IB/srp: Use SRP transport layer error recovery
Enable fast_io_fail_tmo and dev_loss_tmo functionality for the IB SRP
initiator. Add kernel module parameters that allow to specify default
values for these parameters.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Dillow <dillowda@ornl.gov>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 6edab78..15b4d2c 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -86,6 +86,27 @@
MODULE_PARM_DESC(topspin_workarounds,
"Enable workarounds for Topspin/Cisco SRP target bugs if != 0");
+static struct kernel_param_ops srp_tmo_ops;
+
+static int srp_fast_io_fail_tmo = 15;
+module_param_cb(fast_io_fail_tmo, &srp_tmo_ops, &srp_fast_io_fail_tmo,
+ S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(fast_io_fail_tmo,
+ "Number of seconds between the observation of a transport"
+ " layer error and failing all I/O. \"off\" means that this"
+ " functionality is disabled.");
+
+static int srp_dev_loss_tmo = 60;
+module_param_cb(dev_loss_tmo, &srp_tmo_ops, &srp_dev_loss_tmo,
+ S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(dev_loss_tmo,
+ "Maximum number of seconds that the SRP transport should"
+ " insulate transport layer errors. After this time has been"
+ " exceeded the SCSI host is removed. Should be"
+ " between 1 and " __stringify(SCSI_DEVICE_BLOCK_MAX_TIMEOUT)
+ " if fast_io_fail_tmo has not been set. \"off\" means that"
+ " this functionality is disabled.");
+
static void srp_add_one(struct ib_device *device);
static void srp_remove_one(struct ib_device *device);
static void srp_recv_completion(struct ib_cq *cq, void *target_ptr);
@@ -102,6 +123,44 @@
static struct ib_sa_client srp_sa_client;
+static int srp_tmo_get(char *buffer, const struct kernel_param *kp)
+{
+ int tmo = *(int *)kp->arg;
+
+ if (tmo >= 0)
+ return sprintf(buffer, "%d", tmo);
+ else
+ return sprintf(buffer, "off");
+}
+
+static int srp_tmo_set(const char *val, const struct kernel_param *kp)
+{
+ int tmo, res;
+
+ if (strncmp(val, "off", 3) != 0) {
+ res = kstrtoint(val, 0, &tmo);
+ if (res)
+ goto out;
+ } else {
+ tmo = -1;
+ }
+ if (kp->arg == &srp_fast_io_fail_tmo)
+ res = srp_tmo_valid(tmo, srp_dev_loss_tmo);
+ else
+ res = srp_tmo_valid(srp_fast_io_fail_tmo, tmo);
+ if (res)
+ goto out;
+ *(int *)kp->arg = tmo;
+
+out:
+ return res;
+}
+
+static struct kernel_param_ops srp_tmo_ops = {
+ .get = srp_tmo_get,
+ .set = srp_tmo_set,
+};
+
static inline struct srp_target_port *host_to_target(struct Scsi_Host *host)
{
return (struct srp_target_port *) host->hostdata;
@@ -688,23 +747,42 @@
spin_unlock_irqrestore(&target->lock, flags);
}
-static void srp_reset_req(struct srp_target_port *target, struct srp_request *req)
+static void srp_finish_req(struct srp_target_port *target,
+ struct srp_request *req, int result)
{
struct scsi_cmnd *scmnd = srp_claim_req(target, req, NULL);
if (scmnd) {
srp_free_req(target, req, scmnd, 0);
- scmnd->result = DID_RESET << 16;
+ scmnd->result = result;
scmnd->scsi_done(scmnd);
}
}
-static int srp_reconnect_target(struct srp_target_port *target)
+static void srp_terminate_io(struct srp_rport *rport)
{
- struct Scsi_Host *shost = target->scsi_host;
- int i, ret;
+ struct srp_target_port *target = rport->lld_data;
+ int i;
- scsi_target_block(&shost->shost_gendev);
+ for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
+ struct srp_request *req = &target->req_ring[i];
+ srp_finish_req(target, req, DID_TRANSPORT_FAILFAST << 16);
+ }
+}
+
+/*
+ * It is up to the caller to ensure that srp_rport_reconnect() calls are
+ * serialized and that no concurrent srp_queuecommand(), srp_abort(),
+ * srp_reset_device() or srp_reset_host() calls will occur while this function
+ * is in progress. One way to realize that is not to call this function
+ * directly but to call srp_reconnect_rport() instead since that last function
+ * serializes calls of this function via rport->mutex and also blocks
+ * srp_queuecommand() calls before invoking this function.
