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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c66
1 files changed, 44 insertions, 22 deletions
diff --git a/fs/namei.c b/fs/namei.c
index a780ea515c4..e2ba62820a0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1374,6 +1374,34 @@ static inline int can_lookup(struct inode *inode)
return 1;
}
+unsigned int full_name_hash(const unsigned char *name, unsigned int len)
+{
+ unsigned long hash = init_name_hash();
+ while (len--)
+ hash = partial_name_hash(*name++, hash);
+ return end_name_hash(hash);
+}
+EXPORT_SYMBOL(full_name_hash);
+
+/*
+ * We know there's a real path component here of at least
+ * one character.
+ */
+static inline unsigned long hash_name(const char *name, unsigned int *hashp)
+{
+ unsigned long hash = init_name_hash();
+ unsigned long len = 0, c;
+
+ c = (unsigned char)*name;
+ do {
+ len++;
+ hash = partial_name_hash(c, hash);
+ c = (unsigned char)name[len];
+ } while (c && c != '/');
+ *hashp = end_name_hash(hash);
+ return len;
+}
+
/*
* Name resolution.
* This is the basic name resolution function, turning a pathname into
@@ -1394,31 +1422,22 @@ static int link_path_walk(const char *name, struct nameidata *nd)
/* At this point we know we have a real path component. */
for(;;) {
- unsigned long hash;
struct qstr this;
- unsigned int c;
+ long len;
int type;
err = may_lookup(nd);
if (err)
break;
+ len = hash_name(name, &this.hash);
this.name = name;
- c = *(const unsigned char *)name;
-
- hash = init_name_hash();
- do {
- name++;
- hash = partial_name_hash(c, hash);
- c = *(const unsigned char *)name;
- } while (c && (c != '/'));
- this.len = name - (const char *) this.name;
- this.hash = end_name_hash(hash);
+ this.len = len;
type = LAST_NORM;
- if (this.name[0] == '.') switch (this.len) {
+ if (name[0] == '.') switch (len) {
case 2:
- if (this.name[1] == '.') {
+ if (name[1] == '.') {
type = LAST_DOTDOT;
nd->flags |= LOOKUP_JUMPED;
}
@@ -1437,12 +1456,18 @@ static int link_path_walk(const char *name, struct nameidata *nd)
}
}
- /* remove trailing slashes? */
- if (!c)
+ if (!name[len])
goto last_component;
- while (*++name == '/');
- if (!*name)
+ /*
+ * If it wasn't NUL, we know it was '/'. Skip that
+ * slash, and continue until no more slashes.
+ */
+ do {
+ len++;
+ } while (unlikely(name[len] == '/'));
+ if (!name[len])
goto last_component;
+ name += len;
err = walk_component(nd, &next, &this, type, LOOKUP_FOLLOW);
if (err < 0)
@@ -1775,24 +1800,21 @@ static struct dentry *lookup_hash(struct nameidata *nd)
struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
{
struct qstr this;
- unsigned long hash;
unsigned int c;
WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex));
this.name = name;
this.len = len;
+ this.hash = full_name_hash(name, len);
if (!len)
return ERR_PTR(-EACCES);
- hash = init_name_hash();
while (len--) {
c = *(const unsigned char *)name++;
if (c == '/' || c == '\0')
return ERR_PTR(-EACCES);
- hash = partial_name_hash(c, hash);
}
- this.hash = end_name_hash(hash);
/*
* See if the low-level filesystem might want
* to use its own hash..