Il 15/02/2013 11:58, Peter Lieven ha scritto:
> this patch adds iscsi_truncate which effectively allows for online
> resizing of iscsi volumes. for this to work you have to resize
> the volume on your storage and then call block_resize command
> in qemu which will issue a readcapacity16 to update the capacity.
>
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/iscsi.c | 74
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 74 insertions(+)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index deb3b68..37f12b3 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -67,6 +67,12 @@ typedef struct IscsiAIOCB {
> #endif
> } IscsiAIOCB;
>
> +struct IscsiTask {
> + IscsiLun *iscsilun;
> + int status;
> + int complete;
> +};
> +
> #define NOP_INTERVAL 5000
> #define MAX_NOP_FAILURES 3
>
> @@ -700,6 +706,73 @@ iscsi_getlength(BlockDriverState *bs)
> return len;
> }
>
> +static void
> +iscsi_readcapacity16_cb(struct iscsi_context *iscsi, int status,
> + void *command_data, void *opaque)
> +{
> + struct IscsiTask *itask = opaque;
> + struct scsi_readcapacity16 *rc16;
> + struct scsi_task *task = command_data;
> +
> + if (status != 0) {
> + error_report("iSCSI: Failed to read capacity of iSCSI lun. %s",
> + iscsi_get_error(iscsi));
> + itask->status = 1;
> + itask->complete = 1;
> + scsi_free_scsi_task(task);
> + return;
> + }
> +
> + rc16 = scsi_datain_unmarshall(task);
> + if (rc16 == NULL) {
> + error_report("iSCSI: Failed to unmarshall readcapacity16 data.");
> + itask->status = 1;
> + itask->complete = 1;
> + scsi_free_scsi_task(task);
> + return;
> + }
> +
> + itask->iscsilun->block_size = rc16->block_length;
> + itask->iscsilun->num_blocks = rc16->returned_lba + 1;
> +
> + itask->status = 0;
> + itask->complete = 1;
> + scsi_free_scsi_task(task);
> +}
> +
> +static int iscsi_truncate(BlockDriverState *bs, int64_t offset)
> +{
> + IscsiLun *iscsilun = bs->opaque;
> + struct IscsiTask itask;
> + struct scsi_task *task = NULL;
> +
> + if (iscsilun->type != TYPE_DISK) {
> + return -ENOTSUP;
> + }
> +
> + itask.iscsilun = iscsilun;
> + itask.status = 0;
> + itask.complete = 0;
> +
> + task = iscsi_readcapacity16_task(iscsilun->iscsi, iscsilun->lun,
> + iscsi_readcapacity16_cb, &itask);
You can use iscsi_readcapacity16_sync. In fact, you probably should
extract code from iscsi_open and reuse it here.
Paolo
> + if (task == NULL) {
> + error_report("iSCSI: failed to send readcapacity16 command.");
> + return -EINVAL;
> + }
> +
> + while (!itask.complete) {
> + iscsi_set_events(iscsilun);
> + qemu_aio_wait();
> + }
> +
> + if (offset > iscsi_getlength(bs)) {
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> static int parse_chap(struct iscsi_context *iscsi, const char *target)
> {
> QemuOptsList *list;
> @@ -1093,6 +1166,7 @@ static BlockDriver bdrv_iscsi = {
> .create_options = iscsi_create_options,
>
> .bdrv_getlength = iscsi_getlength,
> + .bdrv_truncate = iscsi_truncate,
>
> .bdrv_aio_readv = iscsi_aio_readv,
> .bdrv_aio_writev = iscsi_aio_writev,
