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block/io: bdrv_co_do_copy_on_readv: use and support qiov_offset
Use and support new API in bdrv_co_do_copy_on_readv. Note that in case of allocated-in-top we need to shrink read size to MIN(..) by hand, as pre-patch this was actually done implicitly by qemu_iovec_concat (and we used local_qiov.size). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190604161514.262241-6-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-6-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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parent
ac850bf099
commit
1143ec5ebf
18
block/io.c
18
block/io.c
@ -1227,7 +1227,7 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
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static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
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int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
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int flags)
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size_t qiov_offset, int flags)
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{
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BlockDriverState *bs = child->bs;
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@ -1239,7 +1239,6 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
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void *bounce_buffer;
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BlockDriver *drv = bs->drv;
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QEMUIOVector local_qiov;
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int64_t cluster_offset;
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int64_t cluster_bytes;
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size_t skip_bytes;
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@ -1302,6 +1301,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
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assert(skip_bytes < pnum);
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if (ret <= 0) {
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QEMUIOVector local_qiov;
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/* Must copy-on-read; use the bounce buffer */
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pnum = MIN(pnum, MAX_BOUNCE_BUFFER);
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qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum);
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@ -1339,16 +1340,15 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
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}
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if (!(flags & BDRV_REQ_PREFETCH)) {
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qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes,
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qemu_iovec_from_buf(qiov, qiov_offset + progress,
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bounce_buffer + skip_bytes,
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pnum - skip_bytes);
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}
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} else if (!(flags & BDRV_REQ_PREFETCH)) {
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/* Read directly into the destination */
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qemu_iovec_init(&local_qiov, qiov->niov);
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qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes);
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ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size,
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&local_qiov, 0, 0);
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qemu_iovec_destroy(&local_qiov);
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ret = bdrv_driver_preadv(bs, offset + progress,
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MIN(pnum - skip_bytes, bytes - progress),
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qiov, qiov_offset + progress, 0);
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if (ret < 0) {
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goto err;
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}
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@ -1422,7 +1422,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
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}
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if (!ret || pnum != bytes) {
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ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, flags);
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ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, 0, flags);
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goto out;
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} else if (flags & BDRV_REQ_PREFETCH) {
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goto out;
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