ocfs2: Fix empty lvb check

The check for an empty lvb should check the entire buffer not just the first
byte.

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

2 files changed, 16 insertions, 5 deletions

diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 4fc1be3a3fa2..bf873919b009 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -315,6 +315,15 @@ enum dlm_lockres_list {
         DLM_BLOCKED_LIST
 };
 
+static inline int dlm_lvb_is_empty(char *lvb)
+{
+        int i;
+        for (i=0; i<DLM_LVB_LEN; i++)
+                if (lvb[i])
+                        return 0;
+        return 1;
+}
+
 static inline struct list_head *
 dlm_list_idx_to_ptr(struct dlm_lock_resource *res, enum dlm_lockres_list idx)
 {
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index b568bb6617d8..8a3f0173ff56 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1021,8 +1021,9 @@ static int dlm_add_lock_to_array(struct dlm_lock *lock,
                     ml->type == LKM_PRMODE) {
                         /* if it is already set, this had better be a PR
                          * and it has to match */
-                        if (mres->lvb[0] && (ml->type == LKM_EXMODE ||
-                            memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
+                        if (!dlm_lvb_is_empty(mres->lvb) &&
+                            (ml->type == LKM_EXMODE ||
+                             memcmp(mres->lvb, lock->lksb->lvb, DLM_LVB_LEN))) {
                                 mlog(ML_ERROR, "mismatched lvbs!\n");
                                 __dlm_print_one_lock_resource(lock->lockres);
                                 BUG();
@@ -1554,7 +1555,7 @@ static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
                 lksb->flags |= (ml->flags &
                                 (DLM_LKSB_PUT_LVB|DLM_LKSB_GET_LVB));
                         
-                if (mres->lvb[0]) {
+                if (!dlm_lvb_is_empty(mres->lvb)) {
                         if (lksb->flags & DLM_LKSB_PUT_LVB) {
                                 /* other node was trying to update
                                  * lvb when node died.  recreate the
@@ -1565,8 +1566,9 @@ static int dlm_process_recovery_data(struct dlm_ctxt *dlm,
                                  * most recent valid lvb info */
                                 BUG_ON(ml->type != LKM_EXMODE &&
                                        ml->type != LKM_PRMODE);
-                                if (res->lvb[0] && (ml->type == LKM_EXMODE ||
-                                    memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
+                                if (!dlm_lvb_is_empty(res->lvb) &&
+                                    (ml->type == LKM_EXMODE ||
+                                     memcmp(res->lvb, mres->lvb, DLM_LVB_LEN))) {
                                         mlog(ML_ERROR, "received bad lvb!\n");
                                         __dlm_print_one_lock_resource(res);
                                         BUG();