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qemu/block/iscsi.c
Peter Lieven e1123a3b40 block/iscsi: allow caching of the allocation map 
until now the allocation map was used only as a hint if a cluster
is allocated or not. If a block was not allocated (or Qemu had
no info about the allocation status) a get_block_status call was
issued to check the allocation status and possibly avoid
a subsequent read of unallocated sectors. If a block known to be
allocated the get_block_status call was omitted. In the other case
a get_block_status call was issued before every read to avoid
the necessity for a consistent allocation map. To avoid the
potential overhead of calling get_block_status for each and
every read request this took only place for the bigger requests.

This patch enhances this mechanism to cache the allocation
status and avoid calling get_block_status for blocks where
the allocation status has been queried before. This allows
for bypassing the read request even for smaller requests and
additionally omits calling get_block_status for known to be
unallocated blocks.

Signed-off-by: Peter Lieven <pl@kamp.de>
Message-Id: <1468831940-15556-3-git-send-email-pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-19 08:34:53 +02:00

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/*
* QEMU Block driver for iSCSI images
*
* Copyright (c) 2010-2011 Ronnie Sahlberg <ronniesahlberg@gmail.com>
* Copyright (c) 2012-2016 Peter Lieven <pl@kamp.de>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (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.
*/
#include "qemu/osdep.h"
#include <poll.h>
#include <math.h>
#include <arpa/inet.h>
#include "qemu-common.h"
#include "qemu/config-file.h"
#include "qemu/error-report.h"
#include "qemu/bitops.h"
#include "qemu/bitmap.h"
#include "block/block_int.h"
#include "block/scsi.h"
#include "qemu/iov.h"
#include "sysemu/sysemu.h"
#include "qmp-commands.h"
#include "qapi/qmp/qstring.h"
#include "crypto/secret.h"
#include <iscsi/iscsi.h>
#include <iscsi/scsi-lowlevel.h>
#ifdef __linux__
#include <scsi/sg.h>
#endif
typedef struct IscsiLun {
struct iscsi_context *iscsi;
AioContext *aio_context;
int lun;
enum scsi_inquiry_peripheral_device_type type;
int block_size;
uint64_t num_blocks;
int events;
QEMUTimer *nop_timer;
QEMUTimer *event_timer;
struct scsi_inquiry_logical_block_provisioning lbp;
struct scsi_inquiry_block_limits bl;
unsigned char *zeroblock;
/* The allocmap tracks which clusters (pages) on the iSCSI target are
* allocated and which are not. In case a target returns zeros for
* unallocated pages (iscsilun->lprz) we can directly return zeros instead
* of reading zeros over the wire if a read request falls within an
* unallocated block. As there are 3 possible states we need 2 bitmaps to
* track. allocmap_valid keeps track if QEMU's information about a page is
* valid. allocmap tracks if a page is allocated or not. In case QEMU has no
* valid information about a page the corresponding allocmap entry should be
* switched to unallocated as well to force a new lookup of the allocation
* status as lookups are generally skipped if a page is suspect to be
* allocated. If a iSCSI target is opened with cache.direct = on the
* allocmap_valid does not exist turning all cached information invalid so
* that a fresh lookup is made for any page even if allocmap entry returns
* it's unallocated. */
unsigned long *allocmap;
unsigned long *allocmap_valid;
long allocmap_size;
int cluster_sectors;
bool use_16_for_rw;
bool write_protected;
bool lbpme;
bool lbprz;
bool dpofua;
bool has_write_same;
bool request_timed_out;
} IscsiLun;
typedef struct IscsiTask {
int status;
int complete;
int retries;
int do_retry;
struct scsi_task *task;
Coroutine *co;
QEMUBH *bh;
IscsiLun *iscsilun;
QEMUTimer retry_timer;
int err_code;
} IscsiTask;
typedef struct IscsiAIOCB {
BlockAIOCB common;
QEMUIOVector *qiov;
QEMUBH *bh;
IscsiLun *iscsilun;
struct scsi_task *task;
uint8_t *buf;
int status;
int64_t sector_num;
int nb_sectors;
int ret;
#ifdef __linux__
sg_io_hdr_t *ioh;
#endif
} IscsiAIOCB;
/* libiscsi uses time_t so its enough to process events every second */
#define EVENT_INTERVAL 1000
#define NOP_INTERVAL 5000
#define MAX_NOP_FAILURES 3
#define ISCSI_CMD_RETRIES ARRAY_SIZE(iscsi_retry_times)
static const unsigned iscsi_retry_times[] = {8, 32, 128, 512, 2048, 8192, 32768};
/* this threshold is a trade-off knob to choose between
* the potential additional overhead of an extra GET_LBA_STATUS request
* vs. unnecessarily reading a lot of zero sectors over the wire.
* If a read request is greater or equal than ISCSI_CHECKALLOC_THRES
* sectors we check the allocation status of the area covered by the
* request first if the allocationmap indicates that the area might be
* unallocated. */
#define ISCSI_CHECKALLOC_THRES 64
static void
iscsi_bh_cb(void *p)
{
IscsiAIOCB *acb = p;
qemu_bh_delete(acb->bh);
g_free(acb->buf);
acb->buf = NULL;
acb->common.cb(acb->common.opaque, acb->status);
if (acb->task != NULL) {
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
qemu_aio_unref(acb);
}
static void
iscsi_schedule_bh(IscsiAIOCB *acb)
{
if (acb->bh) {
return;
}
acb->bh = aio_bh_new(acb->iscsilun->aio_context, iscsi_bh_cb, acb);
qemu_bh_schedule(acb->bh);
}
static void iscsi_co_generic_bh_cb(void *opaque)
{
struct IscsiTask *iTask = opaque;
iTask->complete = 1;
qemu_bh_delete(iTask->bh);
qemu_coroutine_enter(iTask->co);
}
static void iscsi_retry_timer_expired(void *opaque)
{
struct IscsiTask *iTask = opaque;
iTask->complete = 1;
if (iTask->co) {
qemu_coroutine_enter(iTask->co);
}
}
static inline unsigned exp_random(double mean)
{
return -mean * log((double)rand() / RAND_MAX);
}
/* SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST was introduced in
* libiscsi 1.10.0, together with other constants we need. Use it as
* a hint that we have to define them ourselves if needed, to keep the
* minimum required libiscsi version at 1.9.0. We use an ASCQ macro for
* the test because SCSI_STATUS_* is an enum.
*
* To guard against future changes where SCSI_SENSE_ASCQ_* also becomes
* an enum, check against the LIBISCSI_API_VERSION macro, which was
* introduced in 1.11.0. If it is present, there is no need to define
* anything.
