[PATCH] __d_path needs vfsmount_lock

From: Mike Waychison <Michael.Waychison@Sun.COM>

- protect vfsmount->mnt_parent by taking vfsmount_lock in __d_path

diff --git a/fs/dcache.c b/fs/dcache.c
index b6d266fac29f5eae327ab11c12a00919c7cd080f..83166383bf94a029b8b061a7ab5d37a7ce00542d 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1296,10 +1296,14 @@ static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt,
                        break;
                if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
                        /* Global root? */
-                       if (vfsmnt->mnt_parent == vfsmnt)
+                       spin_lock(&vfsmount_lock);
+                       if (vfsmnt->mnt_parent == vfsmnt) {
+                               spin_unlock(&vfsmount_lock);
                                goto global_root;
+                       }
                        dentry = vfsmnt->mnt_mountpoint;
                        vfsmnt = vfsmnt->mnt_parent;
+                       spin_unlock(&vfsmount_lock);
                        continue;
                }
                parent = dentry->d_parent;