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scsi-disk: commonize iovec creation between reads and writes
Also, consistently use qiov.size instead of iov.iov_len.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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bonzini authored and Kevin Wolf committed Sep 20, 2011
1 parent c3adb5b commit 103b40f
Showing 1 changed file with 18 additions and 24 deletions.
42 changes: 18 additions & 24 deletions hw/scsi-disk.c
Expand Up @@ -108,6 +108,13 @@ static void scsi_cancel_io(SCSIRequest *req)
r->req.aiocb = NULL;
}

static uint32_t scsi_init_iovec(SCSIDiskReq *r)
{
r->iov.iov_len = MIN(r->sector_count * 512, SCSI_DMA_BUF_SIZE);
qemu_iovec_init_external(&r->qiov, &r->iov, 1);
return r->qiov.size / 512;
}

static void scsi_read_complete(void * opaque, int ret)
{
SCSIDiskReq *r = (SCSIDiskReq *)opaque;
Expand All @@ -125,12 +132,12 @@ static void scsi_read_complete(void * opaque, int ret)
}
}

DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->iov.iov_len);
DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->qiov.size);

n = r->iov.iov_len / 512;
n = r->qiov.size / 512;
r->sector += n;
r->sector_count -= n;
scsi_req_data(&r->req, r->iov.iov_len);
scsi_req_data(&r->req, r->qiov.size);
}

static void scsi_flush_complete(void * opaque, int ret)
Expand Down Expand Up @@ -181,16 +188,10 @@ static void scsi_read_data(SCSIRequest *req)
return;
}

n = r->sector_count;
if (n > SCSI_DMA_BUF_SIZE / 512)
n = SCSI_DMA_BUF_SIZE / 512;

if (s->tray_open) {
scsi_read_complete(r, -ENOMEDIUM);
}
r->iov.iov_len = n * 512;
qemu_iovec_init_external(&r->qiov, &r->iov, 1);

n = scsi_init_iovec(r);
bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_READ);
r->req.aiocb = bdrv_aio_readv(s->bs, r->sector, &r->qiov, n,
scsi_read_complete, r);
Expand Down Expand Up @@ -239,7 +240,6 @@ static void scsi_write_complete(void * opaque, int ret)
{
SCSIDiskReq *r = (SCSIDiskReq *)opaque;
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
uint32_t len;
uint32_t n;

if (r->req.aiocb != NULL) {
Expand All @@ -253,19 +253,15 @@ static void scsi_write_complete(void * opaque, int ret)
}
}

n = r->iov.iov_len / 512;
n = r->qiov.size / 512;
r->sector += n;
r->sector_count -= n;
if (r->sector_count == 0) {
scsi_req_complete(&r->req, GOOD);
} else {
len = r->sector_count * 512;
if (len > SCSI_DMA_BUF_SIZE) {
len = SCSI_DMA_BUF_SIZE;
}
r->iov.iov_len = len;
DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, len);
scsi_req_data(&r->req, len);
scsi_init_iovec(r);
DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, r->qiov.size);
scsi_req_data(&r->req, r->qiov.size);
}
}

Expand All @@ -284,21 +280,19 @@ static void scsi_write_data(SCSIRequest *req)
return;
}

n = r->iov.iov_len / 512;
n = r->qiov.size / 512;
if (n) {
if (s->tray_open) {
scsi_write_complete(r, -ENOMEDIUM);
}
qemu_iovec_init_external(&r->qiov, &r->iov, 1);

bdrv_acct_start(s->bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_WRITE);
r->req.aiocb = bdrv_aio_writev(s->bs, r->sector, &r->qiov, n,
scsi_write_complete, r);
scsi_write_complete, r);
if (r->req.aiocb == NULL) {
scsi_write_complete(r, -ENOMEM);
}
} else {
/* Invoke completion routine to fetch data from host. */
/* Called for the first time. Ask the driver to send us more data. */
scsi_write_complete(r, 0);
}
}
Expand Down

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