[PATCH v2 5/5] nvme-fc: wait for initial connect attempt to finish
Daniel Wagner
dwagner at suse.de
Wed Feb 21 05:24:04 PST 2024
The TCP and RDMA transport are doing a synchronous connects, that is the
syscal returns with the final result. The operation either fails or
succeeds. The FC transport offloads the connect attempt to a workqueue
and thus it's an asynchronous operation.
This async connect feature was introduced to mitigate problems with
transient connect errors and the task to coordinate retries with
userspace (nvme-cli).
Unfortunately, this makes the transports behave differently on the
initial attempt. Streamline nvme-fc to wait for the initial connection
attempt to succeed or fail.
In order to support also the async connection attempt introduce a new
flag for userspace. The default is a synchronous initial connect
attempt.
Link: https://lore.kernel.org/linux-nvme/0605ac36-16d5-2026-d3c6-62d346db6dfb@gmail.com/
Signed-off-by: Daniel Wagner <dwagner at suse.de>
---
drivers/nvme/host/fabrics.c | 17 ++++++++++++++++-
drivers/nvme/host/fabrics.h | 3 +++
drivers/nvme/host/fc.c | 26 +++++++++++++++++++++++++-
3 files changed, 44 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 888285fe2289..52c95259debd 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -678,6 +678,7 @@ static const match_table_t opt_tokens = {
#ifdef CONFIG_NVME_TCP_TLS
{ NVMF_OPT_TLS, "tls" },
#endif
+ { NVMF_OPT_CONNECT_ASYNC, "connect_async=%d" },
{ NVMF_OPT_ERR, NULL }
};
@@ -706,6 +707,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
opts->tls = false;
opts->tls_key = NULL;
opts->keyring = NULL;
+ opts->connect_async = false;
options = o = kstrdup(buf, GFP_KERNEL);
if (!options)
@@ -1024,6 +1026,19 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
}
opts->tls = true;
break;
+ case NVMF_OPT_CONNECT_ASYNC:
+ if (match_int(args, &token)) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (token < 0 || token > 1) {
+ pr_err("Invalid connect_async %d value\n",
+ token);
+ ret = -EINVAL;
+ goto out;
+ }
+ opts->connect_async = token;
+ break;
default:
pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
p);
@@ -1259,7 +1274,7 @@ EXPORT_SYMBOL_GPL(nvmf_ctrl_options_put);
NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
NVMF_OPT_DISABLE_SQFLOW | NVMF_OPT_DISCOVERY |\
NVMF_OPT_FAIL_FAST_TMO | NVMF_OPT_DHCHAP_SECRET |\
- NVMF_OPT_DHCHAP_CTRL_SECRET)
+ NVMF_OPT_DHCHAP_CTRL_SECRET | NVMF_OPT_CONNECT_ASYNC)
static struct nvme_ctrl *
nvmf_create_ctrl(struct device *dev, const char *buf)
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index 8436533aed16..75bc61401e1b 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -73,6 +73,7 @@ enum {
NVMF_OPT_TLS = 1 << 25,
NVMF_OPT_KEYRING = 1 << 26,
NVMF_OPT_TLS_KEY = 1 << 27,
+ NVMF_OPT_CONNECT_ASYNC = 1 << 28,
};
/**
@@ -116,6 +117,7 @@ enum {
* @nr_poll_queues: number of queues for polling I/O
* @tos: type of service
* @fast_io_fail_tmo: Fast I/O fail timeout in seconds
+ * @connect_async: Don't wait for the intial connect attempt to succeed or fail
*/
struct nvmf_ctrl_options {
struct kref ref;
@@ -146,6 +148,7 @@ struct nvmf_ctrl_options {
unsigned int nr_poll_queues;
