[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_da_btree.c b/fs/xfs/xfs_da_btree.c
index 2947804..ae4b18c 100644
--- a/fs/xfs/xfs_da_btree.c
+++ b/fs/xfs/xfs_da_btree.c
@@ -1530,6 +1530,28 @@
}
}
+enum xfs_dacmp
+xfs_da_compname(
+ struct xfs_da_args *args,
+ const char *name,
+ int len)
+{
+ return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
+ XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
+}
+
+static xfs_dahash_t
+xfs_default_hashname(
+ struct xfs_name *name)
+{
+ return xfs_da_hashname(name->name, name->len);
+}
+
+const struct xfs_nameops xfs_default_nameops = {
+ .hashname = xfs_default_hashname,
+ .compname = xfs_da_compname
+};
+
/*
* Add a block to the btree ahead of the file.
* Return the new block number to the caller.
diff --git a/fs/xfs/xfs_da_btree.h b/fs/xfs/xfs_da_btree.h
index 7facf86..e64c692 100644
--- a/fs/xfs/xfs_da_btree.h
+++ b/fs/xfs/xfs_da_btree.h
@@ -99,6 +99,15 @@
*========================================================================*/
/*
+ * Search comparison results
+ */
+enum xfs_dacmp {
+ XFS_CMP_DIFFERENT, /* names are completely different */
+ XFS_CMP_EXACT, /* names are exactly the same */
+ XFS_CMP_CASE /* names are same but differ in case */
+};
+
+/*
* Structure to ease passing around component names.
*/
typedef struct xfs_da_args {
@@ -127,6 +136,7 @@
unsigned char rename; /* T/F: this is an atomic rename op */
unsigned char addname; /* T/F: this is an add operation */
unsigned char oknoent; /* T/F: ok to return ENOENT, else die */
+ enum xfs_dacmp cmpresult; /* name compare result for lookups */
} xfs_da_args_t;
/*
@@ -201,6 +211,14 @@
(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
+/*
+ * Name ops for directory and/or attr name operations
+ */
+struct xfs_nameops {
+ xfs_dahash_t (*hashname)(struct xfs_name *);
+ enum xfs_dacmp (*compname)(struct xfs_da_args *, const char *, int);
+};
+
#ifdef __KERNEL__
/*========================================================================
@@ -249,6 +267,10 @@
xfs_dabuf_t *dead_buf);
uint xfs_da_hashname(const uchar_t *name_string, int name_length);
+enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
+ const char *name, int len);
+
+
xfs_da_state_t *xfs_da_state_alloc(void);
void xfs_da_state_free(xfs_da_state_t *state);
diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index 0284af1..675899b 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -65,6 +65,7 @@
(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;
}
/*
@@ -164,7 +165,7 @@
args.name = name->name;
args.namelen = name->len;
- args.hashval = xfs_da_hashname(name->name, name->len);
+ args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = inum;
args.dp = dp;
args.firstblock = first;
@@ -210,11 +211,12 @@
args.name = name->name;
args.namelen = name->len;
- args.hashval = xfs_da_hashname(name->name, name->len);
+ args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.dp = dp;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
args.oknoent = 1;
+ args.cmpresult = XFS_CMP_DIFFERENT;
if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
rval = xfs_dir2_sf_lookup(&args);
@@ -257,7 +259,7 @@
args.name = name->name;
args.namelen = name->len;
- args.hashval = xfs_da_hashname(name->name, name->len);
+ args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = ino;
args.dp = dp;
args.firstblock = first;
@@ -340,7 +342,7 @@
args.name = name->name;
args.namelen = name->len;
- args.hashval = xfs_da_hashname(name->name, name->len);
+ args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.inumber = inum;
args.dp = dp;
args.firstblock = first;
@@ -388,7 +390,7 @@
args.name = name->name;
args.namelen = name->len;
- args.hashval = xfs_da_hashname(name->name, name->len);
+ args.hashval = dp->i_mount->m_dirnameops->hashname(name);
args.dp = dp;
args.whichfork = XFS_DATA_FORK;
args.trans = tp;
diff --git a/fs/xfs/xfs_dir2_block.c b/fs/xfs/xfs_dir2_block.c
index e8a7aca..9858849 100644
--- a/fs/xfs/xfs_dir2_block.c
+++ b/fs/xfs/xfs_dir2_block.c
@@ -643,6 +643,7 @@
int mid; /* binary search current idx */
xfs_mount_t *mp; /* filesystem mount point */
xfs_trans_t *tp; /* transaction pointer */
+ enum xfs_dacmp cmp; /* comparison result */
dp = args->dp;
tp = args->trans;
@@ -697,20 +698,31 @@
dep = (xfs_dir2_data_entry_t *)
((char *)block + xfs_dir2_dataptr_to_off(mp, addr));
/*
- * Compare, if it's right give back buffer & entry number.
