kernel/linux.git/fs/cachefiles, branch v6.19.11

Merge tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-12-02T00:13:46+00:00

Pull directory locking updates from Christian Brauner: "This contains the work to add centralized APIs for directory locking operations. This series is part of a larger effort to change directory operation locking to allow multiple concurrent operations in a directory. The ultimate goal is to lock the target dentry(s) rather than the whole parent directory. To help with changing the locking protocol, this series centralizes locking and lookup in new helper functions. The helpers establish a pattern where it is the dentry that is being locked and unlocked (currently the lock is held on dentry->d_parent->d_inode, but that can change in the future). This also changes vfs_mkdir() to unlock the parent on failure, as well as dput()ing the dentry. This allows end_creating() to only require the target dentry (which may be IS_ERR() after vfs_mkdir()), not the parent" * tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nfsd: fix end_creating() conversion VFS: introduce end_creating_keep() VFS: change vfs_mkdir() to unlock on failure. ecryptfs: use new start_creating/start_removing APIs Add start_renaming_two_dentries() VFS/ovl/smb: introduce start_renaming_dentry() VFS/nfsd/ovl: introduce start_renaming() and end_renaming() VFS: add start_creating_killable() and start_removing_killable() VFS: introduce start_removing_dentry() smb/server: use end_removing_noperm for for target of smb2_create_link() VFS: introduce start_creating_noperm() and start_removing_noperm() VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing() VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating() VFS: tidy up do_unlinkat() VFS: introduce start_dirop() and end_dirop() debugfs: rename end_creating() to debugfs_end_creating()

VFS: introduce end_creating_keep()

2025-11-14T12:15:58+00:00

Occasionally the caller of end_creating() wants to keep using the dentry. Rather then requiring them to dget() the dentry (when not an error) before calling end_creating(), provide end_creating_keep() which does this. cachefiles and overlayfs make use of this. Reviewed-by: Amir Goldstein Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-16-neilb@ownmail.net Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: Christian Brauner

VFS: change vfs_mkdir() to unlock on failure.

2025-11-14T12:15:58+00:00

vfs_mkdir() already drops the reference to the dentry on failure but it leaves the parent locked. This complicates end_creating() which needs to unlock the parent even though the dentry is no longer available. If we change vfs_mkdir() to unlock on failure as well as releasing the dentry, we can remove the "parent" arg from end_creating() and simplify the rules for calling it. Note that cachefiles_get_directory() can choose to substitute an error instead of actually calling vfs_mkdir(), for fault injection. In that case it needs to call end_creating(), just as vfs_mkdir() now does on error. ovl_create_real() will now unlock on error. So the conditional end_creating() after the call is removed, and end_creating() is called internally on error. Reviewed-by: Amir Goldstein Reviewed-by: Jeff Layton Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-15-neilb@ownmail.net Signed-off-by: Christian Brauner

VFS: introduce start_removing_dentry()

2025-11-14T12:15:57+00:00

start_removing_dentry() is similar to start_removing() but instead of providing a name for lookup, the target dentry is given. start_removing_dentry() checks that the dentry is still hashed and in the parent, and if so it locks and increases the refcount so that end_removing() can be used to finish the operation. This is used in cachefiles, overlayfs, smb/server, and apparmor. There will be other users including ecryptfs. As start_removing_dentry() takes an extra reference to the dentry (to be put by end_removing()), there is no need to explicitly take an extra reference to stop d_delete() from using dentry_unlink_inode() to negate the dentry - as in cachefiles_delete_object(), and ksmbd_vfs_unlink(). cachefiles_bury_object() now gets an extra ref to the victim, which is drops. As it includes the needed end_removing() calls, the caller doesn't need them. Reviewed-by: Amir Goldstein Reviewed-by: Namjae Jeon Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-9-neilb@ownmail.net Signed-off-by: Christian Brauner

VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing()

