libceph: isolate message page field manipulation
Define a function ceph_msg_data_set_pages(), which more clearly
abstracts the assignment page-related fields for data in a ceph
message structure. Use this new function in the osd client and mds
client.
Ideally, these fields would never be set more than once (with
BUG_ON() calls to guarantee that). At the moment though the osd
client sets these every time it receives a message, and in the event
of a communication problem this can happen more than once. (This
will be resolved shortly, but setting up these helpers first makes
it all a bit easier to work with.)
Rearrange the field order in a ceph_msg structure to group those
that are used to define the possible data payloads.
This partially resolves:
http://tracker.ceph.com/issues/4263
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index ce1669f..cec39cb 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2689,6 +2689,17 @@
}
EXPORT_SYMBOL(ceph_con_keepalive);
+void ceph_msg_data_set_pages(struct ceph_msg *msg, struct page **pages,
+ unsigned int page_count, size_t alignment)
+{
+ /* BUG_ON(msg->pages); */
+ /* BUG_ON(msg->page_count); */
+
+ msg->pages = pages;
+ msg->page_count = page_count;
+ msg->page_alignment = alignment & ~PAGE_MASK;
+}
+EXPORT_SYMBOL(ceph_msg_data_set_pages);
/*
* construct a new message with given type, size