iscsi: retry read, write, flush and unmap on unit attention check conditions

the storage might return a check condition status for various reasons.
(e.g. bus reset, capacity change, thin-provisioning info etc.)

currently all these informative status responses lead to an I/O error
which is populated to the guest. this patch introduces a retry mechanism
to avoid this.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Lieven 2013-02-21 16:15:54 +01:00 committed by Paolo Bonzini
parent 76c48503c4
commit 1dde716ed6

View File

@ -60,8 +60,11 @@ typedef struct IscsiAIOCB {
uint8_t *buf;
int status;
int canceled;
int retries;
size_t read_size;
size_t read_offset;
int64_t sector_num;
int nb_sectors;
#ifdef __linux__
sg_io_hdr_t *ioh;
#endif
@ -69,6 +72,7 @@ typedef struct IscsiAIOCB {
#define NOP_INTERVAL 5000
#define MAX_NOP_FAILURES 3
#define ISCSI_CMD_RETRIES 5
static void
iscsi_bh_cb(void *p)
@ -191,6 +195,8 @@ iscsi_process_write(void *arg)
iscsi_set_events(iscsilun);
}
static int
iscsi_aio_writev_acb(IscsiAIOCB *acb);
static void
iscsi_aio_write16_cb(struct iscsi_context *iscsi, int status,
@ -208,7 +214,19 @@ iscsi_aio_write16_cb(struct iscsi_context *iscsi, int status,
}
acb->status = 0;
if (status < 0) {
if (status != 0) {
if (status == SCSI_STATUS_CHECK_CONDITION
&& acb->task->sense.key == SCSI_SENSE_UNIT_ATTENTION
&& acb->retries-- > 0) {
if (acb->task != NULL) {
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
if (iscsi_aio_writev_acb(acb) == 0) {
iscsi_set_events(acb->iscsilun);
return;
}
}
error_report("Failed to write16 data to iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
@ -222,15 +240,10 @@ 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)
static int
iscsi_aio_writev_acb(IscsiAIOCB *acb)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
struct iscsi_context *iscsi = acb->iscsilun->iscsi;
size_t size;
uint32_t num_sectors;
uint64_t lba;
@ -239,19 +252,13 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
#endif
int ret;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
trace_iscsi_aio_writev(iscsi, sector_num, nb_sectors, opaque, acb);
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->canceled = 0;
acb->bh = NULL;
acb->status = -EINPROGRESS;
acb->buf = NULL;
/* this will allow us to get rid of 'buf' completely */
size = nb_sectors * BDRV_SECTOR_SIZE;
size = acb->nb_sectors * BDRV_SECTOR_SIZE;
#if !defined(LIBISCSI_FEATURE_IOVECTOR)
data.size = MIN(size, acb->qiov->size);
@ -270,48 +277,76 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
if (acb->task == NULL) {
error_report("iSCSI: Failed to allocate task for scsi WRITE16 "
"command. %s", iscsi_get_error(iscsi));
qemu_aio_release(acb);
return NULL;
return -1;
}
memset(acb->task, 0, sizeof(struct scsi_task));
acb->task->xfer_dir = SCSI_XFER_WRITE;
acb->task->cdb_size = 16;
acb->task->cdb[0] = 0x8a;
lba = sector_qemu2lun(sector_num, iscsilun);
lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
*(uint32_t *)&acb->task->cdb[2] = htonl(lba >> 32);
*(uint32_t *)&acb->task->cdb[6] = htonl(lba & 0xffffffff);
num_sectors = size / iscsilun->block_size;
num_sectors = size / acb->iscsilun->block_size;
*(uint32_t *)&acb->task->cdb[10] = htonl(num_sectors);
acb->task->expxferlen = size;
#if defined(LIBISCSI_FEATURE_IOVECTOR)
ret = iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
ret = iscsi_scsi_command_async(iscsi, acb->iscsilun->lun, acb->task,
iscsi_aio_write16_cb,
NULL,
acb);
#else
ret = iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
ret = iscsi_scsi_command_async(iscsi, acb->iscsilun->lun, acb->task,
iscsi_aio_write16_cb,
&data,
acb);
#endif
if (ret != 0) {
scsi_free_scsi_task(acb->task);
g_free(acb->buf);
qemu_aio_release(acb);
return NULL;
return -1;
}
#if defined(LIBISCSI_FEATURE_IOVECTOR)
scsi_task_set_iov_out(acb->task, (struct scsi_iovec*) acb->qiov->iov, acb->qiov->niov);
#endif
iscsi_set_events(iscsilun);
return 0;
}
static BlockDriverAIOCB *
iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
