write zeroes is emulated by unmap if the
target supports unmapping an unmapped blocks
read as zero.
Signed-off-by: Peter Lieven <p...@kamp.de>
---
block/iscsi.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/block/iscsi.c b/block/iscsi.c
index 98be71e..683692a 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -906,6 +906,68 @@ static int coroutine_fn
iscsi_co_is_allocated(BlockDriverState *bs,
return ret;
}
+static void
+iscsi_co_write_zeroes_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 = 0;
+
+ if (status != 0) {
+ error_report("iSCSI: Failed to unmap data on iSCSI lun. %s",
+ iscsi_get_error(iscsi));
+ iTask->status = 1;
+ }
+
+ scsi_free_scsi_task(task);
+
+ if (iTask->co) {
+ qemu_coroutine_enter(iTask->co, NULL);
+ }
+}
+
+static int
+coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
+ int nb_sectors)
+{
+ IscsiLun *iscsilun = bs->opaque;
+ struct IscsiTask iTask;
+ struct unmap_list list[1];
+
+ if (!iscsilun->lbprz || !iscsilun->lbpu) {
+ /* fall back to writev */
+ return -ENOTSUP;
+ }
+
+ iTask.iscsilun = iscsilun;
+ iTask.status = 0;
+ iTask.complete = 0;
+ iTask.bs = bs;
+
+ list[0].lba = sector_qemu2lun(sector_num, iscsilun);
+ list[0].num = nb_sectors * BDRV_SECTOR_SIZE / iscsilun->block_size;
+
+ if (iscsi_unmap_task(iscsilun->iscsi, iscsilun->lun, 0, 0, &list[0], 1,
+ iscsi_co_write_zeroes_cb, &iTask) == NULL) {
+ return -EIO;
+ }
+
+ while (!iTask.complete) {
+ iscsi_set_events(iscsilun);
+ iTask.co = qemu_coroutine_self();
+ qemu_coroutine_yield();
+ }
+
+ if (iTask.status != 0) {
+ return -EIO;
+ }
+
+ return 0;
+}
+
static int parse_chap(struct iscsi_context *iscsi, const char *target)
{
QemuOptsList *list;
@@ -1417,6 +1479,7 @@ static BlockDriver bdrv_iscsi = {
.bdrv_truncate = iscsi_truncate,
.bdrv_co_is_allocated = iscsi_co_is_allocated,
+ .bdrv_co_write_zeroes = iscsi_co_write_zeroes,
.bdrv_aio_readv = iscsi_aio_readv,
.bdrv_aio_writev = iscsi_aio_writev,
--
1.7.9.5