*/
#if !defined(SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST) && \
!defined(LIBISCSI_API_VERSION)
#define SCSI_STATUS_TASK_SET_FULL 0x28
#define SCSI_STATUS_TIMEOUT 0x0f000002
#define SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST 0x2600
#define SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR 0x1a00
#endif
static int iscsi_translate_sense(struct scsi_sense *sense)
{
int ret;
switch (sense->key) {
case SCSI_SENSE_NOT_READY:
return -EBUSY;
case SCSI_SENSE_DATA_PROTECTION:
return -EACCES;
case SCSI_SENSE_COMMAND_ABORTED:
return -ECANCELED;
case SCSI_SENSE_ILLEGAL_REQUEST:
/* Parse ASCQ */
break;
default:
return -EIO;
}
switch (sense->ascq) {
case SCSI_SENSE_ASCQ_PARAMETER_LIST_LENGTH_ERROR:
case SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE:
case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB:
case SCSI_SENSE_ASCQ_INVALID_FIELD_IN_PARAMETER_LIST:
ret = -EINVAL;
break;
case SCSI_SENSE_ASCQ_LBA_OUT_OF_RANGE:
ret = -ENOSPC;
break;
case SCSI_SENSE_ASCQ_LOGICAL_UNIT_NOT_SUPPORTED:
ret = -ENOTSUP;
break;
case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT:
case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_CLOSED:
case SCSI_SENSE_ASCQ_MEDIUM_NOT_PRESENT_TRAY_OPEN:
ret = -ENOMEDIUM;
break;
case SCSI_SENSE_ASCQ_WRITE_PROTECTED:
ret = -EACCES;
break;
default:
ret = -EIO;
break;
}
return ret;
}
static void
iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
struct IscsiTask *iTask = opaque;
struct scsi_task *task = command_data;
iTask->status = status;
iTask->do_retry = 0;
iTask->task = task;
if (status != SCSI_STATUS_GOOD) {
if (iTask->retries++ < ISCSI_CMD_RETRIES) {
if (status == SCSI_STATUS_CHECK_CONDITION
&& task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
error_report("iSCSI CheckCondition: %s",
iscsi_get_error(iscsi));
iTask->do_retry = 1;
goto out;
}
if (status == SCSI_STATUS_BUSY ||
status == SCSI_STATUS_TIMEOUT ||
status == SCSI_STATUS_TASK_SET_FULL) {
unsigned retry_time =
exp_random(iscsi_retry_times[iTask->retries - 1]);
if (status == SCSI_STATUS_TIMEOUT) {
/* make sure the request is rescheduled AFTER the
* reconnect is initiated */
retry_time = EVENT_INTERVAL * 2;
iTask->iscsilun->request_timed_out = true;
}
error_report("iSCSI Busy/TaskSetFull/TimeOut"
" (retry #%u in %u ms): %s",
iTask->retries, retry_time,
iscsi_get_error(iscsi));
aio_timer_init(iTask->iscsilun->aio_context,
&iTask->retry_timer, QEMU_CLOCK_REALTIME,
SCALE_MS, iscsi_retry_timer_expired, iTask);
timer_mod(&iTask->retry_timer,
qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + retry_time);
iTask->do_retry = 1;
return;
}
}
iTask->err_code = iscsi_translate_sense(&task->sense);
error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));
}
out:
if (iTask->co) {
iTask->bh = aio_bh_new(iTask->iscsilun->aio_context,
iscsi_co_generic_bh_cb, iTask);
qemu_bh_schedule(iTask->bh);
} else {
iTask->complete = 1;
}
}
static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
{
*iTask = (struct IscsiTask) {
.co = qemu_coroutine_self(),
.iscsilun = iscsilun,
};
}
static void
iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
void *private_data)
{
IscsiAIOCB *acb = private_data;
acb->status = -ECANCELED;
iscsi_schedule_bh(acb);
}
static void
iscsi_aio_cancel(BlockAIOCB *blockacb)
{
IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
IscsiLun *iscsilun = acb->iscsilun;
if (acb->status != -EINPROGRESS) {
return;
}
/* send a task mgmt call to the target to cancel the task on the target */
iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
iscsi_abort_task_cb, acb);
}
static const AIOCBInfo iscsi_aiocb_info = {
.aiocb_size = sizeof(IscsiAIOCB),
.cancel_async = iscsi_aio_cancel,
};
static void iscsi_process_read(void *arg);
static void iscsi_process_write(void *arg);
static void
iscsi_set_events(IscsiLun *iscsilun)
{
struct iscsi_context *iscsi = iscsilun->iscsi;
int ev = iscsi_which_events(iscsi);
if (ev != iscsilun->events) {
aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsi),
false,
(ev & POLLIN) ? iscsi_process_read : NULL,
(ev & POLLOUT) ? iscsi_process_write : NULL,
iscsilun);
iscsilun->events = ev;
}
}
static void iscsi_timed_check_events(void *opaque)
{
IscsiLun *iscsilun = opaque;
/* check for timed out requests */
iscsi_service(iscsilun->iscsi, 0);
if (iscsilun->request_timed_out) {
iscsilun->request_timed_out = false;
iscsi_reconnect(iscsilun->iscsi);
}
/* newer versions of libiscsi may return zero events. Ensure we are able
* to return to service once this situation changes. */
iscsi_set_events(iscsilun);
timer_mod(iscsilun->event_timer,
qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
}
static void
iscsi_process_read(void *arg)
{
IscsiLun *iscsilun = arg;
struct iscsi_context *iscsi = iscsilun->iscsi;
iscsi_service(iscsi, POLLIN);
iscsi_set_events(iscsilun);
}
static void
iscsi_process_write(void *arg)
{
IscsiLun *iscsilun = arg;
struct iscsi_context *iscsi = iscsilun->iscsi;
iscsi_service(iscsi, POLLOUT);
iscsi_set_events(iscsilun);
}
static int64_t sector_lun2qemu(int64_t sector, IscsiLun *iscsilun)
{
return sector * iscsilun->block_size / BDRV_SECTOR_SIZE;
}
static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
{
return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
}
static bool is_byte_request_lun_aligned(int64_t offset, int count,
IscsiLun *iscsilun)
{
if (offset % iscsilun->block_size || count % iscsilun->block_size) {
error_report("iSCSI misaligned request: "
"iscsilun->block_size %u, offset %" PRIi64
", count %d",
iscsilun->block_size, offset, count);
return false;
}
return true;
}
static bool is_sector_request_lun_aligned(int64_t sector_num, int nb_sectors,
IscsiLun *iscsilun)
{
assert(nb_sectors <= BDRV_REQUEST_MAX_SECTORS);
return is_byte_request_lun_aligned(sector_num << BDRV_SECTOR_BITS,
nb_sectors << BDRV_SECTOR_BITS,
iscsilun);
}
static void iscsi_allocmap_free(IscsiLun *iscsilun)
{
g_free(iscsilun->allocmap);
g_free(iscsilun->allocmap_valid);
iscsilun->allocmap = NULL;
iscsilun->allocmap_valid = NULL;
}
static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags)
{
iscsi_allocmap_free(iscsilun);
iscsilun->allocmap_size =
DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun),
iscsilun->cluster_sectors);
iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size);
if (!iscsilun->allocmap) {
return -ENOMEM;
}
if (open_flags & BDRV_O_NOCACHE) {
/* in case that cache.direct = on all allocmap entries are
* treated as invalid to force a relookup of the block
* status on every read request */
return 0;
}
iscsilun->allocmap_valid = bitmap_try_new(iscsilun->allocmap_size);
if (!iscsilun->allocmap_valid) {
/* if we are under memory pressure free the allocmap as well */
iscsi_allocmap_free(iscsilun);
return -ENOMEM;
}
return 0;
}
static void
iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors, bool allocated, bool valid)
{
int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk;
if (iscsilun->allocmap == NULL) {
return;
}
/* expand to entirely contain all affected clusters */
cl_num_expanded = sector_num / iscsilun->cluster_sectors;
nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors,
iscsilun->cluster_sectors) - cl_num_expanded;
/* shrink to touch only completely contained clusters */
cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors);
nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors
- cl_num_shrunk;
if (allocated) {
bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded);
} else {
bitmap_clear(iscsilun->allocmap, cl_num_shrunk, nb_cls_shrunk);
}
if (iscsilun->allocmap_valid == NULL) {
return;
}
if (valid) {
bitmap_set(iscsilun->allocmap_valid, cl_num_shrunk, nb_cls_shrunk);
} else {
bitmap_clear(iscsilun->allocmap_valid, cl_num_expanded,
nb_cls_expanded);
}
}
static void
iscsi_allocmap_set_allocated(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors)
{
iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, true, true);
}
static void
iscsi_allocmap_set_unallocated(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors)
{
/* Note: if cache.direct=on the fifth argument to iscsi_allocmap_update
* is ignored, so this will in effect be an iscsi_allocmap_set_invalid.
