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kernel/drivers/xen/xen-scsiback.c

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/*
* Xen SCSI backend driver
*
* Copyright (c) 2008, FUJITSU Limited
*
* Based on the blkback driver code.
* Adaption to kernel taget core infrastructure taken from vhost/scsi.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#define pr_fmt(fmt) "xen-pvscsi: " fmt
#include <linux/module.h>
#include <linux/utsname.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/configfs.h>
#include <generated/utsrelease.h>
#include <scsi/scsi_host.h> /* SG_ALL */
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <asm/hypervisor.h>
#include <xen/xen.h>
#include <xen/balloon.h>
#include <xen/events.h>
#include <xen/xenbus.h>
#include <xen/grant_table.h>
#include <xen/page.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/vscsiif.h>
#define VSCSI_VERSION "v0.1"
#define VSCSI_NAMELEN 32
struct ids_tuple {
unsigned int hst; /* host */
unsigned int chn; /* channel */
unsigned int tgt; /* target */
unsigned int lun; /* LUN */
};
struct v2p_entry {
struct ids_tuple v; /* translate from */
struct scsiback_tpg *tpg; /* translate to */
unsigned int lun;
struct kref kref;
struct list_head l;
};
struct vscsibk_info {
struct xenbus_device *dev;
domid_t domid;
unsigned int irq;
struct vscsiif_back_ring ring;
spinlock_t ring_lock;
atomic_t nr_unreplied_reqs;
spinlock_t v2p_lock;
struct list_head v2p_entry_lists;
wait_queue_head_t waiting_to_free;
struct gnttab_page_cache free_pages;
};
/* theoretical maximum of grants for one request */
#define VSCSI_MAX_GRANTS (SG_ALL + VSCSIIF_SG_TABLESIZE)
/*
* VSCSI_GRANT_BATCH is the maximum number of grants to be processed in one
* call to map/unmap grants. Don't choose it too large, as there are arrays
* with VSCSI_GRANT_BATCH elements allocated on the stack.
*/
#define VSCSI_GRANT_BATCH 16
struct vscsibk_pend {
uint16_t rqid;
uint8_t cmnd[VSCSIIF_MAX_COMMAND_SIZE];
uint8_t cmd_len;
uint8_t sc_data_direction;
uint16_t n_sg; /* real length of SG list */
uint16_t n_grants; /* SG pages and potentially SG list */
uint32_t data_len;
uint32_t result;
struct vscsibk_info *info;
struct v2p_entry *v2p;
struct scatterlist *sgl;
uint8_t sense_buffer[VSCSIIF_SENSE_BUFFERSIZE];
grant_handle_t grant_handles[VSCSI_MAX_GRANTS];
struct page *pages[VSCSI_MAX_GRANTS];
struct se_cmd se_cmd;
struct completion tmr_done;
};
#define VSCSI_DEFAULT_SESSION_TAGS 128
struct scsiback_nexus {
/* Pointer to TCM session for I_T Nexus */
struct se_session *tvn_se_sess;
};
struct scsiback_tport {
/* SCSI protocol the tport is providing */
u8 tport_proto_id;
/* Binary World Wide unique Port Name for pvscsi Target port */
u64 tport_wwpn;
/* ASCII formatted WWPN for pvscsi Target port */
char tport_name[VSCSI_NAMELEN];
/* Returned by scsiback_make_tport() */
struct se_wwn tport_wwn;
};
struct scsiback_tpg {
/* scsiback port target portal group tag for TCM */
u16 tport_tpgt;
/* track number of TPG Port/Lun Links wrt explicit I_T Nexus shutdown */
int tv_tpg_port_count;
/* xen-pvscsi references to tpg_nexus, protected by tv_tpg_mutex */
int tv_tpg_fe_count;
/* list for scsiback_list */
struct list_head tv_tpg_list;
/* Used to protect access for tpg_nexus */
struct mutex tv_tpg_mutex;
/* Pointer to the TCM pvscsi I_T Nexus for this TPG endpoint */
struct scsiback_nexus *tpg_nexus;
/* Pointer back to scsiback_tport */
struct scsiback_tport *tport;
/* Returned by scsiback_make_tpg() */
struct se_portal_group se_tpg;
/* alias used in xenstore */
char param_alias[VSCSI_NAMELEN];
/* list of info structures related to this target portal group */
struct list_head info_list;
};
#define SCSIBACK_INVALID_HANDLE (~0)
static bool log_print_stat;
module_param(log_print_stat, bool, 0644);
static int scsiback_max_buffer_pages = 1024;
module_param_named(max_buffer_pages, scsiback_max_buffer_pages, int, 0644);
MODULE_PARM_DESC(max_buffer_pages,
"Maximum number of free pages to keep in backend buffer");
/* Global spinlock to protect scsiback TPG list */
static DEFINE_MUTEX(scsiback_mutex);
static LIST_HEAD(scsiback_list);
static void scsiback_get(struct vscsibk_info *info)
{
atomic_inc(&info->nr_unreplied_reqs);
}
static void scsiback_put(struct vscsibk_info *info)
{
if (atomic_dec_and_test(&info->nr_unreplied_reqs))
wake_up(&info->waiting_to_free);
}
static unsigned long vaddr_page(struct page *page)
{
unsigned long pfn = page_to_pfn(page);
return (unsigned long)pfn_to_kaddr(pfn);
}
static unsigned long vaddr(struct vscsibk_pend *req, int seg)
{
return vaddr_page(req->pages[seg]);
}
static void scsiback_print_status(char *sense_buffer, int errors,
struct vscsibk_pend *pending_req)
{
struct scsiback_tpg *tpg = pending_req->v2p->tpg;
pr_err("[%s:%d] cmnd[0]=%02x -> st=%02x msg=%02x host=%02x\n",
