From 1143ec5ebf48d6dbf61f600eb5f875aefffb8fb6 Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 4 Jun 2019 19:15:07 +0300 Subject: [PATCH] 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 Acked-by: Stefan Hajnoczi Message-id: 20190604161514.262241-6-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-6-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi --- block/io.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/block/io.c b/block/io.c index fd2fc7d5ff..5817bb9405 100644 --- a/block/io.c +++ b/block/io.c @@ -1227,7 +1227,7 @@ bdrv_driver_pwritev_compressed(BlockDriverState *bs, uint64_t offset, static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, int64_t offset, unsigned int bytes, QEMUIOVector *qiov, - int flags) + size_t qiov_offset, int flags) { BlockDriverState *bs = child->bs; @@ -1239,7 +1239,6 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, void *bounce_buffer; BlockDriver *drv = bs->drv; - QEMUIOVector local_qiov; int64_t cluster_offset; int64_t cluster_bytes; size_t skip_bytes; @@ -1302,6 +1301,8 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, assert(skip_bytes < pnum); if (ret <= 0) { + QEMUIOVector local_qiov; + /* Must copy-on-read; use the bounce buffer */ pnum = MIN(pnum, MAX_BOUNCE_BUFFER); qemu_iovec_init_buf(&local_qiov, bounce_buffer, pnum); @@ -1339,16 +1340,15 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child, } if (!(flags & BDRV_REQ_PREFETCH)) { - qemu_iovec_from_buf(qiov, progress, bounce_buffer + skip_bytes, + qemu_iovec_from_buf(qiov, qiov_offset + progress, + bounce_buffer + skip_bytes, pnum - skip_bytes); } } else if (!(flags & BDRV_REQ_PREFETCH)) { /* Read directly into the destination */ - qemu_iovec_init(&local_qiov, qiov->niov); - qemu_iovec_concat(&local_qiov, qiov, progress, pnum - skip_bytes); - ret = bdrv_driver_preadv(bs, offset + progress, local_qiov.size, - &local_qiov, 0, 0); - qemu_iovec_destroy(&local_qiov); + ret = bdrv_driver_preadv(bs, offset + progress, + MIN(pnum - skip_bytes, bytes - progress), + qiov, qiov_offset + progress, 0); if (ret < 0) { goto err; } @@ -1422,7 +1422,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, } if (!ret || pnum != bytes) { - ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, flags); + ret = bdrv_co_do_copy_on_readv(child, offset, bytes, qiov, 0, flags); goto out; } else if (flags & BDRV_REQ_PREFETCH) { goto out;