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.