[PATCH v2 nvme-cli 6/5] fabrics: pass in number of write queues

[Sagi Grimberg <sagi@grimberg.me>]

nr_write_queues specifies the number of additional queues that
will be connected. These queues will host write I/O (host to target
payload) while nr_io_queues will host read I/O (target to host payload).

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
---
 Documentation/nvme-connect.txt |  5 +++++
 fabrics.c                      | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Documentation/nvme-connect.txt b/Documentation/nvme-connect.txt
index af78b2a8238f..d4a0e6678475 100644
--- a/Documentation/nvme-connect.txt
+++ b/Documentation/nvme-connect.txt
@@ -16,6 +16,7 @@ SYNOPSIS
 		[--host-traddr=<traddr>   | -w <traddr>]
 		[--hostnqn=<hostnqn>      | -q <hostnqn>]
 		[--nr-io-queues=<#>       | -i <#>]
+		[--nr-write-queues=<#>    | -W <#>]
 		[--queue-size=<#>         | -Q <#>]
 		[--keep-alive-tmo=<#>     | -k <#>]
 		[--reconnect-delay=<#>    | -c <#>]
@@ -75,6 +76,10 @@ OPTIONS
 --nr-io-queues=<#>::
 	Overrides the default number of I/O queues create by the driver.
 
+-W <#>::
+--nr-write-queues=<#>::
+	Adds additional queues that will be used for write I/O.
+
 -Q <#>::
 --queue-size=<#>::
 	Overrides the default number of elements in the I/O queues created
diff --git a/fabrics.c b/fabrics.c
index 93f3410a1c72..bc6a0b7e4e21 100644
--- a/fabrics.c
+++ b/fabrics.c
@@ -53,6 +53,7 @@ static struct config {
 	char *hostnqn;
 	char *hostid;
 	int  nr_io_queues;
+	int  nr_write_queues;
 	int  queue_size;
 	int  keep_alive_tmo;
 	int  reconnect_delay;
@@ -621,6 +622,8 @@ static int build_options(char *argstr, int max_len)
 		    add_argument(&argstr, &max_len, "hostid", cfg.hostid)) ||
 	    add_int_argument(&argstr, &max_len, "nr_io_queues",
 				cfg.nr_io_queues) ||
+	    add_int_argument(&argstr, &max_len, "nr_write_queues",
+				cfg.nr_write_queues) ||
 	    add_int_argument(&argstr, &max_len, "queue_size", cfg.queue_size) ||
 	    add_int_argument(&argstr, &max_len, "keep_alive_tmo",
 				cfg.keep_alive_tmo) ||
@@ -694,6 +697,13 @@ retry:
 		p += len;
 	}
 
+	if (cfg.nr_write_queues) {
+		len = sprintf(p, ",nr_write_queues=%d", cfg.nr_write_queues);
+		if (len < 0)
+			return -EINVAL;
+		p += len;
+	}
+
 	if (cfg.host_traddr) {
 		len = sprintf(p, ",host_traddr=%s", cfg.host_traddr);
 		if (len < 0)
@@ -1009,6 +1019,7 @@ int connect(const char *desc, int argc, char **argv)
 		{"hostnqn",         'q', "LIST", CFG_STRING, &cfg.hostnqn,         required_argument, "user-defined hostnqn" },
 		{"hostid",          'I', "LIST", CFG_STRING, &cfg.hostid,      required_argument, "user-defined hostid (if default not used)"},
 		{"nr-io-queues",    'i', "LIST", CFG_INT, &cfg.nr_io_queues,    required_argument, "number of io queues to use (default is core count)" },
+		{"nr-write-queues",  'W', "LIST", CFG_INT, &cfg.nr_write_queues,    required_argument, "number of write queues to use (default 0)" },
 		{"queue-size",      'Q', "LIST", CFG_INT, &cfg.queue_size,      required_argument, "number of io queue elements to use (default 128)" },
 		{"keep-alive-tmo",  'k', "LIST", CFG_INT, &cfg.keep_alive_tmo,  required_argument, "keep alive timeout period in seconds" },
 		{"reconnect-delay", 'c', "LIST", CFG_INT, &cfg.reconnect_delay, required_argument, "reconnect timeout period in seconds" },
-- 
2.17.1