tpg->tport->tport_name, pending_req->v2p->lun,
pending_req->cmnd[0], errors & 0xff, COMMAND_COMPLETE,
host_byte(errors));
}
static void scsiback_fast_flush_area(struct vscsibk_pend *req)
{
struct gnttab_unmap_grant_ref unmap[VSCSI_GRANT_BATCH];
struct page *pages[VSCSI_GRANT_BATCH];
unsigned int i, invcount = 0;
grant_handle_t handle;
int err;
kfree(req->sgl);
req->sgl = NULL;
req->n_sg = 0;
if (!req->n_grants)
return;
for (i = 0; i < req->n_grants; i++) {
handle = req->grant_handles[i];
if (handle == SCSIBACK_INVALID_HANDLE)
continue;
gnttab_set_unmap_op(&unmap[invcount], vaddr(req, i),
GNTMAP_host_map, handle);
req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
pages[invcount] = req->pages[i];
put_page(pages[invcount]);
invcount++;
if (invcount < VSCSI_GRANT_BATCH)
continue;
err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
BUG_ON(err);
invcount = 0;
}
if (invcount) {
err = gnttab_unmap_refs(unmap, NULL, pages, invcount);
BUG_ON(err);
}
gnttab_page_cache_put(&req->info->free_pages, req->pages,
req->n_grants);
req->n_grants = 0;
}
static void scsiback_free_translation_entry(struct kref *kref)
{
struct v2p_entry *entry = container_of(kref, struct v2p_entry, kref);
struct scsiback_tpg *tpg = entry->tpg;
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_fe_count--;
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(entry);
}
static int32_t scsiback_result(int32_t result)
{
int32_t host_status;
switch (XEN_VSCSIIF_RSLT_HOST(result)) {
case DID_OK:
host_status = XEN_VSCSIIF_RSLT_HOST_OK;
break;
case DID_NO_CONNECT:
host_status = XEN_VSCSIIF_RSLT_HOST_NO_CONNECT;
break;
case DID_BUS_BUSY:
host_status = XEN_VSCSIIF_RSLT_HOST_BUS_BUSY;
break;
case DID_TIME_OUT:
host_status = XEN_VSCSIIF_RSLT_HOST_TIME_OUT;
break;
case DID_BAD_TARGET:
host_status = XEN_VSCSIIF_RSLT_HOST_BAD_TARGET;
break;
case DID_ABORT:
host_status = XEN_VSCSIIF_RSLT_HOST_ABORT;
break;
case DID_PARITY:
host_status = XEN_VSCSIIF_RSLT_HOST_PARITY;
break;
case DID_ERROR:
host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
break;
case DID_RESET:
host_status = XEN_VSCSIIF_RSLT_HOST_RESET;
break;
case DID_BAD_INTR:
host_status = XEN_VSCSIIF_RSLT_HOST_BAD_INTR;
break;
case DID_PASSTHROUGH:
host_status = XEN_VSCSIIF_RSLT_HOST_PASSTHROUGH;
break;
case DID_SOFT_ERROR:
host_status = XEN_VSCSIIF_RSLT_HOST_SOFT_ERROR;
break;
case DID_IMM_RETRY:
host_status = XEN_VSCSIIF_RSLT_HOST_IMM_RETRY;
break;
case DID_REQUEUE:
host_status = XEN_VSCSIIF_RSLT_HOST_REQUEUE;
break;
case DID_TRANSPORT_DISRUPTED:
host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_DISRUPTED;
break;
case DID_TRANSPORT_FAILFAST:
host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_FAILFAST;
break;
case DID_TRANSPORT_MARGINAL:
host_status = XEN_VSCSIIF_RSLT_HOST_TRANSPORT_MARGINAL;
break;
default:
host_status = XEN_VSCSIIF_RSLT_HOST_ERROR;
break;
}
return (host_status << 16) | (result & 0x00ffff);
}
static void scsiback_send_response(struct vscsibk_info *info,
char *sense_buffer, int32_t result, uint32_t resid,
uint16_t rqid)
{
struct vscsiif_response *ring_res;
int notify;
struct scsi_sense_hdr sshdr;
unsigned long flags;
unsigned len;
spin_lock_irqsave(&info->ring_lock, flags);
ring_res = RING_GET_RESPONSE(&info->ring, info->ring.rsp_prod_pvt);
info->ring.rsp_prod_pvt++;
ring_res->rslt = scsiback_result(result);
ring_res->rqid = rqid;
if (sense_buffer != NULL &&
scsi_normalize_sense(sense_buffer, VSCSIIF_SENSE_BUFFERSIZE,
&sshdr)) {
len = min_t(unsigned, 8 + sense_buffer[7],
VSCSIIF_SENSE_BUFFERSIZE);
memcpy(ring_res->sense_buffer, sense_buffer, len);
ring_res->sense_len = len;
} else {
ring_res->sense_len = 0;
}
ring_res->residual_len = resid;
RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&info->ring, notify);
spin_unlock_irqrestore(&info->ring_lock, flags);
if (notify)
notify_remote_via_irq(info->irq);
}
static void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
uint32_t resid, struct vscsibk_pend *pending_req)
{
scsiback_send_response(pending_req->info, sense_buffer, result,
resid, pending_req->rqid);
if (pending_req->v2p)
kref_put(&pending_req->v2p->kref,
scsiback_free_translation_entry);
}
static void scsiback_cmd_done(struct vscsibk_pend *pending_req)
{
struct vscsibk_info *info = pending_req->info;
unsigned char *sense_buffer;
unsigned int resid;
int errors;
sense_buffer = pending_req->sense_buffer;
resid = pending_req->se_cmd.residual_count;
errors = pending_req->result;
if (errors && log_print_stat)
scsiback_print_status(sense_buffer, errors, pending_req);
scsiback_fast_flush_area(pending_req);
scsiback_do_resp_with_sense(sense_buffer, errors, resid, pending_req);
scsiback_put(info);
/*
* Drop the extra KREF_ACK reference taken by target_submit_cmd_map_sgls()
* ahead of scsiback_check_stop_free() -> transport_generic_free_cmd()
* final se_cmd->cmd_kref put.
