Commit 03396148 authored by Michael Tokarev's avatar Michael Tokarev
Browse files

allow qemu_iovec_from_buffer() to specify offset from which to start copying 



Similar to
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes);
the new prototype is:
 qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
                     const void *buf, size_t bytes);

The processing starts at offset bytes within qiov.

This way, we may copy a bounce buffer directly to
a middle of qiov.

This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.

As with utility implementation, we now assert that the
offset is inside actual iovec.  Nothing changed for
current callers, because `offset' parameter is new.

While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.

Signed-off-by: default avatarMichael Tokarev <mjt@tls.msk.ru>
parent 3d9b4925

block.c

+3 −3
Original line number Diff line number Diff line
@@ -1821,7 +1821,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, 
    }



    skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;

    qemu_iovec_from_buffer(qiov, bounce_buffer + skip_bytes,

    qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,

                        nb_sectors * BDRV_SECTOR_SIZE);



err:
@@ -3382,7 +3382,7 @@ static void bdrv_aio_bh_cb(void *opaque) 
    BlockDriverAIOCBSync *acb = opaque;



    if (!acb->is_write)

        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);

        qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);

    qemu_vfree(acb->bounce);

    acb->common.cb(acb->common.opaque, acb->ret);

    qemu_bh_delete(acb->bh);

block/curl.c

+3 −3
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque) 
            continue;



        if ((s->buf_off >= acb->end)) {

            qemu_iovec_from_buffer(acb->qiov, s->orig_buf + acb->start,

            qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,

                                acb->end - acb->start);

            acb->common.cb(acb->common.opaque, 0);

            qemu_aio_release(acb);
@@ -176,7 +176,7 @@ static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len, 
        {

            char *buf = state->orig_buf + (start - state->buf_start);



            qemu_iovec_from_buffer(acb->qiov, buf, len);

            qemu_iovec_from_buf(acb->qiov, 0, buf, len);

            acb->common.cb(acb->common.opaque, 0);



            return FIND_RET_OK;

block/qcow.c

+1 −1
Original line number Diff line number Diff line
@@ -540,7 +540,7 @@ done: 
    qemu_co_mutex_unlock(&s->lock);



    if (qiov->niov > 1) {

        qemu_iovec_from_buffer(qiov, orig_buf, qiov->size);

        qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);

        qemu_vfree(orig_buf);

    }

block/qcow2.c

+3 −6
Original line number Diff line number Diff line
@@ -590,7 +590,7 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, 
                goto fail;

            }



            qemu_iovec_from_buffer(&hd_qiov,

            qemu_iovec_from_buf(&hd_qiov, 0,

                s->cluster_cache + index_in_cluster * 512,

                512 * cur_nr_sectors);

            break;
@@ -630,11 +630,8 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, 
            if (s->crypt_method) {

                qcow2_encrypt_sectors(s, sector_num,  cluster_data,

                    cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key);

                qemu_iovec_reset(&hd_qiov);

                qemu_iovec_copy(&hd_qiov, qiov, bytes_done,

                    cur_nr_sectors * 512);

                qemu_iovec_from_buffer(&hd_qiov, cluster_data,

                    512 * cur_nr_sectors);

                qemu_iovec_from_buf(qiov, bytes_done,

                    cluster_data, 512 * cur_nr_sectors);

            }

            break;

block/rbd.c

+1 −1
Original line number Diff line number Diff line
@@ -620,7 +620,7 @@ static void rbd_aio_bh_cb(void *opaque) 
    RBDAIOCB *acb = opaque;



    if (acb->cmd == RBD_AIO_READ) {

        qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);

        qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size);

    }

    qemu_vfree(acb->bounce);

    acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret));