scsi: add support for FUA on writes

To force unit access, add a flush operation after the actual write.
WRITE AND VERIFY commands always flush according to SBC, so do it
even though we do not perform the reread.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-04-19 10:10:54 +02:00
parent b77912a77a
commit 7e8c49c561

View file

@ -174,6 +174,45 @@ done:
}
}
static bool scsi_is_cmd_fua(SCSICommand *cmd)
{
switch (cmd->buf[0]) {
case READ_10:
case READ_12:
case READ_16:
case WRITE_10:
case WRITE_12:
case WRITE_16:
return (cmd->buf[1] & 8) != 0;
case WRITE_VERIFY_10:
case WRITE_VERIFY_12:
case WRITE_VERIFY_16:
return true;
case READ_6:
case WRITE_6:
default:
return false;
}
}
static void scsi_write_do_fua(SCSIDiskReq *r)
{
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
if (scsi_is_cmd_fua(&r->req.cmd)) {
bdrv_acct_start(s->qdev.conf.bs, &r->acct, 0, BDRV_ACCT_FLUSH);
r->req.aiocb = bdrv_aio_flush(s->qdev.conf.bs, scsi_flush_complete, r);
return;
}
scsi_req_complete(&r->req, GOOD);
if (!r->req.io_canceled) {
scsi_req_unref(&r->req);
}
}
static void scsi_dma_complete(void *opaque, int ret)
{
SCSIDiskReq *r = (SCSIDiskReq *)opaque;
@ -189,7 +228,12 @@ static void scsi_dma_complete(void *opaque, int ret)
r->sector += r->sector_count;
r->sector_count = 0;
scsi_req_complete(&r->req, GOOD);
if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
scsi_write_do_fua(r);
return;
} else {
scsi_req_complete(&r->req, GOOD);
}
done:
if (!r->req.io_canceled) {
@ -342,7 +386,8 @@ static void scsi_write_complete(void * opaque, int ret)
r->sector += n;
r->sector_count -= n;
if (r->sector_count == 0) {
scsi_req_complete(&r->req, GOOD);
scsi_write_do_fua(r);
return;
} else {
scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
DPRINTF("Write complete tag=0x%x more=%d\n", r->req.tag, r->qiov.size);