*/
iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, true);
}
static void iscsi_allocmap_set_invalid(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors)
{
iscsi_allocmap_update(iscsilun, sector_num, nb_sectors, false, false);
}
static void iscsi_allocmap_invalidate(IscsiLun *iscsilun)
{
if (iscsilun->allocmap) {
bitmap_zero(iscsilun->allocmap, iscsilun->allocmap_size);
}
if (iscsilun->allocmap_valid) {
bitmap_zero(iscsilun->allocmap_valid, iscsilun->allocmap_size);
}
}
static inline bool
iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num,
int nb_sectors)
{
unsigned long size;
if (iscsilun->allocmap == NULL) {
return true;
}
size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
return !(find_next_bit(iscsilun->allocmap, size,
sector_num / iscsilun->cluster_sectors) == size);
}
static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun,
int64_t sector_num, int nb_sectors)
{
unsigned long size;
if (iscsilun->allocmap_valid == NULL) {
return false;
}
size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors);
return (find_next_zero_bit(iscsilun->allocmap_valid, size,
sector_num / iscsilun->cluster_sectors) == size);
}
static int coroutine_fn
iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
QEMUIOVector *iov, int flags)
{
IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask;
uint64_t lba;
uint32_t num_sectors;
bool fua = flags & BDRV_REQ_FUA;
if (fua) {
assert(iscsilun->dpofua);
}
if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
return -EINVAL;
}
if (bs->bl.max_transfer &&
nb_sectors << BDRV_SECTOR_BITS > bs->bl.max_transfer) {
error_report("iSCSI Error: Write of %d sectors exceeds max_xfer_len "
"of %" PRIu32 " bytes", nb_sectors, bs->bl.max_transfer);
return -EINVAL;
}
lba = sector_qemu2lun(sector_num, iscsilun);
num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
if (iscsilun->use_16_for_rw) {
iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
NULL, num_sectors * iscsilun->block_size,
iscsilun->block_size, 0, 0, fua, 0, 0,
iscsi_co_generic_cb, &iTask);
} else {
iTask.task = iscsi_write10_task(iscsilun->iscsi, iscsilun->lun, lba,
NULL, num_sectors * iscsilun->block_size,
iscsilun->block_size, 0, 0, fua, 0, 0,
iscsi_co_generic_cb, &iTask);
}
if (iTask.task == NULL) {
return -ENOMEM;
}
scsi_task_set_iov_out(iTask.task, (struct scsi_iovec *) iov->iov,
iov->niov);
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
if (iTask.do_retry) {
iTask.complete = 0;
goto retry;
}
if (iTask.status != SCSI_STATUS_GOOD) {
iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors);
return iTask.err_code;
}
iscsi_allocmap_set_allocated(iscsilun, sector_num, nb_sectors);
return 0;
}
static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, int *pnum,
BlockDriverState **file)
{
IscsiLun *iscsilun = bs->opaque;
struct scsi_get_lba_status *lbas = NULL;
struct scsi_lba_status_descriptor *lbasd = NULL;
struct IscsiTask iTask;
int64_t ret;
iscsi_co_init_iscsitask(iscsilun, &iTask);
if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
ret = -EINVAL;
goto out;
}
/* default to all sectors allocated */
ret = BDRV_BLOCK_DATA;
ret |= (sector_num << BDRV_SECTOR_BITS) | BDRV_BLOCK_OFFSET_VALID;
*pnum = nb_sectors;
/* LUN does not support logical block provisioning */
if (!iscsilun->lbpme) {
goto out;
}
retry:
if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
sector_qemu2lun(sector_num, iscsilun),
8 + 16, iscsi_co_generic_cb,
&iTask) == NULL) {
ret = -ENOMEM;
goto out;
}
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.do_retry) {
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
iTask.complete = 0;
goto retry;
}
if (iTask.status != SCSI_STATUS_GOOD) {
/* in case the get_lba_status_callout fails (i.e.
