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.
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| @@ -254,6 +254,13 @@ struct file_attr { · 253 unmodified lines | ||
| 254 | 254 | #define FS_XFLAG_DAX 0x00008000 /* use DAX for IO */ |
| 255 | 255 | #define FS_XFLAG_COWEXTSIZE 0x00010000 /* CoW extent size allocator hint */ |
| 256 | 256 | #define FS_XFLAG_VERITY 0x00020000 /* fs-verity enabled */ |
| 257 | +/* | |
| 258 | + * Case handling flags (read-only, cannot be set via ioctl). | |
| 259 | + * Default (neither set) indicates POSIX semantics: case-sensitive | |
| 260 | + * lookups and case-preserving storage. | |
| 261 | + */ | |
| 262 | +#define FS_XFLAG_CASEFOLD 0x00040000 /* case-insensitive lookups */ | |
| 263 | +#define FS_XFLAG_CASENONPRESERVING 0x00080000 /* case not preserved */ | |
| 257 | 264 | #define FS_XFLAG_HASATTR 0x80000000 /* no DIFLAG for this */ |
| 258 | 265 | |
| 259 | 266 | /* the read-only stuff doesn't really belong here, but any other place is |