int tos;
int fast_io_fail_tmo;
+ bool connect_async;
};
int nvmf_ctrl_options_get(struct nvmf_ctrl_options *opts);
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index 7627d10a5812..ebc4ff6b3343 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -169,6 +169,7 @@ struct nvme_fc_ctrl {
struct work_struct ioerr_work;
struct delayed_work connect_work;
+ struct completion connect_completion;
struct kref ref;
unsigned long flags;
@@ -803,6 +804,7 @@ nvme_fc_ctrl_connectivity_loss(struct nvme_fc_ctrl *ctrl)
dev_warn(ctrl->ctrl.device,
"NVME-FC{%d}: Couldn't schedule reset.\n",
ctrl->cnum);
+ complete(&ctrl->connect_completion);
nvme_fc_ctrl_put(ctrl);
}
break;
@@ -871,6 +873,7 @@ nvme_fc_unregister_remoteport(struct nvme_fc_remote_port *portptr)
dev_warn(ctrl->ctrl.device,
"NVME-FC{%d}: controller connectivity lost.\n",
ctrl->cnum);
+ complete(&ctrl->connect_completion);
nvme_fc_ctrl_put(ctrl);
} else
nvme_fc_ctrl_connectivity_loss(ctrl);
@@ -3326,6 +3329,7 @@ nvme_fc_reconnect_or_delete(struct nvme_fc_ctrl *ctrl, int status)
ctrl->cnum, min_t(int, portptr->dev_loss_tmo,
(ctrl->ctrl.opts->max_reconnects *
ctrl->ctrl.opts->reconnect_delay)));
+ complete(&ctrl->connect_completion);
nvme_fc_ctrl_put(ctrl);
}
}
@@ -3385,10 +3389,12 @@ nvme_fc_connect_ctrl_work(struct work_struct *work)
ret = nvme_fc_create_association(ctrl);
if (ret)
nvme_fc_reconnect_or_delete(ctrl, ret);
- else
+ else {
dev_info(ctrl->ctrl.device,
"NVME-FC{%d}: controller connect complete\n",
ctrl->cnum);
+ complete(&ctrl->connect_completion);
+ }
}
@@ -3494,6 +3500,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
INIT_WORK(&ctrl->ctrl.reset_work, nvme_fc_reset_ctrl_work);
INIT_DELAYED_WORK(&ctrl->connect_work, nvme_fc_connect_ctrl_work);
+ init_completion(&ctrl->connect_completion);
INIT_WORK(&ctrl->ioerr_work, nvme_fc_ctrl_ioerr_work);
spin_lock_init(&ctrl->lock);
@@ -3541,6 +3548,9 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
list_add_tail(&ctrl->ctrl_list, &rport->ctrl_list);
spin_unlock_irqrestore(&rport->lock, flags);
+ if (!opts->connect_async)
+ nvme_fc_ctrl_get(ctrl);
+
if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING) ||
!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_CONNECTING)) {
dev_err(ctrl->ctrl.device,
@@ -3557,6 +3567,19 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts,
flush_delayed_work(&ctrl->connect_work);
+ if (!opts->connect_async) {
+ enum nvme_ctrl_state state;
+
+ wait_for_completion(&ctrl->connect_completion);
+ state = nvme_ctrl_state(&ctrl->ctrl);
+ nvme_fc_ctrl_put(ctrl);
+
+ if (state != NVME_CTRL_LIVE) {
+ /* Cleanup is handled by the connect state machine */
+ return ERR_PTR(-EIO);
+ }
+ }
+
dev_info(ctrl->ctrl.device,
"NVME-FC{%d}: new ctrl: NQN \"%s\", hostnqn: %s\n",
ctrl->cnum, nvmf_ctrl_subsysnqn(&ctrl->ctrl), opts->host->nqn);
@@ -3913,6 +3936,7 @@ nvme_fc_delete_controllers(struct nvme_fc_rport *rport)
dev_warn(ctrl->ctrl.device,
"NVME-FC{%d}: transport unloading: deleting ctrl\n",
ctrl->cnum);
+ complete(&ctrl->connect_completion);
nvme_fc_ctrl_put(ctrl);
}
spin_unlock(&rport->lock);
--
2.43.1
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