From c5c6b19d4b8f5431fca05f28ae9e141045022149 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 9 Nov 2010 12:40:00 -0800 Subject: ceph: explicitly specify page alignment in network messages The alignment used for reading data into or out of pages used to be taken from the data_off field in the message header. This only worked as long as the page alignment matched the object offset, breaking direct io to non-page aligned offsets. Instead, explicitly specify the page alignment next to the page vector in the ceph_msg struct, and use that instead of the message header (which probably shouldn't be trusted). The alloc_msg callback is responsible for filling in this field properly when it sets up the page vector. Signed-off-by: Sage Weil --- include/linux/ceph/messenger.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/ceph/messenger.h b/include/linux/ceph/messenger.h index 5956d62c3057..a108b425fee2 100644 --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -82,6 +82,7 @@ struct ceph_msg { struct ceph_buffer *middle; struct page **pages; /* data payload. NOT OWNER. */ unsigned nr_pages; /* size of page array */ + unsigned page_alignment; /* io offset in first page */ struct ceph_pagelist *pagelist; /* instead of pages */ struct list_head list_head; struct kref kref; -- cgit v1.2.3