kernel/linux.git/fs/vboxsf, branch v6.18.21

simplify vboxsf_dir_atomic_open()

2025-09-17T03:59:38+00:00

similar to 9p et.al. Reviewed-by: NeilBrown Signed-off-by: Al Viro

Merge tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T20:43:25+00:00

Pull mmap_prepare updates from Christian Brauner: "Last cycle we introduce f_op->mmap_prepare() in c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). This is preferred to the existing f_op->mmap() hook as it does require a VMA to be established yet, thus allowing the mmap logic to invoke this hook far, far earlier, prior to inserting a VMA into the virtual address space, or performing any other heavy handed operations. This allows for much simpler unwinding on error, and for there to be a single attempt at merging a VMA rather than having to possibly reattempt a merge based on potentially altered VMA state. Far more importantly, it prevents inappropriate manipulation of incompletely initialised VMA state, which is something that has been the cause of bugs and complexity in the past. The intent is to gradually deprecate f_op->mmap, and in that vein this series coverts the majority of file systems to using f_op->mmap_prepare. Prerequisite steps are taken - firstly ensuring all checks for mmap capabilities use the file_has_valid_mmap_hooks() helper rather than directly checking for f_op->mmap (which is now not a valid check) and secondly updating daxdev_mapping_supported() to not require a VMA parameter to allow ext4 and xfs to be converted. Commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for nested file systems") handles the nasty edge-case of nested file systems like overlayfs, which introduces a compatibility shim to allow f_op->mmap_prepare() to be invoked from an f_op->mmap() callback. This allows for nested filesystems to continue to function correctly with all file systems regardless of which callback is used. Once we finally convert all file systems, this shim can be removed. As a result, ecryptfs, fuse, and overlayfs remain unaltered so they can nest all other file systems. We additionally do not update resctl - as this requires an update to remap_pfn_range() (or an alternative to it) which we defer to a later series, equally we do not update cramfs which needs a mixed mapping insertion with the same issue, nor do we update procfs, hugetlbfs, syfs or kernfs all of which require VMAs for internal state and hooks. We shall return to all of these later" * tag 'vfs-6.17-rc1.mmap_prepare' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: doc: update porting, vfs documentation to describe mmap_prepare() fs: replace mmap hook with .mmap_prepare for simple mappings fs: convert most other generic_file_*mmap() users to .mmap_prepare() fs: convert simple use of generic_file_*_mmap() to .mmap_prepare() mm/filemap: introduce generic_file_*_mmap_prepare() helpers fs/xfs: transition from deprecated .mmap hook to .mmap_prepare fs/ext4: transition from deprecated .mmap hook to .mmap_prepare fs/dax: make it possible to check dev dax support without a VMA fs: consistently use can_mmap_file() helper mm/nommu: use file_has_valid_mmap_hooks() helper mm: rename call_mmap/mmap_prepare to vfs_mmap/mmap_prepare

Merge tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-07-28T18:22:56+00:00

