4 files changed, 67 insertions, 10 deletions

diff --git a/fs/ceph/messenger.c b/fs/ceph/messenger.c
index c03b4185c143..506b638a023b 100644
--- a/fs/ceph/messenger.c
+++ b/fs/ceph/messenger.c
@@ -1976,6 +1976,35 @@ void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg)
 }
 
 /*
+ * Revoke a page vector that we may be reading data into
+ */
+void ceph_con_revoke_pages(struct ceph_connection *con, struct page **pages)
+{
+	mutex_lock(&con->mutex);
+	if (con->in_msg && con->in_msg->pages == pages) {
+		unsigned data_len = le32_to_cpu(con->in_hdr.data_len);
+
+		/* skip rest of message */
+		dout("con_revoke_pages %p msg %p pages %p revoked\n", con,
+		     con->in_msg, pages);
+		if (con->in_msg_pos.data_pos < data_len)
+			con->in_base_pos = con->in_msg_pos.data_pos - data_len;
+		else
+			con->in_base_pos = con->in_base_pos -
+				sizeof(struct ceph_msg_header) -
+				sizeof(struct ceph_msg_footer);
+		con->in_msg->pages = NULL;
+		ceph_msg_put(con->in_msg);
+		con->in_msg = NULL;
+		con->in_tag = CEPH_MSGR_TAG_READY;
+	} else {
+		dout("con_revoke_pages %p msg %p pages %p no-op\n",
+		     con, con->in_msg, pages);
+	}
+	mutex_unlock(&con->mutex);
+}
+
+/*
  * Queue a keepalive byte to ensure the tcp connection is alive.
  */
 void ceph_con_keepalive(struct ceph_connection *con)
diff --git a/fs/ceph/messenger.h b/fs/ceph/messenger.h
index 94b55de90331..7e2aab1d3ce2 100644
--- a/fs/ceph/messenger.h
+++ b/fs/ceph/messenger.h
@@ -230,6 +230,8 @@ extern void ceph_con_open(struct ceph_connection *con,
 extern void ceph_con_close(struct ceph_connection *con);
 extern void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg);
 extern void ceph_con_revoke(struct ceph_connection *con, struct ceph_msg *msg);
+extern void ceph_con_revoke_pages(struct ceph_connection *con,
+				  struct page **pages);
 extern void ceph_con_keepalive(struct ceph_connection *con);
 extern struct ceph_connection *ceph_con_get(struct ceph_connection *con);
 extern void ceph_con_put(struct ceph_connection *con);
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index a1800fb63237..374f0013956c 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -87,6 +87,13 @@ void ceph_osdc_release_request(struct kref *kref)
 		ceph_msg_put(req->r_request);
 	if (req->r_reply)
 		ceph_msg_put(req->r_reply);
+	if (req->r_con_filling_pages) {
+		dout("release_request revoking pages %p from con %p\n",
+		     req->r_pages, req->r_con_filling_pages);
+		ceph_con_revoke_pages(req->r_con_filling_pages,
+				      req->r_pages);
+		ceph_con_put(req->r_con_filling_pages);
+	}
 	if (req->r_own_pages)
 		ceph_release_page_vector(req->r_pages,
 					 req->r_num_pages);
@@ -687,7 +694,8 @@ static void handle_timeout(struct work_struct *work)
  * handle osd op reply.  either call the callback if it is specified,
  * or do the completion to wake up the waiting thread.
  */
-static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg)
+static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg,
+			 struct ceph_connection *con)
 {
 	struct ceph_osd_reply_head *rhead = msg->front.iov_base;
 	struct ceph_osd_request *req;
@@ -715,6 +723,16 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 	ceph_osdc_get_request(req);
 	flags = le32_to_cpu(rhead->flags);
 
+	/*
+	 * if this connection filled our pages, drop our reference now, to
+	 * avoid a (safe but slower) revoke later.
+	 */
+	if (req->r_con_filling_pages == con && req->r_pages == msg->pages) {
+		dout(" got pages, dropping con_filling_pages ref %p\n", con);
+		req->r_con_filling_pages = NULL;
+		ceph_con_put(con);
+	}
+
 	if (req->r_reply) {
 		/*
 		 * once we see the message has been received, we don't
@@ -1007,14 +1025,20 @@ static int prepare_pages(struct ceph_connection *con, struct ceph_msg *m,
 	}
 	dout("prepare_pages tid %llu has %d pages, want %d\n",
 	     tid, req->r_num_pages, want);
-	if (likely(req->r_num_pages >= want && !req->r_prepared_pages)) {
-		m->pages = req->r_pages;
-		m->nr_pages = req->r_num_pages;
-		req->r_reply = m;  /* only for duration of read over socket */
-		ceph_msg_get(m);
-		req->r_prepared_pages = 1;
-		ret = 0; /* success */
+	if (unlikely(req->r_num_pages < want))
+		goto out;
+
+	if (req->r_con_filling_pages) {
+		dout("revoking pages %p from old con %p\n", req->r_pages,
+		     req->r_con_filling_pages);
+		ceph_con_revoke_pages(req->r_con_filling_pages, req->r_pages);
+		ceph_con_put(req->r_con_filling_pages);
 	}
+	req->r_con_filling_pages = ceph_con_get(con);
+	req->r_reply = ceph_msg_get(m); /* for duration of read over socket */
+	m->pages = req->r_pages;
+	m->nr_pages = req->r_num_pages;
+	ret = 0; /* success */
 out:
 	mutex_unlock(&osdc->request_mutex);
 	return ret;
@@ -1269,7 +1293,7 @@ static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
 		ceph_osdc_handle_map(osdc, msg);
 		break;
 	case CEPH_MSG_OSD_OPREPLY:
-		handle_reply(osdc, msg);
+		handle_reply(osdc, msg, con);
 		break;
 
 	default:
diff --git a/fs/ceph/osd_client.h b/fs/ceph/osd_client.h
index 2e4cfd1e9f10..8fef71cc4457 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;