[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, 3 insertions, 1 deletions

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 381ebda4f7bc..84583cf73db3 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -95,6 +95,8 @@ xfs_fs_geometry(
                                 XFS_FSOP_GEOM_FLAGS_DIRV2 : 0) |
                         (xfs_sb_version_hassector(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_SECTOR : 0) |
+                        (xfs_sb_version_hasasciici(&mp->m_sb) ?
+                                XFS_FSOP_GEOM_FLAGS_DIRV2CI : 0) |
                         (xfs_sb_version_haslazysbcount(&mp->m_sb) ?
                                 XFS_FSOP_GEOM_FLAGS_LAZYSB : 0) |
                         (xfs_sb_version_hasattr2(&mp->m_sb) ?
@@ -625,7 +627,7 @@ xfs_fs_goingdown(
                         xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
                         thaw_bdev(sb->s_bdev, sb);
                 }
-        
+
                 break;
         }
         case XFS_FSOP_GOING_FLAGS_LOGFLUSH: