On Sat, 2014-02-08 at 18:15 +0100, Thomas Glanzmann wrote:

> The iSCSI target uses one function to send all outbound data. So in
> order to do it right every function that is sending data in multiple
> chunks need to mark it correctly. Of course someone could also do some
> wild guessing and saying that everything that is below 512 Bytes gets
> pushed out. I wonder what Nab has to say about this?

I was simply thinking about something like :
(might need further changes, but I guess this should solve your case)

diff --git a/drivers/target/iscsi/iscsi_target_util.c 
b/drivers/target/iscsi/iscsi_target_util.c
index 0819e688a398..44f0d62a88d6 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -1165,7 +1165,7 @@ send_data:
                iov_count = cmd->iov_misc_count;
        }
 
-       tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
+       tx_sent = tx_data(conn, &iov[0], iov_count, tx_size, 0);
        if (tx_size != tx_sent) {
                if (tx_sent == -EAGAIN) {
                        pr_err("tx_data() returned -EAGAIN\n");
@@ -1196,7 +1196,8 @@ send_hdr:
        iov.iov_base = cmd->pdu;
        iov.iov_len = tx_hdr_size;
 
-       tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
+       data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
+       tx_sent = tx_data(conn, &iov, 1, tx_hdr_size, data_len ? MSG_MORE : 0);
        if (tx_hdr_size != tx_sent) {
                if (tx_sent == -EAGAIN) {
                        pr_err("tx_data() returned -EAGAIN\n");
@@ -1205,7 +1206,6 @@ send_hdr:
                return -1;
        }
 
-       data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
        /*
         * Set iov_off used by padding and data digest tx_data() calls below
         * in order to determine proper offset into cmd->iov_data[]
@@ -1249,7 +1249,8 @@ send_padding:
        if (cmd->padding) {
                struct kvec *iov_p = &cmd->iov_data[iov_off++];
 
-               tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
+               tx_sent = tx_data(conn, iov_p, 1, cmd->padding,
+                                 conn->conn_ops->DataDigest ? MSG_MORE : 0);
                if (cmd->padding != tx_sent) {
                        if (tx_sent == -EAGAIN) {
                                pr_err("tx_data() returned -EAGAIN\n");
@@ -1263,7 +1264,7 @@ send_datacrc:
        if (conn->conn_ops->DataDigest) {
                struct kvec *iov_d = &cmd->iov_data[iov_off];
 
-               tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
+               tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN, 0);
                if (ISCSI_CRC_LEN != tx_sent) {
                        if (tx_sent == -EAGAIN) {
                                pr_err("tx_data() returned -EAGAIN\n");
@@ -1349,11 +1350,12 @@ static int iscsit_do_rx_data(
 
 static int iscsit_do_tx_data(
        struct iscsi_conn *conn,
-       struct iscsi_data_count *count)
+       struct iscsi_data_count *count,
+       int flags)
 {
        int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
        struct kvec *iov_p;
-       struct msghdr msg;
+       struct msghdr msg = { .msg_flags = flags };
 
        if (!conn || !conn->sock || !conn->conn_ops)
                return -1;
@@ -1363,8 +1365,6 @@ static int iscsit_do_tx_data(
                return -1;
        }
 
-       memset(&msg, 0, sizeof(struct msghdr));
-
        iov_p = count->iov;
        iov_len = count->iov_count;
 
@@ -1408,7 +1408,8 @@ int tx_data(
        struct iscsi_conn *conn,
        struct kvec *iov,
        int iov_count,
-       int data)
+       int data,
+       int flags)
 {
        struct iscsi_data_count c;
 
@@ -1421,7 +1422,7 @@ int tx_data(
        c.data_length = data;
        c.type = ISCSI_TX_DATA;
 
-       return iscsit_do_tx_data(conn, &c);
+       return iscsit_do_tx_data(conn, &c, flags);
 }
 
 void iscsit_collect_login_stats(
diff --git a/drivers/target/iscsi/iscsi_target_util.h 
b/drivers/target/iscsi/iscsi_target_util.h
index e4fc34a02f57..1b4f06801adc 100644
--- a/drivers/target/iscsi/iscsi_target_util.h
+++ b/drivers/target/iscsi/iscsi_target_util.h
@@ -54,7 +54,7 @@ extern int iscsit_print_dev_to_proc(char *, char **, off_t, 
int);
 extern int iscsit_print_sessions_to_proc(char *, char **, off_t, int);
 extern int iscsit_print_tpg_to_proc(char *, char **, off_t, int);
 extern int rx_data(struct iscsi_conn *, struct kvec *, int, int);
-extern int tx_data(struct iscsi_conn *, struct kvec *, int, int);
+extern int tx_data(struct iscsi_conn *, struct kvec *, int, int, int);
 extern void iscsit_collect_login_stats(struct iscsi_conn *, u8, u8);
 extern struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *);
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to