Pull misc VFS updates from Christian Brauner: "This contains the usual selections of misc updates for this cycle. Features: - Add ext4 IOCB_DONTCACHE support This refactors the address_space_operations write_begin() and write_end() callbacks to take const struct kiocb * as their first argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate to the filesystem's buffered I/O path. Ext4 is updated to implement handling of the IOCB_DONTCACHE flag and advertises support via the FOP_DONTCACHE file operation flag. Additionally, the i915 driver's shmem write paths are updated to bypass the legacy write_begin/write_end interface in favor of directly calling write_iter() with a constructed synchronous kiocb. Another i915 change replaces a manual write loop with kernel_write() during GEM shmem object creation. Cleanups: - don't duplicate vfs_open() in kernel_file_open() - proc_fd_getattr(): don't bother with S_ISDIR() check - fs/ecryptfs: replace snprintf with sysfs_emit in show function - vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes() - filelock: add new locks_wake_up_waiter() helper - fs: Remove three arguments from block_write_end() - VFS: change old_dir and new_dir in struct renamedata to dentrys - netfs: Remove unused declaration netfs_queue_write_request() Fixes: - eventpoll: Fix semi-unbounded recursion - eventpoll: fix sphinx documentation build warning - fs/read_write: Fix spelling typo - fs: annotate data race between poll_schedule_timeout() and pollwake() - fs/pipe: set FMODE_NOWAIT in create_pipe_files() - docs/vfs: update references to i_mutex to i_rwsem - fs/buffer: remove comment about hard sectorsize - fs/buffer: remove the min and max limit checks in __getblk_slow() - fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable - fs_context: fix parameter name in infofc() macro - fs: Prevent file descriptor table allocations exceeding INT_MAX" * tag 'vfs-6.17-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (24 commits) netfs: Remove unused declaration netfs_queue_write_request() eventpoll: fix sphinx documentation build warning ext4: support uncached buffered I/O mm/pagemap: add write_begin_get_folio() helper function fs: change write_begin/write_end interface to take struct kiocb * drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter drm/i915: Use kernel_write() in shmem object create eventpoll: Fix semi-unbounded recursion vfs: Remove unnecessary list_for_each_entry_safe() from evict_inodes() fs/libfs: don't assume blocksize <= PAGE_SIZE in generic_check_addressable fs/buffer: remove the min and max limit checks in __getblk_slow() fs: Prevent file descriptor table allocations exceeding INT_MAX fs: Remove three arguments from block_write_end() fs/ecryptfs: replace snprintf with sysfs_emit in show function fs: annotate suspected data race between poll_schedule_timeout() and pollwake() docs/vfs: update references to i_mutex to i_rwsem fs/buffer: remove comment about hard sectorsize fs_context: fix parameter name in infofc() macro VFS: change old_dir and new_dir in struct renamedata to dentrys proc_fd_getattr(): don't bother with S_ISDIR() check ...

fs: change write_begin/write_end interface to take struct kiocb *

2025-07-16T12:48:18+00:00

Change the address_space_operations callbacks write_begin() and write_end() to take struct kiocb * as the first argument instead of struct file *. Update all affected function prototypes, implementations, call sites, and related documentation across VFS, filesystems, and block layer. Part of a series refactoring address_space_operations write_begin and write_end callbacks to use struct kiocb for passing write context and flags. Signed-off-by: Taotao Chen Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com Signed-off-by: Christian Brauner

fs: convert most other generic_file_*mmap() users to .mmap_prepare()

2025-06-19T11:56:57+00:00

Update nearly all generic_file_mmap() and generic_file_readonly_mmap() callers to use generic_file_mmap_prepare() and generic_file_readonly_mmap_prepare() respectively. We update blkdev, 9p, afs, erofs, ext2, nfs, ntfs3, smb, ubifs and vboxsf file systems this way. Remaining users we cannot yet update are ecryptfs, fuse and cramfs. The former two are nested file systems that must support any underlying file ssytem, and cramfs inserts a mixed mapping which currently requires a VMA. Once all file systems have been converted to mmap_prepare(), we can then update nested file systems. Signed-off-by: Lorenzo Stoakes Link: https://lore.kernel.org/08db85970d89b17a995d2cffae96fb4cc462377f.1750099179.git.lorenzo.stoakes@oracle.com Signed-off-by: Christian Brauner

new helper: set_default_d_op()

2025-06-11T02:21:16+00:00

... 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 Signed-off-by: Al Viro

vboxsf: Convert to writepages

2025-04-07T07:36:48+00:00

If we add a migrate_folio operation, we can convert the writepage operation to writepages. Further, this lets us optimise by using the same write handle for multiple folios. The large folio support here is illusory; we would need to kmap each page in turn for proper support. But we do remove a few hidden calls to compound_head(). Signed-off-by: "Matthew Wilcox (Oracle)" Link: https://lore.kernel.org/r/20250402150005.2309458-3-willy@infradead.org Signed-off-by: Christian Brauner

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

2025-03-24T17:47:14+00:00

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

2025-03-11T12:06:39+00:00

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 *

2025-02-27T19:00:17+00:00

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