From 189f4bf22bdc3c2402b038016d11fd3cb1c89f07 Mon Sep 17 00:00:00 2001 From: Barry Naujok Date: Wed, 21 May 2008 16:58:55 +1000 Subject: [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 SGI-PV: 981516 SGI-Modid: xfs-linux-melb:xfs-kern:31209a Signed-off-by: Barry Naujok Signed-off-by: Christoph Hellwig --- fs/xfs/xfs_dir2.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-) (limited to 'fs/xfs/xfs_dir2.c') diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c index 882609c699c..b445ec31476 100644 --- a/fs/xfs/xfs_dir2.c +++ b/fs/xfs/xfs_dir2.c @@ -48,6 +48,52 @@ struct xfs_name xfs_name_dotdot = {"..", 2}; 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 @@ xfs_dir_mount( (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; } /* -- cgit v1.2.3