linux/drivers/xen/xen-scsiback.c
Linus Torvalds 5c755fe142 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "It's been a busy development cycle for target-core in a number of
  different areas.

  The fabric API usage for se_node_acl allocation is now within
  target-core code, dropping the external API callers for all fabric
  drivers tree-wide.

  There is a new conversion to RCU hlists for se_node_acl and
  se_portal_group LUN mappings, that turns fast-past LUN lookup into a
  completely lockless code-path.  It also removes the original
  hard-coded limitation of 256 LUNs per fabric endpoint.

  The configfs attributes for backends can now be shared between core
  and driver code, allowing existing drivers to use common code while
  still allowing flexibility for new backend provided attributes.

  The highlights include:

   - Merge sbc_verify_dif_* into common code (sagi)
   - Remove iscsi-target support for obsolete IFMarker/OFMarker
     (Christophe Vu-Brugier)
   - Add bidi support in target/user backend (ilias + vangelis + agover)
   - Move se_node_acl allocation into target-core code (hch)
   - Add crc_t10dif_update common helper (akinobu + mkp)
   - Handle target-core odd SGL mapping for data transfer memory
     (akinobu)
   - Move transport ID handling into target-core (hch)
   - Move task tag into struct se_cmd + support 64-bit tags (bart)
   - Convert se_node_acl->device_list[] to RCU hlist (nab + hch +
     paulmck)
   - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch +
     paulmck)
   - Simplify target backend driver registration (hch)
   - Consolidate + simplify target backend attribute implementations
     (hch + nab)
   - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch)
   - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab)
   - Drop unnecessary core_tpg_register TFO parameter (nab)
   - Use 64-bit LUNs tree-wide (hannes)
   - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits)
  target: Bump core version to v5.0
  target: remove target_core_configfs.h
  target: remove unused TARGET_CORE_CONFIG_ROOT define
  target: consolidate version defines
  target: implement WRITE_SAME with UNMAP bit using ->execute_unmap
  target: simplify UNMAP handling
  target: replace se_cmd->execute_rw with a protocol_data field
  target/user: Fix inconsistent kmap_atomic/kunmap_atomic
  target: Send UA when changing LUN inventory
  target: Send UA upon LUN RESET tmr completion
  target: Send UA on ALUA target port group change
  target: Convert se_lun->lun_deve_lock to normal spinlock
  target: use 'se_dev_entry' when allocating UAs
  target: Remove 'ua_nacl' pointer from se_ua structure
  target_core_alua: Correct UA handling when switching states
  xen-scsiback: Fix compile warning for 64-bit LUN
  target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
  target: use 64-bit LUNs
  target: Drop duplicate + unused se_dev_check_wce
  target: Drop unnecessary core_tpg_register TFO parameter
  ...
2015-07-04 14:13:43 -07:00

