[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>
diff --git a/fs/xfs/linux-2.6/xfs_linux.h b/fs/xfs/linux-2.6/xfs_linux.h
index 4edc469..aded573 100644
--- a/fs/xfs/linux-2.6/xfs_linux.h
+++ b/fs/xfs/linux-2.6/xfs_linux.h
@@ -76,6 +76,7 @@
#include <linux/log2.h>
#include <linux/spinlock.h>
#include <linux/random.h>
+#include <linux/ctype.h>
#include <asm/page.h>
#include <asm/div64.h>
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 41eea24..cce59cc 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -569,7 +569,10 @@
inode->i_mapping->a_ops = &xfs_address_space_operations;
break;
case S_IFDIR:
- inode->i_op = &xfs_dir_inode_operations;
+ if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
+ inode->i_op = &xfs_dir_ci_inode_operations;
+ else
+ inode->i_op = &xfs_dir_inode_operations;
inode->i_fop = &xfs_dir_file_operations;
break;
case S_IFLNK:
diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index 882609c..b445ec3 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -48,6 +48,52 @@
extern const struct xfs_nameops xfs_default_nameops;
+/*
+ * ASCII case-insensitive (ie. A-Z) support for directories that was
+ * used in IRIX.
+ */
+STATIC xfs_dahash_t
+xfs_ascii_ci_hashname(
+ struct xfs_name *name)
+{
+ xfs_dahash_t hash;
+ int i;
+
+ for (i = 0, hash = 0; i < name->len; i++)
+ hash = tolower(name->name[i]) ^ rol32(hash, 7);
+
+ return hash;
+}
+
+STATIC enum xfs_dacmp
+xfs_ascii_ci_compname(
+ struct xfs_da_args *args,
+ const char *name,
+ int len)
+{
+ enum xfs_dacmp result;
+ int i;
+
+ if (args->namelen != len)
+ return XFS_CMP_DIFFERENT;
+
+ result = XFS_CMP_EXACT;
+ for (i = 0; i < len; i++) {
+ if (args->name[i] == name[i])
+ continue;
+ if (tolower(args->name[i]) != tolower(name[i]))
+ return XFS_CMP_DIFFERENT;
+ result = XFS_CMP_CASE;
+ }
+
+ return result;
+}
+
+static struct xfs_nameops xfs_ascii_ci_nameops = {
+ .hashname = xfs_ascii_ci_hashname,
+ .compname = xfs_ascii_ci_compname,
+};
+
void
xfs_dir_mount(
xfs_mount_t *mp)
@@ -67,7 +113,10 @@
(mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
(uint)sizeof(xfs_da_node_entry_t);
mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
- mp->m_dirnameops = &xfs_default_nameops;
+ if (xfs_sb_version_hasasciici(&mp->m_sb))
+ mp->m_dirnameops = &xfs_ascii_ci_nameops;
+ else
+ mp->m_dirnameops = &xfs_default_nameops;
}
/*
diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index 3bed643..6ca7498 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -239,6 +239,7 @@
#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 */
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 381ebda..84583cf 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -95,6 +95,8 @@
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_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
thaw_bdev(sb->s_bdev, sb);
}
-
+
break;
}
case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h
index e3204a3..3f8cf15 100644
--- a/fs/xfs/xfs_sb.h
+++ b/fs/xfs/xfs_sb.h
@@ -46,10 +46,12 @@
#define XFS_SB_VERSION_SECTORBIT 0x0800
#define XFS_SB_VERSION_EXTFLGBIT 0x1000
#define XFS_SB_VERSION_DIRV2BIT 0x2000
+#define XFS_SB_VERSION_BORGBIT 0x4000 /* ASCII only case-insens. */
#define XFS_SB_VERSION_MOREBITSBIT 0x8000
#define XFS_SB_VERSION_OKSASHFBITS \
(XFS_SB_VERSION_EXTFLGBIT | \
- XFS_SB_VERSION_DIRV2BIT)
+ XFS_SB_VERSION_DIRV2BIT | \
+ XFS_SB_VERSION_BORGBIT)
#define XFS_SB_VERSION_OKREALFBITS \
(XFS_SB_VERSION_ATTRBIT | \
XFS_SB_VERSION_NLINKBIT | \
@@ -437,6 +439,12 @@
((sbp)->sb_versionnum & XFS_SB_VERSION_SECTORBIT);
}
+static inline int xfs_sb_version_hasasciici(xfs_sb_t *sbp)
+{
+ return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \
+ (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT);
+}
+
static inline int xfs_sb_version_hasmorebits(xfs_sb_t *sbp)
{
return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4) && \