sanitize pathname component hash calculation

Lift it to lookup_one_len() and link_path_walk() resp. into the
same place where we calculated default hash function of the same
name.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index f6f3ef47bc7438a0137c8c990474d91fdc78a24e..d1a5dfeaf9995e40f0de647070fc656bcb7b417a 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1216,16 +1216,6 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
        struct inode *dir;
        int err;
 
-       /*
-        * See if the low-level filesystem might want
-        * to use its own hash..
-        */
-       if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
-               err = parent->d_op->d_hash(parent, nd->inode, name);
-               if (err < 0)
-                       return err;
-       }
-
        /*
         * Rename seqlock is not required here because in the off chance
         * of a false negative due to a concurrent rename, we're going to
@@ -1414,8 +1404,16 @@ static int link_path_walk(const char *name, struct nameidata *nd)
                        case 1:
                                type = LAST_DOT;
                }
-               if (likely(type == LAST_NORM))
+               if (likely(type == LAST_NORM)) {
+                       struct dentry *parent = nd->path.dentry;
                        nd->flags &= ~LOOKUP_JUMPED;
+                       if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
+                               err = parent->d_op->d_hash(parent, nd->inode,
+                                                          &this);
+                               if (err < 0)
+                                       break;
+                       }
+               }
 
                /* remove trailing slashes? */
                if (!c)
@@ -1722,17 +1720,6 @@ static struct dentry *__lookup_hash(struct qstr *name,
        if (err)
                return ERR_PTR(err);
 
-       /*
-        * See if the low-level filesystem might want
-        * to use its own hash..
-        */
-       if (base->d_flags & DCACHE_OP_HASH) {
-               err = base->d_op->d_hash(base, inode, name);
-               dentry = ERR_PTR(err);
-               if (err < 0)
-                       goto out;
-       }
-
        /*
         * Don't bother with __d_lookup: callers are for creat as
         * well as unlink, so a lot of the time it would cost
@@ -1745,7 +1732,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 
        if (!dentry)
                dentry = d_alloc_and_lookup(base, name, nd);
-out:
+
        return dentry;
 }
 
@@ -1791,6 +1778,15 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
                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..
+        */
+       if (base->d_flags & DCACHE_OP_HASH) {
+               int err = base->d_op->d_hash(base, base->d_inode, &this);
+               if (err < 0)
+                       return ERR_PTR(err);
+       }
 
        return __lookup_hash(&this, base, NULL);
 }