1921 lines
48 KiB
C

/*
* 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 <stdarg.h>
#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 <target/target_core_fabric_configfs.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;
int ring_error;
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;
};
/* 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 scsiback_tmr {
atomic_t tmr_complete;
wait_queue_head_t tmr_wait;
};
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");
static struct kmem_cache *scsiback_cachep;
static DEFINE_SPINLOCK(free_pages_lock);
static int free_pages_num;
static LIST_HEAD(scsiback_free_pages);
/* 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 void put_free_pages(struct page **page, int num)
{
unsigned long flags;
int i = free_pages_num + num, n = num;
if (num == 0)
return;
if (i > scsiback_max_buffer_pages) {
n = min(num, i - scsiback_max_buffer_pages);
gnttab_free_pages(n, page + num - n);
n = num - n;
}
spin_lock_irqsave(&free_pages_lock, flags);
for (i = 0; i < n; i++)
list_add(&page[i]->lru, &scsiback_free_pages);
free_pages_num += n;
spin_unlock_irqrestore(&free_pages_lock, flags);
}
static int get_free_page(struct page **page)
{
unsigned long flags;
spin_lock_irqsave(&free_pages_lock, flags);
if (list_empty(&scsiback_free_pages)) {
spin_unlock_irqrestore(&free_pages_lock, flags);
return gnttab_alloc_pages(1, page);
}
page[0] = list_first_entry(&scsiback_free_pages, struct page, lru);
list_del(&page[0]->lru);
free_pages_num--;
spin_unlock_irqrestore(&free_pages_lock, flags);
return 0;
}
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 drv=%02x\n",
tpg->tport->tport_name, pending_req->v2p->lun,
pending_req->cmnd[0], status_byte(errors), msg_byte(errors),
host_byte(errors), driver_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);
}
put_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 void scsiback_do_resp_with_sense(char *sense_buffer, int32_t result,
uint32_t resid, struct vscsibk_pend *pending_req)
{
struct vscsiif_response *ring_res;
struct vscsibk_info *info = pending_req->info;
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 = result;
ring_res->rqid = pending_req->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);
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);
}
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;
int rc;
memset(pending_req->sense_buffer, 0, VSCSIIF_SENSE_BUFFERSIZE);
memset(se_cmd, 0, sizeof(*se_cmd));
scsiback_get(pending_req->info);
se_cmd->tag = pending_req->rqid;
rc = target_submit_cmd_map_sgls(se_cmd, sess, pending_req->cmnd,
pending_req->sense_buffer, pending_req->v2p->lun,
pending_req->data_len, 0,
pending_req->sc_data_direction, 0,
pending_req->sgl, pending_req->n_sg,
NULL, 0, NULL, 0);
if (rc < 0) {
transport_send_check_condition_and_sense(se_cmd,
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
transport_generic_free_cmd(se_cmd, 0);
}
}
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);
BUG_ON(err);
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;
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 (get_free_page(pg + mapcount)) {
put_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)
{
int rc, err = FAILED;
struct scsiback_tpg *tpg = pending_req->v2p->tpg;
struct se_cmd *se_cmd = &pending_req->se_cmd;
struct scsiback_tmr *tmr;
tmr = kzalloc(sizeof(struct scsiback_tmr), GFP_KERNEL);
if (!tmr)
goto out;
init_waitqueue_head(&tmr->tmr_wait);
transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG,
&pending_req->sense_buffer[0]);
rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
if (rc < 0)
goto out;
se_cmd->se_tmr_req->ref_task_tag = tag;
if (transport_lookup_tmr_lun(se_cmd, pending_req->v2p->lun) < 0)
goto out;
transport_generic_handle_tmr(se_cmd);
wait_event(tmr->tmr_wait, atomic_read(&tmr->tmr_complete));
err = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
SUCCESS : FAILED;
out:
if (tmr) {
transport_generic_free_cmd(&pending_req->se_cmd, 1);
kfree(tmr);
}
scsiback_do_resp_with_sense(NULL, err, 0, pending_req);
kmem_cache_free(scsiback_cachep, 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 int prepare_pending_reqs(struct vscsibk_info *info,
struct vscsiif_request *ring_req,
struct vscsibk_pend *pending_req)
{
struct v2p_entry *v2p;
struct ids_tuple vir;
pending_req->rqid = ring_req->rqid;
pending_req->info = info;
vir.chn = ring_req->channel;
vir.tgt = ring_req->id;
vir.lun = ring_req->lun;
v2p = scsiback_do_translation(info, &vir);
if (!v2p) {
pending_req->v2p = NULL;
pr_debug("the v2p of (chn:%d, tgt:%d, lun:%d) doesn't exist.\n",
vir.chn, vir.tgt, vir.lun);
return -ENODEV;
}
pending_req->v2p = v2p;
/* request range check from frontend */
pending_req->sc_data_direction = ring_req->sc_data_direction;
if ((pending_req->sc_data_direction != DMA_BIDIRECTIONAL) &&
(pending_req->sc_data_direction != DMA_TO_DEVICE) &&