*/
target_put_sess_cmd(&pending_req->se_cmd);
}
static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)
{
struct se_cmd *se_cmd = &pending_req->se_cmd;
struct se_session *sess = pending_req->v2p->tpg->tpg_nexus->tvn_se_sess;
scsiback_get(pending_req->info);
se_cmd->tag = pending_req->rqid;
target_init_cmd(se_cmd, sess, pending_req->sense_buffer,
pending_req->v2p->lun, pending_req->data_len, 0,
pending_req->sc_data_direction, TARGET_SCF_ACK_KREF);
if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl,
pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL))
return;
target_submit(se_cmd);
}
static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
struct page **pg, grant_handle_t *grant, int cnt)
{
int err, i;
if (!cnt)
return 0;
err = gnttab_map_refs(map, NULL, pg, cnt);
for (i = 0; i < cnt; i++) {
if (unlikely(map[i].status != GNTST_okay)) {
pr_err("invalid buffer -- could not remap it\n");
map[i].handle = SCSIBACK_INVALID_HANDLE;
if (!err)
err = -ENOMEM;
} else {
get_page(pg[i]);
}
grant[i] = map[i].handle;
}
return err;
}
static int scsiback_gnttab_data_map_list(struct vscsibk_pend *pending_req,
struct scsiif_request_segment *seg, struct page **pg,
grant_handle_t *grant, int cnt, u32 flags)
{
int mapcount = 0, i, err = 0;
struct gnttab_map_grant_ref map[VSCSI_GRANT_BATCH];
struct vscsibk_info *info = pending_req->info;
for (i = 0; i < cnt; i++) {
if (gnttab_page_cache_get(&info->free_pages, pg + mapcount)) {
gnttab_page_cache_put(&info->free_pages, pg, mapcount);
pr_err("no grant page\n");
return -ENOMEM;
}
gnttab_set_map_op(&map[mapcount], vaddr_page(pg[mapcount]),
flags, seg[i].gref, info->domid);
mapcount++;
if (mapcount < VSCSI_GRANT_BATCH)
continue;
err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
pg += mapcount;
grant += mapcount;
pending_req->n_grants += mapcount;
if (err)
return err;
mapcount = 0;
}
err = scsiback_gnttab_data_map_batch(map, pg, grant, mapcount);
pending_req->n_grants += mapcount;
return err;
}
static int scsiback_gnttab_data_map(struct vscsiif_request *ring_req,
struct vscsibk_pend *pending_req)
{
u32 flags;
int i, err, n_segs, i_seg = 0;
struct page **pg;
struct scsiif_request_segment *seg;
unsigned long end_seg = 0;
unsigned int nr_segments = (unsigned int)ring_req->nr_segments;
unsigned int nr_sgl = 0;
struct scatterlist *sg;
grant_handle_t *grant;
pending_req->n_sg = 0;
pending_req->n_grants = 0;
pending_req->data_len = 0;
nr_segments &= ~VSCSIIF_SG_GRANT;
if (!nr_segments)
return 0;
if (nr_segments > VSCSIIF_SG_TABLESIZE) {
pr_debug("invalid parameter nr_seg = %d\n",
ring_req->nr_segments);
return -EINVAL;
}
if (ring_req->nr_segments & VSCSIIF_SG_GRANT) {
err = scsiback_gnttab_data_map_list(pending_req, ring_req->seg,
pending_req->pages, pending_req->grant_handles,
nr_segments, GNTMAP_host_map | GNTMAP_readonly);
if (err)
return err;
nr_sgl = nr_segments;
nr_segments = 0;
for (i = 0; i < nr_sgl; i++) {
n_segs = ring_req->seg[i].length /
sizeof(struct scsiif_request_segment);
if ((unsigned)ring_req->seg[i].offset +
(unsigned)ring_req->seg[i].length > PAGE_SIZE ||
n_segs * sizeof(struct scsiif_request_segment) !=
ring_req->seg[i].length)
return -EINVAL;
nr_segments += n_segs;
}
if (nr_segments > SG_ALL) {
pr_debug("invalid nr_seg = %d\n", nr_segments);
return -EINVAL;
}
}
/* free of (sgl) in fast_flush_area() */
pending_req->sgl = kmalloc_array(nr_segments,
sizeof(struct scatterlist), GFP_KERNEL);
if (!pending_req->sgl)
return -ENOMEM;
sg_init_table(pending_req->sgl, nr_segments);
pending_req->n_sg = nr_segments;
flags = GNTMAP_host_map;
if (pending_req->sc_data_direction == DMA_TO_DEVICE)
flags |= GNTMAP_readonly;
pg = pending_req->pages + nr_sgl;
grant = pending_req->grant_handles + nr_sgl;
if (!nr_sgl) {
seg = ring_req->seg;
err = scsiback_gnttab_data_map_list(pending_req, seg,
pg, grant, nr_segments, flags);
if (err)
return err;
} else {
for (i = 0; i < nr_sgl; i++) {
seg = (struct scsiif_request_segment *)(
vaddr(pending_req, i) + ring_req->seg[i].offset);
n_segs = ring_req->seg[i].length /
sizeof(struct scsiif_request_segment);
err = scsiback_gnttab_data_map_list(pending_req, seg,
pg, grant, n_segs, flags);
if (err)
return err;
pg += n_segs;
grant += n_segs;
}
end_seg = vaddr(pending_req, 0) + ring_req->seg[0].offset;
seg = (struct scsiif_request_segment *)end_seg;
end_seg += ring_req->seg[0].length;
pg = pending_req->pages + nr_sgl;
}
for_each_sg(pending_req->sgl, sg, nr_segments, i) {
sg_set_page(sg, pg[i], seg->length, seg->offset);
pending_req->data_len += seg->length;
seg++;
if (nr_sgl && (unsigned long)seg >= end_seg) {
i_seg++;
end_seg = vaddr(pending_req, i_seg) +
ring_req->seg[i_seg].offset;
seg = (struct scsiif_request_segment *)end_seg;
end_seg += ring_req->seg[i_seg].length;
}
if (sg->offset >= PAGE_SIZE ||
sg->length > PAGE_SIZE ||
sg->offset + sg->length > PAGE_SIZE)
return -EINVAL;
}
return 0;
}
static void scsiback_disconnect(struct vscsibk_info *info)
{
wait_event(info->waiting_to_free,
atomic_read(&info->nr_unreplied_reqs) == 0);
unbind_from_irqhandler(info->irq, info);
info->irq = 0;
xenbus_unmap_ring_vfree(info->dev, info->ring.sring);
}
static void scsiback_device_action(struct vscsibk_pend *pending_req,
enum tcm_tmreq_table act, int tag)
{
struct scsiback_tpg *tpg = pending_req->v2p->tpg;
struct scsiback_nexus *nexus = tpg->tpg_nexus;
struct se_cmd *se_cmd = &pending_req->se_cmd;
u64 unpacked_lun = pending_req->v2p->lun;
int rc, err = XEN_VSCSIIF_RSLT_RESET_FAILED;
init_completion(&pending_req->tmr_done);
rc = target_submit_tmr(&pending_req->se_cmd, nexus->tvn_se_sess,
&pending_req->sense_buffer[0],
unpacked_lun, NULL, act, GFP_KERNEL,
tag, TARGET_SCF_ACK_KREF);
if (rc)
goto err;
wait_for_completion(&pending_req->tmr_done);
