namei: take the treatment of absolute symlinks to get_link()

rather than letting the callers handle the jump-to-root part of
semantics, do it right in get_link() and return the rest of the
body for the caller to deal with - at that point it's treated
the same way as relative symlinks would be.  And return NULL
when there's no "rest of the body" - those are treated the same
as pure jump symlink would be.

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

1 files changed, 20 insertions, 29 deletions

diff --git a/fs/namei.c b/fs/namei.c
index c5eb77a57974..c6ff9da69cec 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -918,9 +918,24 @@ const char *get_link(struct nameidata *nd)
         res = inode->i_link;
         if (!res) {
                 res = inode->i_op->follow_link(dentry, &last->cookie);
-                if (IS_ERR_OR_NULL(res))
+                if (IS_ERR_OR_NULL(res)) {
                         last->cookie = NULL;
+                        return res;
+                }
+        }
+        if (*res == '/') {
+                if (!nd->root.mnt)
+                        set_root(nd);
+                path_put(&nd->path);
+                nd->path = nd->root;
+                path_get(&nd->root);
+                nd->inode = nd->path.dentry->d_inode;
+                nd->flags |= LOOKUP_JUMPED;
+                while (unlikely(*++res == '/'))
+                        ;
         }
+        if (!*res)
+                res = NULL;
         return res;
 }
 
@@ -1854,24 +1869,9 @@ OK:
                                 /* jumped */
                                 put_link(nd);
                         } else {
-                                if (*s == '/') {
-                                        if (!nd->root.mnt)
-                                                set_root(nd);
-                                        path_put(&nd->path);
-                                        nd->path = nd->root;
-                                        path_get(&nd->root);
-                                        nd->flags |= LOOKUP_JUMPED;
-                                        while (unlikely(*++s == '/'))
-                                                ;
-                                }
-                                nd->inode = nd->path.dentry->d_inode;
-                                if (unlikely(!*s)) {
-                                        put_link(nd);
-                                } else {
-                                        nd->stack[nd->depth - 1].name = name;
-                                        name = s;
-                                        continue;
-                                }
+                                nd->stack[nd->depth - 1].name = name;
+                                name = s;
+                                continue;
                         }
                 }
                 if (!d_can_lookup(nd->path.dentry)) {
@@ -2002,6 +2002,7 @@ static int trailing_symlink(struct nameidata *nd)
         if (unlikely(error))
                 return error;
         nd->flags |= LOOKUP_PARENT;
+        nd->stack[0].name = NULL;
         s = get_link(nd);
         if (unlikely(IS_ERR(s))) {
                 terminate_walk(nd);
@@ -2009,16 +2010,6 @@ static int trailing_symlink(struct nameidata *nd)
         }
         if (unlikely(!s))
                 return 0;
-        if (*s == '/') {
-                if (!nd->root.mnt)
-                        set_root(nd);
-                path_put(&nd->path);
-                nd->path = nd->root;
-                path_get(&nd->root);
-                nd->flags |= LOOKUP_JUMPED;
-        }
-        nd->inode = nd->path.dentry->d_inode;
-        nd->stack[0].name = NULL;
         return link_path_walk(s, nd);
 }