(pending_req->sc_data_direction != DMA_FROM_DEVICE) &&
(pending_req->sc_data_direction != DMA_NONE)) {
pr_debug("invalid parameter data_dir = %d\n",
pending_req->sc_data_direction);
return -EINVAL;
}
pending_req->cmd_len = ring_req->cmd_len;
if (pending_req->cmd_len > VSCSIIF_MAX_COMMAND_SIZE) {
pr_debug("invalid parameter cmd_len = %d\n",
pending_req->cmd_len);
return -EINVAL;
}
memcpy(pending_req->cmnd, ring_req->cmnd, pending_req->cmd_len);
return 0;
}
static int scsiback_do_cmd_fn(struct vscsibk_info *info)
{
struct vscsiif_back_ring *ring = &info->ring;
struct vscsiif_request ring_req;
struct vscsibk_pend *pending_req;
RING_IDX rc, rp;
int err, 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);
info->ring_error = 1;
return 0;
}
while ((rc != rp)) {
if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
break;
pending_req = kmem_cache_alloc(scsiback_cachep, GFP_KERNEL);
if (!pending_req)
return 1;
ring_req = *RING_GET_REQUEST(ring, rc);
ring->req_cons = ++rc;
err = prepare_pending_reqs(info, &ring_req, pending_req);
if (err) {
switch (err) {
case -ENODEV:
result = DID_NO_CONNECT;
break;
default:
result = DRIVER_ERROR;
break;
}
scsiback_do_resp_with_sense(NULL, result << 24, 0,
pending_req);
kmem_cache_free(scsiback_cachep, pending_req);
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,
DRIVER_ERROR << 24, 0, pending_req);
kmem_cache_free(scsiback_cachep, pending_req);
} 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, DRIVER_ERROR << 24,
0, pending_req);
kmem_cache_free(scsiback_cachep, pending_req);
break;
}
/* Yield point for this unbounded loop. */
cond_resched();
}
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;
if (info->ring_error)
return IRQ_HANDLED;
while (scsiback_do_cmd_fn(info))
cond_resched();
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(info->domid, 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;
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);
}
/*
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 *entry;
struct v2p_entry *new;
struct list_head *head = &(info->v2p_entry_lists);
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 */
list_for_each_entry(entry, head, l) {
if ((entry->v.chn == v->chn) &&
(entry->v.tgt == v->tgt) &&
(entry->v.lun == v->lun)) {
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, head);
out:
spin_unlock_irqrestore(&info->v2p_lock, flags);
out_free:
mutex_lock(&tpg->tv_tpg_mutex);
tpg->tv_tpg_fe_count--;
mutex_unlock(&tpg->tv_tpg_mutex);
if (err)
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 specfied
*/
static int scsiback_del_translation_entry(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);
/* Find out the translation entry specified */
list_for_each_entry(entry, head, l) {
if ((entry->v.chn == v->chn) &&
(entry->v.tgt == v->tgt) &&
(entry->v.lun == v->lun)) {
goto found;
}
}
spin_unlock_irqrestore(&info->v2p_lock, flags);
return 1;
found:
/* Delete the translation entry specfied */
__scsiback_del_translation_entry(entry);
spin_unlock_irqrestore(&info->v2p_lock, flags);
return 0;
}
static void scsiback_do_add_lun(struct vscsibk_info *info, const char *state,
char *phy, struct ids_tuple *vir, int try)
{
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) {
xenbus_printf(XBT_NIL, info->dev->nodename, state,
"%d", XenbusStateClosed);
}
}
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)) {
xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
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)) {
xenbus_printf(XBT_NIL, dev->nodename, state,
"%d", XenbusStateClosed);
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;
/* fall through 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 int 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);
dev_set_drvdata(&dev->dev, NULL);
return 0;
}
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);
info->ring_error = 0;
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);
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)
{
/*
* Do not release struct se_cmd's containing a valid TMR pointer.
* These will be released directly in scsiback_device_action()
* with transport_generic_free_cmd().
*/
if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
return 0;
transport_generic_free_cmd(se_cmd, 0);
return 1;
}
static void scsiback_release_cmd(struct se_cmd *se_cmd)
{
struct vscsibk_pend *pending_req = container_of(se_cmd,
struct vscsibk_pend, se_cmd);
kmem_cache_free(scsiback_cachep, pending_req);
}
static int scsiback_shutdown_session(struct se_session *se_sess)
{
return 0;
}
static void scsiback_close_session(struct se_session *se_sess)
{
}
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 int scsiback_write_pending_status(struct se_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 = (DRIVER_SENSE << 24) |
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 se_tmr_req *se_tmr = se_cmd->se_tmr_req;
