From 350b1c32ea58d29e25d63fc25e92dd48f9339546 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Tue, 22 Dec 2009 10:45:45 -0800
Subject: ceph: control access to page vector for incoming data

When we issue an OSD read, we specify a vector of pages that the data is to
be read into.  The request may be sent multiple times, to multiple OSDs, if
the osdmap changes, which means we can get more than one reply.

Only read data into the page vector if the reply is coming from the
OSD we last sent the request to.  Keep track of which connection is using
the vector by taking a reference.  If another connection was already
using the vector before and a new reply comes in on the right connection,
revoke the pages from the other connection.

Signed-off-by: Sage Weil <sage@newdream.net>
---
 fs/ceph/osd_client.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'fs/ceph/osd_client.h')

diff --git a/fs/ceph/osd_client.h b/fs/ceph/osd_client.h
index 2e4cfd1e9f1..8fef71cc445 100644
--- a/fs/ceph/osd_client.h
+++ b/fs/ceph/osd_client.h
@@ -43,11 +43,13 @@ struct ceph_osd_request {
 	struct list_head r_osd_item;
 	struct ceph_osd *r_osd;
 
+	struct ceph_connection *r_con_filling_pages;
+
 	struct ceph_msg  *r_request, *r_reply;
 	int               r_result;
 	int               r_flags;     /* any additional flags for the osd */
 	u32               r_sent;      /* >0 if r_request is sending/sent */
-	int r_prepared_pages, r_got_reply;
+	int               r_got_reply;
 	int		  r_num_prealloc_reply;
 
 	struct ceph_osd_client *r_osdc;
-- 
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