kernel.git/fs/vboxsf, branch linux-6.15.y

Merge tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-03-24T17:47:14Z

Pull vfs async dir updates from Christian Brauner: "This contains cleanups that fell out of the work from async directory handling: - Change kern_path_locked() and user_path_locked_at() to never return a negative dentry. This simplifies the usability of these helpers in various places - Drop d_exact_alias() from the remaining place in NFS where it is still used. This also allows us to drop the d_exact_alias() helper completely - Drop an unnecessary call to fh_update() from nfsd_create_locked() - Change i_op->mkdir() to return a struct dentry Change vfs_mkdir() to return a dentry provided by the filesystems which is hashed and positive. This allows us to reduce the number of cases where the resulting dentry is not positive to very few cases. The code in these places becomes simpler and easier to understand. - Repack DENTRY_* and LOOKUP_* flags" * tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: doc: fix inline emphasis warning VFS: Change vfs_mkdir() to return the dentry. nfs: change mkdir inode_operation to return alternate dentry if needed. fuse: return correct dentry for ->mkdir ceph: return the correct dentry on mkdir hostfs: store inode in dentry after mkdir if possible. Change inode_operations.mkdir to return struct dentry * nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked() nfs/vfs: discard d_exact_alias() VFS: add common error checks to lookup_one_qstr_excl() VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry VFS: repack LOOKUP_ bit flags. VFS: repack DENTRY_ flags.

vboxsf: Add __nonstring annotations for unterminated strings

2025-03-11T12:06:39Z

When a character array without a terminating NUL character has a static initializer, GCC 15's -Wunterminated-string-initialization will only warn if the array lacks the "nonstring" attribute[1]. Mark the arrays with __nonstring to and correctly identify the char array as "not a C string" and thereby eliminate the warning. This effectively reverts the change in 4e7487245abc ("vboxsf: fix building with GCC 15"), to add the annotation that has other uses (i.e. warning if the string is ever used with C string APIs). Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1] Cc: Hans de Goede Cc: Brahmajit Das Cc: Christian Brauner Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20250310222530.work.374-kees@kernel.org Reviewed-by: Hans de Goede Signed-off-by: Christian Brauner

Change inode_operations.mkdir to return struct dentry *

2025-02-27T19:00:17Z

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton Reviewed-by: Jan Kara Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner

vboxsf: fix building with GCC 15

2025-02-07T09:27:24Z

Building with GCC 15 results in build error fs/vboxsf/super.c:24:54: error: initializer-string for array of ‘unsigned char’ is too long [-Werror=unterminated-string-initialization] 24 | static const unsigned char VBSF_MOUNT_SIGNATURE[4] = "\000\377\376\375"; | ^~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors Due to GCC having enabled -Werror=unterminated-string-initialization[0] by default. Separately initializing each array element of VBSF_MOUNT_SIGNATURE to ensure NUL termination, thus satisfying GCC 15 and fixing the build error. [0]: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wno-unterminated-string-initialization Signed-off-by: Brahmajit Das Link: https://lore.kernel.org/r/20250121162648.1408743-1-brahmajit.xyz@gmail.com Reviewed-by: Hans de Goede Signed-off-by: Christian Brauner

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

2025-01-30T17:13:35Z

Pull vfs d_revalidate updates from Al Viro: "Provide stable parent and name to ->d_revalidate() instances Most of the filesystem methods where we care about dentry name and parent have their stability guaranteed by the callers; ->d_revalidate() is the major exception. It's easy enough for callers to supply stable values for expected name and expected parent of the dentry being validated. That kills quite a bit of boilerplate in ->d_revalidate() instances, along with a bunch of races where they used to access ->d_name without sufficient precautions" * tag 'pull-revalidate' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: 9p: fix ->rename_sem exclusion orangefs_d_revalidate(): use stable parent inode and name passed by caller ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller nfs: fix ->d_revalidate() UAF on ->d_name accesses nfs{,4}_lookup_validate(): use stable parent inode passed by caller gfs2_drevalidate(): use stable parent inode and name passed by caller fuse_dentry_revalidate(): use stable parent inode and name passed by caller vfat_revalidate{,_ci}(): use stable parent inode passed by caller exfat_d_revalidate(): use stable parent inode passed by caller fscrypt_d_revalidate(): use stable parent inode passed by caller ceph_d_revalidate(): propagate stable name down into request encoding ceph_d_revalidate(): use stable parent inode passed by caller afs_d_revalidate(): use stable name and parent inode passed by caller Pass parent directory inode and expected name to ->d_revalidate() generic_ci_d_compare(): use shortname_storage ext4 fast_commit: make use of name_snapshot primitives dissolve external_name.u into separate members make take_dentry_name_snapshot() lockless dcache: back inline names with a struct-wrapped array of unsigned long make sure that DNAME_INLINE_LEN is a multiple of word size

Pass parent directory inode and expected name to ->d_revalidate()

2025-01-28T00:25:23Z

->d_revalidate() often needs to access dentry parent and name; that has to be done carefully, since the locking environment varies from caller to caller. We are not guaranteed that dentry in question will not be moved right under us - not unless the filesystem is such that nothing on it ever gets renamed. It can be dealt with, but that results in boilerplate code that isn't even needed - the callers normally have just found the dentry via dcache lookup and want to verify that it's in the right place; they already have the values of ->d_parent and ->d_name stable. There is a couple of exceptions (overlayfs and, to less extent, ecryptfs), but for the majority of calls that song and dance is not needed at all. It's easier to make ecryptfs and overlayfs find and pass those values if there's a ->d_revalidate() instance to be called, rather than doing that in the instances. This commit only changes the calling conventions; making use of supplied values is left to followups. NOTE: some instances need more than just the parent - things like CIFS may need to build an entire path from filesystem root, so they need more precautions than the usual boilerplate. This series doesn't do anything to that need - these filesystems have to keep their locking mechanisms (rename_lock loops, use of dentry_path_raw(), private rwsem a-la v9fs). One thing to keep in mind when using name is that name->name will normally point into the pathname being resolved; the filename in question occupies name->len bytes starting at name->name, and there is NUL somewhere after it, but it the next byte might very well be '/' rather than '\0'. Do not ignore name->len. Reviewed-by: Jeff Layton Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Al Viro

vbox: Enable VBOXGUEST and VBOXSF_FS on ARM64

2025-01-07T14:57:23Z

Now that VirtualBox is able to run as a host on arm64 (e.g. the Apple M3 processors) we can enable VBOXSF_FS (and in turn VBOXGUEST) for this architecture. Tested with various runs of bonnie++ and dbench on an Apple MacBook Pro with the latest Virtualbox 7.1.4 r165100 installed. Signed-off-by: Christian Kujau Link: https://lore.kernel.org/r/7384d96c-2a77-39b0-2306-90129bae9342@nerdbynature.de Reviewed-by: Hans de Goede Signed-off-by: Christian Brauner

fs: Convert aops->write_end to take a folio

2024-08-07T09:32:02Z

Most callers have a folio, and most implementations operate on a folio, so remove the conversion from folio->page->folio to fit through this interface. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

vboxsf: Use a folio in vboxsf_write_end()

2024-08-07T09:32:02Z

Because we have to kmap() the page before calling vboxsf_write(), we can't entirely remove the use of struct page. But we can eliminate some uses of old APIs and remove some unnecessary calls to compound_head(). Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

Merge tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-07-15T18:31:32Z

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