2025-11-14T12:15:56+00:00

start_removing() is similar to start_creating() but will only return a positive dentry with the expectation that it will be removed. This is used by nfsd, cachefiles, and overlayfs. They are changed to also use end_removing() to terminate the action begun by start_removing(). This is a simple alias for end_dirop(). Apart from changes to the error paths, as we no longer need to unlock on a lookup error, an effect on callers is that they don't need to test if the found dentry is positive or negative - they can be sure it is positive. Reviewed-by: Amir Goldstein Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-6-neilb@ownmail.net Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: Christian Brauner

VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()

2025-11-14T12:15:56+00:00

start_creating() is similar to simple_start_creating() but is not so simple. It takes a qstr for the name, includes permission checking, and does NOT report an error if the name already exists, returning a positive dentry instead. This is currently used by nfsd, cachefiles, and overlayfs. end_creating() is called after the dentry has been used. end_creating() drops the reference to the dentry as it is generally no longer needed. This is exactly the first section of end_creating_path() so that function is changed to call the new end_creating() These calls help encapsulate locking rules so that directory locking can be changed. Occasionally this change means that the parent lock is held for a shorter period of time, for example in cachefiles_commit_tmpfile(). As this function now unlocks after an unlink and before the following lookup, it is possible that the lookup could again find a positive dentry, so a while loop is introduced there. In overlayfs the ovl_lookup_temp() function has ovl_tempname() split out to be used in ovl_start_creating_temp(). The other use of ovl_lookup_temp() is preparing for a rename. When rename handling is updated, ovl_lookup_temp() will be removed. Reviewed-by: Jeff Layton Reviewed-by: Amir Goldstein Signed-off-by: NeilBrown Link: https://patch.msgid.link/20251113002050.676694-5-neilb@ownmail.net Tested-by: syzbot@syzkaller.appspotmail.com Signed-off-by: Christian Brauner

vfs: allow mkdir to wait for delegation break on parent

2025-11-12T08:38:35+00:00

In order to add directory delegation support, we need to break delegations on the parent whenever there is going to be a change in the directory. Add a new delegated_inode parameter to vfs_mkdir. All of the existing callers set that to NULL for now, except for do_mkdirat which will properly block until the lease is gone. Reviewed-by: Jan Kara Reviewed-by: NeilBrown Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-6-52f3feebb2f2@kernel.org Signed-off-by: Christian Brauner

VFS: unify old_mnt_idmap and new_mnt_idmap in renamedata

2025-09-23T10:37:35+00:00

A rename operation can only rename within a single mount. Callers of vfs_rename() must and do ensure this is the case. So there is no point in having two mnt_idmaps in renamedata as they are always the same. Only one of them is passed to ->rename in any case. This patch replaces both with a single "mnt_idmap" and changes all callers. Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Signed-off-by: Christian Brauner

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 ...

cachefiles: Fix the incorrect return value in __cachefiles_write()

2025-07-10T07:40:17+00:00

In __cachefiles_write(), if the return value of the write operation > 0, it is set to 0. This makes it impossible to distinguish scenarios where a partial write has occurred, and will affect the outer calling functions: 1) cachefiles_write_complete() will call "term_func" such as netfs_write_subrequest_terminated(). When "ret" in __cachefiles_write() is used as the "transferred_or_error" of this function, it can not distinguish the amount of data written, makes the WARN meaningless. 2) cachefiles_ondemand_fd_write_iter() can only assume all writes were successful by default when "ret" is 0, and unconditionally return the full length specified by user space. Fix it by modifying "ret" to reflect the actual number of bytes written. Furthermore, returning a value greater than 0 from __cachefiles_write() does not affect other call paths, such as cachefiles_issue_write() and fscache_write(). Fixes: 047487c947e8 ("cachefiles: Implement the I/O routines") Signed-off-by: Zizhi Wo Link: https://lore.kernel.org/20250703024418.2809353-1-wozizhi@huaweicloud.com Signed-off-by: Christian Brauner