linux/fs/cachefiles, branch v6.16

cachefiles: Fix the incorrect return value in __cachefiles_write()

2025-07-10T07:40:17Z

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

Merge tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-06-02T22:04:06Z

Pull netfs updates from Christian Brauner: - The main API document has been extensively updated/rewritten - Fix an oops in write-retry due to mis-resetting the I/O iterator - Fix the recording of transferred bytes for short DIO reads - Fix a request's work item to not require a reference, thereby avoiding the need to get rid of it in BH/IRQ context - Fix waiting and waking to be consistent about the waitqueue used - Remove NETFS_SREQ_SEEK_DATA_READ, NETFS_INVALID_WRITE, NETFS_ICTX_WRITETHROUGH, NETFS_READ_HOLE_CLEAR, NETFS_RREQ_DONT_UNLOCK_FOLIOS, and NETFS_RREQ_BLOCKED - Reorder structs to eliminate holes - Remove netfs_io_request::ractl - Only provide proc_link field if CONFIG_PROC_FS=y - Remove folio_queue::marks3 - Fix undifferentiation of DIO reads from unbuffered reads * tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: netfs: Fix undifferentiation of DIO reads from unbuffered reads netfs: Fix wait/wake to be consistent about the waitqueue used netfs: Fix the request's work item to not require a ref netfs: Fix setting of transferred bytes with short DIO reads netfs: Fix oops in write-retry from mis-resetting the subreq iterator fs/netfs: remove unused flag NETFS_RREQ_BLOCKED fs/netfs: remove unused flag NETFS_RREQ_DONT_UNLOCK_FOLIOS folio_queue: remove unused field `marks3` fs/netfs: declare field `proc_link` only if CONFIG_PROC_FS=y fs/netfs: remove `netfs_io_request.ractl` fs/netfs: reorder struct fields to eliminate holes fs/netfs: remove unused enum choice NETFS_READ_HOLE_CLEAR fs/netfs: remove unused flag NETFS_ICTX_WRITETHROUGH fs/netfs: remove unused source NETFS_INVALID_WRITE fs/netfs: remove unused flag NETFS_SREQ_SEEK_DATA_READ

Merge tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-05-26T15:02:43Z

Pull vfs directory lookup updates from Christian Brauner: "This contains cleanups for the lookup_one*() family of helpers. We expose a set of functions with names containing "lookup_one_len" and others without the "_len". This difference has nothing to do with "len". It's rater a historical accident that can be confusing. The functions without "_len" take a "mnt_idmap" pointer. This is found in the "vfsmount" and that is an important question when choosing which to use: do you have a vfsmount, or are you "inside" the filesystem. A related question is "is permission checking relevant here?". nfsd and cachefiles *do* have a vfsmount but *don't* use the non-_len functions. They pass nop_mnt_idmap and refuse to work on filesystems which have any other idmap. This work changes nfsd and cachefile to use the lookup_one family of functions and to explictily pass &nop_mnt_idmap which is consistent with all other vfs interfaces used where &nop_mnt_idmap is explicitly passed. The remaining uses of the "_one" functions do not require permission checks so these are renamed to be "_noperm" and the permission checking is removed. This series also changes these lookup function to take a qstr instead of separate name and len. In many cases this simplifies the call" * tag 'vfs-6.16-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: VFS: change lookup_one_common and lookup_noperm_common to take a qstr Use try_lookup_noperm() instead of d_hash_and_lookup() outside of VFS VFS: rename lookup_one_len family to lookup_noperm and remove permission check cachefiles: Use lookup_one() rather than lookup_one_len() nfsd: Use lookup_one() rather than lookup_one_len() VFS: improve interface for lookup_one functions

netfs: Fix the request's work item to not require a ref

2025-05-21T12:35:20Z

When the netfs_io_request struct's work item is queued, it must be supplied with a ref to the work item struct to prevent it being deallocated whilst on the queue or whilst it is being processed. This is tricky to manage as we have to get a ref before we try and queue it and then we may find it's already queued and is thus already holding a ref - in which case we have to try and get rid of the ref again. The problem comes if we're in BH or IRQ context and need to drop the ref: if netfs_put_request() reduces the count to 0, we have to do the cleanup - but the cleanup may need to wait. Fix this by adding a new work item to the request, ->cleanup_work, and dispatching that when the refcount hits zero. That can then synchronously cancel any outstanding work on the main work item before doing the cleanup. Adding a new work item also deals with another problem upstream where it's sometimes changing the work func in the put function and requeuing it - which has occasionally in the past caused the cleanup to happen incorrectly. As a bonus, this allows us to get rid of the 'was_async' parameter from a bunch of functions. This indicated whether the put function might not be permitted to sleep. Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers") Signed-off-by: David Howells Link: https://lore.kernel.org/20250519090707.2848510-4-dhowells@redhat.com cc: Paulo Alcantara cc: Marc Dionne cc: Steve French cc: linux-cifs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner

gcc-15: add '__nonstring' markers to byte arrays

2025-04-20T18:57:54Z

All of these cases are perfectly valid and good traditional C, but hit by the "you're not NUL-terminating your byte array" warning. And none of the cases want any terminating NUL character. Mark them __nonstring to shut up gcc-15 (and in the case of the ak8974 magnetometer driver, I just removed the explicit array size and let gcc expand the 3-byte and 6-byte arrays by one extra byte, because it was the simpler change). Signed-off-by: Linus Torvalds

cachefiles: Use lookup_one() rather than lookup_one_len()

