nvme-fabrics: Allow ctrl loss timeout configuration
When a host sense that its controller session is damaged,
it tries to re-establish it periodically (reconnect every
reconnect_delay). It may very well be that the controller
is gone and never coming back, in this case the host will
try to reconnect forever.
Add a ctrl_loss_tmo to bound the number of reconnect attempts
to a specific controller (default to a reasonable 10 minutes).
The timeout configuration is actually translated into number of
reconnect attempts and not a schedule on its own but rather
divided with reconnect_delay. This is useful to prevent
racing flows of remove and reconnect, and it doesn't really
matter if we remove slightly sooner than what the user requested.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 5b7386f..990e6fb 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -471,6 +471,16 @@ int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
}
EXPORT_SYMBOL_GPL(nvmf_connect_io_queue);
+bool nvmf_should_reconnect(struct nvme_ctrl *ctrl)
+{
+ if (ctrl->opts->max_reconnects != -1 &&
+ ctrl->opts->nr_reconnects < ctrl->opts->max_reconnects)
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(nvmf_should_reconnect);
+
/**
* nvmf_register_transport() - NVMe Fabrics Library registration function.
* @ops: Transport ops instance to be registered to the
@@ -533,6 +543,7 @@ static const match_table_t opt_tokens = {
{ NVMF_OPT_QUEUE_SIZE, "queue_size=%d" },
{ NVMF_OPT_NR_IO_QUEUES, "nr_io_queues=%d" },
{ NVMF_OPT_RECONNECT_DELAY, "reconnect_delay=%d" },
+ { NVMF_OPT_CTRL_LOSS_TMO, "ctrl_loss_tmo=%d" },
{ NVMF_OPT_KATO, "keep_alive_tmo=%d" },
{ NVMF_OPT_HOSTNQN, "hostnqn=%s" },
{ NVMF_OPT_HOST_TRADDR, "host_traddr=%s" },
@@ -546,6 +557,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
char *options, *o, *p;
int token, ret = 0;
size_t nqnlen = 0;
+ int ctrl_loss_tmo = NVMF_DEF_CTRL_LOSS_TMO;
/* Set defaults */
opts->queue_size = NVMF_DEF_QUEUE_SIZE;
@@ -655,6 +667,16 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
}
opts->kato = token;
break;
+ case NVMF_OPT_CTRL_LOSS_TMO:
+ if (match_int(args, &token)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (token < 0)
+ pr_warn("ctrl_loss_tmo < 0 will reconnect forever\n");
+ ctrl_loss_tmo = token;
+ break;
case NVMF_OPT_HOSTNQN:
if (opts->host) {
pr_err("hostnqn already user-assigned: %s\n",
@@ -710,6 +732,12 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
}
}
+ if (ctrl_loss_tmo < 0)
+ opts->max_reconnects = -1;
+ else
+ opts->max_reconnects = DIV_ROUND_UP(ctrl_loss_tmo,
+ opts->reconnect_delay);
+
if (!opts->host) {
kref_get(&nvmf_default_host->ref);
opts->host = nvmf_default_host;