190 lines
6.7 KiB
C
190 lines
6.7 KiB
C
/*
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* NVMe over Fabrics common host code.
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* Copyright (c) 2015-2016 HGST, a Western Digital Company.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#ifndef _NVME_FABRICS_H
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#define _NVME_FABRICS_H 1
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#include <linux/in.h>
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#include <linux/inet.h>
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#define NVMF_MIN_QUEUE_SIZE 16
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#define NVMF_MAX_QUEUE_SIZE 1024
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#define NVMF_DEF_QUEUE_SIZE 128
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#define NVMF_DEF_RECONNECT_DELAY 10
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/* default to 600 seconds of reconnect attempts before giving up */
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#define NVMF_DEF_CTRL_LOSS_TMO 600
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/*
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* Define a host as seen by the target. We allocate one at boot, but also
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* allow the override it when creating controllers. This is both to provide
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* persistence of the Host NQN over multiple boots, and to allow using
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* multiple ones, for example in a container scenario. Because we must not
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* use different Host NQNs with the same Host ID we generate a Host ID and
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* use this structure to keep track of the relation between the two.
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*/
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struct nvmf_host {
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struct kref ref;
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struct list_head list;
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char nqn[NVMF_NQN_SIZE];
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uuid_t id;
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};
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/**
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* enum nvmf_parsing_opts - used to define the sysfs parsing options used.
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*/
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enum {
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NVMF_OPT_ERR = 0,
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NVMF_OPT_TRANSPORT = 1 << 0,
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NVMF_OPT_NQN = 1 << 1,
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NVMF_OPT_TRADDR = 1 << 2,
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NVMF_OPT_TRSVCID = 1 << 3,
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NVMF_OPT_QUEUE_SIZE = 1 << 4,
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NVMF_OPT_NR_IO_QUEUES = 1 << 5,
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NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
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NVMF_OPT_KATO = 1 << 7,
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NVMF_OPT_HOSTNQN = 1 << 8,
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NVMF_OPT_RECONNECT_DELAY = 1 << 9,
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NVMF_OPT_HOST_TRADDR = 1 << 10,
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NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
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NVMF_OPT_HOST_ID = 1 << 12,
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NVMF_OPT_DUP_CONNECT = 1 << 13,
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};
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/**
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* struct nvmf_ctrl_options - Used to hold the options specified
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* with the parsing opts enum.
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* @mask: Used by the fabrics library to parse through sysfs options
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* on adding a NVMe controller.
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* @transport: Holds the fabric transport "technology name" (for a lack of
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* better description) that will be used by an NVMe controller
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* being added.
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* @subsysnqn: Hold the fully qualified NQN subystem name (format defined
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* in the NVMe specification, "NVMe Qualified Names").
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* @traddr: The transport-specific TRADDR field for a port on the
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* subsystem which is adding a controller.
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* @trsvcid: The transport-specific TRSVCID field for a port on the
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* subsystem which is adding a controller.
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* @host_traddr: A transport-specific field identifying the NVME host port
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* to use for the connection to the controller.
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* @queue_size: Number of IO queue elements.
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* @nr_io_queues: Number of controller IO queues that will be established.
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* @reconnect_delay: Time between two consecutive reconnect attempts.
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* @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
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* @kato: Keep-alive timeout.
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* @host: Virtual NVMe host, contains the NQN and Host ID.
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* @max_reconnects: maximum number of allowed reconnect attempts before removing
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* the controller, (-1) means reconnect forever, zero means remove
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* immediately;
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*/
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struct nvmf_ctrl_options {
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unsigned mask;
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char *transport;
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char *subsysnqn;
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char *traddr;
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char *trsvcid;
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char *host_traddr;
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size_t queue_size;
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unsigned int nr_io_queues;
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unsigned int reconnect_delay;
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bool discovery_nqn;
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bool duplicate_connect;
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unsigned int kato;
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struct nvmf_host *host;
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int max_reconnects;
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};
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/*
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* struct nvmf_transport_ops - used to register a specific
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* fabric implementation of NVMe fabrics.
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* @entry: Used by the fabrics library to add the new
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* registration entry to its linked-list internal tree.
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* @name: Name of the NVMe fabric driver implementation.
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* @required_opts: sysfs command-line options that must be specified
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* when adding a new NVMe controller.
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* @allowed_opts: sysfs command-line options that can be specified
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* when adding a new NVMe controller.
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* @create_ctrl(): function pointer that points to a non-NVMe
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* implementation-specific fabric technology
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* that would go into starting up that fabric
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* for the purpose of conneciton to an NVMe controller
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* using that fabric technology.
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*
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* Notes:
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* 1. At minimum, 'required_opts' and 'allowed_opts' should
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* be set to the same enum parsing options defined earlier.
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* 2. create_ctrl() must be defined (even if it does nothing)
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*/
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struct nvmf_transport_ops {
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struct list_head entry;
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const char *name;
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int required_opts;
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int allowed_opts;
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struct nvme_ctrl *(*create_ctrl)(struct device *dev,
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struct nvmf_ctrl_options *opts);
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};
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static inline bool
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nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
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struct nvmf_ctrl_options *opts)
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{
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if (strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
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strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
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memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
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return false;
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return true;
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}
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int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
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int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
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int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
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int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
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int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
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int nvmf_register_transport(struct nvmf_transport_ops *ops);
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void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
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void nvmf_free_options(struct nvmf_ctrl_options *opts);
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int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
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bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
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static inline blk_status_t nvmf_check_init_req(struct nvme_ctrl *ctrl,
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struct request *rq)
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{
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struct nvme_command *cmd = nvme_req(rq)->cmd;
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/*
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* We cannot accept any other command until the connect command has
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* completed, so only allow connect to pass.
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*/
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if (!blk_rq_is_passthrough(rq) ||
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cmd->common.opcode != nvme_fabrics_command ||
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cmd->fabrics.fctype != nvme_fabrics_type_connect) {
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/*
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* Reconnecting state means transport disruption, which can take
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* a long time and even might fail permanently, fail fast to
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* give upper layers a chance to failover.
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* Deleting state means that the ctrl will never accept commands
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* again, fail it permanently.
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*/
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if (ctrl->state == NVME_CTRL_RECONNECTING ||
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ctrl->state == NVME_CTRL_DELETING) {
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nvme_req(rq)->status = NVME_SC_ABORT_REQ;
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return BLK_STS_IOERR;
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}
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return BLK_STS_RESOURCE; /* try again later */
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}
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return BLK_STS_OK;
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}
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#endif /* _NVME_FABRICS_H */
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