1 files changed, 46 insertions, 0 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 7219a86d34cc..e15fc7d50827 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -244,6 +244,10 @@ static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
         .flags          = 0,
 };
 
+static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
+        .flags          = 0,
+};
+
 static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
         .get_osb        = ocfs2_get_dentry_osb,
         .post_unlock    = ocfs2_dentry_post_unlock,
@@ -622,6 +626,17 @@ static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
                                    &ocfs2_rename_lops, osb);
 }
 
+static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
+                                         struct ocfs2_super *osb)
+{
+        /* nfs_sync lockres doesn't come from a slab so we call init
+         * once on it manually.  */
+        ocfs2_lock_res_init_once(res);
+        ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
+        ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
+                                   &ocfs2_nfs_sync_lops, osb);
+}
+
 void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
                               struct ocfs2_file_private *fp)
 {
@@ -2417,6 +2432,34 @@ void ocfs2_rename_unlock(struct ocfs2_super *osb)
                 ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
 }
 
+int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
+{
+        int status;
+        struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+        if (ocfs2_is_hard_readonly(osb))
+                return -EROFS;
+
+        if (ocfs2_mount_local(osb))
+                return 0;
+
+        status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
+                                    0, 0);
+        if (status < 0)
+                mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
+
+        return status;
+}
+
+void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
+{
+        struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+        if (!ocfs2_mount_local(osb))
+                ocfs2_cluster_unlock(osb, lockres,
+                                     ex ? LKM_EXMODE : LKM_PRMODE);
+}
+
 int ocfs2_dentry_lock(struct dentry *dentry, int ex)
 {
         int ret;
@@ -2798,6 +2841,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
 local:
         ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
         ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
+        ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
 
         osb->cconn = conn;
 
@@ -2833,6 +2877,7 @@ void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
 
         ocfs2_lock_res_free(&osb->osb_super_lockres);
         ocfs2_lock_res_free(&osb->osb_rename_lockres);
+        ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
 
         ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
         osb->cconn = NULL;
@@ -3015,6 +3060,7 @@ static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
 {
         ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
         ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
+        ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
 }
 
 int ocfs2_drop_inode_locks(struct inode *inode)