* because the device is busy or the cmd is not
* supported) we pretend all blocks are allocated
* for backwards compatibility */
goto out;
}
lbas = scsi_datain_unmarshall(iTask.task);
if (lbas == NULL) {
ret = -EIO;
goto out;
}
lbasd = &lbas->descriptors[0];
if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
ret = -EIO;
goto out;
}
*pnum = sector_lun2qemu(lbasd->num_blocks, iscsilun);
if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
ret &= ~BDRV_BLOCK_DATA;
if (iscsilun->lbprz) {
ret |= BDRV_BLOCK_ZERO;
}
}
if (ret & BDRV_BLOCK_ZERO) {
iscsi_allocmap_set_unallocated(iscsilun, sector_num, *pnum);
} else {
iscsi_allocmap_set_allocated(iscsilun, sector_num, *pnum);
}
if (*pnum > nb_sectors) {
*pnum = nb_sectors;
}
out:
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
}
if (ret > 0 && ret & BDRV_BLOCK_OFFSET_VALID) {
*file = bs;
}
return ret;
}
static int coroutine_fn iscsi_co_readv(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
QEMUIOVector *iov)
{
IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask;
uint64_t lba;
uint32_t num_sectors;
if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
return -EINVAL;
}
if (bs->bl.max_transfer &&
nb_sectors << BDRV_SECTOR_BITS > bs->bl.max_transfer) {
error_report("iSCSI Error: Read of %d sectors exceeds max_xfer_len "
"of %" PRIu32 " bytes", nb_sectors, bs->bl.max_transfer);
return -EINVAL;
}
/* if cache.direct is off and we have a valid entry in our allocation map
* we can skip checking the block status and directly return zeroes if
* the request falls within an unallocated area */
if (iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
!iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
if (nb_sectors >= ISCSI_CHECKALLOC_THRES &&
!iscsi_allocmap_is_valid(iscsilun, sector_num, nb_sectors) &&
!iscsi_allocmap_is_allocated(iscsilun, sector_num, nb_sectors)) {
int pnum;
BlockDriverState *file;
/* check the block status from the beginning of the cluster
* containing the start sector */
int64_t ret = iscsi_co_get_block_status(bs,
sector_num - sector_num % iscsilun->cluster_sectors,
BDRV_REQUEST_MAX_SECTORS, &pnum, &file);
if (ret < 0) {
return ret;
}
/* if the whole request falls into an unallocated area we can avoid
* to read and directly return zeroes instead */
if (ret & BDRV_BLOCK_ZERO &&
pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) {
qemu_iovec_memset(iov, 0, 0x00, iov->size);
return 0;
}
}
lba = sector_qemu2lun(sector_num, iscsilun);
num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
if (iscsilun->use_16_for_rw) {
iTask.task = iscsi_read16_task(iscsilun->iscsi, iscsilun->lun, lba,
num_sectors * iscsilun->block_size,
iscsilun->block_size, 0, 0, 0, 0, 0,
iscsi_co_generic_cb, &iTask);
} else {
iTask.task = iscsi_read10_task(iscsilun->iscsi, iscsilun->lun, lba,
num_sectors * iscsilun->block_size,
iscsilun->block_size,
0, 0, 0, 0, 0,
iscsi_co_generic_cb, &iTask);
}
if (iTask.task == NULL) {
return -ENOMEM;
}
scsi_task_set_iov_in(iTask.task, (struct scsi_iovec *) iov->iov, iov->niov);
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
if (iTask.do_retry) {
iTask.complete = 0;
goto retry;
}
if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code;
}
return 0;
}
static int coroutine_fn iscsi_co_flush(BlockDriverState *bs)
{
IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask;
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
0, iscsi_co_generic_cb, &iTask) == NULL) {
return -ENOMEM;
}
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
if (iTask.do_retry) {
iTask.complete = 0;
goto retry;
}
if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code;
}
return 0;
}
#ifdef __linux__
static void
iscsi_aio_ioctl_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
IscsiAIOCB *acb = opaque;
g_free(acb->buf);
acb->buf = NULL;
acb->status = 0;
if (status < 0) {
error_report("Failed to ioctl(SG_IO) to iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = iscsi_translate_sense(&acb->task->sense);
}
acb->ioh->driver_status = 0;
acb->ioh->host_status = 0;
acb->ioh->resid = 0;
acb->ioh->status = status;
#define SG_ERR_DRIVER_SENSE 0x08
if (status == SCSI_STATUS_CHECK_CONDITION && acb->task->datain.size >= 2) {
int ss;
acb->ioh->driver_status |= SG_ERR_DRIVER_SENSE;
acb->ioh->sb_len_wr = acb->task->datain.size - 2;
ss = (acb->ioh->mx_sb_len >= acb->ioh->sb_len_wr) ?
acb->ioh->mx_sb_len : acb->ioh->sb_len_wr;
memcpy(acb->ioh->sbp, &acb->task->datain.data[2], ss);
}
iscsi_schedule_bh(acb);
}
static void iscsi_ioctl_bh_completion(void *opaque)
{
IscsiAIOCB *acb = opaque;
qemu_bh_delete(acb->bh);
acb->common.cb(acb->common.opaque, acb->ret);
qemu_aio_unref(acb);
}
static void iscsi_ioctl_handle_emulated(IscsiAIOCB *acb, int req, void *buf)
{
BlockDriverState *bs = acb->common.bs;
IscsiLun *iscsilun = bs->opaque;
int ret = 0;
switch (req) {
case SG_GET_VERSION_NUM:
*(int *)buf = 30000;
break;
case SG_GET_SCSI_ID:
((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
break;
default:
ret = -EINVAL;
}
assert(!acb->bh);
acb->bh = aio_bh_new(bdrv_get_aio_context(bs),
iscsi_ioctl_bh_completion, acb);
acb->ret = ret;
qemu_bh_schedule(acb->bh);
}
static BlockAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
struct iscsi_data data;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->bh = NULL;
acb->status = -EINPROGRESS;
acb->buf = NULL;
acb->ioh = buf;
if (req != SG_IO) {
iscsi_ioctl_handle_emulated(acb, req, buf);
return &acb->common;
}
if (acb->ioh->cmd_len > SCSI_CDB_MAX_SIZE) {
error_report("iSCSI: ioctl error CDB exceeds max size (%d > %d)",
acb->ioh->cmd_len, SCSI_CDB_MAX_SIZE);
qemu_aio_unref(acb);
return NULL;
}
acb->task = malloc(sizeof(struct scsi_task));
if (acb->task == NULL) {
error_report("iSCSI: Failed to allocate task for scsi command. %s",
iscsi_get_error(iscsi));
qemu_aio_unref(acb);
return NULL;
}
memset(acb->task, 0, sizeof(struct scsi_task));
switch (acb->ioh->dxfer_direction) {
case SG_DXFER_TO_DEV:
acb->task->xfer_dir = SCSI_XFER_WRITE;
break;
case SG_DXFER_FROM_DEV:
acb->task->xfer_dir = SCSI_XFER_READ;
break;
default:
acb->task->xfer_dir = SCSI_XFER_NONE;
break;
}
acb->task->cdb_size = acb->ioh->cmd_len;
memcpy(&acb->task->cdb[0], acb->ioh->cmdp, acb->ioh->cmd_len);
acb->task->expxferlen = acb->ioh->dxfer_len;
data.size = 0;
if (acb->task->xfer_dir == SCSI_XFER_WRITE) {
