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authorSagi Grimberg <sagi@grimberg.me>2017-03-18 20:52:36 +0200
committerJens Axboe <axboe@fb.com>2017-04-04 09:48:23 -0600
commit42a45274c225829637b585e1c994a68f59507108 (patch)
treedf6fd42ca4b5d340776dfe6244faf6c1477487dd
parent7777bdedf31d674c4fd5ebbfbd27a6a6ae0a17e0 (diff)
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>
-rw-r--r--drivers/nvme/host/fabrics.c28
-rw-r--r--drivers/nvme/host/fabrics.h10
2 files changed, 38 insertions, 0 deletions
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;
diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
index 156018182ce4..f5a9c1fb186f 100644
--- a/drivers/nvme/host/fabrics.h
+++ b/drivers/nvme/host/fabrics.h
@@ -21,6 +21,8 @@
#define NVMF_MAX_QUEUE_SIZE 1024
#define NVMF_DEF_QUEUE_SIZE 128
#define NVMF_DEF_RECONNECT_DELAY 10
+/* default to 600 seconds of reconnect attempts before giving up */
+#define NVMF_DEF_CTRL_LOSS_TMO 600
/*
* Define a host as seen by the target. We allocate one at boot, but also
@@ -53,6 +55,7 @@ enum {
NVMF_OPT_HOSTNQN = 1 << 8,
NVMF_OPT_RECONNECT_DELAY = 1 << 9,
NVMF_OPT_HOST_TRADDR = 1 << 10,
+ NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
};
/**
@@ -77,6 +80,10 @@ enum {
* @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
* @kato: Keep-alive timeout.
* @host: Virtual NVMe host, contains the NQN and Host ID.
+ * @nr_reconnects: number of reconnect attempted since the last ctrl failure
+ * @max_reconnects: maximum number of allowed reconnect attempts before removing
+ * the controller, (-1) means reconnect forever, zero means remove
+ * immediately;
*/
struct nvmf_ctrl_options {
unsigned mask;
@@ -91,6 +98,8 @@ struct nvmf_ctrl_options {
bool discovery_nqn;
unsigned int kato;
struct nvmf_host *host;
+ int nr_reconnects;
+ int max_reconnects;
};
/*
@@ -133,5 +142,6 @@ void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
void nvmf_free_options(struct nvmf_ctrl_options *opts);
const char *nvmf_get_subsysnqn(struct nvme_ctrl *ctrl);
int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
+bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
#endif /* _NVME_FABRICS_H */