make handle_dots() leave RCU mode on error

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

1 files changed, 12 insertions, 11 deletions

diff --git a/fs/namei.c b/fs/namei.c
index f09887a45831..ea14bfb04785 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1052,7 +1052,7 @@ static int follow_dotdot_rcu(struct nameidata *nd)
 
                         seq = read_seqcount_begin(&parent->d_seq);
                         if (read_seqcount_retry(&old->d_seq, nd->seq))
-                                return -ECHILD;
+                                goto failed;
                         inode = parent->d_inode;
                         nd->path.dentry = parent;
                         nd->seq = seq;
@@ -1065,8 +1065,14 @@ static int follow_dotdot_rcu(struct nameidata *nd)
         }
         __follow_mount_rcu(nd, &nd->path, &inode, true);
         nd->inode = inode;
-
         return 0;
+
+failed:
+        nd->flags &= ~LOOKUP_RCU;
+        nd->root.mnt = NULL;
+        rcu_read_unlock();
+        br_read_unlock(vfsmount_lock);
+        return -ECHILD;
 }
 
 /*
@@ -1405,9 +1411,8 @@ static int link_path_walk(const char *name, struct nameidata *nd)
                  * parent relationships.
                  */
                 if (unlikely(type != LAST_NORM)) {
-                        err = handle_dots(nd, type);
-                        if (err)
-                                goto return_err;
+                        if (handle_dots(nd, type))
+                                return -ECHILD;
                         continue;
                 }
 
@@ -1441,12 +1446,8 @@ last_component:
                 nd->flags &= lookup_flags | ~LOOKUP_CONTINUE;
                 if (lookup_flags & LOOKUP_PARENT)
                         goto lookup_parent;
-                if (unlikely(type != LAST_NORM)) {
-                        err = handle_dots(nd, type);
-                        if (err)
-                                goto return_err;
-                        return 0;
-                }
+                if (unlikely(type != LAST_NORM))
+                        return handle_dots(nd, type);
                 err = do_lookup(nd, &this, &next, &inode);
                 if (err)
                         break;