if (acb->ioh->iovec_count == 0) {
data.data = acb->ioh->dxferp;
data.size = acb->ioh->dxfer_len;
} else {
scsi_task_set_iov_out(acb->task,
(struct scsi_iovec *) acb->ioh->dxferp,
acb->ioh->iovec_count);
}
}
if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
iscsi_aio_ioctl_cb,
(data.size > 0) ? &data : NULL,
acb) != 0) {
scsi_free_scsi_task(acb->task);
qemu_aio_unref(acb);
return NULL;
}
/* tell libiscsi to read straight into the buffer we got from ioctl */
if (acb->task->xfer_dir == SCSI_XFER_READ) {
if (acb->ioh->iovec_count == 0) {
scsi_task_add_data_in_buffer(acb->task,
acb->ioh->dxfer_len,
acb->ioh->dxferp);
} else {
scsi_task_set_iov_in(acb->task,
(struct scsi_iovec *) acb->ioh->dxferp,
acb->ioh->iovec_count);
}
}
iscsi_set_events(iscsilun);
return &acb->common;
}
#endif
static int64_t
iscsi_getlength(BlockDriverState *bs)
{
IscsiLun *iscsilun = bs->opaque;
int64_t len;
len = iscsilun->num_blocks;
len *= iscsilun->block_size;
return len;
}
static int
coroutine_fn iscsi_co_discard(BlockDriverState *bs, int64_t sector_num,
int nb_sectors)
{
IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask;
struct unmap_list list;
if (!is_sector_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
return -EINVAL;
}
if (!iscsilun->lbp.lbpu) {
/* UNMAP is not supported by the target */
return 0;
}
list.lba = sector_qemu2lun(sector_num, iscsilun);
list.num = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list, 1,
iscsi_co_generic_cb, &iTask) == NULL) {
return -ENOMEM;
}
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
if (iTask.do_retry) {
iTask.complete = 0;
goto retry;
}
if (iTask.status == SCSI_STATUS_CHECK_CONDITION) {
/* the target might fail with a check condition if it
is not happy with the alignment of the UNMAP request
we silently fail in this case */
return 0;
}
if (iTask.status != SCSI_STATUS_GOOD) {
return iTask.err_code;
}
iscsi_allocmap_set_invalid(iscsilun, sector_num, nb_sectors);
return 0;
}
static int
coroutine_fn iscsi_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
int count, BdrvRequestFlags flags)
{
IscsiLun *iscsilun = bs->opaque;
struct IscsiTask iTask;
uint64_t lba;
uint32_t nb_blocks;
bool use_16_for_ws = iscsilun->use_16_for_rw;
if (!is_byte_request_lun_aligned(offset, count, iscsilun)) {
return -ENOTSUP;
}
if (flags & BDRV_REQ_MAY_UNMAP) {
if (!use_16_for_ws && !iscsilun->lbp.lbpws10) {
/* WRITESAME10 with UNMAP is unsupported try WRITESAME16 */
use_16_for_ws = true;
}
if (use_16_for_ws && !iscsilun->lbp.lbpws) {
/* WRITESAME16 with UNMAP is not supported by the target,
* fall back and try WRITESAME10/16 without UNMAP */
flags &= ~BDRV_REQ_MAY_UNMAP;
use_16_for_ws = iscsilun->use_16_for_rw;
}
}
if (!(flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->has_write_same) {
/* WRITESAME without UNMAP is not supported by the target */
return -ENOTSUP;
}
lba = offset / iscsilun->block_size;
nb_blocks = count / iscsilun->block_size;
if (iscsilun->zeroblock == NULL) {
iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
if (iscsilun->zeroblock == NULL) {
return -ENOMEM;
}
}
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
if (use_16_for_ws) {
iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
iscsilun->zeroblock, iscsilun->block_size,
nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
0, 0, iscsi_co_generic_cb, &iTask);
} else {
iTask.task = iscsi_writesame10_task(iscsilun->iscsi, iscsilun->lun, lba,
iscsilun->zeroblock, iscsilun->block_size,
nb_blocks, 0, !!(flags & BDRV_REQ_MAY_UNMAP),
0, 0, iscsi_co_generic_cb, &iTask);
}
if (iTask.task == NULL) {
return -ENOMEM;
}
while (!iTask.complete) {
iscsi_set_events(iscsilun);
qemu_coroutine_yield();
}
if (iTask.status == SCSI_STATUS_CHECK_CONDITION &&
iTask.task->sense.key == SCSI_SENSE_ILLEGAL_REQUEST &&
(iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_OPERATION_CODE ||
iTask.task->sense.ascq == SCSI_SENSE_ASCQ_INVALID_FIELD_IN_CDB)) {
/* WRITE SAME is not supported by the target */
iscsilun->has_write_same = false;
scsi_free_scsi_task(iTask.task);
return -ENOTSUP;
}
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
iTask.task = NULL;
}
if (iTask.do_retry) {
iTask.complete = 0;
goto retry;
}
if (iTask.status != SCSI_STATUS_GOOD) {
iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
count >> BDRV_SECTOR_BITS);
return iTask.err_code;
}
if (flags & BDRV_REQ_MAY_UNMAP) {
iscsi_allocmap_set_invalid(iscsilun, offset >> BDRV_SECTOR_BITS,
count >> BDRV_SECTOR_BITS);
} else {
iscsi_allocmap_set_allocated(iscsilun, offset >> BDRV_SECTOR_BITS,
count >> BDRV_SECTOR_BITS);
}
return 0;
}
static void parse_chap(struct iscsi_context *iscsi, const char *target,
Error **errp)
{
QemuOptsList *list;
QemuOpts *opts;
const char *user = NULL;
const char *password = NULL;
const char *secretid;
char *secret = NULL;
list = qemu_find_opts("iscsi");
if (!list) {
return;
}
opts = qemu_opts_find(list, target);
if (opts == NULL) {
opts = QTAILQ_FIRST(&list->head);
if (!opts) {
return;
}
}
user = qemu_opt_get(opts, "user");
if (!user) {
return;
}
secretid = qemu_opt_get(opts, "password-secret");
password = qemu_opt_get(opts, "password");
if (secretid && password) {
error_setg(errp, "'password' and 'password-secret' properties are "
"mutually exclusive");
return;
}
if (secretid) {
secret = qcrypto_secret_lookup_as_utf8(secretid, errp);
if (!secret) {
return;
}
password = secret;
} else if (!password) {
error_setg(errp, "CHAP username specified but no password was given");
return;
}
if (iscsi_set_initiator_username_pwd(iscsi, user, password)) {
error_setg(errp, "Failed to set initiator username and password");
}
g_free(secret);
}
static void parse_header_digest(struct iscsi_context *iscsi, const char *target,
Error **errp)
{
QemuOptsList *list;
QemuOpts *opts;
const char *digest = NULL;
list = qemu_find_opts("iscsi");
if (!list) {
return;
}
opts = qemu_opts_find(list, target);
if (opts == NULL) {
opts = QTAILQ_FIRST(&list->head);
if (!opts) {
return;
}
}
digest = qemu_opt_get(opts, "header-digest");
if (!digest) {
return;
}
if (!strcmp(digest, "CRC32C")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);
} else if (!strcmp(digest, "NONE")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE);
} else if (!strcmp(digest, "CRC32C-NONE")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C_NONE);