err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
XEN_VSCSIIF_RSLT_RESET_SUCCESS : XEN_VSCSIIF_RSLT_RESET_FAILED;
scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
transport_generic_free_cmd(&pending_req->se_cmd, 0);
return;
err:
scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
}
/*
Perform virtual to physical translation
*/
static struct v2p_entry *scsiback_do_translation(struct vscsibk_info *info,
struct ids_tuple *v)
{
struct v2p_entry *entry;
struct list_head *head = &(info->v2p_entry_lists);
unsigned long flags;
spin_lock_irqsave(&info->v2p_lock, flags);
list_for_each_entry(entry, head, l) {
if ((entry->v.chn == v->chn) &&
(entry->v.tgt == v->tgt) &&
(entry->v.lun == v->lun)) {
kref_get(&entry->kref);
goto out;
}
}
entry = NULL;
out:
spin_unlock_irqrestore(&info->v2p_lock, flags);
return entry;
}
static struct vscsibk_pend *scsiback_get_pend_req(struct vscsiif_back_ring *ring,
struct v2p_entry *v2p)
{
struct scsiback_tpg *tpg = v2p->tpg;
struct scsiback_nexus *nexus = tpg->tpg_nexus;
struct se_session *se_sess = nexus->tvn_se_sess;
struct vscsibk_pend *req;
int tag, cpu, i;
tag = sbitmap_queue_get(&se_sess->sess_tag_pool, &cpu);
if (tag < 0) {
pr_err("Unable to obtain tag for vscsiif_request\n");
return ERR_PTR(-ENOMEM);
}
req = &((struct vscsibk_pend *)se_sess->sess_cmd_map)[tag];
memset(req, 0, sizeof(*req));
req->se_cmd.map_tag = tag;
req->se_cmd.map_cpu = cpu;
for (i = 0; i < VSCSI_MAX_GRANTS; i++)
req->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
return req;
}
static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
struct vscsiif_back_ring *ring,
struct vscsiif_request *ring_req)
{
struct vscsibk_pend *pending_req;
struct v2p_entry *v2p;
struct ids_tuple vir;
/* request range check from frontend */
if ((ring_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
(ring_req->sc_data_direction != DMA_TO_DEVICE) &&
(ring_req->sc_data_direction != DMA_FROM_DEVICE) &&
(ring_req->sc_data_direction != DMA_NONE)) {
pr_debug("invalid parameter data_dir = %d\n",
ring_req->sc_data_direction);
return ERR_PTR(-EINVAL);
}
if (ring_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
pr_debug("invalid parameter cmd_len = %d\n",
ring_req->cmd_len);
return ERR_PTR(-EINVAL);
}
vir.chn = ring_req->channel;
vir.tgt = ring_req->id;
vir.lun = ring_req->lun;
v2p = scsiback_do_translation(info, &vir);
if (!v2p) {
pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
vir.chn, vir.tgt, vir.lun);
return ERR_PTR(-ENODEV);
}
pending_req = scsiback_get_pend_req(ring, v2p);
if (IS_ERR(pending_req)) {
kref_put(&v2p->kref, scsiback_free_translation_entry);
return ERR_PTR(-ENOMEM);
}
pending_req->rqid = ring_req->rqid;
pending_req->info = info;
pending_req->v2p = v2p;
pending_req->sc_data_direction = ring_req->sc_data_direction;
pending_req->cmd_len = ring_req->cmd_len;
memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
return pending_req;
}
static int scsiback_do_cmd_fn(struct vscsibk_info *info,
unsigned int *eoi_flags)
{
struct vscsiif_back_ring *ring = &info->ring;
struct vscsiif_request ring_req;
struct vscsibk_pend *pending_req;
RING_IDX rc, rp;
int more_to_do;
uint32_t result;
rc = ring->req_cons;
rp = ring->sring->req_prod;
rmb(); /* guest system is accessing ring, too */
if (RING_REQUEST_PROD_OVERFLOW(ring, rp)) {
rc = ring->rsp_prod_pvt;
pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
info->domid, rp, rc, rp - rc);
return -EINVAL;
}
while ((rc != rp)) {
*eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
break;
RING_COPY_REQUEST(ring, rc, &ring_req);
ring->req_cons = ++rc;
pending_req = prepare_pending_reqs(info, ring, &ring_req);
if (IS_ERR(pending_req)) {
switch (PTR_ERR(pending_req)) {
case -ENODEV:
result = DID_NO_CONNECT;
break;
default:
result = DID_ERROR;
break;
}
scsiback_send_response(info, NULL, result << 16, 0,
ring_req.rqid);
return 1;
}
switch (ring_req.act) {
case VSCSIIF_ACT_SCSI_CDB:
if (scsiback_gnttab_data_map(&ring_req, pending_req)) {
scsiback_fast_flush_area(pending_req);
scsiback_do_resp_with_sense(NULL,
DID_ERROR << 16, 0, pending_req);
transport_generic_free_cmd(&pending_req->se_cmd, 0);
} else {
scsiback_cmd_exec(pending_req);
}
break;
case VSCSIIF_ACT_SCSI_ABORT:
scsiback_device_action(pending_req, TMR_ABORT_TASK,
ring_req.ref_rqid);
break;
case VSCSIIF_ACT_SCSI_RESET:
scsiback_device_action(pending_req, TMR_LUN_RESET, 0);
break;
default:
pr_err_ratelimited("invalid request\n");
scsiback_do_resp_with_sense(NULL, DID_ERROR << 16, 0,
pending_req);
transport_generic_free_cmd(&pending_req->se_cmd, 0);
break;
}
/* Yield point for this unbounded loop. */
cond_resched();
}
gnttab_page_cache_shrink(&info->free_pages, scsiback_max_buffer_pages);
RING_FINAL_CHECK_FOR_REQUESTS(&info->ring, more_to_do);
return more_to_do;
}
static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
{
struct vscsibk_info *info = dev_id;
int rc;
unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
cond_resched();
/* In case of a ring error we keep the event channel masked. */
if (!rc)
xen_irq_lateeoi(irq, eoi_flags);
return IRQ_HANDLED;
}
static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
evtchn_port_t evtchn)
{
void *area;
struct vscsiif_sring *sring;
int err;
if (info->irq)
return -1;
err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
if (err)
return err;
sring = (struct vscsiif_sring *)area;
BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
err = bind_interdomain_evtchn_to_irq_lateeoi(info->dev, evtchn);
if (err < 0)
goto unmap_page;
info->irq = err;
err = request_threaded_irq(info->irq, NULL, scsiback_irq_fn,
IRQF_ONESHOT, "vscsiif-backend", info);
if (err)
goto free_irq;
return 0;
free_irq:
unbind_from_irqhandler(info->irq, info);
info->irq = 0;
