namei: trim the arguments of get_link()

same story as the previous commit

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

diff --git a/fs/namei.c b/fs/namei.c
index 1ac32178bd4560922c6e16b0ee1ab0cbd7fa0acf..e5715a5678600093641cee25bf09ef30132fbf6b 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -843,27 +843,33 @@ static int may_linkat(struct path *link)
        return -EPERM;
 }
 
-static __always_inline const char *
-get_link(struct path *link, struct nameidata *nd, void **p)
+static __always_inline
+const char *get_link(struct nameidata *nd)
 {
-       struct dentry *dentry = link->dentry;
+       struct saved *last = nd->stack + nd->depth;
+       struct dentry *dentry = nd->link.dentry;
        struct inode *inode = dentry->d_inode;
        int error;
        const char *res;
 
        BUG_ON(nd->flags & LOOKUP_RCU);
 
-       if (link->mnt == nd->path.mnt)
-               mntget(link->mnt);
+       if (nd->link.mnt == nd->path.mnt)
+               mntget(nd->link.mnt);
 
-       res = ERR_PTR(-ELOOP);
-       if (unlikely(current->total_link_count >= 40))
-               goto out;
+       if (unlikely(current->total_link_count >= 40)) {
+               path_put(&nd->path);
+               path_put(&nd->link);
+               return ERR_PTR(-ELOOP);
+       }
+
+       last->link = nd->link;
+       last->cookie = NULL;
 
        cond_resched();
        current->total_link_count++;
 
-       touch_atime(link);
+       touch_atime(&last->link);
 
        error = security_inode_follow_link(dentry);
        res = ERR_PTR(error);
@@ -871,14 +877,13 @@ get_link(struct path *link, struct nameidata *nd, void **p)
                goto out;
 
        nd->last_type = LAST_BIND;
-       *p = NULL;
        res = inode->i_link;
        if (!res) {
-               res = inode->i_op->follow_link(dentry, p, nd);
+               res = inode->i_op->follow_link(dentry, &last->cookie, nd);
                if (IS_ERR(res)) {
 out:
                        path_put(&nd->path);
-                       path_put(link);
+                       path_put(&last->link);
                }
        }
        return res;
@@ -1717,7 +1722,6 @@ static inline u64 hash_name(const char *name)
  */
 static int link_path_walk(const char *name, struct nameidata *nd)
 {
-       struct saved *last = nd->stack;
        int err;
 
        while (*name=='/')
@@ -1795,16 +1799,13 @@ Walked:
 
                        nd->depth++;
                        current->link_count++;
-                       last++;
 
-                       last->link = nd->link;
-                       s = get_link(&last->link, nd, &last->cookie);
+                       s = get_link(nd);
 
                        if (unlikely(IS_ERR(s))) {
                                err = PTR_ERR(s);
                                current->link_count--;
                                nd->depth--;
-                               last--;
                                goto Err;
                        }
                        err = 0;
@@ -1813,7 +1814,6 @@ Walked:
                                put_link(nd);
                                current->link_count--;
                                nd->depth--;
-                               last--;
                        } else {
                                if (*s == '/') {
                                        if (!nd->root.mnt)
@@ -1826,7 +1826,7 @@ Walked:
                                                ;
                                }
                                nd->inode = nd->path.dentry->d_inode;
-                               last->name = name;
+                               nd->stack[nd->depth].name = name;
                                if (!*s)
                                        goto OK;
                                name = s;
@@ -1844,17 +1844,15 @@ Err:
                put_link(nd);
                current->link_count--;
                nd->depth--;
-               last--;
        }
        return err;
 OK:
        if (unlikely(nd->depth)) {
-               name = last->name;
+               name = nd->stack[nd->depth].name;
                err = walk_component(nd, LOOKUP_FOLLOW);
                put_link(nd);
                current->link_count--;
                nd->depth--;
-               last--;
                goto Walked;
        }
        return 0;
@@ -1979,8 +1977,7 @@ static int trailing_symlink(struct nameidata *nd)
        if (unlikely(error))
                return error;
        nd->flags |= LOOKUP_PARENT;
-       nd->stack[0].link = nd->link;
-       s = get_link(&nd->stack[0].link, nd, &nd->stack[0].cookie);
+       s = get_link(nd);
        if (unlikely(IS_ERR(s)))
                return PTR_ERR(s);
        if (unlikely(!s))