} else if (!strcmp(digest, "NONE-CRC32C")) {
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
} else {
error_setg(errp, "Invalid header-digest setting : %s", digest);
}
}
static char *parse_initiator_name(const char *target)
{
QemuOptsList *list;
QemuOpts *opts;
const char *name;
char *iscsi_name;
UuidInfo *uuid_info;
list = qemu_find_opts("iscsi");
if (list) {
opts = qemu_opts_find(list, target);
if (!opts) {
opts = QTAILQ_FIRST(&list->head);
}
if (opts) {
name = qemu_opt_get(opts, "initiator-name");
if (name) {
return g_strdup(name);
}
}
}
uuid_info = qmp_query_uuid(NULL);
if (strcmp(uuid_info->UUID, UUID_NONE) == 0) {
name = qemu_get_vm_name();
} else {
name = uuid_info->UUID;
}
iscsi_name = g_strdup_printf("iqn.2008-11.org.linux-kvm%s%s",
name ? ":" : "", name ? name : "");
qapi_free_UuidInfo(uuid_info);
return iscsi_name;
}
static int parse_timeout(const char *target)
{
QemuOptsList *list;
QemuOpts *opts;
const char *timeout;
list = qemu_find_opts("iscsi");
if (list) {
opts = qemu_opts_find(list, target);
if (!opts) {
opts = QTAILQ_FIRST(&list->head);
}
if (opts) {
timeout = qemu_opt_get(opts, "timeout");
if (timeout) {
return atoi(timeout);
}
}
}
return 0;
}
static void iscsi_nop_timed_event(void *opaque)
{
IscsiLun *iscsilun = opaque;
if (iscsi_get_nops_in_flight(iscsilun->iscsi) >= MAX_NOP_FAILURES) {
error_report("iSCSI: NOP timeout. Reconnecting...");
iscsilun->request_timed_out = true;
} else if (iscsi_nop_out_async(iscsilun->iscsi, NULL, NULL, 0, NULL) != 0) {
error_report("iSCSI: failed to sent NOP-Out. Disabling NOP messages.");
return;
}
timer_mod(iscsilun->nop_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
iscsi_set_events(iscsilun);
}
static void iscsi_readcapacity_sync(IscsiLun *iscsilun, Error **errp)
{
struct scsi_task *task = NULL;
struct scsi_readcapacity10 *rc10 = NULL;
struct scsi_readcapacity16 *rc16 = NULL;
int retries = ISCSI_CMD_RETRIES;
do {
if (task != NULL) {
scsi_free_scsi_task(task);
task = NULL;
}
switch (iscsilun->type) {
case TYPE_DISK:
task = iscsi_readcapacity16_sync(iscsilun->iscsi, iscsilun->lun);
if (task != NULL && task->status == SCSI_STATUS_GOOD) {
rc16 = scsi_datain_unmarshall(task);
if (rc16 == NULL) {
error_setg(errp, "iSCSI: Failed to unmarshall readcapacity16 data.");
} else {
iscsilun->block_size = rc16->block_length;
iscsilun->num_blocks = rc16->returned_lba + 1;
iscsilun->lbpme = !!rc16->lbpme;
iscsilun->lbprz = !!rc16->lbprz;
iscsilun->use_16_for_rw = (rc16->returned_lba > 0xffffffff);
}
break;
}
if (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
&& task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
break;
}
/* Fall through and try READ CAPACITY(10) instead. */
case TYPE_ROM:
task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 0, 0);
if (task != NULL && task->status == SCSI_STATUS_GOOD) {
rc10 = scsi_datain_unmarshall(task);
if (rc10 == NULL) {
error_setg(errp, "iSCSI: Failed to unmarshall readcapacity10 data.");
} else {
iscsilun->block_size = rc10->block_size;
if (rc10->lba == 0) {
/* blank disk loaded */
iscsilun->num_blocks = 0;
} else {
iscsilun->num_blocks = rc10->lba + 1;
}
}
}
break;
default:
return;
}
} while (task != NULL && task->status == SCSI_STATUS_CHECK_CONDITION
&& task->sense.key == SCSI_SENSE_UNIT_ATTENTION
&& retries-- > 0);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
error_setg(errp, "iSCSI: failed to send readcapacity10/16 command");
} else if (!iscsilun->block_size ||
iscsilun->block_size % BDRV_SECTOR_SIZE) {
error_setg(errp, "iSCSI: the target returned an invalid "
"block size of %d.", iscsilun->block_size);
}
if (task) {
scsi_free_scsi_task(task);
}
}
/* TODO Convert to fine grained options */
static QemuOptsList runtime_opts = {
.name = "iscsi",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = "filename",
.type = QEMU_OPT_STRING,
.help = "URL to the iscsi image",
},
{ /* end of list */ }
},
};
static struct scsi_task *iscsi_do_inquiry(struct iscsi_context *iscsi, int lun,
int evpd, int pc, void **inq, Error **errp)
{
int full_size;
struct scsi_task *task = NULL;
task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, 64);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
goto fail;
}
full_size = scsi_datain_getfullsize(task);
if (full_size > task->datain.size) {
scsi_free_scsi_task(task);
/* we need more data for the full list */
task = iscsi_inquiry_sync(iscsi, lun, evpd, pc, full_size);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
goto fail;
}
}
*inq = scsi_datain_unmarshall(task);
if (*inq == NULL) {
error_setg(errp, "iSCSI: failed to unmarshall inquiry datain blob");
goto fail_with_err;
}
return task;
fail:
error_setg(errp, "iSCSI: Inquiry command failed : %s",
iscsi_get_error(iscsi));
fail_with_err:
if (task != NULL) {
scsi_free_scsi_task(task);
}
return NULL;
}
static void iscsi_detach_aio_context(BlockDriverState *bs)
{
IscsiLun *iscsilun = bs->opaque;
aio_set_fd_handler(iscsilun->aio_context, iscsi_get_fd(iscsilun->iscsi),
false, NULL, NULL, NULL);
iscsilun->events = 0;
if (iscsilun->nop_timer) {
timer_del(iscsilun->nop_timer);
timer_free(iscsilun->nop_timer);
iscsilun->nop_timer = NULL;
}
if (iscsilun->event_timer) {
timer_del(iscsilun->event_timer);
timer_free(iscsilun->event_timer);
iscsilun->event_timer = NULL;
}
}
static void iscsi_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
IscsiLun *iscsilun = bs->opaque;
iscsilun->aio_context = new_context;
iscsi_set_events(iscsilun);
/* Set up a timer for sending out iSCSI NOPs */
iscsilun->nop_timer = aio_timer_new(iscsilun->aio_context,
QEMU_CLOCK_REALTIME, SCALE_MS,
iscsi_nop_timed_event, iscsilun);
timer_mod(iscsilun->nop_timer,
qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + NOP_INTERVAL);
/* Set up a timer for periodic calls to iscsi_set_events and to
* scan for command timeout */
iscsilun->event_timer = aio_timer_new(iscsilun->aio_context,
QEMU_CLOCK_REALTIME, SCALE_MS,
iscsi_timed_check_events, iscsilun);
timer_mod(iscsilun->event_timer,
qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + EVENT_INTERVAL);
}
static void iscsi_modesense_sync(IscsiLun *iscsilun)
{
struct scsi_task *task;
struct scsi_mode_sense *ms = NULL;
iscsilun->write_protected = false;
iscsilun->dpofua = false;
task = iscsi_modesense6_sync(iscsilun->iscsi, iscsilun->lun,
