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/*
* NVMe over Fabrics common host code.
* Copyright (c) 2015-2016 HGST, a Western Digital Company.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#ifndef _NVME_FABRICS_H
#define _NVME_FABRICS_H 1
#include <linux/in.h>
#include <linux/inet.h>
#define NVMF_MIN_QUEUE_SIZE 16
#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
* allow the override it when creating controllers. This is both to provide
* persistence of the Host NQN over multiple boots, and to allow using
* multiple ones, for example in a container scenario. Because we must not
* use different Host NQNs with the same Host ID we generate a Host ID and
* use this structure to keep track of the relation between the two.
*/
struct nvmf_host {
struct kref ref;
struct list_head list;
char nqn[NVMF_NQN_SIZE];
uuid_t id;
};
/**
* enum nvmf_parsing_opts - used to define the sysfs parsing options used.
*/
enum {
NVMF_OPT_ERR = 0,
NVMF_OPT_TRANSPORT = 1 << 0,
NVMF_OPT_NQN = 1 << 1,
NVMF_OPT_TRADDR = 1 << 2,
NVMF_OPT_TRSVCID = 1 << 3,
NVMF_OPT_QUEUE_SIZE = 1 << 4,
NVMF_OPT_NR_IO_QUEUES = 1 << 5,
NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
NVMF_OPT_KATO = 1 << 7,
NVMF_OPT_HOSTNQN = 1 << 8,
NVMF_OPT_RECONNECT_DELAY = 1 << 9,
NVMF_OPT_HOST_TRADDR = 1 << 10,
NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
NVMF_OPT_HOST_ID = 1 << 12,
NVMF_OPT_DUP_CONNECT = 1 << 13,
};
/**
* struct nvmf_ctrl_options - Used to hold the options specified
* with the parsing opts enum.
* @mask: Used by the fabrics library to parse through sysfs options
* on adding a NVMe controller.
* @transport: Holds the fabric transport "technology name" (for a lack of
* better description) that will be used by an NVMe controller
* being added.
* @subsysnqn: Hold the fully qualified NQN subystem name (format defined
* in the NVMe specification, "NVMe Qualified Names").
* @traddr: The transport-specific TRADDR field for a port on the
* subsystem which is adding a controller.
* @trsvcid: The transport-specific TRSVCID field for a port on the
* subsystem which is adding a controller.
* @host_traddr: A transport-specific field identifying the NVME host port
* to use for the connection to the controller.
* @queue_size: Number of IO queue elements.
* @nr_io_queues: Number of controller IO queues that will be established.
* @reconnect_delay: Time between two consecutive reconnect attempts.
* @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.
* @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;
char *transport;
char *subsysnqn;
char *traddr;
char *trsvcid;
char *host_traddr;
size_t queue_size;
unsigned int nr_io_queues;
unsigned int reconnect_delay;
bool discovery_nqn;
bool duplicate_connect;
unsigned int kato;
struct nvmf_host *host;
int max_reconnects;
};
/*
* struct nvmf_transport_ops - used to register a specific
* fabric implementation of NVMe fabrics.
* @entry: Used by the fabrics library to add the new
* registration entry to its linked-list internal tree.
* @name: Name of the NVMe fabric driver implementation.
* @required_opts: sysfs command-line options that must be specified
* when adding a new NVMe controller.
* @allowed_opts: sysfs command-line options that can be specified
* when adding a new NVMe controller.
* @create_ctrl(): function pointer that points to a non-NVMe
* implementation-specific fabric technology
* that would go into starting up that fabric
* for the purpose of conneciton to an NVMe controller
* using that fabric technology.
*
* Notes:
* 1. At minimum, 'required_opts' and 'allowed_opts' should
* be set to the same enum parsing options defined earlier.
* 2. create_ctrl() must be defined (even if it does nothing)
*/
struct nvmf_transport_ops {
struct list_head entry;
const char *name;
int required_opts;
int allowed_opts;
struct nvme_ctrl *(*create_ctrl)(struct device *dev,
struct nvmf_ctrl_options *opts);
};
static inline bool
nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
struct nvmf_ctrl_options *opts)
{
if (strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
return false;
return true;
}
int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
int nvmf_register_transport(struct nvmf_transport_ops *ops);
void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
void nvmf_free_options(struct nvmf_ctrl_options *opts);
int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
static inline blk_status_t nvmf_check_init_req(struct nvme_ctrl *ctrl,
struct request *rq)
{
struct nvme_command *cmd = nvme_req(rq)->cmd;
/*
* We cannot accept any other command until the connect command has
* completed, so only allow connect to pass.
*/
if (!blk_rq_is_passthrough(rq) ||
cmd->common.opcode != nvme_fabrics_command ||
cmd->fabrics.fctype != nvme_fabrics_type_connect) {
/*
* Reconnecting state means transport disruption, which can take
* a long time and even might fail permanently, fail fast to
* give upper layers a chance to failover.
* Deleting state means that the ctrl will never accept commands
* again, fail it permanently.
*/
if (ctrl->state == NVME_CTRL_RECONNECTING ||
ctrl->state == NVME_CTRL_DELETING) {
nvme_req(rq)->status = NVME_SC_ABORT_REQ;
return BLK_STS_IOERR;
}
return BLK_STS_RESOURCE; /* try again later */
}
return BLK_STS_OK;
}
#endif /* _NVME_FABRICS_H */
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