From df893d25ceea3c0dcbe6d6b425309317fab6b22e Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Tue, 4 Jun 2019 19:15:13 +0300 Subject: [PATCH] block/qcow2: implement .bdrv_co_preadv_part Implement and use new interface to get rid of hd_qiov. Signed-off-by: Vladimir Sementsov-Ogievskiy Acked-by: Stefan Hajnoczi Message-id: 20190604161514.262241-12-vsementsov@virtuozzo.com Message-Id: <20190604161514.262241-12-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi --- block/qcow2-cluster.c | 5 +++-- block/qcow2.c | 49 +++++++++++++++++++------------------------ 2 files changed, 25 insertions(+), 29 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index cc5609e27a..0e4524d450 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -452,8 +452,9 @@ static int coroutine_fn do_perform_cow_read(BlockDriverState *bs, * interface. This avoids double I/O throttling and request tracking, * which can lead to deadlock when block layer copy-on-read is enabled. */ - ret = bs->drv->bdrv_co_preadv(bs, src_cluster_offset + offset_in_cluster, - qiov->size, qiov, 0); + ret = bs->drv->bdrv_co_preadv_part(bs, + src_cluster_offset + offset_in_cluster, + qiov->size, qiov, 0, 0); if (ret < 0) { return ret; } diff --git a/block/qcow2.c b/block/qcow2.c index b2b87d1a8d..ec1fff9dd1 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -76,7 +76,8 @@ qcow2_co_preadv_compressed(BlockDriverState *bs, uint64_t file_cluster_offset, uint64_t offset, uint64_t bytes, - QEMUIOVector *qiov); + QEMUIOVector *qiov, + size_t qiov_offset); static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) { @@ -1967,21 +1968,18 @@ out: return ret; } -static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, QEMUIOVector *qiov, - int flags) +static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs, + uint64_t offset, uint64_t bytes, + QEMUIOVector *qiov, + size_t qiov_offset, int flags) { BDRVQcow2State *s = bs->opaque; int offset_in_cluster; int ret; unsigned int cur_bytes; /* number of bytes in current iteration */ uint64_t cluster_offset = 0; - uint64_t bytes_done = 0; - QEMUIOVector hd_qiov; uint8_t *cluster_data = NULL; - qemu_iovec_init(&hd_qiov, qiov->niov); - while (bytes != 0) { /* prepare next request */ @@ -2000,34 +1998,31 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, offset_in_cluster = offset_into_cluster(s, offset); - qemu_iovec_reset(&hd_qiov); - qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes); - switch (ret) { case QCOW2_CLUSTER_UNALLOCATED: if (bs->backing) { BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); - ret = bdrv_co_preadv(bs->backing, offset, cur_bytes, - &hd_qiov, 0); + ret = bdrv_co_preadv_part(bs->backing, offset, cur_bytes, + qiov, qiov_offset, 0); if (ret < 0) { goto fail; } } else { /* Note: in this case, no need to wait */ - qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); + qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); } break; case QCOW2_CLUSTER_ZERO_PLAIN: case QCOW2_CLUSTER_ZERO_ALLOC: - qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); + qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); break; case QCOW2_CLUSTER_COMPRESSED: ret = qcow2_co_preadv_compressed(bs, cluster_offset, offset, cur_bytes, - &hd_qiov); + qiov, qiov_offset); if (ret < 0) { goto fail; } @@ -2075,12 +2070,12 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, ret = -EIO; goto fail; } - qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes); + qemu_iovec_from_buf(qiov, qiov_offset, cluster_data, cur_bytes); } else { BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); - ret = bdrv_co_preadv(s->data_file, - cluster_offset + offset_in_cluster, - cur_bytes, &hd_qiov, 0); + ret = bdrv_co_preadv_part(s->data_file, + cluster_offset + offset_in_cluster, + cur_bytes, qiov, qiov_offset, 0); if (ret < 0) { goto fail; } @@ -2095,12 +2090,11 @@ static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, bytes -= cur_bytes; offset += cur_bytes; - bytes_done += cur_bytes; + qiov_offset += cur_bytes; } ret = 0; fail: - qemu_iovec_destroy(&hd_qiov); qemu_vfree(cluster_data); return ret; @@ -4101,7 +4095,8 @@ qcow2_co_preadv_compressed(BlockDriverState *bs, uint64_t file_cluster_offset, uint64_t offset, uint64_t bytes, - QEMUIOVector *qiov) + QEMUIOVector *qiov, + size_t qiov_offset) { BDRVQcow2State *s = bs->opaque; int ret = 0, csize, nb_csectors; @@ -4132,7 +4127,7 @@ qcow2_co_preadv_compressed(BlockDriverState *bs, goto fail; } - qemu_iovec_from_buf(qiov, 0, out_buf + offset_in_cluster, bytes); + qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes); fail: qemu_vfree(out_buf); @@ -4679,8 +4674,8 @@ static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, BDRVQcow2State *s = bs->opaque; BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); - return bs->drv->bdrv_co_preadv(bs, qcow2_vm_state_offset(s) + pos, - qiov->size, qiov, 0); + return bs->drv->bdrv_co_preadv_part(bs, qcow2_vm_state_offset(s) + pos, + qiov->size, qiov, 0, 0); } /* @@ -5222,7 +5217,7 @@ BlockDriver bdrv_qcow2 = { .bdrv_has_zero_init_truncate = bdrv_has_zero_init_1, .bdrv_co_block_status = qcow2_co_block_status, - .bdrv_co_preadv = qcow2_co_preadv, + .bdrv_co_preadv_part = qcow2_co_preadv_part, .bdrv_co_pwritev = qcow2_co_pwritev, .bdrv_co_flush_to_os = qcow2_co_flush_to_os,