blob: 938c5680715af9303e3b22ad0ce5a6f5f2e04c63 [file] [log] [blame]
/*
* QEMU Block driver for iSCSI images
*
* Copyright (c) 2010-2011 Ronnie Sahlberg <ronniesahlberg@gmail.com>
*
* 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 "config-host.h"
#include <poll.h>
#include "qemu-common.h"
#include "qemu-error.h"
#include "block_int.h"
#include "trace.h"
#include <iscsi/iscsi.h>
#include <iscsi/scsi-lowlevel.h>
typedef struct IscsiLun {
struct iscsi_context *iscsi;
int lun;
int block_size;
unsigned long num_blocks;
} IscsiLun;
typedef struct IscsiAIOCB {
BlockDriverAIOCB common;
QEMUIOVector *qiov;
QEMUBH *bh;
IscsiLun *iscsilun;
struct scsi_task *task;
uint8_t *buf;
int status;
int canceled;
size_t read_size;
size_t read_offset;
} IscsiAIOCB;
struct IscsiTask {
IscsiLun *iscsilun;
BlockDriverState *bs;
int status;
int complete;
};
static void
iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
void *private_data)
{
}
static void
iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
{
IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
IscsiLun *iscsilun = acb->iscsilun;
acb->common.cb(acb->common.opaque, -ECANCELED);
acb->canceled = 1;
/* 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, NULL);
/* then also cancel the task locally in libiscsi */
iscsi_scsi_task_cancel(iscsilun->iscsi, acb->task);
}
static AIOPool iscsi_aio_pool = {
.aiocb_size = sizeof(IscsiAIOCB),
.cancel = iscsi_aio_cancel,
};
static void iscsi_process_read(void *arg);
static void iscsi_process_write(void *arg);
static int iscsi_process_flush(void *arg)
{
IscsiLun *iscsilun = arg;
return iscsi_queue_length(iscsilun->iscsi) > 0;
}
static void
iscsi_set_events(IscsiLun *iscsilun)
{
struct iscsi_context *iscsi = iscsilun->iscsi;
qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), iscsi_process_read,
(iscsi_which_events(iscsi) & POLLOUT)
? iscsi_process_write : NULL,
iscsi_process_flush, NULL, iscsilun);
}
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 int
iscsi_schedule_bh(QEMUBHFunc *cb, IscsiAIOCB *acb)
{
acb->bh = qemu_bh_new(cb, acb);
if (!acb->bh) {
error_report("oom: could not create iscsi bh");
return -EIO;
}
qemu_bh_schedule(acb->bh);
return 0;
}
static void
iscsi_readv_writev_bh_cb(void *p)
{
IscsiAIOCB *acb = p;
qemu_bh_delete(acb->bh);
if (acb->canceled == 0) {
acb->common.cb(acb->common.opaque, acb->status);
}
qemu_aio_release(acb);
}
static void
iscsi_aio_write10_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
IscsiAIOCB *acb = opaque;
trace_iscsi_aio_write10_cb(iscsi, status, acb, acb->canceled);
g_free(acb->buf);
if (acb->canceled != 0) {
qemu_aio_release(acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
return;
}
acb->status = 0;
if (status < 0) {
error_report("Failed to write10 data to iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
}
iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
{
return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
}
static BlockDriverAIOCB *
iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
size_t size;
int fua = 0;
/* set FUA on writes when cache mode is write through */
if (!(bs->open_flags & BDRV_O_CACHE_WB)) {
fua = 1;
}
acb = qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
trace_iscsi_aio_writev(iscsi, sector_num, nb_sectors, opaque, acb);
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->canceled = 0;
/* XXX we should pass the iovec to write10 to avoid the extra copy */
/* this will allow us to get rid of 'buf' completely */
size = nb_sectors * BDRV_SECTOR_SIZE;
acb->buf = g_malloc(size);
qemu_iovec_to_buffer(acb->qiov, acb->buf);
acb->task = iscsi_write10_task(iscsi, iscsilun->lun, acb->buf, size,
sector_qemu2lun(sector_num, iscsilun),
fua, 0, iscsilun->block_size,
iscsi_aio_write10_cb, acb);
if (acb->task == NULL) {
error_report("iSCSI: Failed to send write10 command. %s",
iscsi_get_error(iscsi));
g_free(acb->buf);
qemu_aio_release(acb);
return NULL;
}
iscsi_set_events(iscsilun);
return &acb->common;
}
static void
iscsi_aio_read10_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
IscsiAIOCB *acb = opaque;
trace_iscsi_aio_read10_cb(iscsi, status, acb, acb->canceled);
if (acb->canceled != 0) {
qemu_aio_release(acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
return;
}
acb->status = 0;
if (status != 0) {
error_report("Failed to read10 data from iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
}
iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
static BlockDriverAIOCB *
iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
size_t qemu_read_size, lun_read_size;
int i;
qemu_read_size = BDRV_SECTOR_SIZE * (size_t)nb_sectors;
acb = qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
trace_iscsi_aio_readv(iscsi, sector_num, nb_sectors, opaque, acb);
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->canceled = 0;
acb->read_size = qemu_read_size;
acb->buf = NULL;
/* If LUN blocksize is bigger than BDRV_BLOCK_SIZE a read from QEMU
* may be misaligned to the LUN, so we may need to read some extra
* data.
