exportfs: clear DISCONNECTED on all parents sooner

Once we've found any connected parent, we know all our parents are
connected--that's true even if there's a concurrent rename.  May as well
clear them all at once and be done with it.

Reviewed-by: Cristoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 21 insertions, 4 deletions

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 87e6dca69e43..c65b748688ff 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -90,6 +90,24 @@ find_disconnected_root(struct dentry *dentry)
         return dentry;
 }
 
+static void clear_disconnected(struct dentry *dentry)
+{
+        dget(dentry);
+        while (dentry->d_flags & DCACHE_DISCONNECTED) {
+                struct dentry *parent = dget_parent(dentry);
+
+                WARN_ON_ONCE(IS_ROOT(dentry));
+
+                spin_lock(&dentry->d_lock);
+                dentry->d_flags &= ~DCACHE_DISCONNECTED;
+                spin_unlock(&dentry->d_lock);
+
+                dput(dentry);
+                dentry = parent;
+        }
+        dput(dentry);
+}
+
 /*
  * Make sure target_dir is fully connected to the dentry tree.
  *
@@ -128,10 +146,9 @@ reconnect_path(struct vfsmount *mnt, struct dentry *target_dir, char *nbuf)
 
                 if (!IS_ROOT(pd)) {
                         /* must have found a connected parent - great */
-                        spin_lock(&pd->d_lock);
-                        pd->d_flags &= ~DCACHE_DISCONNECTED;
-                        spin_unlock(&pd->d_lock);
-                        noprogress = 0;
+                        clear_disconnected(target_dir);
+                        dput(pd);
+                        break;
                 } else {
                         /*
                          * We have hit the top of a disconnected path, try to