mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

scsi: support FUA on reads

Browse Source 
To force unit access on reads, flush the cache *before* doing the read.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-04-19 11:55:28 +02:00
parent a0e66a699e
commit ac66842646
1 changed files with 42 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
hw/scsi-disk.c
View File

@ -278,12 +278,48 @@ done:
}
}
/* Actually issue a read to the block device. */
static void scsi_do_read(void *opaque, int ret)
{
SCSIDiskReq *r = opaque;
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
uint32_t n;
if (r->req.aiocb != NULL) {
r->req.aiocb = NULL;
bdrv_acct_done(s->qdev.conf.bs, &r->acct);
}
if (ret < 0) {
if (scsi_handle_rw_error(r, -ret)) {
goto done;
}
}
if (r->req.sg) {
dma_acct_start(s->qdev.conf.bs, &r->acct, r->req.sg, BDRV_ACCT_READ);
r->req.resid -= r->req.sg->size;
r->req.aiocb = dma_bdrv_read(s->qdev.conf.bs, r->req.sg, r->sector,
scsi_dma_complete, r);
} else {
n = scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
bdrv_acct_start(s->qdev.conf.bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_READ);
r->req.aiocb = bdrv_aio_readv(s->qdev.conf.bs, r->sector, &r->qiov, n,
scsi_read_complete, r);
}
done:
if (!r->req.io_canceled) {
scsi_req_unref(&r->req);
}
}
/* Read more data from scsi device into buffer. */
static void scsi_read_data(SCSIRequest *req)
{
SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
uint32_t n;
bool first;
if (r->sector_count == (uint32_t)-1) {
DPRINTF("Read buf_len=%zd\n", r->iov.iov_len);
@ -315,17 +351,13 @@ static void scsi_read_data(SCSIRequest *req)
return;
}
first = !r->started;
r->started = true;
if (r->req.sg) {
dma_acct_start(s->qdev.conf.bs, &r->acct, r->req.sg, BDRV_ACCT_READ);
r->req.resid -= r->req.sg->size;
r->req.aiocb = dma_bdrv_read(s->qdev.conf.bs, r->req.sg, r->sector,
scsi_dma_complete, r);
if (first && 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_do_read, r);
} else {
n = scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
bdrv_acct_start(s->qdev.conf.bs, &r->acct, n * BDRV_SECTOR_SIZE, BDRV_ACCT_READ);
r->req.aiocb = bdrv_aio_readv(s->qdev.conf.bs, r->sector, &r->qiov, n,
scsi_read_complete, r);
scsi_do_read(r, 0);
}
}