ceph: add pagelist_reserve, pagelist_truncate, pagelist_set_cursor
These facilitate preallocation of pages so that we can encode into the pagelist
in an atomic context.
Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/include/linux/ceph/pagelist.h b/include/linux/ceph/pagelist.h
index cc9327a..9660d6b 100644
--- a/include/linux/ceph/pagelist.h
+++ b/include/linux/ceph/pagelist.h
@@ -8,6 +8,14 @@
void *mapped_tail;
size_t length;
size_t room;
+ struct list_head free_list;
+ size_t num_pages_free;
+};
+
+struct ceph_pagelist_cursor {
+ struct ceph_pagelist *pl; /* pagelist, for error checking */
+ struct list_head *page_lru; /* page in list */
+ size_t room; /* room remaining to reset to */
};
static inline void ceph_pagelist_init(struct ceph_pagelist *pl)
@@ -16,11 +24,24 @@
pl->mapped_tail = NULL;
pl->length = 0;
pl->room = 0;
+ INIT_LIST_HEAD(&pl->free_list);
+ pl->num_pages_free = 0;
}
+
extern int ceph_pagelist_release(struct ceph_pagelist *pl);
extern int ceph_pagelist_append(struct ceph_pagelist *pl, const void *d, size_t l);
+extern int ceph_pagelist_reserve(struct ceph_pagelist *pl, size_t space);
+
+extern int ceph_pagelist_free_reserve(struct ceph_pagelist *pl);
+
+extern void ceph_pagelist_set_cursor(struct ceph_pagelist *pl,
+ struct ceph_pagelist_cursor *c);
+
+extern int ceph_pagelist_truncate(struct ceph_pagelist *pl,
+ struct ceph_pagelist_cursor *c);
+
static inline int ceph_pagelist_encode_64(struct ceph_pagelist *pl, u64 v)
{
__le64 ev = cpu_to_le64(v);