From 42a45274c225829637b585e1c994a68f59507108 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Sat, 18 Mar 2017 20:52:36 +0200 Subject: 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 Signed-off-by: Sagi Grimberg Signed-off-by: Jens Axboe --- drivers/nvme/host/fabrics.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/nvme/host/fabrics.c') diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c index 5b7386f69f4d..990e6fb32a63 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; -- cgit v1.2.3