From 5163f95a08cbf058ae16452c2242c5600fedc32e Mon Sep 17 00:00:00 2001 From: Barry Naujok Date: Wed, 21 May 2008 16:41:01 +1000 Subject: [XFS] Name operation vector for hash and compare Adds two pieces of functionality for the basis of case-insensitive support in XFS: 1. A comparison result enumerated type: xfs_dacmp. It represents an exact match, case-insensitive match or no match at all. This patch only implements different and exact results. 2. xfs_nameops vector for specifying how to perform the hash generation of filenames and comparision methods. In this patch the hash vector points to the existing xfs_da_hashname function and the comparison method does a length compare, and if the same, does a memcmp and return the xfs_dacmp result. All filename functions that use the hash (create, lookup remove, rename, etc) now use the xfs_nameops.hashname function and all directory lookup functions also use the xfs_nameops.compname function. The lookup functions also handle case-insensitive results even though the default comparison function cannot return that. And important aspect of the lookup functions is that an exact match always has precedence over a case-insensitive. So while a case-insensitive match is found, we have to keep looking just in case there is an exact match. In the meantime, the info for the first case-insensitive match is retained if no exact match is found. SGI-PV: 981519 SGI-Modid: xfs-linux-melb:xfs-kern:31205a Signed-off-by: Barry Naujok Signed-off-by: Christoph Hellwig --- fs/xfs/xfs_dir2_sf.c | 62 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 36 insertions(+), 26 deletions(-) (limited to 'fs/xfs/xfs_dir2_sf.c') diff --git a/fs/xfs/xfs_dir2_sf.c b/fs/xfs/xfs_dir2_sf.c index ca33bc62edc..dcd09cada43 100644 --- a/fs/xfs/xfs_dir2_sf.c +++ b/fs/xfs/xfs_dir2_sf.c @@ -814,6 +814,7 @@ xfs_dir2_sf_lookup( int i; /* entry index */ xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */ xfs_dir2_sf_t *sfp; /* shortform structure */ + enum xfs_dacmp cmp; /* comparison result */ xfs_dir2_trace_args("sf_lookup", args); xfs_dir2_sf_check(args); @@ -836,6 +837,7 @@ xfs_dir2_sf_lookup( */ if (args->namelen == 1 && args->name[0] == '.') { args->inumber = dp->i_ino; + args->cmpresult = XFS_CMP_EXACT; return XFS_ERROR(EEXIST); } /* @@ -844,27 +846,39 @@ xfs_dir2_sf_lookup( if (args->namelen == 2 && args->name[0] == '.' && args->name[1] == '.') { args->inumber = xfs_dir2_sf_get_inumber(sfp, &sfp->hdr.parent); + args->cmpresult = XFS_CMP_EXACT; return XFS_ERROR(EEXIST); } /* * Loop over all the entries trying to match ours. */ - for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); - i < sfp->hdr.count; - i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { - if (sfep->namelen == args->namelen && - sfep->name[0] == args->name[0] && - memcmp(args->name, sfep->name, args->namelen) == 0) { - args->inumber = - xfs_dir2_sf_get_inumber(sfp, - xfs_dir2_sf_inumberp(sfep)); - return XFS_ERROR(EEXIST); + for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); i < sfp->hdr.count; + i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { + /* + * Compare name and if it's an exact match, return the inode + * number. If it's the first case-insensitive match, store the + * inode number and continue looking for an exact match. + */ + cmp = dp->i_mount->m_dirnameops->compname(args, sfep->name, + sfep->namelen); + if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) { + args->cmpresult = cmp; + args->inumber = xfs_dir2_sf_get_inumber(sfp, + xfs_dir2_sf_inumberp(sfep)); + if (cmp == XFS_CMP_EXACT) + return XFS_ERROR(EEXIST); } } + ASSERT(args->oknoent); + /* + * Here, we can only be doing a lookup (not a rename or replace). + * If a case-insensitive match was found earlier, return "found". + */ + if (args->cmpresult == XFS_CMP_CASE) + return XFS_ERROR(EEXIST); /* * Didn't find it. */ - ASSERT(args->oknoent); return XFS_ERROR(ENOENT); } @@ -904,24 +918,21 @@ xfs_dir2_sf_removename( * Loop over the old directory entries. * Find the one we're deleting. */ - for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); - i < sfp->hdr.count; - i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { - if (sfep->namelen == args->namelen && - sfep->name[0] == args->name[0] && - memcmp(sfep->name, args->name, args->namelen) == 0) { + for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); i < sfp->hdr.count; + i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { + if (xfs_da_compname(args, sfep->name, sfep->namelen) == + XFS_CMP_EXACT) { ASSERT(xfs_dir2_sf_get_inumber(sfp, - xfs_dir2_sf_inumberp(sfep)) == - args->inumber); + xfs_dir2_sf_inumberp(sfep)) == + args->inumber); break; } } /* * Didn't find it. */ - if (i == sfp->hdr.count) { + if (i == sfp->hdr.count) return XFS_ERROR(ENOENT); - } /* * Calculate sizes. */ @@ -1042,11 +1053,10 @@ xfs_dir2_sf_replace( */ else { for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); - i < sfp->hdr.count; - i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { - if (sfep->namelen == args->namelen && - sfep->name[0] == args->name[0] && - memcmp(args->name, sfep->name, args->namelen) == 0) { + i < sfp->hdr.count; + i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) { + if (xfs_da_compname(args, sfep->name, sfep->namelen) == + XFS_CMP_EXACT) { #if XFS_BIG_INUMS || defined(DEBUG) ino = xfs_dir2_sf_get_inumber(sfp, xfs_dir2_sf_inumberp(sfep)); -- cgit v1.2.3