2025-04-07T07:25:32Z

cachefiles uses some VFS interfaces (such as vfs_mkdir) which take an explicit mnt_idmap, and it passes &nop_mnt_idmap as cachefiles doesn't yet support idmapped mounts. It also uses the lookup_one_len() family of functions which implicitly use &nop_mnt_idmap. This mixture of implicit and explicit could be confusing. When we eventually update cachefiles to support idmap mounts it would be best if all places which need an idmap determined from the mount point were similar and easily found. So this patch changes cachefiles to use lookup_one(), lookup_one_unlocked(), and lookup_one_positive_unlocked(), passing &nop_mnt_idmap. This has the benefit of removing the remaining user of the lookup_one_len functions where permission checking is actually needed. Other callers don't care about permission checking and using these function only where permission checking is needed is a valuable simplification. This requires passing the name in a qstr. This is easily done with QSTR() as the name is always nul terminated, and often strlen is used anyway. ->d_name_len is removed as no longer useful. Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250319031545.2999807-4-neil@brown.name Signed-off-by: Christian Brauner

cachefiles: Fix oops in vfs_mkdir from cachefiles_get_directory

2025-03-25T13:59:14Z

Commit c54b386969a5 ("VFS: Change vfs_mkdir() to return the dentry.") changed cachefiles_get_directory, replacing "subdir" with a ERR_PTR from the result of cachefiles_inject_write_error, which is either 0 or some error code. This causes an oops when the resulting pointer is passed to vfs_mkdir. Use a similar pattern to what is used earlier in the function; replace subdir with either the return value from vfs_mkdir, or the ERR_PTR of the cachefiles_inject_write_error() return value, but only if it is non zero. Fixes: c54b386969a5 ("VFS: Change vfs_mkdir() to return the dentry.") cc: netfs@lists.linux.dev Signed-off-by: Marc Dionne Link: https://lore.kernel.org/r/20250325125905.395372-1-marc.dionne@auristor.com 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

2025-03-24T17:47:14Z

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.

VFS: Change vfs_mkdir() to return the dentry.

2025-03-05T10:52:50Z

vfs_mkdir() does not guarantee to leave the child dentry hashed or make it positive on success, and in many such cases the filesystem had to use a different dentry which it can now return. This patch changes vfs_mkdir() to return the dentry provided by the filesystems which is hashed and positive when provided. This reduces the number of cases where the resulting dentry is not positive to a handful which don't deserve extra efforts. The only callers of vfs_mkdir() which are interested in the resulting inode are in-kernel filesystem clients: cachefiles, nfsd, smb/server. The only filesystems that don't reliably provide the inode are: - kernfs, tracefs which these clients are unlikely to be interested in - cifs in some configurations would need to do a lookup to find the created inode, but doesn't. cifs cannot be exported via NFS, is unlikely to be used by cachefiles, and smb/server only has a soft requirement for the inode, so this is unlikely to be a problem in practice. - hostfs, nfs, cifs may need to do a lookup (rarely for NFS) and it is possible for a race to make that lookup fail. Actual failure is unlikely and providing callers handle negative dentries graceful they will fail-safe. So this patch removes the lookup code in nfsd and smb/server and adjusts them to fail safe if a negative dentry is provided: - cache-files already fails safe by restarting the task from the top - it still does with this change, though it no longer calls cachefiles_put_directory() as that will crash if the dentry is negative. - nfsd reports "Server-fault" which it what it used to do if the lookup failed. This will never happen on any file-systems that it can actually export, so this is of no consequence. I removed the fh_update() call as that is not needed and out-of-place. A subsequent nfsd_create_setattr() call will call fh_update() when needed. - smb/server only wants the inode to call ksmbd_smb_inherit_owner() which updates ->i_uid (without calling notify_change() or similar) which can be safely skipping on cifs (I hope). If a different dentry is returned, the first one is put. If necessary the fact that it is new can be determined by comparing pointers. A new dentry will certainly have a new pointer (as the old is put after the new is obtained). Similarly if an error is returned (via ERR_PTR()) the original dentry is put. Reviewed-by: Jeff Layton Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250227013949.536172-7-neilb@suse.de Signed-off-by: Christian Brauner

make use of anon_inode_getfile_fmode()

2025-02-21T09:25:31Z

["fallen through the cracks" misc stuff] A bunch of anon_inode_getfile() callers follow it with adjusting ->f_mode; we have a helper doing that now, so let's make use of it. Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20250118014434.GT1977892@ZenIV Reviewed-by: Jan Kara Signed-off-by: Christian Brauner