Fix the -ESTALE handling in do_filp_open()

Instead of playing sick games with path saving, cleanups, just retry
the entire thing once with LOOKUP_REVAL added.  Post-.34 we'll convert
all -ESTALE handling in there to that style, rather than playing with
many retry loops deep in the call chain.

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

1 files changed, 9 insertions, 11 deletions

diff --git a/fs/namei.c b/fs/namei.c
index d930f1856ed2..94a5e60779f9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1604,11 +1604,12 @@ struct file *do_filp_open(int dfd, const char *pathname,
         struct file *filp;
         struct nameidata nd;
         int error;
-        struct path path, save;
+        struct path path;
         struct dentry *dir;
         int count = 0;
         int will_truncate;
         int flag = open_to_namei_flags(open_flag);
+        int force_reval = 0;
 
         /*
          * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only
@@ -1660,9 +1661,12 @@ struct file *do_filp_open(int dfd, const char *pathname,
         /*
          * Create - we need to know the parent.
          */
+reval:
         error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
         if (error)
                 return ERR_PTR(error);
+        if (force_reval)
+                nd.flags |= LOOKUP_REVAL;
         error = path_walk(pathname, &nd);
         if (error) {
                 if (nd.root.mnt)
@@ -1854,17 +1858,7 @@ do_link:
         error = security_inode_follow_link(path.dentry, &nd);
         if (error)
                 goto exit_dput;
-        save = nd.path;
-        path_get(&save);
         error = __do_follow_link(&path, &nd);
-        if (error == -ESTALE) {
-                /* nd.path had been dropped */
-                nd.path = save;
-                path_get(&nd.path);
-                nd.flags |= LOOKUP_REVAL;
-                error = __do_follow_link(&path, &nd);
-        }
-        path_put(&save);
         path_put(&path);
         if (error) {
                 /* Does someone understand code flow here? Or it is only
@@ -1874,6 +1868,10 @@ do_link:
                 release_open_intent(&nd);
                 if (nd.root.mnt)
                         path_put(&nd.root);
+                if (error == -ESTALE && !force_reval) {
+                        force_reval = 1;
+                        goto reval;
+                }
                 return ERR_PTR(error);
         }
         nd.flags &= ~LOOKUP_PARENT;