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: 112 (parallel deletion of files mounted by different clients on the same back-end hangs and/or does not completely delete)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=112

1 files changed, 48 insertions, 0 deletions

diff --git a/xlators/features/locks/src/common.c b/xlators/features/locks/src/common.c
index 5f115f6fa53..11841e92d07 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
@@ -48,6 +49,53 @@ __insert_and_merge (pl_inode_t *pl_inode, posix_lock_t *lock,
 				    ? &pl_inode->ext_list	\
 				    : &pl_inode->int_list)
 
+
+int
+__pl_inode_is_empty (pl_inode_t *pl_inode)
+{
+        int is_empty = 1;
+
+        if (!list_empty (&pl_inode->ext_list))
+                is_empty = 0;
+
+        if (!list_empty (&pl_inode->int_list))
+                is_empty = 0;
+
+        if (!list_empty (&pl_inode->dir_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)
 {