[XFS] XFS: ASCII case-insensitive support

Implement ASCII case-insensitive support. It's primary purpose is for
supporting existing filesystems that already use this case-insensitive
mode migrated from IRIX. But, if you only need ASCII-only case-insensitive
support (ie. English only) and will never use another language, then this
mode is perfectly adequate.

ASCII-CI is implemented by generating hashes based on lower-case letters
and doing lower-case compares. It implements a new xfs_nameops vector for
doing the hashes and comparisons for all filename operations.

To create a filesystem with this CI mode, use: # mkfs.xfs -n version=ci
<device>

SGI-PV: 981516
SGI-Modid: xfs-linux-melb:xfs-kern:31209a

Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index 3bed6433d050..6ca749897c58 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -239,6 +239,7 @@ typedef struct xfs_fsop_resblks {
 #define XFS_FSOP_GEOM_FLAGS_LOGV2       0x0100  /* log format version 2 */
 #define XFS_FSOP_GEOM_FLAGS_SECTOR      0x0200  /* sector sizes >1BB    */
 #define XFS_FSOP_GEOM_FLAGS_ATTR2       0x0400  /* inline attributes rework */
+#define XFS_FSOP_GEOM_FLAGS_DIRV2CI     0x1000  /* ASCII only CI names */
 #define XFS_FSOP_GEOM_FLAGS_LAZYSB      0x4000  /* lazy superblock counters */