merging pick_link() with get_link(), part 3

After a pure jump ("/" or procfs-style symlink) we don't need to
hold the link anymore.  link_path_walk() dropped it if such case
had been detected, lookup_last/do_last() (i.e. old trailing_symlink())
left it on the stack - it ended up calling terminate_walk() shortly
anyway, which would've purged the entire stack.

Do it in get_link() itself instead.  Simpler logics that way...

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

diff --git a/fs/namei.c b/fs/namei.c
index 9678bb2..f844378 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1154,7 +1154,9 @@ const char *get_link(struct nameidata *nd)
                } else {
                        res = get(dentry, inode, &last->done);
                }
-               if (IS_ERR_OR_NULL(res))
+               if (!res)
+                       goto all_done;
+               if (IS_ERR(res))
                        return res;
        }
        if (*res == '/') {
@@ -1164,9 +1166,11 @@ const char *get_link(struct nameidata *nd)
                while (unlikely(*++res == '/'))
                        ;
        }
-       if (!*res)
-               res = NULL;
-       return res;
+       if (*res)
+               return res;
+all_done: // pure jump
+       put_link(nd);
+       return NULL;
 }
 
 /*
@@ -2211,11 +2215,7 @@ OK:
 
                        if (IS_ERR(s))
                                return PTR_ERR(s);
-                       err = 0;
-                       if (unlikely(!s)) {
-                               /* jumped */
-                               put_link(nd);
-                       } else {
+                       if (likely(s)) {
                                nd->stack[nd->depth - 1].name = name;
                                name = s;
                                continue;