[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 <bnaujok@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
diff --git a/fs/xfs/xfs_dir2_sf.c b/fs/xfs/xfs_dir2_sf.c
index ca33bc6..dcd09ca 100644
--- a/fs/xfs/xfs_dir2_sf.c
+++ b/fs/xfs/xfs_dir2_sf.c
@@ -814,6 +814,7 @@
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 @@
*/
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 @@
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 @@
* 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 @@
*/
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));