+ */
+static int srp_rport_reconnect(struct srp_rport *rport)
+{
+ struct srp_target_port *target = rport->lld_data;
+ int i, ret;
srp_disconnect_target(target);
/*
@@ -725,8 +803,7 @@
for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
struct srp_request *req = &target->req_ring[i];
- if (req->scmnd)
- srp_reset_req(target, req);
+ srp_finish_req(target, req, DID_RESET << 16);
}
INIT_LIST_HEAD(&target->free_tx);
@@ -736,28 +813,9 @@
if (ret == 0)
ret = srp_connect_target(target);
- scsi_target_unblock(&shost->shost_gendev, ret == 0 ? SDEV_RUNNING :
- SDEV_TRANSPORT_OFFLINE);
- target->transport_offline = !!ret;
-
- if (ret)
- goto err;
-
- shost_printk(KERN_INFO, target->scsi_host, PFX "reconnect succeeded\n");
-
- return ret;
-
-err:
- shost_printk(KERN_ERR, target->scsi_host,
- PFX "reconnect failed (%d), removing target port.\n", ret);
-
- /*
- * We couldn't reconnect, so kill our target port off.
- * However, we have to defer the real removal because we
- * are in the context of the SCSI error handler now, which
- * will deadlock if we call scsi_remove_host().
- */
- srp_queue_remove_work(target);
+ if (ret == 0)
+ shost_printk(KERN_INFO, target->scsi_host,
+ PFX "reconnect succeeded\n");
return ret;
}
@@ -1356,10 +1414,11 @@
struct srp_cmd *cmd;
struct ib_device *dev;
unsigned long flags;
- int len;
+ int len, result;
- if (unlikely(target->transport_offline)) {
- scmnd->result = DID_NO_CONNECT << 16;
+ result = srp_chkready(target->rport);
+ if (unlikely(result)) {
+ scmnd->result = result;
scmnd->scsi_done(scmnd);
return 0;
}
@@ -1757,7 +1816,7 @@
if (srp_send_tsk_mgmt(target, req->index, scmnd->device->lun,
SRP_TSK_ABORT_TASK) == 0)
ret = SUCCESS;
- else if (target->transport_offline)
+ else if (target->rport->state == SRP_RPORT_LOST)
ret = FAST_IO_FAIL;
else
ret = FAILED;
@@ -1784,7 +1843,7 @@
for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) {
struct srp_request *req = &target->req_ring[i];
if (req->scmnd && req->scmnd->device == scmnd->device)
- srp_reset_req(target, req);
+ srp_finish_req(target, req, DID_RESET << 16);
}
return SUCCESS;
@@ -1793,14 +1852,10 @@
static int srp_reset_host(struct scsi_cmnd *scmnd)
{
struct srp_target_port *target = host_to_target(scmnd->device->host);
- int ret = FAILED;
shost_printk(KERN_ERR, target->scsi_host, PFX "SRP reset_host called\n");
- if (!srp_reconnect_target(target))
- ret = SUCCESS;
-
- return ret;
+ return srp_reconnect_rport(target->rport) == 0 ? SUCCESS : FAILED;
}
static int srp_slave_configure(struct scsi_device *sdev)
@@ -2637,7 +2692,13 @@
}
static struct srp_function_template ib_srp_transport_functions = {
+ .has_rport_state = true,
+ .reset_timer_if_blocked = true,
+ .fast_io_fail_tmo = &srp_fast_io_fail_tmo,
+ .dev_loss_tmo = &srp_dev_loss_tmo,
+ .reconnect = srp_rport_reconnect,
.rport_delete = srp_rport_delete,
+ .terminate_rport_io = srp_terminate_io,
};
static int __init srp_init_module(void)