unmap_page:
xenbus_unmap_ring_vfree(info->dev, area);
return err;
}
static int scsiback_map(struct vscsibk_info *info)
{
struct xenbus_device *dev = info->dev;
unsigned int ring_ref;
evtchn_port_t evtchn;
int err;
err = xenbus_gather(XBT_NIL, dev->otherend,
"ring-ref", "%u", &ring_ref,
"event-channel", "%u", &evtchn, NULL);
if (err) {
xenbus_dev_fatal(dev, err, "reading %s ring", dev->otherend);
return err;
}
return scsiback_init_sring(info, ring_ref, evtchn);
}
/*
Check for a translation entry being present
*/
static struct v2p_entry *scsiback_chk_translation_entry(
struct vscsibk_info *info, struct ids_tuple *v)
{
struct list_head *head = &(info->v2p_entry_lists);
struct v2p_entry *entry;
list_for_each_entry(entry, head, l)
if ((entry->v.chn == v->chn) &&
(entry->v.tgt == v->tgt) &&
(entry->v.lun == v->lun))
return entry;
return NULL;
}
/*
Add a new translation entry
*/
static int scsiback_add_translation_entry(struct vscsibk_info *info,
char *phy, struct ids_tuple *v)
{
int err = 0;
struct v2p_entry *new;
unsigned long flags;
char *lunp;
unsigned long long unpacked_lun;
struct se_lun *se_lun;
struct scsiback_tpg *tpg_entry, *tpg = NULL;
char *error = "doesn't exist";
lunp = strrchr(phy, ':');
if (!lunp) {
pr_err("illegal format of physical device %s\n", phy);
return -EINVAL;
}
*lunp = 0;
lunp++;
err = kstrtoull(lunp, 10, &unpacked_lun);
if (err < 0) {
pr_err("lun number not valid: %s\n", lunp);
return err;
}
mutex_lock(&scsiback_mutex);
list_for_each_entry(tpg_entry, &scsiback_list, tv_tpg_list) {
if (!strcmp(phy, tpg_entry->tport->tport_name) ||
!strcmp(phy, tpg_entry->param_alias)) {
mutex_lock(&tpg_entry->se_tpg.tpg_lun_mutex);
hlist_for_each_entry(se_lun, &tpg_entry->se_tpg.tpg_lun_hlist, link) {
if (se_lun->unpacked_lun == unpacked_lun) {
if (!tpg_entry->tpg_nexus)
error = "nexus undefined";
else
tpg = tpg_entry;
break;
}
}
mutex_unlock(&tpg_entry->se_tpg.tpg_lun_mutex);
break;
}
}
if (tpg) {
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_fe_count++;
mutex_unlock(&tpg->tv_tpg_mutex);
}
mutex_unlock(&scsiback_mutex);
if (!tpg) {
pr_err("%s:%llu %s\n", phy, unpacked_lun, error);
return -ENODEV;
}
new = kmalloc(sizeof(struct v2p_entry), GFP_KERNEL);
if (new == NULL) {
err = -ENOMEM;
goto out_free;
}
spin_lock_irqsave(&info->v2p_lock, flags);
/* Check double assignment to identical virtual ID */
if (scsiback_chk_translation_entry(info, v)) {
pr_warn("Virtual ID is already used. Assignment was not performed.\n");
err = -EEXIST;
goto out;
}
/* Create a new translation entry and add to the list */
kref_init(&new->kref);
new->v = *v;
new->tpg = tpg;
new->lun = unpacked_lun;
list_add_tail(&new->l, &info->v2p_entry_lists);
out:
spin_unlock_irqrestore(&info->v2p_lock, flags);
out_free:
if (err) {
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_fe_count--;
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(new);
}
return err;
}
static void __scsiback_del_translation_entry(struct v2p_entry *entry)
{
list_del(&entry->l);
kref_put(&entry->kref, scsiback_free_translation_entry);
}
/*
Delete the translation entry specified
*/
static int scsiback_del_translation_entry(struct vscsibk_info *info,
struct ids_tuple *v)
{
struct v2p_entry *entry;
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&info->v2p_lock, flags);
/* Find out the translation entry specified */
entry = scsiback_chk_translation_entry(info, v);
if (entry)
__scsiback_del_translation_entry(entry);
else
ret = -ENOENT;
spin_unlock_irqrestore(&info->v2p_lock, flags);
return ret;
}
static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
char *phy, struct ids_tuple *vir, int try)
{
struct v2p_entry *entry;
unsigned long flags;
int err;
if (try) {
spin_lock_irqsave(&info->v2p_lock, flags);
entry = scsiback_chk_translation_entry(info, vir);
spin_unlock_irqrestore(&info->v2p_lock, flags);
if (entry)
return;
}
if (!scsiback_add_translation_entry(info, phy, vir)) {
if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateInitialised)) {
pr_err("xenbus_printf error %s\n", state);
scsiback_del_translation_entry(info, vir);
}
} else if (!try) {
err = xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateClosed);
if (err)
xenbus_dev_error(info->dev, err,
"%s: writing %s", __func__, state);
}
}
static void scsiback_do_del_lun(struct vscsibk_info *info, const char *state,
struct ids_tuple *vir)
{
if (!scsiback_del_translation_entry(info, vir)) {
if (xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateClosed))
pr_err("xenbus_printf error %s\n", state);
}
}
#define VSCSIBACK_OP_ADD_OR_DEL_LUN 1
#define VSCSIBACK_OP_UPDATEDEV_STATE 2
static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
char *ent)
{
int err;
struct ids_tuple vir;
char *val;
int device_state;
char phy[VSCSI_NAMELEN];
char str[64];
char state[64];
struct xenbus_device *dev = info->dev;
/* read status */
snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
if (XENBUS_EXIST_ERR(err))
return;
/* physical SCSI device */
snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
if (IS_ERR(val)) {
err = xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
if (err)
xenbus_dev_error(info->dev, err,
"%s: writing %s", __func__, state);
return;
}
strlcpy(phy, val, VSCSI_NAMELEN);
kfree(val);
/* virtual SCSI device */
snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
&vir.hst, &vir.chn, &vir.tgt, &vir.lun);
if (XENBUS_EXIST_ERR(err)) {
err = xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
if (err)
xenbus_dev_error(info->dev, err,
"%s: writing %s", __func__, state);
return;
}
switch (op) {
case VSCSIBACK_OP_ADD_OR_DEL_LUN:
switch (device_state) {
case XenbusStateInitialising:
scsiback_do_add_lun(info, state, phy, &vir, 0);
break;
case XenbusStateConnected:
