir(): return 0 or -E...
rpc_create_client_dir(): don't bother with rpc_populate()
rpc_new_dir(): the last argument is always NULL
rpc_pipe: expand the calls of rpc_mkdir_populate()
rpc_gssd_dummy_populate(): don't bother with rpc_populate()
rpc_mkpipe_dentry(): switch to simple_start_creating()
rpc_pipe: saner primitive for creating regular files
rpc_pipe: saner primitive for creating subdirectories
rpc_pipe: don't overdo directory locking
rpc_mkpipe_dentry(): saner calling conventions
rpc_unlink(): saner calling conventions
rpc_populate(): lift cleanup into callers
rpc_unlink(): use simple_recursive_removal()
rpc_{rmdir_,}depopulate(): use simple_recursive_removal() instead
rpc_pipe: clean failure exits in fill_super
new helper: simple_start_creating()
Set the things up for kernel-initiated creation of object in
a tree-in-dcache filesystem. With respect to locking it's
an equivalent of filename_create() - we either get a negative
dentry with locked parent, or ERR_PTR() and no locks taken.
tracefs and debugfs had that open-coded as part of their
object creation machinery; switched to calling new helper.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... to be used instead of manually assigning to ->s_d_op.
All in-tree filesystem converted (and field itself is renamed,
so any out-of-tree ones in need of conversion will be caught
by compiler).
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The lookup_one_len family of functions is (now) only used internally by
a filesystem on itself either
- in a context where permission checking is irrelevant such as by a
virtual filesystem populating itself, or xfs accessing its ORPHANAGE
or dquota accessing the quota file; or
- in a context where a permission check (MAY_EXEC on the parent) has just
been performed such as a network filesystem finding in "silly-rename"
file in the same directory. This is also the context after the
_parentat() functions where currently lookup_one_qstr_excl() is used.
So the permission check is pointless.
The name "one_len" is unhelpful in understanding the purpose of these
functions and should be changed. Most of the callers pass the len as
"strlen()" so using a qstr and QSTR() can simplify the code.
This patch renames these functions (include lookup_positive_unlocked()
which is part of the family despite the name) to have a name based on
"lookup_noperm". They are changed to receive a 'struct qstr' instead
of separate name and len. In a few cases the use of QSTR() results in a
new call to strlen().
try_lookup_noperm() takes a pointer to a qstr instead of the whole
qstr. This is consistent with d_hash_and_lookup() (which is nearly
identical) and useful for lookup_noperm_unlocked().
The new lookup_noperm_common() doesn't take a qstr yet. That will be
tidied up in a subsequent patch.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
Existing primitive has several problems:
1) calling conventions are clumsy - it returns a dentry reference
that is either identical to its second argument or is an ERR_PTR(-E...);
in both cases no refcount changes happen. Inconvenient for users and
bug-prone; it would be better to have it return 0 on success and -E... on
failure.
2) it allows cross-directory moves; however, no such caller have
ever materialized and considering the way debugfs is used, it's unlikely
to happen in the future. What's more, any such caller would have fun
issues to deal with wrt interplay with recursive removal. It also makes
the calling conventions clumsier...
3) tautological rename fails; the callers have no race-free way
to deal with that.
4) new name must have been formed by the caller; quite a few
callers have it done by sprintf/kasprintf/etc., ending up with considerable
boilerplate.
Proposed replacement: int debugfs_change_name(dentry, fmt, ...). All callers
convert to that easily, and it's simpler internally.
IMO debugfs_rename() should go; if we ever get a real-world use case for
cross-directory moves in debugfs, we can always look into the right way
to handle that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20250112080705.141166-21-viro@zeniv.linux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The reason we need that crap is the dual use ->d_fsdata has there -
it's both holding a debugfs_fsdata reference after the first
debugfs_file_get() (actually, after the call of proxy ->open())
*and* it serves as a place to stash a reference to real file_operations
from object creation to the first open. Oh, and it's triple use,
actually - that stashed reference might be to debugfs_short_fops.
Bugger that for a game of solidiers - just put the operations
reference into debugfs-private augmentation of inode. And split
debugfs_full_file_operations into full and short cases, so that
debugfs_get_file() could tell one from another.
Voila - ->d_fsdata holds NULL until the first (successful) debugfs_get_file()
and a reference to struct debugfs_fsdata afterwards.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20250112080705.141166-4-viro@zeniv.linux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All it takes is having full_proxy_open() collect the information
about available methods and store it in debugfs_fsdata.
