virtio-blk: Use bdrv_aio_multiwrite
It is quite common for virtio-blk to submit more than one write request in a row to the qemu block layer. Use bdrv_aio_multiwrite to allow block drivers to optimize its handling of the requests. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
parent
40b4f53967
commit
91553dcc9e
@ -252,16 +252,41 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
|
|||||||
}
|
}
|
||||||
#endif /* __linux__ */
|
#endif /* __linux__ */
|
||||||
|
|
||||||
static void virtio_blk_handle_write(VirtIOBlockReq *req)
|
static void do_multiwrite(BlockDriverState *bs, BlockRequest *blkreq,
|
||||||
|
int num_writes)
|
||||||
{
|
{
|
||||||
BlockDriverAIOCB *acb;
|
int i, ret;
|
||||||
|
ret = bdrv_aio_multiwrite(bs, blkreq, num_writes);
|
||||||
|
|
||||||
acb = bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
|
if (ret != 0) {
|
||||||
req->qiov.size / 512, virtio_blk_rw_complete, req);
|
for (i = 0; i < num_writes; i++) {
|
||||||
if (!acb) {
|
if (blkreq[i].error) {
|
||||||
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
|
virtio_blk_req_complete(blkreq[i].opaque, VIRTIO_BLK_S_IOERR);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes,
|
||||||
|
VirtIOBlockReq *req, BlockDriverState **old_bs)
|
||||||
|
{
|
||||||
|
if (req->dev->bs != *old_bs || *num_writes == 32) {
|
||||||
|
if (*old_bs != NULL) {
|
||||||
|
do_multiwrite(*old_bs, blkreq, *num_writes);
|
||||||
|
}
|
||||||
|
*num_writes = 0;
|
||||||
|
*old_bs = req->dev->bs;
|
||||||
|
}
|
||||||
|
|
||||||
|
blkreq[*num_writes].sector = req->out->sector;
|
||||||
|
blkreq[*num_writes].nb_sectors = req->qiov.size / 512;
|
||||||
|
blkreq[*num_writes].qiov = &req->qiov;
|
||||||
|
blkreq[*num_writes].cb = virtio_blk_rw_complete;
|
||||||
|
blkreq[*num_writes].opaque = req;
|
||||||
|
blkreq[*num_writes].error = 0;
|
||||||
|
|
||||||
|
(*num_writes)++;
|
||||||
|
}
|
||||||
|
|
||||||
static void virtio_blk_handle_read(VirtIOBlockReq *req)
|
static void virtio_blk_handle_read(VirtIOBlockReq *req)
|
||||||
{
|
{
|
||||||
@ -278,6 +303,9 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
|
|||||||
{
|
{
|
||||||
VirtIOBlock *s = to_virtio_blk(vdev);
|
VirtIOBlock *s = to_virtio_blk(vdev);
|
||||||
VirtIOBlockReq *req;
|
VirtIOBlockReq *req;
|
||||||
|
BlockRequest blkreq[32];
|
||||||
|
int num_writes = 0;
|
||||||
|
BlockDriverState *old_bs = NULL;
|
||||||
|
|
||||||
while ((req = virtio_blk_get_request(s))) {
|
while ((req = virtio_blk_get_request(s))) {
|
||||||
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
|
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
|
||||||
@ -299,13 +327,18 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
|
|||||||
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
|
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
|
||||||
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
|
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
|
||||||
req->elem.out_num - 1);
|
req->elem.out_num - 1);
|
||||||
virtio_blk_handle_write(req);
|
virtio_blk_handle_write(blkreq, &num_writes, req, &old_bs);
|
||||||
} else {
|
} else {
|
||||||
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
|
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
|
||||||
req->elem.in_num - 1);
|
req->elem.in_num - 1);
|
||||||
virtio_blk_handle_read(req);
|
virtio_blk_handle_read(req);
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
if (num_writes > 0) {
|
||||||
|
do_multiwrite(old_bs, blkreq, num_writes);
|
||||||
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* FIXME: Want to check for completions before returning to guest mode,
|
* FIXME: Want to check for completions before returning to guest mode,
|
||||||
* so cached reads and writes are reported as quickly as possible. But
|
* so cached reads and writes are reported as quickly as possible. But
|
||||||
@ -324,7 +357,8 @@ static void virtio_blk_dma_restart_bh(void *opaque)
|
|||||||
s->rq = NULL;
|
s->rq = NULL;
|
||||||
|
|
||||||
while (req) {
|
while (req) {
|
||||||
virtio_blk_handle_write(req);
|
bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
|
||||||
|
req->qiov.size / 512, virtio_blk_rw_complete, req);
|
||||||
req = req->next;
|
req = req->next;
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user