Commit 03c90063 authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

scsi-disk: Switch to byte-based aio block access 



Sector-based blk_aio_readv() and blk_aio_writev() should die; switch
to byte-based blk_aio_preadv() and blk_aio_pwritev() instead.

As part of the cleanup, scsi_init_iovec() no longer needs to return
a value, and reword a comment.

[ kwolf: Fix read accounting change ]

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent d4f510eb

hw/scsi/scsi-disk.c

+20 −21
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ static void scsi_check_condition(SCSIDiskReq *r, SCSISense sense) 
    scsi_req_complete(&r->req, CHECK_CONDITION);

}



static uint32_t scsi_init_iovec(SCSIDiskReq *r, size_t size)

static void scsi_init_iovec(SCSIDiskReq *r, size_t size)

{

    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
@@ -118,7 +118,6 @@ static uint32_t scsi_init_iovec(SCSIDiskReq *r, size_t size) 
    }

    r->iov.iov_len = MIN(r->sector_count * 512, r->buflen);

    qemu_iovec_init_external(&r->qiov, &r->iov, 1);

    return r->qiov.size / 512;

}



static void scsi_disk_save_request(QEMUFile *f, SCSIRequest *req)
@@ -316,7 +315,6 @@ done: 
static void scsi_do_read(SCSIDiskReq *r, int ret)

{

    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

    uint32_t n;



    assert (r->req.aiocb == NULL);
@@ -340,11 +338,12 @@ static void scsi_do_read(SCSIDiskReq *r, int ret) 
        r->req.aiocb = dma_blk_read(s->qdev.conf.blk, r->req.sg, r->sector,

                                    scsi_dma_complete, r);

    } else {

        n = scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);

        scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);

        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,

                         n * BDRV_SECTOR_SIZE, BLOCK_ACCT_READ);

        r->req.aiocb = blk_aio_readv(s->qdev.conf.blk, r->sector, &r->qiov, n,

                                     scsi_read_complete, r);

                         r->qiov.size, BLOCK_ACCT_READ);

        r->req.aiocb = blk_aio_preadv(s->qdev.conf.blk,

                                      r->sector << BDRV_SECTOR_BITS, &r->qiov,

                                      0, scsi_read_complete, r);

    }



done:
@@ -504,7 +503,6 @@ static void scsi_write_data(SCSIRequest *req) 
{

    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);

    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

    uint32_t n;



    /* No data transfer may already be in progress */

    assert(r->req.aiocb == NULL);
@@ -544,11 +542,11 @@ static void scsi_write_data(SCSIRequest *req) 
        r->req.aiocb = dma_blk_write(s->qdev.conf.blk, r->req.sg, r->sector,

                                     scsi_dma_complete, r);

    } else {

        n = r->qiov.size / 512;

        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,

                         n * BDRV_SECTOR_SIZE, BLOCK_ACCT_WRITE);

        r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, r->sector, &r->qiov, n,

                                      scsi_write_complete, r);

                         r->qiov.size, BLOCK_ACCT_WRITE);

        r->req.aiocb = blk_aio_pwritev(s->qdev.conf.blk,

                                       r->sector << BDRV_SECTOR_BITS, &r->qiov,

                                       0, scsi_write_complete, r);

    }

}
@@ -1730,12 +1728,12 @@ static void scsi_write_same_complete(void *opaque, int ret) 
    if (data->iov.iov_len) {

        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,

                         data->iov.iov_len, BLOCK_ACCT_WRITE);

        /* blk_aio_write doesn't like the qiov size being different from

         * nb_sectors, make sure they match.

         */

        /* Reinitialize qiov, to handle unaligned WRITE SAME request

         * where final qiov may need smaller size */

        qemu_iovec_init_external(&data->qiov, &data->iov, 1);

        r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, data->sector,

                                      &data->qiov, data->iov.iov_len / 512,

        r->req.aiocb = blk_aio_pwritev(s->qdev.conf.blk,

                                       data->sector << BDRV_SECTOR_BITS,

                                       &data->qiov, 0,

                                       scsi_write_same_complete, data);

        return;

    }
@@ -1803,8 +1801,9 @@ static void scsi_disk_emulate_write_same(SCSIDiskReq *r, uint8_t *inbuf) 
    scsi_req_ref(&r->req);

    block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,

                     data->iov.iov_len, BLOCK_ACCT_WRITE);

    r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, data->sector,

                                  &data->qiov, data->iov.iov_len / 512,

    r->req.aiocb = blk_aio_pwritev(s->qdev.conf.blk,

                                   data->sector << BDRV_SECTOR_BITS,

                                   &data->qiov, 0,

                                   scsi_write_same_complete, data);

}