From 56851698c23430f0f291d6e50da344e6b414f3b9 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Fri, 13 Jan 2006 18:05:44 -0600 Subject: [PATCH] [SCSI] iscsi: data digest page cache usage fix Users can write to a page while we are sending it and making digest calculations. This ends up causing us to retry the command when a digest error is later reported. By using sock_no_sendpage when data digests are calculated we can avoid a lot of (not all but it helps) the retries becuase sock_no_sendpage is not zero copy. Signed-off-by: Alex Aizman Signed-off-by: Dmitry Yusupov Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- drivers/scsi/iscsi_tcp.c | 16 +++++++++------- drivers/scsi/iscsi_tcp.h | 2 ++ 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index cd1491e52361..5e8b3135574c 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -1318,15 +1318,15 @@ iscsi_conn_restore_callbacks(struct iscsi_conn *conn) * to use tcp_sendmsg(). */ static inline int -iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags) +iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags) { + struct socket *sk = conn->sock; int res; if ((int)buf->sg.offset >= 0) { int offset = buf->sg.offset + buf->sent; - /* tcp_sendpage */ - res = sk->ops->sendpage(sk, buf->sg.page, offset, size, flags); + res = conn->sendpage(sk, buf->sg.page, offset, size, flags); } else { struct msghdr msg; @@ -1354,7 +1354,6 @@ iscsi_send(struct socket *sk, struct iscsi_buf *buf, int size, int flags) static inline int iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen) { - struct socket *sk = conn->sock; int flags = 0; /* MSG_DONTWAIT; */ int res, size; @@ -1363,7 +1362,7 @@ iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen) if (buf->sent + size != buf->sg.length || datalen) flags |= MSG_MORE; - res = iscsi_send(sk, buf, size, flags); + res = iscsi_send(conn, buf, size, flags); debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res); if (res >= 0) { conn->txdata_octets += res; @@ -1394,7 +1393,6 @@ static inline int iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf, int *count, int *sent) { - struct socket *sk = conn->sock; int flags = 0; /* MSG_DONTWAIT; */ int res, size; @@ -1405,7 +1403,7 @@ iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf, if (buf->sent + size != buf->sg.length || *count != size) flags |= MSG_MORE; - res = iscsi_send(sk, buf, size, flags); + res = iscsi_send(conn, buf, size, flags); debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n", size, buf->sent, *count, *sent, res); if (res >= 0) { @@ -2713,6 +2711,8 @@ iscsi_conn_bind(iscsi_sessionh_t sessionh, iscsi_connh_t connh, */ iscsi_conn_set_callbacks(conn); + conn->sendpage = conn->sock->ops->sendpage; + /* * set receive state machine into initial state */ @@ -3467,6 +3467,8 @@ iscsi_conn_set_param(iscsi_connh_t connh, enum iscsi_param param, if (conn->data_rx_tfm) crypto_free_tfm(conn->data_rx_tfm); } + conn->sendpage = conn->datadgst_en ? + sock_no_sendpage : conn->sock->ops->sendpage; break; case ISCSI_PARAM_INITIAL_R2T_EN: session->initial_r2t_en = value; diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h index 9badafe8820d..c8bb5b0bcb4b 100644 --- a/drivers/scsi/iscsi_tcp.h +++ b/drivers/scsi/iscsi_tcp.h @@ -191,6 +191,8 @@ struct iscsi_conn { uint32_t sendpage_failures_cnt; uint32_t discontiguous_hdr_cnt; uint32_t eh_abort_cnt; + + ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int); }; struct iscsi_session { -- 2.30.2