diff options
Diffstat (limited to 'block/iscsi.c')
| -rw-r--r-- | block/iscsi.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/block/iscsi.c b/block/iscsi.c new file mode 100644 index 0000000000..938c568071 --- /dev/null +++ b/block/iscsi.c @@ -0,0 +1,591 @@ +/* + * 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); |