Fix cache lookup and hash calculations when handling paths with
different cases.
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
---
fs/cifs/dfs_cache.c | 168 ++++++++++++++++++++++++--------------------
1 file changed, 93 insertions(+), 75 deletions(-)
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index c52fec3c4092..f7c4874ddc17 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -424,12 +424,24 @@ int dfs_cache_init(void)
return rc;
}
-static inline unsigned int cache_entry_hash(const void *data, int size)
+static int cache_entry_hash(const void *data, int size, unsigned int *hash)
{
- unsigned int h;
+ int i, clen;
+ const unsigned char *s = data;
+ wchar_t c;
+ unsigned int h = 0;
- h = jhash(data, size, 0);
- return h & (CACHE_HTABLE_SIZE - 1);
+ for (i = 0; i < size; i += clen) {
+ clen = cache_cp->char2uni(&s[i], size - i, &c);
+ if (unlikely(clen < 0)) {
+ cifs_dbg(VFS, "%s: can't convert char\n", __func__);
+ return clen;
+ }
+ c = cifs_toupper(c);
+ h = jhash(&c, sizeof(c), h);
+ }
+ *hash = h % CACHE_HTABLE_SIZE;
+ return 0;
}
/* Check whether second path component of @path is SYSVOL or NETLOGON */
@@ -522,9 +534,7 @@ static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
}
/* Allocate a new cache entry */
-static struct cache_entry *alloc_cache_entry(const char *path,
- const struct dfs_info3_param *refs,
- int numrefs)
+static struct cache_entry *alloc_cache_entry(struct dfs_info3_param *refs, int numrefs)
{
struct cache_entry *ce;
int rc;
@@ -533,11 +543,9 @@ static struct cache_entry *alloc_cache_entry(const char *path,
if (!ce)
return ERR_PTR(-ENOMEM);
- ce->path = kstrdup(path, GFP_KERNEL);
- if (!ce->path) {
- kmem_cache_free(cache_slab, ce);
- return ERR_PTR(-ENOMEM);
- }
+ ce->path = refs[0].path_name;
+ refs[0].path_name = NULL;
+
INIT_HLIST_NODE(&ce->hlist);
INIT_LIST_HEAD(&ce->tlist);
@@ -579,12 +587,18 @@ static void remove_oldest_entry_locked(void)
}
/* Add a new DFS cache entry */
-static int add_cache_entry_locked(const char *path, unsigned int hash,
- struct dfs_info3_param *refs, int numrefs)
+static int add_cache_entry_locked(struct dfs_info3_param *refs, int numrefs)
{
+ int rc;
struct cache_entry *ce;
+ unsigned int hash;
- ce = alloc_cache_entry(path, refs, numrefs);
+ convert_delimiter(refs[0].path_name, '\\');
+ rc = cache_entry_hash(refs[0].path_name, strlen(refs[0].path_name), &hash);
+ if (rc)
+ return rc;
+
+ ce = alloc_cache_entry(refs, numrefs);
if (IS_ERR(ce))
return PTR_ERR(ce);
@@ -604,57 +618,69 @@ static int add_cache_entry_locked(const char *path, unsigned int hash,
return 0;
}
-static struct cache_entry *__lookup_cache_entry(const char *path)
+/* Check if two DFS paths are equal. @s1 and @s2 are expected to be in @cache_cp's charset */
+static bool dfs_path_equal(const char *s1, int len1, const char *s2, int len2)
+{
+ int i, l1, l2;
+ wchar_t c1, c2;
+
+ if (len1 != len2)
+ return false;
+
+ for (i = 0; i < len1; i += l1) {
+ l1 = cache_cp->char2uni(&s1[i], len1 - i, &c1);
+ l2 = cache_cp->char2uni(&s2[i], len2 - i, &c2);
+ if (unlikely(l1 < 0 && l2 < 0)) {
+ if (s1[i] != s2[i])
+ return false;
+ l1 = 1;
+ continue;
+ }
+ if (l1 != l2)
+ return false;
+ if (cifs_toupper(c1) != cifs_toupper(c2))
+ return false;
+ }
+ return true;
+}
+
+static struct cache_entry *__lookup_cache_entry(const char *path, unsigned int hash, int len)
{
struct cache_entry *ce;
- unsigned int h;
- bool found = false;
- h = cache_entry_hash(path, strlen(path));
-
- hlist_for_each_entry(ce, &cache_htable[h], hlist) {
- if (!strcasecmp(path, ce->path)) {
- found = true;
+ hlist_for_each_entry(ce, &cache_htable[hash], hlist) {
+ if (dfs_path_equal(ce->path, strlen(ce->path), path, len)) {
dump_ce(ce);
- break;
+ return ce;
}
}
-
- if (!found)
- ce = ERR_PTR(-ENOENT);
- return ce;
+ return ERR_PTR(-EEXIST);
}
/*
- * Find a DFS cache entry in hash table and optionally check prefix path against
- * @path.
- * Use whole path components in the match.
- * Must be called with htable_rw_lock held.
+ * Find a DFS cache entry in hash table and optionally check prefix path against normalized @path.
*
- * Return ERR_PTR(-ENOENT) if the entry is not found.
+ * Use whole path components in the match. Must be called with htable_rw_lock held.
+ *
+ * Return ERR_PTR(-EEXIST) if the entry is not found.
