Il 27/06/2013 15:11, Peter Lieven ha scritto:
> if the device supports unmapping and unmapped blocks read as
> zero ensure that the whole device is unmapped and report
> .has_zero_init = 1 in this case to speed up qemu-img convert.
This can still take several minutes. Do you need any special timeout in
libiscsi?
Perhaps we can have a new "discard_zeroes" field in bdrv_get_info, and
the unmap functionality can be moved up to qemu-img convert?
Paolo
>
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/iscsi.c | 72
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 71 insertions(+), 1 deletion(-)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 92e66a6..621ca40 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -1436,7 +1436,8 @@ static int iscsi_truncate(BlockDriverState *bs, int64_t
> offset)
>
> static int iscsi_has_zero_init(BlockDriverState *bs)
> {
> - return 0;
> + IscsiLun *iscsilun = bs->opaque;
> + return (iscsilun->lbpu && iscsilun->lbprz) ? 1 : 0;
> }
>
> static int iscsi_create(const char *filename, QEMUOptionParameter *options)
> @@ -1446,6 +1447,7 @@ static int iscsi_create(const char *filename,
> QEMUOptionParameter *options)
> BlockDriverState bs;
> IscsiLun *iscsilun = NULL;
> QDict *bs_options;
> + struct scsi_task *task = NULL;
>
> memset(&bs, 0, sizeof(BlockDriverState));
>
> @@ -1481,7 +1483,75 @@ static int iscsi_create(const char *filename,
> QEMUOptionParameter *options)
> }
>
> ret = 0;
> +
> + if (iscsilun->lbpu && iscsilun->lbprz) {
> + uint64_t lba = 0;
> + while (lba < iscsilun->num_blocks) {
> + struct scsi_get_lba_status *lbas = NULL;
> + struct scsi_lba_status_descriptor *lbasd = NULL;
> + enum scsi_provisioning_type provisioning;
> + uint32_t nb_sectors;
> +
> + task = iscsi_get_lba_status_sync(iscsilun->iscsi, iscsilun->lun,
> + lba, 8 + 16);
> + if (task == NULL || task->status != SCSI_STATUS_GOOD) {
> + error_report("iSCSI: Failed to get_lba_status on iSCSI lun.
> %s",
> + iscsi_get_error(iscsilun->iscsi));
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + lbas = scsi_datain_unmarshall(task);
> + if (lbas == NULL) {
> + error_report("iSCSI: failed to unmarshall inquiry datain
> blob");
> + ret = -EINVAL;
> + goto out;
> + }
> + lbasd = &lbas->descriptors[0];
> + if (lbasd->lba != lba) {
> + ret = -EINVAL;
> + goto out;
> + }
> + nb_sectors = lbasd->num_blocks;
> + provisioning = lbasd->provisioning;
> + scsi_free_scsi_task(task);
> + task = NULL;
> +
> + /* blocks from lba to lba + nb_sectors - 1 are not mapped
> + * and read as zero (lbprz==1) so we can skip them */
> + if (provisioning != SCSI_PROVISIONING_TYPE_MAPPED) {
> + lba += nb_sectors;
> + continue;
> + }
> +
> + uint64_t lba2 = lba + nb_sectors;
> + while (lba < lba2) {
> + struct unmap_list list[1];
> + list[0].lba = lba;
> + list[0].num = iscsilun->max_unmap;
> + if (lba + list[0].num > iscsilun->num_blocks) {
> + list[0].num = iscsilun->num_blocks - lba;
> + }
> + task = iscsi_unmap_sync(iscsilun->iscsi,
> + iscsilun->lun,
> + 0, 0, &list[0], 1);
> + if (task == NULL || task->status != SCSI_STATUS_GOOD) {
> + error_report("iSCSI: Failed to unmap data on iSCSI lun.
> %s",
> + iscsi_get_error(iscsilun->iscsi));
> + ret = -EINVAL;
> + goto out;
> + }
> + scsi_free_scsi_task(task);
> + task = NULL;
> + lba += list[0].num;
> + }
> + }
> + }
> +
> out:
> + if (task) {
> + scsi_free_scsi_task(task);
> + }
> if (iscsilun->iscsi != NULL) {
> iscsi_destroy_context(iscsilun->iscsi);
> }
>
