namei: kill nd->link

Just store it in nd->stack[nd->depth].link right in pick_link().
Now that we make sure of stack expansion in pick_link(), we can
do so...

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

diff --git a/fs/namei.c b/fs/namei.c
index 82cb1bc9a1bf0b868b0a69741a8fab783ef021fc..277ca86fc6c622b9e0b620b8f7cf96180f97bd7c 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -495,10 +495,7 @@ EXPORT_SYMBOL(path_put);
 #define EMBEDDED_LEVELS 2
 struct nameidata {
        struct path     path;
-       union {
-               struct qstr     last;
-               struct path     link;
-       };
+       struct qstr     last;
        struct path     root;
        struct inode    *inode; /* path.dentry.d_inode */
        unsigned int    flags;
@@ -787,7 +784,7 @@ static inline int may_follow_link(struct nameidata *nd)
                return 0;
 
        /* Allowed if owner and follower match. */
-       inode = nd->link.dentry->d_inode;
+       inode = nd->stack[0].link.dentry->d_inode;
        if (uid_eq(current_cred()->fsuid, inode->i_uid))
                return 0;
 
@@ -800,8 +797,8 @@ static inline int may_follow_link(struct nameidata *nd)
        if (uid_eq(parent->i_uid, inode->i_uid))
                return 0;
 
-       audit_log_link_denied("follow_link", &nd->link);
-       path_put(&nd->link);
+       audit_log_link_denied("follow_link", &nd->stack[0].link);
+       path_put(&nd->stack[0].link);
        path_put(&nd->path);
        return -EACCES;
 }
@@ -879,14 +876,13 @@ static __always_inline
 const char *get_link(struct nameidata *nd)
 {
        struct saved *last = nd->stack + nd->depth;
-       struct dentry *dentry = nd->link.dentry;
+       struct dentry *dentry = last->link.dentry;
        struct inode *inode = dentry->d_inode;
        int error;
        const char *res;
 
        BUG_ON(nd->flags & LOOKUP_RCU);
 
-       last->link = nd->link;
        last->cookie = NULL;
        nd->depth++;
 
@@ -1560,6 +1556,7 @@ static void terminate_walk(struct nameidata *nd)
 static int pick_link(struct nameidata *nd, struct path *link)
 {
        int error;
+       struct saved *last;
        if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
                path_to_nameidata(link, nd);
                return -ELOOP;
@@ -1578,7 +1575,8 @@ static int pick_link(struct nameidata *nd, struct path *link)
                return error;
        }
 
-       nd->link = *link;
+       last = nd->stack + nd->depth;
+       last->link = *link;
        return 1;
 }