trace_iscsi_aio_writev(iscsilun->iscsi, sector_num, nb_sectors, opaque, acb);
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->nb_sectors = nb_sectors;
acb->sector_num = sector_num;
acb->retries = ISCSI_CMD_RETRIES;
if (iscsi_aio_writev_acb(acb) != 0) {
if (acb->task) {
scsi_free_scsi_task(acb->task);
}
qemu_aio_release(acb);
return NULL;
}
iscsi_set_events(iscsilun);
return &acb->common;
}
static int
iscsi_aio_readv_acb(IscsiAIOCB *acb);
static void
iscsi_aio_read16_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
@ -326,6 +361,18 @@ iscsi_aio_read16_cb(struct iscsi_context *iscsi, int status,
acb->status = 0;
if (status != 0) {
if (status == SCSI_STATUS_CHECK_CONDITION
&& acb->task->sense.key == SCSI_SENSE_UNIT_ATTENTION
&& acb->retries-- > 0) {
if (acb->task != NULL) {
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
if (iscsi_aio_readv_acb(acb) == 0) {
iscsi_set_events(acb->iscsilun);
return;
}
}
error_report("Failed to read16 data from iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
@ -334,35 +381,20 @@ iscsi_aio_read16_cb(struct iscsi_context *iscsi, int status,
iscsi_schedule_bh(acb);
}
static BlockDriverAIOCB *
iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
static int
iscsi_aio_readv_acb(IscsiAIOCB *acb)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
size_t qemu_read_size;
struct iscsi_context *iscsi = acb->iscsilun->iscsi;
uint64_t lba;
uint32_t num_sectors;
int ret;
#if !defined(LIBISCSI_FEATURE_IOVECTOR)
int i;
#endif
int ret;
uint64_t lba;
uint32_t num_sectors;
qemu_read_size = BDRV_SECTOR_SIZE * (size_t)nb_sectors;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
trace_iscsi_aio_readv(iscsi, sector_num, nb_sectors, opaque, acb);
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->canceled = 0;
acb->bh = NULL;
acb->status = -EINPROGRESS;
acb->read_size = qemu_read_size;
acb->buf = NULL;
/* If LUN blocksize is bigger than BDRV_BLOCK_SIZE a read from QEMU
@ -370,30 +402,29 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
* data.
*/
acb->read_offset = 0;
if (iscsilun->block_size > BDRV_SECTOR_SIZE) {
uint64_t bdrv_offset = BDRV_SECTOR_SIZE * sector_num;
if (acb->iscsilun->block_size > BDRV_SECTOR_SIZE) {
uint64_t bdrv_offset = BDRV_SECTOR_SIZE * acb->sector_num;
acb->read_offset = bdrv_offset % iscsilun->block_size;
acb->read_offset = bdrv_offset % acb->iscsilun->block_size;
}
num_sectors = (qemu_read_size + iscsilun->block_size
num_sectors = (acb->read_size + acb->iscsilun->block_size
+ acb->read_offset - 1)
/ iscsilun->block_size;
/ acb->iscsilun->block_size;
acb->task = malloc(sizeof(struct scsi_task));
if (acb->task == NULL) {
error_report("iSCSI: Failed to allocate task for scsi READ16 "
"command. %s", iscsi_get_error(iscsi));
qemu_aio_release(acb);
return NULL;
return -1;
}
memset(acb->task, 0, sizeof(struct scsi_task));
acb->task->xfer_dir = SCSI_XFER_READ;
lba = sector_qemu2lun(sector_num, iscsilun);
acb->task->expxferlen = qemu_read_size;
lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
acb->task->expxferlen = acb->read_size;
switch (iscsilun->type) {
switch (acb->iscsilun->type) {
case TYPE_DISK:
acb->task->cdb_size = 16;
acb->task->cdb[0] = 0x88;
@ -409,14 +440,12 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
break;
}
ret = iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
ret = iscsi_scsi_command_async(iscsi, acb->iscsilun->lun, acb->task,
iscsi_aio_read16_cb,
NULL,
acb);
if (ret != 0) {
scsi_free_scsi_task(acb->task);
qemu_aio_release(acb);
return NULL;
return -1;
}
#if defined(LIBISCSI_FEATURE_IOVECTOR)
@ -428,12 +457,42 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
acb->qiov->iov[i].iov_base);
}
#endif
return 0;
}
static BlockDriverAIOCB *
iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb,
void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
trace_iscsi_aio_readv(iscsilun->iscsi, sector_num, nb_sectors, opaque, acb);
acb->nb_sectors = nb_sectors;
acb->sector_num = sector_num;
acb->iscsilun = iscsilun;
acb->qiov = qiov;
acb->read_size = BDRV_SECTOR_SIZE * (size_t)acb->nb_sectors;
