fs: Add case sensitivity flags to file_kattr

Enable upper layers such as NFSD to retrieve case sensitivity
information from file systems by adding FS_XFLAG_CASEFOLD and
FS_XFLAG_CASENONPRESERVING flags.

Filesystems report case-insensitive or case-nonpreserving behavior
by setting these flags directly in fa->fsx_xflags. The default
(flags unset) indicates POSIX semantics: case-sensitive and
case-preserving. Both flags are added to FS_XFLAG_RDONLY_MASK so
FS_IOC_FSSETXATTR silently strips them, keeping the new xflags
strictly a reporting interface. Callers that want to toggle
casefolding continue to use FS_IOC_SETFLAGS with FS_CASEFOLD_FL,
the established UAPI on filesystems that support the operation
(ext4 and f2fs on empty directories).

Case sensitivity information is exported to userspace via the
fa_xflags field in the FS_IOC_FSGETXATTR ioctl and file_getattr()
system call.

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Roland Mainz <roland.mainz@nrubsig.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patch.msgid.link/20260507-case-sensitivity-v14-2-e62cc8200435@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Chuck Lever
2026-05-07 04:52:55 -04:00
committed by Christian Brauner
parent 14c3197ecf
commit 3035e44541
3 changed files with 13 additions and 1 deletions

View File

@@ -37,6 +37,8 @@ void fileattr_fill_xflags(struct file_kattr *fa, u32 xflags)
fa->flags |= FS_PROJINHERIT_FL;
if (fa->fsx_xflags & FS_XFLAG_VERITY)
fa->flags |= FS_VERITY_FL;
if (fa->fsx_xflags & FS_XFLAG_CASEFOLD)
fa->flags |= FS_CASEFOLD_FL;
}
EXPORT_SYMBOL(fileattr_fill_xflags);
@@ -67,6 +69,8 @@ void fileattr_fill_flags(struct file_kattr *fa, u32 flags)
fa->fsx_xflags |= FS_XFLAG_PROJINHERIT;
if (fa->flags & FS_VERITY_FL)
fa->fsx_xflags |= FS_XFLAG_VERITY;
if (fa->flags & FS_CASEFOLD_FL)
fa->fsx_xflags |= FS_XFLAG_CASEFOLD;
}
EXPORT_SYMBOL(fileattr_fill_flags);

View File

@@ -16,7 +16,8 @@
/* Read-only inode flags */
#define FS_XFLAG_RDONLY_MASK \
(FS_XFLAG_PREALLOC | FS_XFLAG_HASATTR | FS_XFLAG_VERITY)
(FS_XFLAG_PREALLOC | FS_XFLAG_HASATTR | FS_XFLAG_VERITY | \
FS_XFLAG_CASEFOLD | FS_XFLAG_CASENONPRESERVING)
/* Flags to indicate valid value of fsx_ fields */
#define FS_XFLAG_VALUES_MASK \

View File

@@ -254,6 +254,13 @@ struct file_attr {
#define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */
#define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */
#define FS_XFLAG_VERITY 0x00020000 /* fs-verity enabled */
/*
* Case handling flags (read-only, cannot be set via ioctl).
* Default (neither set) indicates POSIX semantics: case-sensitive
* lookups and case-preserving storage.
*/
#define FS_XFLAG_CASEFOLD 0x00040000 /* case-insensitive lookups */
#define FS_XFLAG_CASENONPRESERVING 0x00080000 /* case not preserved */
#define FS_XFLAG_HASATTR 0x80000000 /* no DIFLAG for this */
/* the read-only stuff doesn't really belong here, but any other place is