scsiback_do_add_lun(info, state, phy, &vir, 1);
break;
case XenbusStateClosing:
scsiback_do_del_lun(info, state, &vir);
break;
default:
break;
}
break;
case VSCSIBACK_OP_UPDATEDEV_STATE:
if (device_state == XenbusStateInitialised) {
/* modify vscsi-devs/dev-x/state */
if (xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateConnected)) {
pr_err("xenbus_printf error %s\n", str);
scsiback_del_translation_entry(info, &vir);
xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
}
}
break;
/* When it is necessary, processing is added here. */
default:
break;
}
}
static void scsiback_do_lun_hotplug(struct vscsibk_info *info, int op)
{
int i;
char **dir;
unsigned int ndir = 0;
dir = xenbus_directory(XBT_NIL, info->dev->nodename, "vscsi-devs",
&ndir);
if (IS_ERR(dir))
return;
for (i = 0; i < ndir; i++)
scsiback_do_1lun_hotplug(info, op, dir[i]);
kfree(dir);
}
static void scsiback_frontend_changed(struct xenbus_device *dev,
enum xenbus_state frontend_state)
{
struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
switch (frontend_state) {
case XenbusStateInitialising:
break;
case XenbusStateInitialised:
if (scsiback_map(info))
break;
scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateConnected:
scsiback_do_lun_hotplug(info, VSCSIBACK_OP_UPDATEDEV_STATE);
if (dev->state == XenbusStateConnected)
break;
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateClosing:
if (info->irq)
scsiback_disconnect(info);
xenbus_switch_state(dev, XenbusStateClosing);
break;
case XenbusStateClosed:
xenbus_switch_state(dev, XenbusStateClosed);
if (xenbus_dev_is_online(dev))
break;
fallthrough; /* if not online */
case XenbusStateUnknown:
device_unregister(&dev->dev);
break;
case XenbusStateReconfiguring:
scsiback_do_lun_hotplug(info, VSCSIBACK_OP_ADD_OR_DEL_LUN);
xenbus_switch_state(dev, XenbusStateReconfigured);
break;
default:
xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
frontend_state);
break;
}
}
/*
Release the translation entry specfied
*/
static void scsiback_release_translation_entry(struct vscsibk_info *info)
{
struct v2p_entry *entry, *tmp;
struct list_head *head = &(info->v2p_entry_lists);
unsigned long flags;
spin_lock_irqsave(&info->v2p_lock, flags);
list_for_each_entry_safe(entry, tmp, head, l)
__scsiback_del_translation_entry(entry);
spin_unlock_irqrestore(&info->v2p_lock, flags);
}
static void scsiback_remove(struct xenbus_device *dev)
{
struct vscsibk_info *info = dev_get_drvdata(&dev->dev);
if (info->irq)
scsiback_disconnect(info);
scsiback_release_translation_entry(info);
gnttab_page_cache_shrink(&info->free_pages, 0);
dev_set_drvdata(&dev->dev, NULL);
}
static int scsiback_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int err;
struct vscsibk_info *info = kzalloc(sizeof(struct vscsibk_info),
GFP_KERNEL);
pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id);
if (!info) {
xenbus_dev_fatal(dev, -ENOMEM, "allocating backend structure");
return -ENOMEM;
}
info->dev = dev;
dev_set_drvdata(&dev->dev, info);
info->domid = dev->otherend_id;
spin_lock_init(&info->ring_lock);
atomic_set(&info->nr_unreplied_reqs, 0);
init_waitqueue_head(&info->waiting_to_free);
info->dev = dev;
info->irq = 0;
INIT_LIST_HEAD(&info->v2p_entry_lists);
spin_lock_init(&info->v2p_lock);
gnttab_page_cache_init(&info->free_pages);
err = xenbus_printf(XBT_NIL, dev->nodename, "feature-sg-grant", "%u",
SG_ALL);
if (err)
xenbus_dev_error(dev, err, "writing feature-sg-grant");
err = xenbus_switch_state(dev, XenbusStateInitWait);
if (err)
goto fail;
return 0;
fail:
pr_warn("%s failed\n", __func__);
scsiback_remove(dev);
return err;
}
static char *scsiback_dump_proto_id(struct scsiback_tport *tport)
{
switch (tport->tport_proto_id) {
case SCSI_PROTOCOL_SAS:
return "SAS";
case SCSI_PROTOCOL_FCP:
return "FCP";
case SCSI_PROTOCOL_ISCSI:
return "iSCSI";
default:
break;
}
return "Unknown";
}
static char *scsiback_get_fabric_wwn(struct se_portal_group *se_tpg)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
struct scsiback_tport *tport = tpg->tport;
return &tport->tport_name[0];
}
static u16 scsiback_get_tag(struct se_portal_group *se_tpg)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
return tpg->tport_tpgt;
}
static struct se_wwn *
scsiback_make_tport(struct target_fabric_configfs *tf,
struct config_group *group,
const char *name)
{
struct scsiback_tport *tport;
char *ptr;
u64 wwpn = 0;
int off = 0;
tport = kzalloc(sizeof(struct scsiback_tport), GFP_KERNEL);
if (!tport)
return ERR_PTR(-ENOMEM);
tport->tport_wwpn = wwpn;
/*
* Determine the emulated Protocol Identifier and Target Port Name
* based on the incoming configfs directory name.
*/
ptr = strstr(name, "naa.");
if (ptr) {
tport->tport_proto_id = SCSI_PROTOCOL_SAS;
goto check_len;
}
ptr = strstr(name, "fc.");
if (ptr) {
tport->tport_proto_id = SCSI_PROTOCOL_FCP;
off = 3; /* Skip over "fc." */
goto check_len;
}
ptr = strstr(name, "iqn.");
if (ptr) {
tport->tport_proto_id = SCSI_PROTOCOL_ISCSI;
goto check_len;
}
pr_err("Unable to locate prefix for emulated Target Port: %s\n", name);
kfree(tport);
return ERR_PTR(-EINVAL);
check_len:
if (strlen(name) >= VSCSI_NAMELEN) {
pr_err("Emulated %s Address: %s, exceeds max: %d\n", name,
scsiback_dump_proto_id(tport), VSCSI_NAMELEN);
kfree(tport);
return ERR_PTR(-EINVAL);
}
snprintf(&tport->tport_name[0], VSCSI_NAMELEN, "%s", &name[off]);
pr_debug("Allocated emulated Target %s Address: %s\n",
scsiback_dump_proto_id(tport), name);
return &tport->tport_wwn;
}
static void scsiback_drop_tport(struct se_wwn *wwn)
{
struct scsiback_tport *tport = container_of(wwn,
struct scsiback_tport, tport_wwn);
pr_debug("Deallocating emulated Target %s Address: %s\n",
scsiback_dump_proto_id(tport), tport->tport_name);
kfree(tport);
}
