On Thu, 2018-01-18 at 15:39 -0700, Jens Axboe wrote:
> When you do have a solid test case, please please submit a blktests
> test case for it! This needs to be something we can regularly in
> testing.
Hello Jens,
That sounds like a good idea to me. BTW, I think the reason why so far I
can reproduce these queue stalls easier than others is because I modified the
SRP initiator to make it easy to cause the .get_budget() call to succeed and
the scsi_queue_rq() to return BLK_STS_BUSY. A possible next step is to apply
a similar change to the scsi_debug driver. The change I made is as follows:
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
b/drivers/infiniband/ulp/srp/ib_srp.c
index 0c887ebfbc64..7f3c4a197425 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -3135,6 +3135,16 @@ static int srp_reset_host(struct scsi_cmnd *scmnd)
return srp_reconnect_rport(target->rport) == 0 ? SUCCESS : FAILED;
}
+static int srp_target_alloc(struct scsi_target *starget)
+{
+ struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
+ struct srp_target_port *target = host_to_target(shost);
+
+ if (target->target_can_queue)
+ starget->can_queue = target->target_can_queue;
+ return 0;
+}
+
static int srp_slave_alloc(struct scsi_device *sdev)
{
struct Scsi_Host *shost = sdev->host;
@@ -3348,6 +3358,7 @@ static struct scsi_host_template srp_template = {
.module = THIS_MODULE,
.name = "InfiniBand SRP initiator",
.proc_name = DRV_NAME,
+ .target_alloc = srp_target_alloc,
.slave_alloc = srp_slave_alloc,
.slave_configure = srp_slave_configure,
.info = srp_target_info,
@@ -3515,6 +3526,7 @@ enum {
SRP_OPT_QUEUE_SIZE = 1 << 14,
SRP_OPT_IP_SRC = 1 << 15,
SRP_OPT_IP_DEST = 1 << 16,
+ SRP_OPT_TARGET_CAN_QUEUE= 1 << 17,
};
static unsigned int srp_opt_mandatory[] = {
@@ -3536,6 +3548,7 @@ static const match_table_t srp_opt_tokens = {
{ SRP_OPT_SERVICE_ID, "service_id=%s" },
{ SRP_OPT_MAX_SECT, "max_sect=%d" },
{ SRP_OPT_MAX_CMD_PER_LUN, "max_cmd_per_lun=%d" },
+ { SRP_OPT_TARGET_CAN_QUEUE, "target_can_queue=%d" },
{ SRP_OPT_IO_CLASS, "io_class=%x" },
{ SRP_OPT_INITIATOR_EXT, "initiator_ext=%s" },
{ SRP_OPT_CMD_SG_ENTRIES, "cmd_sg_entries=%u" },
@@ -3724,6 +3737,15 @@ static int srp_parse_options(struct net *net, const char
*buf,
target->scsi_host->cmd_per_lun = token;
break;
+ case SRP_OPT_TARGET_CAN_QUEUE:
+ if (match_int(args, &token) || token < 1) {
+ pr_warn("bad max target_can_queue parameter
'%s'\n",
+ p);
+ goto out;
+ }
+ target->target_can_queue = token;
+ break;
+
case SRP_OPT_IO_CLASS:
if (match_hex(args, &token)) {
pr_warn("bad IO class parameter '%s'\n", p);
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h
b/drivers/infiniband/ulp/srp/ib_srp.h
index d66c9057d5ea..70334fa3de8e 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -216,6 +216,7 @@ struct srp_target_port {
char target_name[32];
unsigned int scsi_id;
unsigned int sg_tablesize;
+ unsigned int target_can_queue;
int mr_pool_size;
int mr_per_cmd;
int queue_size;
Bart.