acb->retries = ISCSI_CMD_RETRIES;
if (iscsi_aio_readv_acb(acb) != 0) {
if (acb->task) {
scsi_free_scsi_task(acb->task);
}
qemu_aio_release(acb);
return NULL;
}
iscsi_set_events(iscsilun);
return &acb->common;
}
static int
iscsi_aio_flush_acb(IscsiAIOCB *acb);
static void
iscsi_synccache10_cb(struct iscsi_context *iscsi, int status,
@ -446,7 +505,19 @@ iscsi_synccache10_cb(struct iscsi_context *iscsi, int status,
}
acb->status = 0;
if (status < 0) {
if (status != 0) {
if (status == SCSI_STATUS_CHECK_CONDITION
&& acb->task->sense.key == SCSI_SENSE_UNIT_ATTENTION
&& acb->retries-- > 0) {
if (acb->task != NULL) {
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
if (iscsi_aio_flush_acb(acb) == 0) {
iscsi_set_events(acb->iscsilun);
return;
}
}
error_report("Failed to sync10 data on iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
@ -455,29 +526,43 @@ iscsi_synccache10_cb(struct iscsi_context *iscsi, int status,
iscsi_schedule_bh(acb);
}
static BlockDriverAIOCB *
iscsi_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
static int
iscsi_aio_flush_acb(IscsiAIOCB *acb)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
struct iscsi_context *iscsi = acb->iscsilun->iscsi;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->canceled = 0;
acb->bh = NULL;
acb->status = -EINPROGRESS;
acb->buf = NULL;
acb->task = iscsi_synchronizecache10_task(iscsi, iscsilun->lun,
acb->task = iscsi_synchronizecache10_task(iscsi, acb->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));
return -1;
}
return 0;
}
static BlockDriverAIOCB *
iscsi_aio_flush(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->retries = ISCSI_CMD_RETRIES;
if (iscsi_aio_flush_acb(acb) != 0) {
qemu_aio_release(acb);
return NULL;
}
@ -487,6 +572,8 @@ iscsi_aio_flush(BlockDriverState *bs,
return &acb->common;
}
static int iscsi_aio_discard_acb(IscsiAIOCB *acb);
static void
iscsi_unmap_cb(struct iscsi_context *iscsi, int status,
void *command_data, void *opaque)
@ -498,7 +585,19 @@ iscsi_unmap_cb(struct iscsi_context *iscsi, int status,
}
acb->status = 0;
if (status < 0) {
if (status != 0) {
if (status == SCSI_STATUS_CHECK_CONDITION
&& acb->task->sense.key == SCSI_SENSE_UNIT_ATTENTION
&& acb->retries-- > 0) {
if (acb->task != NULL) {
scsi_free_scsi_task(acb->task);
acb->task = NULL;
}
if (iscsi_aio_discard_acb(acb) == 0) {
iscsi_set_events(acb->iscsilun);
return;
}
}
error_report("Failed to unmap data on iSCSI lun. %s",
iscsi_get_error(iscsi));
acb->status = -EIO;
@ -507,34 +606,50 @@ iscsi_unmap_cb(struct iscsi_context *iscsi, int status,
iscsi_schedule_bh(acb);
}
static BlockDriverAIOCB *
iscsi_aio_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
struct iscsi_context *iscsi = iscsilun->iscsi;
IscsiAIOCB *acb;
static int iscsi_aio_discard_acb(IscsiAIOCB *acb) {
struct iscsi_context *iscsi = acb->iscsilun->iscsi;
struct unmap_list list[1];
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->canceled = 0;
acb->bh = NULL;
acb->status = -EINPROGRESS;
acb->buf = NULL;
list[0].lba = sector_qemu2lun(sector_num, iscsilun);
list[0].num = nb_sectors * BDRV_SECTOR_SIZE / iscsilun->block_size;
list[0].lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
list[0].num = acb->nb_sectors * BDRV_SECTOR_SIZE / acb->iscsilun->block_size;
acb->task = iscsi_unmap_task(iscsi, iscsilun->lun,
acb->task = iscsi_unmap_task(iscsi, acb->iscsilun->lun,
0, 0, &list[0], 1,
iscsi_unmap_cb,
acb);
if (acb->task == NULL) {
error_report("iSCSI: Failed to send unmap command. %s",
iscsi_get_error(iscsi));
return -1;
}
return 0;
}
static BlockDriverAIOCB *
iscsi_aio_discard(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque)
{
IscsiLun *iscsilun = bs->opaque;
IscsiAIOCB *acb;
acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
acb->iscsilun = iscsilun;
acb->nb_sectors = nb_sectors;
acb->sector_num = sector_num;
acb->retries = ISCSI_CMD_RETRIES;
if (iscsi_aio_discard_acb(acb) != 0) {
if (acb->task) {
scsi_free_scsi_task(acb->task);
}
qemu_aio_release(acb);
return NULL;
}