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.
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);
--
1.7.9.5