+ * Compare name and if it's an exact match, return the index
+ * and buffer. If it's the first case-insensitive match, store
+ * the index and buffer and continue looking for an exact match.
*/
- if (dep->namelen == args->namelen &&
- dep->name[0] == args->name[0] &&
- memcmp(dep->name, args->name, args->namelen) == 0) {
+ cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+ if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
+ args->cmpresult = cmp;
*bpp = bp;
*entno = mid;
- return 0;
+ if (cmp == XFS_CMP_EXACT)
+ return 0;
}
- } while (++mid < be32_to_cpu(btp->count) && be32_to_cpu(blp[mid].hashval) == hash);
+ } while (++mid < be32_to_cpu(btp->count) &&
+ be32_to_cpu(blp[mid].hashval) == hash);
+
+ 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 success.
+ */
+ if (args->cmpresult == XFS_CMP_CASE)
+ return 0;
/*
* No match, release the buffer and return ENOENT.
*/
- ASSERT(args->oknoent);
xfs_da_brelse(tp, bp);
return XFS_ERROR(ENOENT);
}
@@ -1033,6 +1045,7 @@
xfs_dir2_sf_t *sfp; /* shortform structure */
__be16 *tagp; /* end of data entry */
xfs_trans_t *tp; /* transaction pointer */
+ struct xfs_name name;
xfs_dir2_trace_args("sf_to_block", args);
dp = args->dp;
@@ -1187,8 +1200,10 @@
tagp = xfs_dir2_data_entry_tag_p(dep);
*tagp = cpu_to_be16((char *)dep - (char *)block);
xfs_dir2_data_log_entry(tp, bp, dep);
- blp[2 + i].hashval = cpu_to_be32(xfs_da_hashname(
- (char *)sfep->name, sfep->namelen));
+ name.name = sfep->name;
+ name.len = sfep->namelen;
+ blp[2 + i].hashval = cpu_to_be32(mp->m_dirnameops->
+ hashname(&name));
blp[2 + i].address = cpu_to_be32(xfs_dir2_byte_to_dataptr(mp,
(char *)dep - (char *)block));
offset = (int)((char *)(tagp + 1) - (char *)block);
diff --git a/fs/xfs/xfs_dir2_data.c b/fs/xfs/xfs_dir2_data.c
index fb8c9e0..498f8d6 100644
--- a/fs/xfs/xfs_dir2_data.c
+++ b/fs/xfs/xfs_dir2_data.c
@@ -65,6 +65,7 @@
xfs_mount_t *mp; /* filesystem mount point */
char *p; /* current data position */
int stale; /* count of stale leaves */
+ struct xfs_name name;
mp = dp->i_mount;
d = bp->data;
@@ -140,7 +141,9 @@
addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
(xfs_dir2_data_aoff_t)
((char *)dep - (char *)d));
- hash = xfs_da_hashname((char *)dep->name, dep->namelen);
+ name.name = dep->name;
+ name.len = dep->namelen;
+ hash = mp->m_dirnameops->hashname(&name);
for (i = 0; i < be32_to_cpu(btp->count); i++) {
if (be32_to_cpu(lep[i].address) == addr &&
be32_to_cpu(lep[i].hashval) == hash)
diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index e334334..b52903b 100644
--- a/fs/xfs/xfs_dir2_leaf.c
+++ b/fs/xfs/xfs_dir2_leaf.c
@@ -1331,6 +1331,8 @@
xfs_mount_t *mp; /* filesystem mount point */
xfs_dir2_db_t newdb; /* new data block number */
xfs_trans_t *tp; /* transaction pointer */
+ xfs_dabuf_t *cbp; /* case match data buffer */
+ enum xfs_dacmp cmp; /* name compare result */
dp = args->dp;
tp = args->trans;
@@ -1354,9 +1356,11 @@
* Loop over all the entries with the right hash value
* looking to match the name.
*/
+ cbp = NULL;
for (lep = &leaf->ents[index], dbp = NULL, curdb = -1;
- index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
- lep++, index++) {
+ index < be16_to_cpu(leaf->hdr.count) &&
+ be32_to_cpu(lep->hashval) == args->hashval;
+ lep++, index++) {
/*
* Skip over stale leaf entries.
*/
@@ -1371,12 +1375,12 @@
* need to pitch the old one and read the new one.
*/
if (newdb != curdb) {
- if (dbp)
+ if (dbp != cbp)
xfs_da_brelse(tp, dbp);
- if ((error =
- xfs_da_read_buf(tp, dp,
- xfs_dir2_db_to_da(mp, newdb), -1, &dbp,
- XFS_DATA_FORK))) {
+ error = xfs_da_read_buf(tp, dp,
+ xfs_dir2_db_to_da(mp, newdb),
+ -1, &dbp, XFS_DATA_FORK);
+ if (error) {
xfs_da_brelse(tp, lbp);
return error;
}
@@ -1386,24 +1390,46 @@
/*
* Point to the data entry.
