pull dropping RCU on success of link_path_walk() into path_lookupat()

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

1 files changed, 12 insertions, 18 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 450b686e9682..8f10a9ff9f6b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -539,14 +539,6 @@ err_unlock:
         return -ECHILD;
 }
 
-/* Try to drop out of rcu-walk mode if we were in it, otherwise do nothing.  */
-static inline int nameidata_drop_rcu_last_maybe(struct nameidata *nd)
-{
-        if (likely(nd->flags & LOOKUP_RCU))
-                return nameidata_drop_rcu_last(nd);
-        return 0;
-}
-
 /**
  * release_open_intent - free up open intent resources
  * @nd: pointer to nameidata
@@ -1339,7 +1331,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
         while (*name=='/')
                 name++;
         if (!*name)
-                goto return_base;
+                return 0;
 
         if (nd->depth)
                 lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE);
@@ -1448,7 +1440,7 @@ last_component:
                                 } else
                                         follow_dotdot(nd);
                         }
-                        goto return_base;
+                        return 0;
                 }
                 err = do_lookup(nd, &this, &next, &inode);
                 if (err)
@@ -1471,13 +1463,10 @@ last_component:
                         if (!nd->inode->i_op->lookup)
                                 break;
                 }
-                goto return_base;
+                return 0;
 lookup_parent:
                 nd->last = this;
                 nd->last_type = type;
-return_base:
-                if (nameidata_drop_rcu_last_maybe(nd))
-                        return -ECHILD;
                 return 0;
 out_dput:
                 if (!(nd->flags & LOOKUP_RCU))
@@ -1598,10 +1587,15 @@ static int path_lookupat(int dfd, const char *name,
 
         if (nd->flags & LOOKUP_RCU) {
                 /* RCU dangling. Cancel it. */
-                nd->flags &= ~LOOKUP_RCU;
-                nd->root.mnt = NULL;
-                rcu_read_unlock();
-                br_read_unlock(vfsmount_lock);
+                if (!retval) {
+                        if (nameidata_drop_rcu_last(nd))
+                                retval = -ECHILD;
+                } else {
+                        nd->flags &= ~LOOKUP_RCU;
+                        nd->root.mnt = NULL;
+                        rcu_read_unlock();
+                        br_read_unlock(vfsmount_lock);
+                }
         }
 
         if (!retval)