Wrappers are called only after full_proxy_open() has succeeded
calling debugfs_get_file(), so they are guaranteed to have
->d_fsdata already pointing to debugfs_fsdata.
As the result, they can check if method is absent and bugger off
early, without any atomic operations, etc. - same effect as what
we'd have from NULL method. Which makes the entire proxy_fops
contents unconditional, making it completely pointless - we can
just put those methods (unconditionally) into
debugfs_full_proxy_file_operations and forget about dynamic
allocation, replace_fops, etc.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20250112080705.141166-3-viro@zeniv.linux.org.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Geert reported that my previous short fops debugfs changes
broke m68k, because it only has mandatory alignement of two,
so we can't stash the "is it short" information into the
pointer (as we already did with the "is it real" bit.)
Instead, exploit the fact that debugfs_file_get() called on
an already open file will already find that the fsdata is
no longer the real fops but rather the allocated data that
already distinguishes full/short ops, so only open() needs
to be able to distinguish. We can achieve that by using two
different open functions.
Unfortunately this requires another set of full file ops,
increasing the size by 536 bytes (x86-64), but that's still
a reasonable trade-off given that only converting some of
the wireless stack gained over 28k. This brings the total
cost of this to around 1k, for wins of 28k (all x86-64).
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/CAMuHMdWu_9-L2Te101w8hU7H_2yobJFPXSwwUmGHSJfaPWDKiQ@mail.gmail.com
Fixes: 8dc6d81c6b ("debugfs: add small file operations for most files")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/20241129121536.30989-2-johannes@sipsolutions.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As struct file_operations is really big, but (most) debugfs
files only use simple_open, read, write and perhaps seek, and
don't need anything else, this wastes a lot of space for NULL
pointers.
Add a struct debugfs_short_fops and some bookkeeping code in
debugfs so that users can use that with debugfs_create_file()
using _Generic to figure out which function to use.
Converting mac80211 to use it where possible saves quite a
bit of space:
1010127 205064 1220 1216411 128f9b net/mac80211/mac80211.ko (before)
981199 205064 1220 1187483 121e9b net/mac80211/mac80211.ko (after)
-------
-28928 = ~28KiB
With a marginal space cost in debugfs:
8701 550 16 9267 2433 fs/debugfs/inode.o (before)
25233 325 32 25590 63f6 fs/debugfs/file.o (before)
8914 558 16 9488 2510 fs/debugfs/inode.o (after)
25380 325 32 25737 6489 fs/debugfs/file.o (after)
---------------
+360 +8
(All on x86-64)
A simple spatch suggests there are more than 300 instances,
not even counting the ones hidden in macros like in mac80211,
that could be trivially converted, for additional savings of
about 240 bytes for each.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20241022151838.26f9925fb959.Ia80b55e934bbfc45ce0df42a3233d34b35508046@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs mount API updates from Christian Brauner:
- Add a generic helper to parse uid and gid mount options.
Currently we open-code the same logic in various filesystems which is
error prone, especially since the verification of uid and gid mount
options is a sensitive operation in the face of idmappings.
Add a generic helper and convert all filesystems over to it. Make
sure that filesystems that are mountable in unprivileged containers
verify that the specified uid and gid can be represented in the
owning namespace of the filesystem.
- Convert hostfs to the new mount api.
* tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fuse: Convert to new uid/gid option parsing helpers
fuse: verify {g,u}id mount options correctly
fat: Convert to new uid/gid option parsing helpers
fat: Convert to new mount api
fat: move debug into fat_mount_options
vboxsf: Convert to new uid/gid option parsing helpers
tracefs: Convert to new uid/gid option parsing helpers
smb: client: Convert to new uid/gid option parsing helpers
tmpfs: Convert to new uid/gid option parsing helpers
ntfs3: Convert to new uid/gid option parsing helpers
isofs: Convert to new uid/gid option parsing helpers
hugetlbfs: Convert to new uid/gid option parsing helpers
ext4: Convert to new uid/gid option parsing helpers
exfat: Convert to new uid/gid option parsing helpers
efivarfs: Convert to new uid/gid option parsing helpers
debugfs: Convert to new uid/gid option parsing helpers
autofs: Convert to new uid/gid option parsing helpers
fs_parse: add uid & gid option option parsing helpers
hostfs: Add const qualifier to host_root in hostfs_fill_super()
hostfs: convert hostfs to use the new mount API