static u32 scsiback_tpg_get_inst_index(struct se_portal_group *se_tpg)
{
return 1;
}
static int scsiback_check_stop_free(struct se_cmd *se_cmd)
{
return transport_generic_free_cmd(se_cmd, 0);
}
static void scsiback_release_cmd(struct se_cmd *se_cmd)
{
target_free_tag(se_cmd->se_sess, se_cmd);
}
static u32 scsiback_sess_get_index(struct se_session *se_sess)
{
return 0;
}
static int scsiback_write_pending(struct se_cmd *se_cmd)
{
/* Go ahead and process the write immediately */
target_execute_cmd(se_cmd);
return 0;
}
static void scsiback_set_default_node_attrs(struct se_node_acl *nacl)
{
}
static int scsiback_get_cmd_state(struct se_cmd *se_cmd)
{
return 0;
}
static int scsiback_queue_data_in(struct se_cmd *se_cmd)
{
struct vscsibk_pend *pending_req = container_of(se_cmd,
struct vscsibk_pend, se_cmd);
pending_req->result = SAM_STAT_GOOD;
scsiback_cmd_done(pending_req);
return 0;
}
static int scsiback_queue_status(struct se_cmd *se_cmd)
{
struct vscsibk_pend *pending_req = container_of(se_cmd,
struct vscsibk_pend, se_cmd);
if (se_cmd->sense_buffer &&
((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
(se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE)))
pending_req->result = SAM_STAT_CHECK_CONDITION;
else
pending_req->result = se_cmd->scsi_status;
scsiback_cmd_done(pending_req);
return 0;
}
static void scsiback_queue_tm_rsp(struct se_cmd *se_cmd)
{
struct vscsibk_pend *pending_req = container_of(se_cmd,
struct vscsibk_pend, se_cmd);
complete(&pending_req->tmr_done);
}
static void scsiback_aborted_task(struct se_cmd *se_cmd)
{
}
static ssize_t scsiback_tpg_param_alias_show(struct config_item *item,
char *page)
{
struct se_portal_group *se_tpg = param_to_tpg(item);
struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
se_tpg);
ssize_t rb;
mutex_lock(&tpg->tv_tpg_mutex);
rb = snprintf(page, PAGE_SIZE, "%s\n", tpg->param_alias);
mutex_unlock(&tpg->tv_tpg_mutex);
return rb;
}
static ssize_t scsiback_tpg_param_alias_store(struct config_item *item,
const char *page, size_t count)
{
struct se_portal_group *se_tpg = param_to_tpg(item);
struct scsiback_tpg *tpg = container_of(se_tpg, struct scsiback_tpg,
se_tpg);
int len;
if (strlen(page) >= VSCSI_NAMELEN) {
pr_err("param alias: %s, exceeds max: %d\n", page,
VSCSI_NAMELEN);
return -EINVAL;
}
mutex_lock(&tpg->tv_tpg_mutex);
len = snprintf(tpg->param_alias, VSCSI_NAMELEN, "%s", page);
if (tpg->param_alias[len - 1] == '\n')
tpg->param_alias[len - 1] = '\0';
mutex_unlock(&tpg->tv_tpg_mutex);
return count;
}
CONFIGFS_ATTR(scsiback_tpg_param_, alias);
static struct configfs_attribute *scsiback_param_attrs[] = {
&scsiback_tpg_param_attr_alias,
NULL,
};
static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
struct se_session *se_sess, void *p)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
tpg->tpg_nexus = p;
return 0;
}
static int scsiback_make_nexus(struct scsiback_tpg *tpg,
const char *name)
{
struct scsiback_nexus *tv_nexus;
int ret = 0;
mutex_lock(&tpg->tv_tpg_mutex);
if (tpg->tpg_nexus) {
pr_debug("tpg->tpg_nexus already exists\n");
ret = -EEXIST;
goto out_unlock;
}
tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
if (!tv_nexus) {
ret = -ENOMEM;
goto out_unlock;
}
tv_nexus->tvn_se_sess = target_setup_session(&tpg->se_tpg,
VSCSI_DEFAULT_SESSION_TAGS,
sizeof(struct vscsibk_pend),
TARGET_PROT_NORMAL, name,
tv_nexus, scsiback_alloc_sess_cb);
if (IS_ERR(tv_nexus->tvn_se_sess)) {
kfree(tv_nexus);
ret = -ENOMEM;
goto out_unlock;
}
out_unlock:
mutex_unlock(&tpg->tv_tpg_mutex);
return ret;
}
static int scsiback_drop_nexus(struct scsiback_tpg *tpg)
{
struct se_session *se_sess;
struct scsiback_nexus *tv_nexus;
mutex_lock(&tpg->tv_tpg_mutex);
tv_nexus = tpg->tpg_nexus;
if (!tv_nexus) {
mutex_unlock(&tpg->tv_tpg_mutex);
return -ENODEV;
}
se_sess = tv_nexus->tvn_se_sess;
if (!se_sess) {
mutex_unlock(&tpg->tv_tpg_mutex);
return -ENODEV;
}
if (tpg->tv_tpg_port_count != 0) {
mutex_unlock(&tpg->tv_tpg_mutex);
pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG port count: %d\n",
tpg->tv_tpg_port_count);
return -EBUSY;
}
if (tpg->tv_tpg_fe_count != 0) {
mutex_unlock(&tpg->tv_tpg_mutex);
pr_err("Unable to remove xen-pvscsi I_T Nexus with active TPG frontend count: %d\n",
tpg->tv_tpg_fe_count);
return -EBUSY;
}
pr_debug("Removing I_T Nexus to emulated %s Initiator Port: %s\n",
scsiback_dump_proto_id(tpg->tport),
tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
/*
* Release the SCSI I_T Nexus to the emulated xen-pvscsi Target Port
*/
target_remove_session(se_sess);
tpg->tpg_nexus = NULL;
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(tv_nexus);
return 0;
}
static ssize_t scsiback_tpg_nexus_show(struct config_item *item, char *page)
{
struct se_portal_group *se_tpg = to_tpg(item);
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
struct scsiback_nexus *tv_nexus;
ssize_t ret;
mutex_lock(&tpg->tv_tpg_mutex);
tv_nexus = tpg->tpg_nexus;
if (!tv_nexus) {
mutex_unlock(&tpg->tv_tpg_mutex);
return -ENODEV;
}
ret = snprintf(page, PAGE_SIZE, "%s\n",
tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
mutex_unlock(&tpg->tv_tpg_mutex);
return ret;
}
static ssize_t scsiback_tpg_nexus_store(struct config_item *item,
const char *page, size_t count)
{
struct se_portal_group *se_tpg = to_tpg(item);
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
struct scsiback_tport *tport_wwn = tpg->tport;
unsigned char i_port[VSCSI_NAMELEN], *ptr, *port_ptr;
int ret;
/*
* Shutdown the active I_T nexus if 'NULL' is passed.
*/
if (!strncmp(page, "NULL", 4)) {
ret = scsiback_drop_nexus(tpg);
return (!ret) ? count : ret;
}
/*
* Otherwise make sure the passed virtual Initiator port WWN matches
* the fabric protocol_id set in scsiback_make_tport(), and call
* scsiback_make_nexus().
