this patch changes the driver to uses 16 Byte CDBs for
READ/WRITE only if the target requires 64bit lba addressing.
On one hand this saves 6 bytes in each PDU on the other
hand it seems that 10 Byte CDBs seems to be much better
supported and tested as a recent issue I had with a
major storage supplier lined out.
For WRITESAME the logic is a bit more tricky as WRITESAME10
with UNMAP was added really late. Thus a fallback to WRITESAME16
is possible if it supports UNMAP and WRITESAME10 not.
Signed-off-by: Peter Lieven <address@hidden>
---
block/iscsi.c | 58 +++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 40 insertions(+), 18 deletions(-)
diff --git a/block/iscsi.c b/block/iscsi.c
index d241e83..019b324 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -65,6 +65,7 @@ typedef struct IscsiLun {
unsigned char *zeroblock;
unsigned long *allocationmap;
int cluster_sectors;
+ bool use_16_for_rw;
} IscsiLun;
typedef struct IscsiTask {
@@ -368,10 +369,17 @@ static int coroutine_fn iscsi_co_writev(BlockDriverState
*bs,
num_sectors = sector_qemu2lun(nb_sectors, iscsilun);
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
- iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
- data, num_sectors * iscsilun->block_size,
- iscsilun->block_size, 0, 0, 0, 0, 0,
- iscsi_co_generic_cb, &iTask);
+ if (iscsilun->use_16_for_rw) {
+ iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,
+ data, num_sectors *
iscsilun->block_size,
+ iscsilun->block_size, 0, 0, 0, 0, 0,
+ iscsi_co_generic_cb, &iTask);
+ } else {
+ iTask.task = iscsi_write10_task(iscsilun->iscsi, iscsilun->lun, lba,
+ data, num_sectors *
iscsilun->block_size,
+ iscsilun->block_size, 0, 0, 0, 0, 0,
+ iscsi_co_generic_cb, &iTask);
+ }
if (iTask.task == NULL) {
g_free(buf);
return -ENOMEM;
@@ -545,20 +553,17 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState
*bs,
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
- switch (iscsilun->type) {
- case TYPE_DISK:
+ 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);
- break;
- default:
+ } 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);
- break;
}
if (iTask.task == NULL) {
return -ENOMEM;
@@ -864,19 +869,27 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs,
int64_t sector_num,
struct IscsiTask iTask;
uint64_t lba;
uint32_t nb_blocks;
+ bool use_16_for_ws = iscsilun->use_16_for_rw;
if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {
return -EINVAL;
}
- if ((flags & BDRV_REQ_MAY_UNMAP) && !iscsilun->lbp.lbpws) {
- /* WRITE SAME with UNMAP is not supported by the target,
- * fall back and try WRITE SAME without UNMAP */
- flags &= ~BDRV_REQ_MAY_UNMAP;
+ 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) {
- /* WRITE SAME without UNMAP is not supported by the target */
+ /* WRITESAME without UNMAP is not supported by the target */
return -ENOTSUP;
}
@@ -889,10 +902,18 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs,
int64_t sector_num,
iscsi_co_init_iscsitask(iscsilun, &iTask);
retry:
- if (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) == NULL) {
+ 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;
}
@@ -1087,6 +1108,7 @@ static void iscsi_readcapacity_sync(IscsiLun *iscsilun,
Error **errp)
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;