NFS: Stop sillyname renames and unmounts from racing
Added an active/deactive mechanism to the nfs_server structure
allowing async operations to hold off umount until the
operations are done.
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 0b0c72a..fda1635 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -202,6 +202,7 @@
static int nfs_xdev_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
static void nfs_kill_super(struct super_block *);
+static void nfs_put_super(struct super_block *);
static struct file_system_type nfs_fs_type = {
.owner = THIS_MODULE,
@@ -223,6 +224,7 @@
.alloc_inode = nfs_alloc_inode,
.destroy_inode = nfs_destroy_inode,
.write_inode = nfs_write_inode,
+ .put_super = nfs_put_super,
.statfs = nfs_statfs,
.clear_inode = nfs_clear_inode,
.umount_begin = nfs_umount_begin,
@@ -325,6 +327,28 @@
unregister_filesystem(&nfs_fs_type);
}
+void nfs_sb_active(struct nfs_server *server)
+{
+ atomic_inc(&server->active);
+}
+
+void nfs_sb_deactive(struct nfs_server *server)
+{
+ if (atomic_dec_and_test(&server->active))
+ wake_up(&server->active_wq);
+}
+
+static void nfs_put_super(struct super_block *sb)
+{
+ struct nfs_server *server = NFS_SB(sb);
+ /*
+ * Make sure there are no outstanding ops to this server.
+ * If so, wait for them to finish before allowing the
+ * unmount to continue.
+ */
+ wait_event(server->active_wq, atomic_read(&server->active) == 0);
+}
+
/*
* Deliver file system statistics to userspace
*/