patch 02 - limit iSER requests so there are always RDMA mempools
available
Signed-off-by: Robin Humble <[EMAIL PROTECTED]>
--
diff -ruN ../tgt/usr/iscsi/iscsid.c ./usr/iscsi/iscsid.c
--- ../tgt/usr/iscsi/iscsid.c 2008-01-24 18:45:27.000000000 +1100
+++ ./usr/iscsi/iscsid.c 2008-01-24 18:43:34.000000000 +1100
@@ -893,6 +893,21 @@
}
}
+static int max_queue_cmds_available(struct iscsi_connection *conn)
+{
+ int max_queue_cmd;
+ int max_safe_cmds;
+
+ max_safe_cmds = conn->tp->queue_cmds_available(conn);
+ if (max_safe_cmds < 0) {
+ eprintf("iSER max_safe_cmds %d < 0\n", max_safe_cmds );
+ return 0;
+ }
+ max_queue_cmd = min( MAX_QUEUE_CMD, max_safe_cmds );
+
+ return max_queue_cmd;
+}
+
static int iscsi_cmd_rsp_build(struct iscsi_task *task)
{
struct iscsi_connection *conn = task->conn;
@@ -908,7 +923,8 @@
rsp->cmd_status = scsi_get_result(&task->scmd);
rsp->statsn = cpu_to_be32(conn->stat_sn++);
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
calc_residual(rsp, task);
@@ -935,7 +951,8 @@
rsp->cmd_status = SAM_STAT_CHECK_CONDITION;
rsp->statsn = cpu_to_be32(conn->stat_sn++);
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
calc_residual(rsp, task);
@@ -989,7 +1006,8 @@
datalen = conn->data_inout_max_length;
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
conn->rsp.datasize = datalen;
hton24(rsp->dlength, datalen);
@@ -1523,6 +1541,7 @@
conn->exp_stat_sn = be32_to_cpu(req->exp_statsn);
len = ntoh24(req->dlength);
+
task = iscsi_alloc_task(conn, 0, len);
if (task)
conn->rx_task = task;
@@ -1639,7 +1658,8 @@
rsp->itt = task->req.itt;
rsp->statsn = cpu_to_be32(conn->stat_sn++);
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
return 0;
}
@@ -1662,7 +1682,8 @@
rsp->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
rsp->statsn = cpu_to_be32(conn->stat_sn++);
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
/* TODO: honor max_burst */
conn->rsp.datasize = task->len;
@@ -1686,7 +1707,8 @@
rsp->statsn = cpu_to_be32(conn->stat_sn++);
rsp->exp_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn);
- rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn + MAX_QUEUE_CMD);
+ rsp->max_cmdsn = cpu_to_be32(conn->session->exp_cmd_sn +
+ max_queue_cmds_available(conn));
return 0;
}
diff -ruN ../tgt/usr/iscsi/iscsi_rdma.c ./usr/iscsi/iscsi_rdma.c
--- ../tgt/usr/iscsi/iscsi_rdma.c 2008-01-24 18:45:44.000000000 +1100
+++ ./usr/iscsi/iscsi_rdma.c 2008-01-24 18:43:34.000000000 +1100
@@ -1643,6 +1643,22 @@
}
}
+/*
+ * we know how many iSER connections we have, and also how many areas are
+ * allocated from our mempool, so we can trivially calculate how many
+ * more cmds we can handle without running out of rdma areas.
+ */
+static int iscsi_rdma_queue_cmds_available(struct iscsi_connection *conn)
+{
+ struct conn_info *ci = RDMA_CONN(conn);
+ struct iser_device *dev = ci->dev;
+ int cmds;
+
+ cmds = (mempool_num - dev->mempool_used)/iser_conn_cnt;
+
+ return cmds;
+}
+
static void *iscsi_rdma_alloc_data_buf(struct iscsi_connection *conn,
size_t sz)
{
@@ -1735,6 +1751,7 @@
.ep_show = iscsi_rdma_show,
.ep_event_modify = iscsi_rdma_event_modify,
.alloc_data_buf = iscsi_rdma_alloc_data_buf,
+ .queue_cmds_available = iscsi_rdma_queue_cmds_available,
.free_data_buf = iscsi_rdma_free_data_buf,
.ep_getsockname = iscsi_rdma_getsockname,
.ep_getpeername = iscsi_rdma_getpeername,
diff -ruN ../tgt/usr/iscsi/iscsi_tcp.c ./usr/iscsi/iscsi_tcp.c
--- ../tgt/usr/iscsi/iscsi_tcp.c 2008-01-24 18:45:27.000000000 +1100
+++ ./usr/iscsi/iscsi_tcp.c 2008-01-24 18:43:34.000000000 +1100
@@ -36,6 +36,8 @@
#include "tgtd.h"
#include "util.h"
+#define MAX_TCP_QUEUE_CMD 128
+
static void iscsi_tcp_event_handler(int fd, int events, void *data);
static struct iscsi_transport iscsi_tcp;
@@ -322,6 +324,10 @@
free(task);
}
+static int iscsi_tcp_queue_cmds_available(struct iscsi_connection *conn) {
+ return MAX_TCP_QUEUE_CMD;
+}
+
static void *iscsi_tcp_alloc_data_buf(struct iscsi_connection *conn, size_t sz)
{
return valloc(sz);
@@ -365,6 +371,7 @@
.ep_show = iscsi_tcp_show,
.ep_event_modify = iscsi_event_modify,
.alloc_data_buf = iscsi_tcp_alloc_data_buf,
+ .queue_cmds_available = iscsi_tcp_queue_cmds_available,
.free_data_buf = iscsi_tcp_free_data_buf,
.ep_getsockname = iscsi_tcp_getsockname,
.ep_getpeername = iscsi_tcp_getpeername,
diff -ruN ../tgt/usr/iscsi/transport.h ./usr/iscsi/transport.h
--- ../tgt/usr/iscsi/transport.h 2008-01-24 18:45:27.000000000 +1100
+++ ./usr/iscsi/transport.h 2008-01-24 18:43:34.000000000 +1100
@@ -32,6 +32,7 @@
int (*ep_show)(struct iscsi_connection *conn, char *buf, int rest);
void (*ep_event_modify)(struct iscsi_connection *conn, int events);
void *(*alloc_data_buf)(struct iscsi_connection *conn, size_t sz);
+ int (*queue_cmds_available)(struct iscsi_connection *conn);
void (*free_data_buf)(struct iscsi_connection *conn, void *buf);
int (*ep_getsockname)(struct iscsi_connection *conn,
struct sockaddr *sa, socklen_t *len);
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