iscsi/iser-target: Support multi-sequence sendtargets text response
In case sendtargets response is larger than initiator MRDSL, we
send a partial sendtargets response (setting F=0, C=1, TTT!=0xffffffff),
accept a consecutive empty text message and send the rest of the payload.
In case we are done, we set F=1, C=0, TTT=0xffffffff.
We do that by storing the sendtargets response bytes done under
the session.
This patch also makes iscsit_find_cmd_from_itt public for isert.
(Re-add cmd->maxcmdsn_inc and clear in iscsit_build_text_rsp - nab)
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 75c29b6..f533a0d 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1994,6 +1994,7 @@
cmd->cmd_sn = be32_to_cpu(hdr->cmdsn);
cmd->exp_stat_sn = be32_to_cpu(hdr->exp_statsn);
cmd->data_direction = DMA_NONE;
+ cmd->text_in_ptr = NULL;
return 0;
}
@@ -2007,9 +2008,13 @@
int cmdsn_ret;
if (!text_in) {
- pr_err("Unable to locate text_in buffer for sendtargets"
- " discovery\n");
- goto reject;
+ cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
+ if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
+ pr_err("Unable to locate text_in buffer for sendtargets"
+ " discovery\n");
+ goto reject;
+ }
+ goto empty_sendtargets;
}
if (strncmp("SendTargets", text_in, 11) != 0) {
pr_err("Received Text Data that is not"
@@ -2036,6 +2041,7 @@
list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
spin_unlock_bh(&conn->cmd_lock);
+empty_sendtargets:
iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
@@ -3385,7 +3391,8 @@
static int
iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
- enum iscsit_transport_type network_transport)
+ enum iscsit_transport_type network_transport,
+ int skip_bytes, bool *completed)
{
char *payload = NULL;
struct iscsi_conn *conn = cmd->conn;
@@ -3476,9 +3483,16 @@
end_of_buf = 1;
goto eob;
}
- memcpy(payload + payload_len, buf, len);
- payload_len += len;
- target_name_printed = 1;
+
+ if (skip_bytes && len <= skip_bytes) {
+ skip_bytes -= len;
+ } else {
+ memcpy(payload + payload_len, buf, len);
+ payload_len += len;
+ target_name_printed = 1;
+ if (len > skip_bytes)
+ skip_bytes = 0;
+ }
}
len = sprintf(buf, "TargetAddress="
@@ -3494,15 +3508,24 @@
end_of_buf = 1;
goto eob;
}
- memcpy(payload + payload_len, buf, len);
- payload_len += len;
+
+ if (skip_bytes && len <= skip_bytes) {
+ skip_bytes -= len;
+ } else {
+ memcpy(payload + payload_len, buf, len);
+ payload_len += len;
+ if (len > skip_bytes)
+ skip_bytes = 0;
+ }
}
spin_unlock(&tpg->tpg_np_lock);
}
spin_unlock(&tiqn->tiqn_tpg_lock);
eob:
- if (end_of_buf)
+ if (end_of_buf) {
+ *completed = false;
break;
+ }
if (cmd->cmd_flags & IFC_SENDTARGETS_SINGLE)
break;
@@ -3520,13 +3543,23 @@
enum iscsit_transport_type network_transport)
{
int text_length, padding;
+ bool completed = true;
- text_length = iscsit_build_sendtargets_response(cmd, network_transport);
+ text_length = iscsit_build_sendtargets_response(cmd, network_transport,
+ cmd->read_data_done,
+ &completed);
if (text_length < 0)
return text_length;
+ if (completed) {
+ hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+ } else {
+ hdr->flags |= ISCSI_FLAG_TEXT_CONTINUE;
+ cmd->read_data_done += text_length;
+ if (cmd->targ_xfer_tag == 0xFFFFFFFF)
+ cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
+ }
hdr->opcode = ISCSI_OP_TEXT_RSP;
- hdr->flags |= ISCSI_FLAG_CMD_FINAL;
padding = ((-text_length) & 3);
hton24(hdr->dlength, text_length);
hdr->itt = cmd->init_task_tag;
@@ -3535,21 +3568,25 @@
hdr->statsn = cpu_to_be32(cmd->stat_sn);
iscsit_increment_maxcmdsn(cmd, conn->sess);
+ /*
+ * Reset maxcmdsn_inc in multi-part text payload exchanges to
+ * correctly increment MaxCmdSN for each response answering a
+ * non immediate text request with a valid CmdSN.
+ */
+ cmd->maxcmdsn_inc = 0;
hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
hdr->max_cmdsn = cpu_to_be32(conn->sess->max_cmd_sn);
- pr_debug("Built Text Response: ITT: 0x%08x, StatSN: 0x%08x,"
- " Length: %u, CID: %hu\n", cmd->init_task_tag, cmd->stat_sn,
- text_length, conn->cid);
+ pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
+ " Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
+ cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
+ !!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
+ !!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
return text_length + padding;
}
EXPORT_SYMBOL(iscsit_build_text_rsp);
-/*
- * FIXME: Add support for F_BIT and C_BIT when the length is longer than
- * MaxRecvDataSegmentLength.
- */
static int iscsit_send_text_rsp(
struct iscsi_cmd *cmd,
struct iscsi_conn *conn)
@@ -4013,9 +4050,15 @@
ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
break;
case ISCSI_OP_TEXT:
- cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
- if (!cmd)
- goto reject;
+ if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
+ cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
+ if (!cmd)
+ goto reject;
+ } else {
+ cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
+ if (!cmd)
+ goto reject;
+ }
ret = iscsit_handle_text_cmd(conn, cmd, buf);
break;