locks: keep ref on the inode while locks are held

keeping refs on the inode while there are held locks prevents the
inode from getting pruned away

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 315 (generation number support)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=315

1 files changed, 52 insertions, 1 deletions

diff --git a/xlators/features/locks/src/common.c b/xlators/features/locks/src/common.c
index 08dc451e16e..b9037688a3f 100644
--- a/xlators/features/locks/src/common.c
+++ b/xlators/features/locks/src/common.c
@@ -35,6 +35,7 @@
 #include "common-utils.h"
 
 #include "locks.h"
+#include "common.h"
 
 
 static int
@@ -43,7 +44,7 @@ static void
 __insert_and_merge (pl_inode_t *pl_inode, posix_lock_t *lock);
 
 static pl_dom_list_t *
-allocate_domain(const char *volume)
+allocate_domain (const char *volume)
 {
         pl_dom_list_t *dom = NULL;
 
@@ -95,6 +96,56 @@ found:
         return dom;
 }
 
+
+int
+__pl_inode_is_empty (pl_inode_t *pl_inode)
+{
+        pl_dom_list_t *dom = NULL;
+        int            is_empty = 1;
+
+        if (!list_empty (&pl_inode->ext_list))
+                is_empty = 0;
+
+        list_for_each_entry (dom, &pl_inode->dom_list, inode_list) {
+                if (!list_empty (&dom->entrylk_list))
+                        is_empty = 0;
+
+                if (!list_empty (&dom->inodelk_list))
+                        is_empty = 0;
+        }
+
+        return is_empty;
+}
+
+void
+pl_update_refkeeper (xlator_t *this, inode_t *inode)
+{
+        pl_inode_t *pl_inode  = NULL;
+        int         is_empty  = 0;
+        int         need_unref = 0;
+
+        pl_inode = pl_inode_get (this, inode);
+
+        pthread_mutex_lock (&pl_inode->mutex);
+        {
+                is_empty = __pl_inode_is_empty (pl_inode);
+
+                if (is_empty && pl_inode->refkeeper) {
+                        need_unref = 1;
+                        pl_inode->refkeeper = NULL;
+                }
+
+                if (!is_empty && !pl_inode->refkeeper) {
+                        pl_inode->refkeeper = inode_ref (inode);
+                }
+        }
+        pthread_mutex_unlock (&pl_inode->mutex);
+
+        if (need_unref)
+                inode_unref (inode);
+}
+
+
 pl_inode_t *
 pl_inode_get (xlator_t *this, inode_t *inode)
 {