*/
if (strlen(page) >= VSCSI_NAMELEN) {
pr_err("Emulated NAA Sas Address: %s, exceeds max: %d\n",
page, VSCSI_NAMELEN);
return -EINVAL;
}
snprintf(&i_port[0], VSCSI_NAMELEN, "%s", page);
ptr = strstr(i_port, "naa.");
if (ptr) {
if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_SAS) {
pr_err("Passed SAS Initiator Port %s does not match target port protoid: %s\n",
i_port, scsiback_dump_proto_id(tport_wwn));
return -EINVAL;
}
port_ptr = &i_port[0];
goto check_newline;
}
ptr = strstr(i_port, "fc.");
if (ptr) {
if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_FCP) {
pr_err("Passed FCP Initiator Port %s does not match target port protoid: %s\n",
i_port, scsiback_dump_proto_id(tport_wwn));
return -EINVAL;
}
port_ptr = &i_port[3]; /* Skip over "fc." */
goto check_newline;
}
ptr = strstr(i_port, "iqn.");
if (ptr) {
if (tport_wwn->tport_proto_id != SCSI_PROTOCOL_ISCSI) {
pr_err("Passed iSCSI Initiator Port %s does not match target port protoid: %s\n",
i_port, scsiback_dump_proto_id(tport_wwn));
return -EINVAL;
}
port_ptr = &i_port[0];
goto check_newline;
}
pr_err("Unable to locate prefix for emulated Initiator Port: %s\n",
i_port);
return -EINVAL;
/*
* Clear any trailing newline for the NAA WWN
*/
check_newline:
if (i_port[strlen(i_port) - 1] == '\n')
i_port[strlen(i_port) - 1] = '\0';
ret = scsiback_make_nexus(tpg, port_ptr);
if (ret < 0)
return ret;
return count;
}
CONFIGFS_ATTR(scsiback_tpg_, nexus);
static struct configfs_attribute *scsiback_tpg_attrs[] = {
&scsiback_tpg_attr_nexus,
NULL,
};
static ssize_t
scsiback_wwn_version_show(struct config_item *item, char *page)
{
return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
UTS_RELEASE"\n",
VSCSI_VERSION, utsname()->sysname, utsname()->machine);
}
CONFIGFS_ATTR_RO(scsiback_wwn_, version);
static struct configfs_attribute *scsiback_wwn_attrs[] = {
&scsiback_wwn_attr_version,
NULL,
};
static int scsiback_port_link(struct se_portal_group *se_tpg,
struct se_lun *lun)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_port_count++;
mutex_unlock(&tpg->tv_tpg_mutex);
return 0;
}
static void scsiback_port_unlink(struct se_portal_group *se_tpg,
struct se_lun *lun)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_port_count--;
mutex_unlock(&tpg->tv_tpg_mutex);
}
static struct se_portal_group *
scsiback_make_tpg(struct se_wwn *wwn, const char *name)
{
struct scsiback_tport *tport = container_of(wwn,
struct scsiback_tport, tport_wwn);
struct scsiback_tpg *tpg;
u16 tpgt;
int ret;
if (strstr(name, "tpgt_") != name)
return ERR_PTR(-EINVAL);
ret = kstrtou16(name + 5, 10, &tpgt);
if (ret)
return ERR_PTR(ret);
tpg = kzalloc(sizeof(struct scsiback_tpg), GFP_KERNEL);
if (!tpg)
return ERR_PTR(-ENOMEM);
mutex_init(&tpg->tv_tpg_mutex);
INIT_LIST_HEAD(&tpg->tv_tpg_list);
INIT_LIST_HEAD(&tpg->info_list);
tpg->tport = tport;
tpg->tport_tpgt = tpgt;
ret = core_tpg_register(wwn, &tpg->se_tpg, tport->tport_proto_id);
if (ret < 0) {
kfree(tpg);
return NULL;
}
mutex_lock(&scsiback_mutex);
list_add_tail(&tpg->tv_tpg_list, &scsiback_list);
mutex_unlock(&scsiback_mutex);
return &tpg->se_tpg;
}
static void scsiback_drop_tpg(struct se_portal_group *se_tpg)
{
struct scsiback_tpg *tpg = container_of(se_tpg,
struct scsiback_tpg, se_tpg);
mutex_lock(&scsiback_mutex);
list_del(&tpg->tv_tpg_list);
mutex_unlock(&scsiback_mutex);
/*
* Release the virtual I_T Nexus for this xen-pvscsi TPG
*/
scsiback_drop_nexus(tpg);
/*
* Deregister the se_tpg from TCM.
*/
core_tpg_deregister(se_tpg);
kfree(tpg);
}
static int scsiback_check_true(struct se_portal_group *se_tpg)
{
return 1;
}
static int scsiback_check_false(struct se_portal_group *se_tpg)
{
return 0;
}
static const struct target_core_fabric_ops scsiback_ops = {
.module = THIS_MODULE,
.fabric_name = "xen-pvscsi",
.tpg_get_wwn = scsiback_get_fabric_wwn,
.tpg_get_tag = scsiback_get_tag,
.tpg_check_demo_mode = scsiback_check_true,
.tpg_check_demo_mode_cache = scsiback_check_true,
.tpg_check_demo_mode_write_protect = scsiback_check_false,
.tpg_check_prod_mode_write_protect = scsiback_check_false,
.tpg_get_inst_index = scsiback_tpg_get_inst_index,
.check_stop_free = scsiback_check_stop_free,
.release_cmd = scsiback_release_cmd,
.sess_get_index = scsiback_sess_get_index,
.sess_get_initiator_sid = NULL,
.write_pending = scsiback_write_pending,
.set_default_node_attributes = scsiback_set_default_node_attrs,
.get_cmd_state = scsiback_get_cmd_state,
.queue_data_in = scsiback_queue_data_in,
.queue_status = scsiback_queue_status,
.queue_tm_rsp = scsiback_queue_tm_rsp,
.aborted_task = scsiback_aborted_task,
/*
* Setup callers for generic logic in target_core_fabric_configfs.c
*/
.fabric_make_wwn = scsiback_make_tport,
.fabric_drop_wwn = scsiback_drop_tport,
.fabric_make_tpg = scsiback_make_tpg,
.fabric_drop_tpg = scsiback_drop_tpg,
.fabric_post_link = scsiback_port_link,
.fabric_pre_unlink = scsiback_port_unlink,
.tfc_wwn_attrs = scsiback_wwn_attrs,
.tfc_tpg_base_attrs = scsiback_tpg_attrs,
.tfc_tpg_param_attrs = scsiback_param_attrs,
.default_submit_type = TARGET_DIRECT_SUBMIT,
.direct_submit_supp = 1,
};
static const struct xenbus_device_id scsiback_ids[] = {
{ "vscsi" },
{ "" }
};
static struct xenbus_driver scsiback_driver = {
.ids = scsiback_ids,
.probe = scsiback_probe,
.remove = scsiback_remove,
.otherend_changed = scsiback_frontend_changed
};
static int __init scsiback_init(void)
{
int ret;
if (!xen_domain())
return -ENODEV;
pr_debug("xen-pvscsi: fabric module %s on %s/%s on "UTS_RELEASE"\n",
VSCSI_VERSION, utsname()->sysname, utsname()->machine);
ret = xenbus_register_backend(&scsiback_driver);
if (ret)
goto out;
ret = target_register_template(&scsiback_ops);
if (ret)
goto out_unregister_xenbus;
return 0;
out_unregister_xenbus:
xenbus_unregister_driver(&scsiback_driver);
out:
pr_err("%s: error %d\n", __func__, ret);
return ret;
}
static void __exit scsiback_exit(void)
{
target_unregister_template(&scsiback_ops);
xenbus_unregister_driver(&scsiback_driver);
}
module_init(scsiback_init);
module_exit(scsiback_exit);
MODULE_DESCRIPTION("Xen SCSI backend driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("xen-backend:vscsi");
MODULE_AUTHOR("Juergen Gross <jgross@suse.com>");
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