1 files changed, 25 insertions, 9 deletions

diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 165fe9e2d570..053d92a745b9 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -101,6 +101,7 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
                              unsigned long timeout,
                              int do_now)
 {
+        struct autofs_info *ino;
         struct dentry *p;
 
         DPRINTK("top %p %.*s",
@@ -110,14 +111,6 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
         if (!simple_positive(top))
                 return 1;
 
-        /* Timeout of a tree mount is determined by its top dentry */
-        if (!autofs4_can_expire(top, timeout, do_now))
-                return 1;
-
-        /* Is someone visiting anywhere in the tree ? */
-        if (may_umount_tree(mnt))
-                return 1;
-
         spin_lock(&dcache_lock);
         for (p = top; p; p = next_dentry(p, top)) {
                 /* Negative dentry - give up */
@@ -130,17 +123,40 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
                 p = dget(p);
                 spin_unlock(&dcache_lock);
 
+                /*
+                 * Is someone visiting anywhere in the subtree ?
+                 * If there's no mount we need to check the usage
+                 * count for the autofs dentry.
+                 */
+                ino = autofs4_dentry_ino(p);
                 if (d_mountpoint(p)) {
-                        /* First busy => tree busy */
                         if (autofs4_mount_busy(mnt, p)) {
                                 dput(p);
                                 return 1;
                         }
+                } else {
+                        unsigned int ino_count = atomic_read(&ino->count);
+
+                        /* allow for dget above and top is already dgot */
+                        if (p == top)
+                                ino_count += 2;
+                        else
+                                ino_count++;
+
+                        if (atomic_read(&p->d_count) > ino_count) {
+                                dput(p);
+                                return 1;
+                        }
                 }
                 dput(p);
                 spin_lock(&dcache_lock);
         }
         spin_unlock(&dcache_lock);
+
+        /* Timeout of a tree mount is ultimately determined by its top dentry */
+        if (!autofs4_can_expire(top, timeout, do_now))
+                return 1;
+
         return 0;
 }