1, SCSI_MODESENSE_PC_CURRENT,
0x3F, 0, 255);
if (task == NULL) {
error_report("iSCSI: Failed to send MODE_SENSE(6) command: %s",
iscsi_get_error(iscsilun->iscsi));
goto out;
}
if (task->status != SCSI_STATUS_GOOD) {
error_report("iSCSI: Failed MODE_SENSE(6), LUN assumed writable");
goto out;
}
ms = scsi_datain_unmarshall(task);
if (!ms) {
error_report("iSCSI: Failed to unmarshall MODE_SENSE(6) data: %s",
iscsi_get_error(iscsilun->iscsi));
goto out;
}
iscsilun->write_protected = ms->device_specific_parameter & 0x80;
iscsilun->dpofua = ms->device_specific_parameter & 0x10;
out:
if (task) {
scsi_free_scsi_task(task);
}
}
/*
* We support iscsi url's on the form
* iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
*/
static int iscsi_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = NULL;
struct iscsi_url *iscsi_url = NULL;
struct scsi_task *task = NULL;
struct scsi_inquiry_standard *inq = NULL;
struct scsi_inquiry_supported_pages *inq_vpd;
char *initiator_name = NULL;
QemuOpts *opts;
Error *local_err = NULL;
const char *filename;
int i, ret = 0, timeout = 0;
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
qemu_opts_absorb_qdict(opts, options, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto out;
}
filename = qemu_opt_get(opts, "filename");
iscsi_url = iscsi_parse_full_url(iscsi, filename);
if (iscsi_url == NULL) {
error_setg(errp, "Failed to parse URL : %s", filename);
ret = -EINVAL;
goto out;
}
memset(iscsilun, 0, sizeof(IscsiLun));
initiator_name = parse_initiator_name(iscsi_url->target);
iscsi = iscsi_create_context(initiator_name);
if (iscsi == NULL) {
error_setg(errp, "iSCSI: Failed to create iSCSI context.");
ret = -ENOMEM;
goto out;
}
if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
error_setg(errp, "iSCSI: Failed to set target name.");
ret = -EINVAL;
goto out;
}
if (iscsi_url->user[0] != '\0') {
ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
iscsi_url->passwd);
if (ret != 0) {
error_setg(errp, "Failed to set initiator username and password");
ret = -EINVAL;
goto out;
}
}
/* check if we got CHAP username/password via the options */
parse_chap(iscsi, iscsi_url->target, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto out;
}
if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
error_setg(errp, "iSCSI: Failed to set session type to normal.");
ret = -EINVAL;
goto out;
}
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
/* check if we got HEADER_DIGEST via the options */
parse_header_digest(iscsi, iscsi_url->target, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto out;
}
/* timeout handling is broken in libiscsi before 1.15.0 */
timeout = parse_timeout(iscsi_url->target);
#if defined(LIBISCSI_API_VERSION) && LIBISCSI_API_VERSION >= 20150621
iscsi_set_timeout(iscsi, timeout);
#else
if (timeout) {
error_report("iSCSI: ignoring timeout value for libiscsi <1.15.0");
}
#endif
if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
error_setg(errp, "iSCSI: Failed to connect to LUN : %s",
iscsi_get_error(iscsi));
ret = -EINVAL;
goto out;
}
iscsilun->iscsi = iscsi;
iscsilun->aio_context = bdrv_get_aio_context(bs);
iscsilun->lun = iscsi_url->lun;
iscsilun->has_write_same = true;
task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 0, 0,
(void **) &inq, errp);
if (task == NULL) {
ret = -EINVAL;
goto out;
}
iscsilun->type = inq->periperal_device_type;
scsi_free_scsi_task(task);
task = NULL;
iscsi_modesense_sync(iscsilun);
if (iscsilun->dpofua) {
bs->supported_write_flags = BDRV_REQ_FUA;
}
bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
/* Check the write protect flag of the LUN if we want to write */
if (iscsilun->type == TYPE_DISK && (flags & BDRV_O_RDWR) &&
iscsilun->write_protected) {
error_setg(errp, "Cannot open a write protected LUN as read-write");
ret = -EACCES;
goto out;
}
iscsi_readcapacity_sync(iscsilun, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto out;
}
bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun);
/* We don't have any emulation for devices other than disks and CD-ROMs, so
* this must be sg ioctl compatible. We force it to be sg, otherwise qemu
* will try to read from the device to guess the image format.
*/
if (iscsilun->type != TYPE_DISK && iscsilun->type != TYPE_ROM) {
bs->sg = true;
}
task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
SCSI_INQUIRY_PAGECODE_SUPPORTED_VPD_PAGES,
(void **) &inq_vpd, errp);
if (task == NULL) {
ret = -EINVAL;
goto out;
}
for (i = 0; i < inq_vpd->num_pages; i++) {
struct scsi_task *inq_task;
struct scsi_inquiry_logical_block_provisioning *inq_lbp;
struct scsi_inquiry_block_limits *inq_bl;
switch (inq_vpd->pages[i]) {
case SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING:
inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
SCSI_INQUIRY_PAGECODE_LOGICAL_BLOCK_PROVISIONING,
(void **) &inq_lbp, errp);
if (inq_task == NULL) {
ret = -EINVAL;
goto out;
}
memcpy(&iscsilun->lbp, inq_lbp,
sizeof(struct scsi_inquiry_logical_block_provisioning));
scsi_free_scsi_task(inq_task);
break;
case SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS:
inq_task = iscsi_do_inquiry(iscsilun->iscsi, iscsilun->lun, 1,
SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS,
(void **) &inq_bl, errp);
if (inq_task == NULL) {
ret = -EINVAL;
goto out;
}
memcpy(&iscsilun->bl, inq_bl,
sizeof(struct scsi_inquiry_block_limits));
scsi_free_scsi_task(inq_task);
break;
default:
break;
}
}
scsi_free_scsi_task(task);
task = NULL;
iscsi_attach_aio_context(bs, iscsilun->aio_context);
/* Guess the internal cluster (page) size of the iscsi target by the means
* of opt_unmap_gran. Transfer the unmap granularity only if it has a
* reasonable size */
if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 &&
iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) {
iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran *
iscsilun->block_size) >> BDRV_SECTOR_BITS;
if (iscsilun->lbprz) {
ret = iscsi_allocmap_init(iscsilun, bs->open_flags);
}
}
out:
qemu_opts_del(opts);
g_free(initiator_name);
if (iscsi_url != NULL) {
iscsi_destroy_url(iscsi_url);
}
if (task != NULL) {
scsi_free_scsi_task(task);
}
if (ret) {
if (iscsi != NULL) {
if (iscsi_is_logged_in(iscsi)) {
iscsi_logout_sync(iscsi);
}
iscsi_destroy_context(iscsi);
}
memset(iscsilun, 0, sizeof(IscsiLun));
}
return ret;
}
