libceph: reference counting pagelist

this allow pagelist to present data that may be sent multiple times.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/ceph/pagelist.h b/include/linux/ceph/pagelist.h
index 9660d6b0a35d..5f871d84ddce 100644
--- a/include/linux/ceph/pagelist.h
+++ b/include/linux/ceph/pagelist.h
@@ -2,6 +2,7 @@
 #define __FS_CEPH_PAGELIST_H
 
 #include <linux/list.h>
+#include <linux/atomic.h>
 
 struct ceph_pagelist {
         struct list_head head;
@@ -10,6 +11,7 @@ struct ceph_pagelist {
         size_t room;
         struct list_head free_list;
         size_t num_pages_free;
+        atomic_t refcnt;
 };
 
 struct ceph_pagelist_cursor {
@@ -26,9 +28,10 @@ static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
         pl->room = 0;
         INIT_LIST_HEAD(&pl->free_list);
         pl->num_pages_free = 0;
+        atomic_set(&pl->refcnt, 1);
 }
 
-extern int ceph_pagelist_release(struct ceph_pagelist *pl);
+extern void ceph_pagelist_release(struct ceph_pagelist *pl);
 
 extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);