On 08/12/2014 10:20, Ming Lei wrote:
> Currently block can not handle big write well when write
> size is bigger than INT_MAX, so split the write zero into
> smaller size of chunks to meet block's requirement.
>
> This patch fixes one WRITE SAME 16 failure in linux VM side.
Can you just set max_ws_blocks instead?
Paolo
> Cc: Max Reitz <mre...@redhat.com>
> Signed-off-by: Ming Lei <ming....@canonical.com>
> ---
> hw/scsi/scsi-disk.c | 67
> +++++++++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 57 insertions(+), 10 deletions(-)
>
> diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
> index 2f75d7d..a843f9b 100644
> --- a/hw/scsi/scsi-disk.c
> +++ b/hw/scsi/scsi-disk.c
> @@ -42,6 +42,9 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
> #include <scsi/sg.h>
> #endif
>
> +/* bytes in one single write should be held in one 'int' variable */
> +#define SCSI_WRITE_ZERO_MAX (INT_MAX)
> +
> #define SCSI_WRITE_SAME_MAX 524288
> #define SCSI_DMA_BUF_SIZE 131072
> #define SCSI_MAX_INQUIRY_LEN 256
> @@ -1618,10 +1621,53 @@ typedef struct WriteSameCBData {
> SCSIDiskReq *r;
> int64_t sector;
> int nb_sectors;
> + int curr_sectors;
> + int flags;
> QEMUIOVector qiov;
> struct iovec iov;
> } WriteSameCBData;
>
> +static void scsi_write_zero_complete(void *opaque, int ret)
> +{
> + WriteSameCBData *data = opaque;
> + SCSIDiskReq *r = data->r;
> + SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
> +
> + assert(r->req.aiocb != NULL);
> + r->req.aiocb = NULL;
> + block_acct_done(blk_get_stats(s->qdev.conf.blk), &r->acct);
> + if (r->req.io_canceled) {
> + scsi_req_cancel_complete(&r->req);
> + goto done;
> + }
> +
> + if (ret < 0) {
> + if (scsi_handle_rw_error(r, -ret)) {
> + goto done;
> + }
> + }
> +
> + data->nb_sectors -= data->curr_sectors;
> + data->sector += data->curr_sectors;
> + data->curr_sectors = MIN(data->nb_sectors, SCSI_WRITE_ZERO_MAX / 512);
> + if (data->nb_sectors) {
> + block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
> + data->curr_sectors * s->qdev.blocksize,
> + BLOCK_ACCT_WRITE);
> + r->req.aiocb = blk_aio_write_zeroes(s->qdev.conf.blk,
> + data->sector,
> + data->curr_sectors,
> + data->flags, scsi_write_zero_complete, data);
> + return;
> + }
> +
> + scsi_req_complete(&r->req, GOOD);
> +
> +done:
> + scsi_req_unref(&r->req);
> + g_free(data);
> +}
> +
> static void scsi_write_same_complete(void *opaque, int ret)
> {
> WriteSameCBData *data = opaque;
> @@ -1686,25 +1732,26 @@ static void scsi_disk_emulate_write_same(SCSIDiskReq
> *r, uint8_t *inbuf)
> return;
> }
>
> + data = g_new0(WriteSameCBData, 1);
> + data->r = r;
> + data->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
> + data->nb_sectors = nb_sectors * (s->qdev.blocksize / 512);
> + data->curr_sectors = MIN(data->nb_sectors, SCSI_WRITE_ZERO_MAX / 512);
> if (buffer_is_zero(inbuf, s->qdev.blocksize)) {
> - int flags = (req->cmd.buf[1] & 0x8) ? BDRV_REQ_MAY_UNMAP : 0;
> + data->flags = (req->cmd.buf[1] & 0x8) ? BDRV_REQ_MAY_UNMAP : 0;
>
> /* The request is used as the AIO opaque value, so add a ref. */
> scsi_req_ref(&r->req);
> block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
> - nb_sectors * s->qdev.blocksize,
> - BLOCK_ACCT_WRITE);
> + data->curr_sectors * s->qdev.blocksize,
> + BLOCK_ACCT_WRITE);
> r->req.aiocb = blk_aio_write_zeroes(s->qdev.conf.blk,
> - r->req.cmd.lba * (s->qdev.blocksize / 512),
> - nb_sectors * (s->qdev.blocksize / 512),
> - flags, scsi_aio_complete, r);
> + data->sector,
> + data->curr_sectors,
> + data->flags, scsi_write_zero_complete, data);
> return;
> }
>
> - data = g_new0(WriteSameCBData, 1);
> - data->r = r;
> - data->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
> - data->nb_sectors = nb_sectors * (s->qdev.blocksize / 512);
> data->iov.iov_len = MIN(data->nb_sectors * 512, SCSI_WRITE_SAME_MAX);
> data->iov.iov_base = buf = blk_blockalign(s->qdev.conf.blk,
> data->iov.iov_len);
>