*/
acb->read_offset = 0;
if (iscsilun->block_size > BDRV_SECTOR_SIZE) {
uint64_t bdrv_offset = BDRV_SECTOR_SIZE * sector_num;
acb->read_offset = bdrv_offset % iscsilun->block_size;
}
lun_read_size = (qemu_read_size + iscsilun->block_size
+ acb->read_offset - 1)
/ iscsilun->block_size * iscsilun->block_size;
acb->task = iscsi_read10_task(iscsi, iscsilun->lun,
sector_qemu2lun(sector_num, iscsilun),
lun_read_size, iscsilun->block_size,
iscsi_aio_read10_cb, acb);
if (acb->task == NULL) {
error_report("iSCSI: Failed to send read10 command. %s",
iscsi_get_error(iscsi));
qemu_aio_release(acb);
return NULL;
}
for (i = 0; i < acb->qiov->niov; i++) {
scsi_task_add_data_in_buffer(acb->task,
acb->qiov->iov[i].iov_len,
acb->qiov->iov[i].iov_base);
}
iscsi_set_events(iscsilun);
return &acb->common;
}
static void
iscsi_synccache10_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
IscsiAIOCB *acb = opaque;
if (acb->canceled != 0) {
qemu_aio_release(acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
return;
}
acb->status = 0;
if (status < 0) {
error_report("Failed to sync10 data on iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
}
iscsi_schedule_bh(iscsi_readv_writev_bh_cb, acb);
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
static BlockDriverAIOCB *
iscsi_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aio_pool, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->canceled = 0;
acb->task = iscsi_synchronizecache10_task(iscsi, iscsilun->lun,
0, 0, 0, 0,
iscsi_synccache10_cb,
acb);
if (acb->task == NULL) {
error_report("iSCSI: Failed to send synchronizecache10 command. %s",
iscsi_get_error(iscsi));
qemu_aio_release(acb);
return NULL;
}
iscsi_set_events(iscsilun);
return &acb->common;
}
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 void
iscsi_readcapacity10_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
{
struct IscsiTask *itask = opaque;
struct scsi_readcapacity10 *rc10;
struct scsi_task *task = command_data;
if (status != 0) {
error_report("iSCSI: Failed to read capacity of iSCSI lun. %s",
iscsi_get_error(iscsi));
itask->status = 1;
itask->complete = 1;
scsi_free_scsi_task(task);
return;
}
rc10 = scsi_datain_unmarshall(task);
if (rc10 == NULL) {
error_report("iSCSI: Failed to unmarshall readcapacity10 data.");
itask->status = 1;
itask->complete = 1;
scsi_free_scsi_task(task);
return;
}
itask->iscsilun->block_size = rc10->block_size;
itask->iscsilun->num_blocks = rc10->lba;
itask->bs->total_sectors = (uint64_t)rc10->lba *
rc10->block_size / BDRV_SECTOR_SIZE ;
itask->status = 0;
itask->complete = 1;
scsi_free_scsi_task(task);
}
static void
iscsi_connect_cb(struct iscsi_context *iscsi, int status, void *command_data,
void *opaque)
{
struct IscsiTask *itask = opaque;
struct scsi_task *task;
if (status != 0) {
itask->status = 1;
itask->complete = 1;
return;
}
task = iscsi_readcapacity10_task(iscsi, itask->iscsilun->lun, 0, 0,
iscsi_readcapacity10_cb, opaque);