*/
- dep = (xfs_dir2_data_entry_t *)
- ((char *)dbp->data +
- xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
+ dep = (xfs_dir2_data_entry_t *)((char *)dbp->data +
+ xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
/*
- * If it matches then return it.
+ * Compare name and if it's an exact match, return the index
+ * and buffer. If it's the first case-insensitive match, store
+ * the index and buffer and continue looking for an exact match.
*/
- if (dep->namelen == args->namelen &&
- dep->name[0] == args->name[0] &&
- memcmp(dep->name, args->name, args->namelen) == 0) {
- *dbpp = dbp;
+ cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+ if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
+ args->cmpresult = cmp;
*indexp = index;
- return 0;
+ /*
+ * case exact match: release the stored CI buffer if it
+ * exists and return the current buffer.
+ */
+ if (cmp == XFS_CMP_EXACT) {
+ if (cbp && cbp != dbp)
+ xfs_da_brelse(tp, cbp);
+ *dbpp = dbp;
+ return 0;
+ }
+ cbp = dbp;
}
}
+ ASSERT(args->oknoent);
+ /*
+ * Here, we can only be doing a lookup (not a rename or replace).
+ * If a case-insensitive match was found earlier, release the current
+ * buffer and return the stored CI matching buffer.
+ */
+ if (args->cmpresult == XFS_CMP_CASE) {
+ if (cbp != dbp)
+ xfs_da_brelse(tp, dbp);
+ *dbpp = cbp;
+ return 0;
+ }
/*
* No match found, return ENOENT.
*/
- ASSERT(args->oknoent);
+ ASSERT(cbp == NULL);
if (dbp)
xfs_da_brelse(tp, dbp);
xfs_da_brelse(tp, lbp);
diff --git a/fs/xfs/xfs_dir2_node.c b/fs/xfs/xfs_dir2_node.c
index e29b7c6..fedf8f9 100644
--- a/fs/xfs/xfs_dir2_node.c
+++ b/fs/xfs/xfs_dir2_node.c
@@ -556,6 +556,7 @@
xfs_mount_t *mp; /* filesystem mount point */
xfs_dir2_db_t newdb; /* new data block number */
xfs_trans_t *tp; /* transaction pointer */
+ enum xfs_dacmp cmp; /* comparison result */
dp = args->dp;
tp = args->trans;
@@ -620,17 +621,21 @@
dep = (xfs_dir2_data_entry_t *)((char *)curbp->data +
xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
/*
- * Compare the entry, return it if it matches.
+ * Compare the entry and if it's an exact match, return
+ * EEXIST immediately. If it's the first case-insensitive
+ * match, store the inode number and continue looking.
*/
- if (dep->namelen == args->namelen && memcmp(dep->name,
- args->name, args->namelen) == 0) {
+ cmp = mp->m_dirnameops->compname(args, dep->name, dep->namelen);
+ if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
+ args->cmpresult = cmp;
args->inumber = be64_to_cpu(dep->inumber);
di = (int)((char *)dep - (char *)curbp->data);
error = EEXIST;
- goto out;
+ if (cmp == XFS_CMP_EXACT)
+ goto out;
}
}
- /* Didn't find a match. */
+ /* Didn't find an exact match. */
error = ENOENT;
di = -1;
ASSERT(index == be16_to_cpu(leaf->hdr.count) || args->oknoent);
@@ -1813,6 +1818,8 @@
error = xfs_da_node_lookup_int(state, &rval);
if (error)
rval = error;
+ else if (rval == ENOENT && args->cmpresult == XFS_CMP_CASE)
+ rval = EEXIST; /* a case-insensitive match was found */
/*
* Release the btree blocks and leaf block.
*/
@@ -1856,9 +1863,8 @@
* Look up the entry we're deleting, set up the cursor.
*/
error = xfs_da_node_lookup_int(state, &rval);
- if (error) {
+ if (error)
rval = error;
- }
/*
* Didn't find it, upper layer screwed up.
*/
@@ -1875,9 +1881,8 @@
*/
error = xfs_dir2_leafn_remove(args, blk->bp, blk->index,
&state->extrablk, &rval);
- if (error) {
+ if (error)
return error;
- }
/*
* Fix the hash values up the btree.
*/
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));
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 96d8791..2a75f17 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -61,6 +61,7 @@
struct xfs_extdelta;
struct xfs_swapext;
struct xfs_mru_cache;
+struct xfs_nameops;
/*
* Prototypes and functions for the Data Migration subsystem.
@@ -315,6 +316,7 @@
__uint8_t m_inode_quiesce;/* call quiesce on new inodes.
field governed by m_ilock */
__uint8_t m_sectbb_log; /* sectlog - BBSHIFT */
+ const struct xfs_nameops *m_dirnameops; /* vector of dir name ops */
int m_dirblksize; /* directory block sz--bytes */
int m_dirblkfsbs; /* directory block sz--fsbs */
xfs_dablk_t m_dirdatablk; /* blockno of dir data v2 */