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Diffstat (limited to 'net/rds/ib_recv.c')
-rw-r--r--net/rds/ib_recv.c53
1 files changed, 47 insertions, 6 deletions
diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 5709bad2832..cd7a6cfcab0 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -555,6 +555,47 @@ u64 rds_ib_piggyb_ack(struct rds_ib_connection *ic)
return rds_ib_get_ack(ic);
}
+static struct rds_header *rds_ib_get_header(struct rds_connection *conn,
+ struct rds_ib_recv_work *recv,
+ u32 data_len)
+{
+ struct rds_ib_connection *ic = conn->c_transport_data;
+ void *hdr_buff = &ic->i_recv_hdrs[recv - ic->i_recvs];
+ void *addr;
+ u32 misplaced_hdr_bytes;
+
+ /*
+ * Support header at the front (RDS 3.1+) as well as header-at-end.
+ *
+ * Cases:
+ * 1) header all in header buff (great!)
+ * 2) header all in data page (copy all to header buff)
+ * 3) header split across hdr buf + data page
+ * (move bit in hdr buff to end before copying other bit from data page)
+ */
+ if (conn->c_version > RDS_PROTOCOL_3_0 || data_len == RDS_FRAG_SIZE)
+ return hdr_buff;
+
+ if (data_len <= (RDS_FRAG_SIZE - sizeof(struct rds_header))) {
+ addr = kmap_atomic(recv->r_frag->f_page, KM_SOFTIRQ0);
+ memcpy(hdr_buff,
+ addr + recv->r_frag->f_offset + data_len,
+ sizeof(struct rds_header));
+ kunmap_atomic(addr, KM_SOFTIRQ0);
+ return hdr_buff;
+ }
+
+ misplaced_hdr_bytes = (sizeof(struct rds_header) - (RDS_FRAG_SIZE - data_len));
+
+ memmove(hdr_buff + misplaced_hdr_bytes, hdr_buff, misplaced_hdr_bytes);
+
+ addr = kmap_atomic(recv->r_frag->f_page, KM_SOFTIRQ0);
+ memcpy(hdr_buff, addr + recv->r_frag->f_offset + data_len,
+ sizeof(struct rds_header) - misplaced_hdr_bytes);
+ kunmap_atomic(addr, KM_SOFTIRQ0);
+ return hdr_buff;
+}
+
/*
* It's kind of lame that we're copying from the posted receive pages into
* long-lived bitmaps. We could have posted the bitmaps and rdma written into
@@ -645,7 +686,7 @@ struct rds_ib_ack_state {
};
static void rds_ib_process_recv(struct rds_connection *conn,
- struct rds_ib_recv_work *recv, u32 byte_len,
+ struct rds_ib_recv_work *recv, u32 data_len,
struct rds_ib_ack_state *state)
{
struct rds_ib_connection *ic = conn->c_transport_data;
@@ -655,9 +696,9 @@ static void rds_ib_process_recv(struct rds_connection *conn,
/* XXX shut down the connection if port 0,0 are seen? */
rdsdebug("ic %p ibinc %p recv %p byte len %u\n", ic, ibinc, recv,
- byte_len);
+ data_len);
- if (byte_len < sizeof(struct rds_header)) {
+ if (data_len < sizeof(struct rds_header)) {
rds_ib_conn_error(conn, "incoming message "
"from %pI4 didn't inclue a "
"header, disconnecting and "
@@ -665,9 +706,9 @@ static void rds_ib_process_recv(struct rds_connection *conn,
&conn->c_faddr);
return;
}
- byte_len -= sizeof(struct rds_header);
+ data_len -= sizeof(struct rds_header);
- ihdr = &ic->i_recv_hdrs[recv - ic->i_recvs];
+ ihdr = rds_ib_get_header(conn, recv, data_len);
/* Validate the checksum. */
if (!rds_message_verify_checksum(ihdr)) {
@@ -687,7 +728,7 @@ static void rds_ib_process_recv(struct rds_connection *conn,
if (ihdr->h_credit)
rds_ib_send_add_credits(conn, ihdr->h_credit);
- if (ihdr->h_sport == 0 && ihdr->h_dport == 0 && byte_len == 0) {
+ if (ihdr->h_sport == 0 && ihdr->h_dport == 0 && data_len == 0) {
/* This is an ACK-only packet. The fact that it gets
* special treatment here is that historically, ACKs
* were rather special beasts.