static void iscsi_close(BlockDriverState *bs)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
iscsi_detach_aio_context(bs);
if (iscsi_is_logged_in(iscsi)) {
iscsi_logout_sync(iscsi);
}
iscsi_destroy_context(iscsi);
g_free(iscsilun->zeroblock);
iscsi_allocmap_free(iscsilun);
memset(iscsilun, 0, sizeof(IscsiLun));
}
static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
{
/* We don't actually refresh here, but just return data queried in
* iscsi_open(): iscsi targets don't change their limits. */
IscsiLun *iscsilun = bs->opaque;
uint64_t max_xfer_len = iscsilun->use_16_for_rw ? 0xffffffff : 0xffff;
bs->bl.request_alignment = iscsilun->block_size;
if (iscsilun->bl.max_xfer_len) {
max_xfer_len = MIN(max_xfer_len, iscsilun->bl.max_xfer_len);
}
if (max_xfer_len * iscsilun->block_size < INT_MAX) {
bs->bl.max_transfer = max_xfer_len * iscsilun->block_size;
}
if (iscsilun->lbp.lbpu) {
if (iscsilun->bl.max_unmap < 0xffffffff / iscsilun->block_size) {
bs->bl.max_pdiscard =
iscsilun->bl.max_unmap * iscsilun->block_size;
}
bs->bl.pdiscard_alignment =
iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
} else {
bs->bl.pdiscard_alignment = iscsilun->block_size;
}
if (iscsilun->bl.max_ws_len < 0xffffffff / iscsilun->block_size) {
bs->bl.max_pwrite_zeroes =
iscsilun->bl.max_ws_len * iscsilun->block_size;
}
if (iscsilun->lbp.lbpws) {
bs->bl.pwrite_zeroes_alignment =
iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
} else {
bs->bl.pwrite_zeroes_alignment = iscsilun->block_size;
}
if (iscsilun->bl.opt_xfer_len &&
iscsilun->bl.opt_xfer_len < INT_MAX / iscsilun->block_size) {
bs->bl.opt_transfer = pow2floor(iscsilun->bl.opt_xfer_len *
iscsilun->block_size);
}
}
/* Note that this will not re-establish a connection with an iSCSI target - it
* is effectively a NOP. */
static int iscsi_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
IscsiLun *iscsilun = state->bs->opaque;
if (state->flags & BDRV_O_RDWR && iscsilun->write_protected) {
error_setg(errp, "Cannot open a write protected LUN as read-write");
return -EACCES;
}
return 0;
}
static void iscsi_reopen_commit(BDRVReopenState *reopen_state)
{
IscsiLun *iscsilun = reopen_state->bs->opaque;
/* the cache.direct status might have changed */
if (iscsilun->allocmap != NULL) {
iscsi_allocmap_init(iscsilun, reopen_state->flags);
}
}
static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
{
IscsiLun *iscsilun = bs->opaque;
Error *local_err = NULL;
if (iscsilun->type != TYPE_DISK) {
return -ENOTSUP;
}
iscsi_readcapacity_sync(iscsilun, &local_err);
if (local_err != NULL) {
error_free(local_err);
return -EIO;
}
if (offset > iscsi_getlength(bs)) {
return -EINVAL;
}
if (iscsilun->allocmap != NULL) {
iscsi_allocmap_init(iscsilun, bs->open_flags);
}
return 0;
}
static int iscsi_create(const char *filename, QemuOpts *opts, Error **errp)
{
int ret = 0;
int64_t total_size = 0;
BlockDriverState *bs;
IscsiLun *iscsilun = NULL;
QDict *bs_options;
bs = bdrv_new();
/* Read out options */
total_size = DIV_ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
BDRV_SECTOR_SIZE);
bs->opaque = g_new0(struct IscsiLun, 1);
iscsilun = bs->opaque;
bs_options = qdict_new();
qdict_put(bs_options, "filename", qstring_from_str(filename));
ret = iscsi_open(bs, bs_options, 0, NULL);
QDECREF(bs_options);
if (ret != 0) {
goto out;
}
iscsi_detach_aio_context(bs);
if (iscsilun->type != TYPE_DISK) {
ret = -ENODEV;
goto out;
}
if (bs->total_sectors < total_size) {
ret = -ENOSPC;
goto out;
}
ret = 0;
out:
if (iscsilun->iscsi != NULL) {
iscsi_destroy_context(iscsilun->iscsi);
}
g_free(bs->opaque);
bs->opaque = NULL;
bdrv_unref(bs);
return ret;
}
static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
IscsiLun *iscsilun = bs->opaque;
bdi->unallocated_blocks_are_zero = iscsilun->lbprz;
bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws;
bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE;
return 0;
}
static void iscsi_invalidate_cache(BlockDriverState *bs,
Error **errp)
{
IscsiLun *iscsilun = bs->opaque;
iscsi_allocmap_invalidate(iscsilun);
}
static QemuOptsList iscsi_create_opts = {
.name = "iscsi-create-opts",
.head = QTAILQ_HEAD_INITIALIZER(iscsi_create_opts.head),
.desc = {
{
.name = BLOCK_OPT_SIZE,
.type = QEMU_OPT_SIZE,
.help = "Virtual disk size"
},
{ /* end of list */ }
}
};
static BlockDriver bdrv_iscsi = {
.format_name = "iscsi",
.protocol_name = "iscsi",
.instance_size = sizeof(IscsiLun),
.bdrv_needs_filename = true,
.bdrv_file_open = iscsi_open,
.bdrv_close = iscsi_close,
.bdrv_create = iscsi_create,
.create_opts = &iscsi_create_opts,
.bdrv_reopen_prepare = iscsi_reopen_prepare,
.bdrv_reopen_commit = iscsi_reopen_commit,
.bdrv_invalidate_cache = iscsi_invalidate_cache,
.bdrv_getlength = iscsi_getlength,
.bdrv_get_info = iscsi_get_info,
.bdrv_truncate = iscsi_truncate,
.bdrv_refresh_limits = iscsi_refresh_limits,
.bdrv_co_get_block_status = iscsi_co_get_block_status,
.bdrv_co_discard = iscsi_co_discard,
.bdrv_co_pwrite_zeroes = iscsi_co_pwrite_zeroes,
.bdrv_co_readv = iscsi_co_readv,
.bdrv_co_writev_flags = iscsi_co_writev_flags,
.bdrv_co_flush_to_disk = iscsi_co_flush,
#ifdef __linux__
.bdrv_aio_ioctl = iscsi_aio_ioctl,
#endif
.bdrv_detach_aio_context = iscsi_detach_aio_context,
.bdrv_attach_aio_context = iscsi_attach_aio_context,
};
static QemuOptsList qemu_iscsi_opts = {
.name = "iscsi",
.head = QTAILQ_HEAD_INITIALIZER(qemu_iscsi_opts.head),
.desc = {
{
.name = "user",
.type = QEMU_OPT_STRING,
.help = "username for CHAP authentication to target",
},{
.name = "password",
.type = QEMU_OPT_STRING,
.help = "password for CHAP authentication to target",
},{
.name = "password-secret",
.type = QEMU_OPT_STRING,
.help = "ID of the secret providing password for CHAP "
"authentication to target",
},{
.name = "header-digest",
.type = QEMU_OPT_STRING,
.help = "HeaderDigest setting. "
"{CRC32C|CRC32C-NONE|NONE-CRC32C|NONE}",
},{
.name = "initiator-name",
.type = QEMU_OPT_STRING,
.help = "Initiator iqn name to use when connecting",
},{
.name = "timeout",
.type = QEMU_OPT_NUMBER,
.help = "Request timeout in seconds (default 0 = no timeout)",
},
{ /* end of list */ }
},
};
static void iscsi_block_init(void)
{
bdrv_register(&bdrv_iscsi);
qemu_add_opts(&qemu_iscsi_opts);
}
block_init(iscsi_block_init);
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