iscsi: add .bdrv_get_block_status

this patch adds a coroutine for .bdrv_co_block_status as well as
a generic framework that can be used to build coroutines in block/iscsi.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Lieven 2013-07-19 09:19:40 +02:00 committed by Paolo Bonzini
parent f18a7cbb09
commit 54a5c1d5db
1 changed files with 136 additions and 0 deletions

View File

@ -58,6 +58,15 @@ typedef struct IscsiLun {
struct scsi_inquiry_block_limits bl;
} IscsiLun;
typedef struct IscsiTask {
int status;
int complete;
int retries;
int do_retry;
struct scsi_task *task;
Coroutine *co;
} IscsiTask;
typedef struct IscsiAIOCB {
BlockDriverAIOCB common;
QEMUIOVector *qiov;
@ -111,6 +120,41 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
qemu_bh_schedule(acb->bh);
}
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->complete = 1;
iTask->status = status;
iTask->do_retry = 0;
iTask->task = task;
if (iTask->retries-- > 0 && status == SCSI_STATUS_CHECK_CONDITION
&& task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
iTask->do_retry = 1;
goto out;
}
if (status != SCSI_STATUS_GOOD) {
error_report("iSCSI: Failure. %s", iscsi_get_error(iscsi));
}
out:
if (iTask->co) {
qemu_coroutine_enter(iTask->co, NULL);
}
}
static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask *iTask)
{
*iTask = (struct IscsiTask) {
.co = qemu_coroutine_self(),
.retries = ISCSI_CMD_RETRIES,
};
}
static void
iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
@ -848,6 +892,96 @@ iscsi_getlength(BlockDriverState *bs)
return len;
}
static int64_t coroutine_fn iscsi_co_get_block_status(BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, int *pnum)
{
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_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 == 0) {
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 = -EIO;
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;
}
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 compatiblity */
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 (*pnum > nb_sectors) {
*pnum = nb_sectors;
}
if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
ret &= ~BDRV_BLOCK_DATA;
if (iscsilun->lbprz) {
ret |= BDRV_BLOCK_ZERO;
}
}
out:
if (iTask.task != NULL) {
scsi_free_scsi_task(iTask.task);
}
return ret;
}
static int parse_chap(struct iscsi_context *iscsi, const char *target)
{
QemuOptsList *list;
@ -1398,6 +1532,8 @@ static BlockDriver bdrv_iscsi = {
.bdrv_getlength = iscsi_getlength,
.bdrv_truncate = iscsi_truncate,
.bdrv_co_get_block_status = iscsi_co_get_block_status,
.bdrv_aio_readv = iscsi_aio_readv,
.bdrv_aio_writev = iscsi_aio_writev,
.bdrv_aio_flush = iscsi_aio_flush,