libceph: have osd requests support pagelist data

Add support for recording a ceph pagelist as data associated with an
osd request.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

include/linux/ceph/osd_client.h

@@ -53,6 +53,7 @@ struct ceph_osd {
 enum ceph_osd_data_type {
 	CEPH_OSD_DATA_TYPE_NONE,
 	CEPH_OSD_DATA_TYPE_PAGES,
+	CEPH_OSD_DATA_TYPE_PAGELIST,
 #ifdef CONFIG_BLOCK
 	CEPH_OSD_DATA_TYPE_BIO,
 #endif /* CONFIG_BLOCK */
@@ -68,6 +69,7 @@ struct ceph_osd_data {
 			bool		pages_from_pool;
 			bool		own_pages;
 		};
+		struct ceph_pagelist	*pagelist;
 #ifdef CONFIG_BLOCK
 		struct bio       	*bio;
 #endif /* CONFIG_BLOCK */

net/ceph/osd_client.c

@@ -1757,6 +1757,9 @@ static void ceph_osdc_msg_data_set(struct ceph_msg *msg,
 		if (osd_data->length)
 			ceph_msg_data_set_pages(msg, osd_data->pages,
 				osd_data->length, osd_data->alignment);
+	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
+		BUG_ON(!osd_data->pagelist->length);
+		ceph_msg_data_set_pagelist(msg, osd_data->pagelist);
 #ifdef CONFIG_BLOCK
 	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
 		ceph_msg_data_set_bio(msg, osd_data->bio);