struct scsiback_tmr *tmr = se_tmr->fabric_tmr_ptr;
atomic_set(&tmr->tmr_complete, 1);
wake_up(&tmr->tmr_wait);
}
static void scsiback_aborted_task(struct se_cmd *se_cmd)
{
}
static ssize_t scsiback_tpg_param_show_alias(struct se_portal_group *se_tpg,
char *page)
{
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_store_alias(struct se_portal_group *se_tpg,
const char *page, size_t count)
{
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;
}
TF_TPG_PARAM_ATTR(scsiback, alias, S_IRUGO | S_IWUSR);
static struct configfs_attribute *scsiback_param_attrs[] = {
&scsiback_tpg_param_alias.attr,
NULL,
};
static int scsiback_make_nexus(struct scsiback_tpg *tpg,
const char *name)
{
struct se_portal_group *se_tpg;
struct se_session *se_sess;
struct scsiback_nexus *tv_nexus;
mutex_lock(&tpg->tv_tpg_mutex);
if (tpg->tpg_nexus) {
mutex_unlock(&tpg->tv_tpg_mutex);
pr_debug("tpg->tpg_nexus already exists\n");
return -EEXIST;
}
se_tpg = &tpg->se_tpg;
tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
if (!tv_nexus) {
mutex_unlock(&tpg->tv_tpg_mutex);
return -ENOMEM;
}
/*
* Initialize the struct se_session pointer
*/
tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
if (IS_ERR(tv_nexus->tvn_se_sess)) {
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(tv_nexus);
return -ENOMEM;
}
se_sess = tv_nexus->tvn_se_sess;
/*
* Since we are running in 'demo mode' this call with generate a
* struct se_node_acl for the scsiback struct se_portal_group with
* the SCSI Initiator port name of the passed configfs group 'name'.
*/
tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
se_tpg, (unsigned char *)name);
if (!tv_nexus->tvn_se_sess->se_node_acl) {
mutex_unlock(&tpg->tv_tpg_mutex);
pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
name);
goto out;
}
/* Now register the TCM pvscsi virtual I_T Nexus as active. */
transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
tv_nexus->tvn_se_sess, tv_nexus);
tpg->tpg_nexus = tv_nexus;
mutex_unlock(&tpg->tv_tpg_mutex);
return 0;
out:
transport_free_session(se_sess);
kfree(tv_nexus);
return -ENOMEM;
}
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
*/
transport_deregister_session(tv_nexus->tvn_se_sess);
tpg->tpg_nexus = NULL;
mutex_unlock(&tpg->tv_tpg_mutex);
kfree(tv_nexus);
return 0;
}
static ssize_t scsiback_tpg_show_nexus(struct se_portal_group *se_tpg,
char *page)
{
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_store_nexus(struct se_portal_group *se_tpg,
const char *page,
size_t count)
{
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;
}
TF_TPG_BASE_ATTR(scsiback, nexus, S_IRUGO | S_IWUSR);
static struct configfs_attribute *scsiback_tpg_attrs[] = {
&scsiback_tpg_nexus.attr,
NULL,
};
static ssize_t
scsiback_wwn_show_attr_version(struct target_fabric_configfs *tf,
char *page)
{
return sprintf(page, "xen-pvscsi fabric module %s on %s/%s on "
UTS_RELEASE"\n",
VSCSI_VERSION, utsname()->sysname, utsname()->machine);
}
TF_WWN_ATTR_RO(scsiback, version);
static struct configfs_attribute *scsiback_wwn_attrs[] = {
&scsiback_wwn_version.attr,
NULL,
};
static char *scsiback_get_fabric_name(void)
{
return "xen-pvscsi";
}
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,
struct config_group *group,
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,
.name = "xen-pvscsi",
.get_fabric_name = scsiback_get_fabric_name,
.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,
.shutdown_session = scsiback_shutdown_session,
.close_session = scsiback_close_session,
.sess_get_index = scsiback_sess_get_index,
.sess_get_initiator_sid = NULL,
.write_pending = scsiback_write_pending,
.write_pending_status = scsiback_write_pending_status,
.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,
};
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 void scsiback_init_pend(void *p)
{
struct vscsibk_pend *pend = p;
int i;
memset(pend, 0, sizeof(*pend));
for (i = 0; i < VSCSI_MAX_GRANTS; i++)
pend->grant_handles[i] = SCSIBACK_INVALID_HANDLE;
}
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);
scsiback_cachep = kmem_cache_create("vscsiif_cache",
sizeof(struct vscsibk_pend), 0, 0, scsiback_init_pend);
if (!scsiback_cachep)
return -ENOMEM;
ret = xenbus_register_backend(&scsiback_driver);
if (ret)
goto out_cache_destroy;
ret = target_register_template(&scsiback_ops);
if (ret)
goto out_unregister_xenbus;
return 0;
out_unregister_xenbus:
xenbus_unregister_driver(&scsiback_driver);
out_cache_destroy:
kmem_cache_destroy(scsiback_cachep);
pr_err("%s: error %d\n", __func__, ret);
return ret;
}
static void __exit scsiback_exit(void)
{
struct page *page;
while (free_pages_num) {
if (get_free_page(&page))
BUG();
gnttab_free_pages(1, &page);
}
target_unregister_template(&scsiback_ops);
xenbus_unregister_driver(&scsiback_driver);
kmem_cache_destroy(scsiback_cachep);
}
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>");