5 files changed, 38 insertions, 9 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 6cdeaa76f27f..83d2ddb27186 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -1989,7 +1989,8 @@ static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
 {
         struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
 
-        if (lvb->lvb_version == OCFS2_LVB_VERSION
+        if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
+            && lvb->lvb_version == OCFS2_LVB_VERSION
             && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
                 return 1;
         return 0;
@@ -2382,7 +2383,8 @@ int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno, int ex)
                 return status;
 
         lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
-        if (lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
+        if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+            lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
                 *seqno = be32_to_cpu(lvb->lvb_os_seqno);
         return status;
 }
@@ -3627,7 +3629,8 @@ static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
         struct ocfs2_global_disk_dqinfo *gdinfo;
         int status = 0;
 
-        if (lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
+        if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+            lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
                 info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
                 info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
                 oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
diff --git a/fs/ocfs2/stack_o2cb.c b/fs/ocfs2/stack_o2cb.c
index fcd120f1493a..3f661376a2de 100644
--- a/fs/ocfs2/stack_o2cb.c
+++ b/fs/ocfs2/stack_o2cb.c
@@ -236,6 +236,16 @@ static int o2cb_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
         return dlm_status_to_errno(lksb->lksb_o2dlm.status);
 }
 
+/*
+ * o2dlm aways has a "valid" LVB. If the dlm loses track of the LVB
+ * contents, it will zero out the LVB.  Thus the caller can always trust
+ * the contents.
+ */
+static int o2cb_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
+{
+        return 1;
+}
+
 static void *o2cb_dlm_lvb(union ocfs2_dlm_lksb *lksb)
 {
         return (void *)(lksb->lksb_o2dlm.lvb);
@@ -354,6 +364,7 @@ static struct ocfs2_stack_operations o2cb_stack_ops = {
         .dlm_lock       = o2cb_dlm_lock,
         .dlm_unlock     = o2cb_dlm_unlock,
         .lock_status    = o2cb_dlm_lock_status,
+        .lvb_valid      = o2cb_dlm_lvb_valid,
         .lock_lvb       = o2cb_dlm_lvb,
         .dump_lksb      = o2cb_dump_lksb,
 };
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index 9b76d41a8ac6..ff4c798a5635 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -738,6 +738,13 @@ static int user_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
         return lksb->lksb_fsdlm.sb_status;
 }
 
+static int user_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
+{
+        int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
+
+        return !invalid;
+}
+
 static void *user_dlm_lvb(union ocfs2_dlm_lksb *lksb)
 {
         if (!lksb->lksb_fsdlm.sb_lvbptr)
@@ -873,6 +880,7 @@ static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
         .dlm_lock       = user_dlm_lock,
         .dlm_unlock     = user_dlm_unlock,
         .lock_status    = user_dlm_lock_status,
+        .lvb_valid      = user_dlm_lvb_valid,
         .lock_lvb       = user_dlm_lvb,
         .plock          = user_plock,
         .dump_lksb      = user_dlm_dump_lksb,
diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c
index 68b668b0e60a..3f2f1c45b7b6 100644
--- a/fs/ocfs2/stackglue.c
+++ b/fs/ocfs2/stackglue.c
@@ -6,7 +6,7 @@
  * Code which implements an OCFS2 specific interface to underlying
  * cluster stacks.
  *
- * Copyright (C) 2007 Oracle.  All rights reserved.
+ * Copyright (C) 2007, 2009 Oracle.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
@@ -271,11 +271,12 @@ int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
 }
 EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status);
 
-/*
- * Why don't we cast to ocfs2_meta_lvb?  The "clean" answer is that we
- * don't cast at the glue level.  The real answer is that the header
- * ordering is nigh impossible.
- */
+int ocfs2_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
+{
+        return active_stack->sp_ops->lvb_valid(lksb);
+}
+EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb_valid);
+
 void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb)
 {
         return active_stack->sp_ops->lock_lvb(lksb);
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
index c571af375ef8..03a44d60eac9 100644
--- a/fs/ocfs2/stackglue.h
+++ b/fs/ocfs2/stackglue.h
@@ -186,6 +186,11 @@ struct ocfs2_stack_operations {
         int (*lock_status)(union ocfs2_dlm_lksb *lksb);
 
         /*
+         * Return non-zero if the LVB is valid.
+         */
+        int (*lvb_valid)(union ocfs2_dlm_lksb *lksb);
+
+        /*
          * Pull the lvb pointer off of the stack-specific lksb.
          */
         void *(*lock_lvb)(union ocfs2_dlm_lksb *lksb);
@@ -252,6 +257,7 @@ int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
                      struct ocfs2_lock_res *astarg);
 
 int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb);
+int ocfs2_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb);
 void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb);
 void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb);