diff options
Diffstat (limited to 'block/qcow.c')
| -rw-r--r-- | block/qcow.c | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/block/qcow.c b/block/qcow.c index d7c385a91d..436ad518be 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -617,13 +617,15 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { BDRVQcowState *s = bs->opaque; - int index_in_cluster; + int offset_in_cluster; int ret = 0, n; uint64_t cluster_offset; struct iovec hd_iov; QEMUIOVector hd_qiov; uint8_t *buf; void *orig_buf; + int64_t offset = sector_num * BDRV_SECTOR_SIZE; + int64_t bytes = nb_sectors * BDRV_SECTOR_SIZE; if (qiov->niov > 1) { buf = orig_buf = qemu_try_blockalign(bs, qiov->size); @@ -637,36 +639,35 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, qemu_co_mutex_lock(&s->lock); - while (nb_sectors != 0) { + while (bytes != 0) { /* prepare next request */ - ret = get_cluster_offset(bs, sector_num << 9, - 0, 0, 0, 0, &cluster_offset); + ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset); if (ret < 0) { break; } - index_in_cluster = sector_num & (s->cluster_sectors - 1); - n = s->cluster_sectors - index_in_cluster; - if (n > nb_sectors) { - n = nb_sectors; + offset_in_cluster = offset & (s->cluster_size - 1); + n = s->cluster_size - offset_in_cluster; + if (n > bytes) { + n = bytes; } if (!cluster_offset) { if (bs->backing) { /* read from the base image */ hd_iov.iov_base = (void *)buf; - hd_iov.iov_len = n * 512; + hd_iov.iov_len = n; qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); qemu_co_mutex_unlock(&s->lock); /* qcow2 emits this on bs->file instead of bs->backing */ BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); - ret = bdrv_co_readv(bs->backing, sector_num, n, &hd_qiov); + ret = bdrv_co_preadv(bs->backing, offset, n, &hd_qiov, 0); qemu_co_mutex_lock(&s->lock); if (ret < 0) { break; } } else { /* Note: in this case, no need to wait */ - memset(buf, 0, 512 * n); + memset(buf, 0, n); } } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { /* add AIO support for compressed blocks ? */ @@ -674,21 +675,19 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, ret = -EIO; break; } - memcpy(buf, - s->cluster_cache + index_in_cluster * 512, 512 * n); + memcpy(buf, s->cluster_cache + offset_in_cluster, n); } else { if ((cluster_offset & 511) != 0) { ret = -EIO; break; } hd_iov.iov_base = (void *)buf; - hd_iov.iov_len = n * 512; + hd_iov.iov_len = n; qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); qemu_co_mutex_unlock(&s->lock); BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); - ret = bdrv_co_readv(bs->file, - (cluster_offset >> 9) + index_in_cluster, - n, &hd_qiov); + ret = bdrv_co_preadv(bs->file, cluster_offset + offset_in_cluster, + n, &hd_qiov, 0); qemu_co_mutex_lock(&s->lock); if (ret < 0) { break; @@ -696,8 +695,7 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, if (bs->encrypted) { assert(s->crypto); if (qcrypto_block_decrypt(s->crypto, - sector_num * BDRV_SECTOR_SIZE, buf, - n * BDRV_SECTOR_SIZE, NULL) < 0) { + offset, buf, n, NULL) < 0) { ret = -EIO; break; } @@ -705,9 +703,9 @@ static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, } ret = 0; - nb_sectors -= n; - sector_num += n; - buf += n * 512; + bytes -= n; + offset += n; + buf += n; } qemu_co_mutex_unlock(&s->lock); |