commit ebf18f47093e968105767eed4a0aa155e86b224e
author Alex Elder <elder@inktank.com> Mon Mar 04 22:29:57 2013 -0600
committer Sage Weil <sage@inktank.com> Wed May 01 21:16:41 2013 -0700
tree 90122481017a894850e46b8c86987bd31548fddc
parent 27fa83852ba275361eaa1a1283cf6704fa8191a6

ceph: only set message data pointers if non-empty

Change it so we only assign outgoing data information for messages
if there is outgoing data to send.

This then allows us to add a few more (currently commented-out)
assertions.

This is related to:
    http://tracker.ceph.com/issues/4284

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>

net/ceph/messenger.c

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index d118353..1965d78 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2692,6 +2692,8 @@
 void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
 		size_t length, size_t alignment)
 {
+	/* BUG_ON(!pages); */
+	/* BUG_ON(!length); */
 	/* BUG_ON(msg->pages); */
 	/* BUG_ON(msg->page_count); */
 
@@ -2705,6 +2707,7 @@
 				struct ceph_pagelist *pagelist)
 {
 	/* BUG_ON(!pagelist); */
+	/* BUG_ON(!pagelist->length); */
 	/* BUG_ON(msg->pagelist); */
 
 	msg->pagelist = pagelist;
@@ -2723,6 +2726,7 @@
 void ceph_msg_data_set_trail(struct ceph_msg *msg, struct ceph_pagelist *trail)
 {
 	/* BUG_ON(!trail); */
+	/* BUG_ON(!trail->length); */
 	/* BUG_ON(msg->trail); */
 
 	msg->trail = trail;

net/ceph/osd_client.c

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 387e312..4402e91 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -1759,8 +1759,10 @@
 	osd_data = &req->r_data_out;
 	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
 		BUG_ON(osd_data->length > (u64) SIZE_MAX);
-		ceph_msg_data_set_pages(req->r_request, osd_data->pages,
-			osd_data->length, osd_data->alignment);
+		if (osd_data->length)
+			ceph_msg_data_set_pages(req->r_request,
+				osd_data->pages, osd_data->length,
+				osd_data->alignment);
 #ifdef CONFIG_BLOCK
 	} else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
 		ceph_msg_data_set_bio(req->r_request, osd_data->bio);
@@ -1768,7 +1770,8 @@
 	} else {
 		BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_NONE);
 	}
-	ceph_msg_data_set_trail(req->r_request, &req->r_trail);
+	if (req->r_trail.length)
+		ceph_msg_data_set_trail(req->r_request, &req->r_trail);
 
 	register_request(osdc, req);