if (task == NULL) {
error_report("iSCSI: failed to send readcapacity command.");
itask->status = 1;
itask->complete = 1;
return;
}
}
/*
* We support iscsi url's on the form
* iscsi://[<username>%<password>@]<host>[:<port>]/<targetname>/<lun>
*/
static int iscsi_open(BlockDriverState *bs, const char *filename, int flags)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = NULL;
struct iscsi_url *iscsi_url = NULL;
struct IscsiTask task;
int ret;
if ((BDRV_SECTOR_SIZE % 512) != 0) {
error_report("iSCSI: Invalid BDRV_SECTOR_SIZE. "
"BDRV_SECTOR_SIZE(%lld) is not a multiple "
"of 512", BDRV_SECTOR_SIZE);
return -EINVAL;
}
memset(iscsilun, 0, sizeof(IscsiLun));
/* Should really append the KVM name after the ':' here */
iscsi = iscsi_create_context("iqn.2008-11.org.linux-kvm:");
if (iscsi == NULL) {
error_report("iSCSI: Failed to create iSCSI context.");
ret = -ENOMEM;
goto failed;
}
iscsi_url = iscsi_parse_full_url(iscsi, filename);
if (iscsi_url == NULL) {
error_report("Failed to parse URL : %s %s", filename,
iscsi_get_error(iscsi));
ret = -EINVAL;
goto failed;
}
if (iscsi_set_targetname(iscsi, iscsi_url->target)) {
error_report("iSCSI: Failed to set target name.");
ret = -EINVAL;
goto failed;
}
if (iscsi_url->user != NULL) {
ret = iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user,
iscsi_url->passwd);
if (ret != 0) {
error_report("Failed to set initiator username and password");
ret = -EINVAL;
goto failed;
}
}
if (iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL) != 0) {
error_report("iSCSI: Failed to set session type to normal.");
ret = -EINVAL;
goto failed;
}
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
task.iscsilun = iscsilun;
task.status = 0;
task.complete = 0;
task.bs = bs;
iscsilun->iscsi = iscsi;
iscsilun->lun = iscsi_url->lun;
if (iscsi_full_connect_async(iscsi, iscsi_url->portal, iscsi_url->lun,
iscsi_connect_cb, &task)
!= 0) {
error_report("iSCSI: Failed to start async connect.");
ret = -EINVAL;
goto failed;
}
while (!task.complete) {
iscsi_set_events(iscsilun);
qemu_aio_wait();
}
if (task.status != 0) {
error_report("iSCSI: Failed to connect to LUN : %s",
iscsi_get_error(iscsi));
ret = -EINVAL;
goto failed;
}
if (iscsi_url != NULL) {
iscsi_destroy_url(iscsi_url);
}
return 0;
failed:
if (iscsi_url != NULL) {
iscsi_destroy_url(iscsi_url);
}
if (iscsi != NULL) {
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;
qemu_aio_set_fd_handler(iscsi_get_fd(iscsi), NULL, NULL, NULL, NULL, NULL);
iscsi_destroy_context(iscsi);
memset(iscsilun, 0, sizeof(IscsiLun));
}
static BlockDriver bdrv_iscsi = {
.format_name = "iscsi",
.protocol_name = "iscsi",
.instance_size = sizeof(IscsiLun),
.bdrv_file_open = iscsi_open,
.bdrv_close = iscsi_close,
.bdrv_getlength = iscsi_getlength,
.bdrv_aio_readv = iscsi_aio_readv,
.bdrv_aio_writev = iscsi_aio_writev,
.bdrv_aio_flush = iscsi_aio_flush,
};
static void iscsi_block_init(void)
{
bdrv_register(&bdrv_iscsi);
}
block_init(iscsi_block_init);