*/
-static struct cache_entry *lookup_cache_entry(const char *path, unsigned int *hash)
+static struct cache_entry *lookup_cache_entry(const char *path)
{
- struct cache_entry *ce = ERR_PTR(-ENOENT);
- unsigned int h;
+ struct cache_entry *ce;
int cnt = 0;
- char *npath;
- char *s, *e;
- char sep;
+ const char *s = path, *e;
+ char sep = *s;
+ unsigned int hash;
+ int rc;
- npath = kstrdup(path, GFP_KERNEL);
- if (!npath)
- return ERR_PTR(-ENOMEM);
-
- s = npath;
- sep = *npath;
while ((s = strchr(s, sep)) && ++cnt < 3)
s++;
if (cnt < 3) {
- h = cache_entry_hash(path, strlen(path));
- ce = __lookup_cache_entry(path);
- goto out;
+ rc = cache_entry_hash(path, strlen(path), &hash);
+ if (rc)
+ return ERR_PTR(rc);
+ return __lookup_cache_entry(path, hash, strlen(path));
}
/*
* Handle paths that have more than two path components and are a complete prefix of the DFS
@@ -662,36 +688,29 @@ static struct cache_entry *lookup_cache_entry(const char *path, unsigned int *ha
*
* See MS-DFSC 3.2.5.5 "Receiving a Root Referral Request or Link Referral Request".
*/
- h = cache_entry_hash(npath, strlen(npath));
- e = npath + strlen(npath) - 1;
+ e = path + strlen(path) - 1;
while (e > s) {
- char tmp;
+ int len;
/* skip separators */
while (e > s && *e == sep)
e--;
if (e == s)
- goto out;
-
- tmp = *(e+1);
- *(e+1) = 0;
-
- ce = __lookup_cache_entry(npath);
- if (!IS_ERR(ce)) {
- h = cache_entry_hash(npath, strlen(npath));
break;
- }
- *(e+1) = tmp;
+ len = e + 1 - path;
+ rc = cache_entry_hash(path, len, &hash);
+ if (rc)
+ return ERR_PTR(rc);
+ ce = __lookup_cache_entry(path, hash, len);
+ if (!IS_ERR(ce))
+ return ce;
+
/* backward until separator */
while (e > s && *e != sep)
e--;
}
-out:
- if (hash)
- *hash = h;
- kfree(npath);
- return ce;
+ return ERR_PTR(-EEXIST);
}
/**
@@ -717,7 +736,7 @@ static int update_cache_entry_locked(const char *path, const struct dfs_info3_pa
struct cache_entry *ce;
char *s, *th = NULL;
- ce = lookup_cache_entry(path, NULL);
+ ce = lookup_cache_entry(path);
if (IS_ERR(ce))
return PTR_ERR(ce);
@@ -767,7 +786,6 @@ static int get_dfs_referral(const unsigned int xid, struct cifs_ses *ses, const
static int cache_refresh_path(const unsigned int xid, struct cifs_ses *ses, const char *path)
{
int rc;
- unsigned int hash;
struct cache_entry *ce;
struct dfs_info3_param *refs = NULL;
int numrefs = 0;
@@ -777,7 +795,7 @@ static int cache_refresh_path(const unsigned int xid, struct cifs_ses *ses, cons
down_write(&htable_rw_lock);
- ce = lookup_cache_entry(path, &hash);
+ ce = lookup_cache_entry(path);
if (!IS_ERR(ce)) {
if (!cache_entry_expired(ce)) {
dump_ce(ce);
@@ -808,7 +826,7 @@ static int cache_refresh_path(const unsigned int xid, struct cifs_ses *ses, cons
remove_oldest_entry_locked();
}
- rc = add_cache_entry_locked(path, hash, refs, numrefs);
+ rc = add_cache_entry_locked(refs, numrefs);
if (!rc)
atomic_inc(&cache_count);
@@ -940,7 +958,7 @@ int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses, const struct nl
down_read(&htable_rw_lock);
- ce = lookup_cache_entry(npath, NULL);
+ ce = lookup_cache_entry(npath);
if (IS_ERR(ce)) {
up_read(&htable_rw_lock);
rc = PTR_ERR(ce);
@@ -987,7 +1005,7 @@ int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
down_read(&htable_rw_lock);
- ce = lookup_cache_entry(path, NULL);
+ ce = lookup_cache_entry(path);
if (IS_ERR(ce)) {
rc = PTR_ERR(ce);
goto out_unlock;
@@ -1044,7 +1062,7 @@ int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses,
down_write(&htable_rw_lock);
- ce = lookup_cache_entry(npath, NULL);
+ ce = lookup_cache_entry(npath);
if (IS_ERR(ce)) {
rc = PTR_ERR(ce);
goto out_unlock;
@@ -1098,7 +1116,7 @@ int dfs_cache_noreq_update_tgthint(const char *path, const struct dfs_cache_tgt_
down_write(&htable_rw_lock);
- ce = lookup_cache_entry(path, NULL);
+ ce = lookup_cache_entry(path);
if (IS_ERR(ce)) {
rc = PTR_ERR(ce);
goto out_unlock;
@@ -1147,7 +1165,7 @@ int dfs_cache_get_tgt_referral(const char *path, const struct dfs_cache_tgt_iter
down_read(&htable_rw_lock);
- ce = lookup_cache_entry(path, NULL);
+ ce = lookup_cache_entry(path);
if (IS_ERR(ce)) {
rc = PTR_ERR(ce);
goto out_unlock;
--
2.31.1
