/*
* Common code for the NVMe target.
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/pci-p2pdma.h>
#include "nvmet.h"
struct workqueue_struct *buffered_io_wq;
static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
static DEFINE_IDA(cntlid_ida);
/*
* This read/write semaphore is used to synchronize access to configuration
* information on a target system that will result in discovery log page
* information change for at least one host.
* The full list of resources to protected by this semaphore is:
*
* - subsystems list
* - per-subsystem allowed hosts list
* - allow_any_host subsystem attribute
* - nvmet_genctr
* - the nvmet_transports array
*
* When updating any of those lists/structures write lock should be obtained,
* while when reading (popolating discovery log page or checking host-subsystem
* link) read lock is obtained to allow concurrent reads.
*/
DECLARE_RWSEM(nvmet_config_sem);
u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
u64 nvmet_ana_chgcnt;
DECLARE_RWSEM(nvmet_ana_sem);
static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
const char *subsysnqn);
u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
size_t len)
{
if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len)
return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;
return 0;
}
u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len