forked from luck/tmp_suning_uos_patched
42a45274c2
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>
148 lines
5.5 KiB
C
148 lines
5.5 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_be 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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};
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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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* @nr_reconnects: number of reconnect attempted since the last ctrl failure
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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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unsigned int kato;
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struct nvmf_host *host;
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int nr_reconnects;
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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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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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const char *nvmf_get_subsysnqn(struct nvme_ctrl *ctrl);
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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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#endif /* _NVME_FABRICS_H */
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