diff options
| -rw-r--r-- | block/qcow2-cluster.c | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 277764f36c..b7671fc1de 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -390,22 +390,18 @@ int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num, return 0; } -static int coroutine_fn copy_sectors(BlockDriverState *bs, - uint64_t start_sect, - uint64_t cluster_offset, - int n_start, int n_end) +static int coroutine_fn do_perform_cow(BlockDriverState *bs, + uint64_t src_cluster_offset, + uint64_t cluster_offset, + int offset_in_cluster, + int bytes) { BDRVQcow2State *s = bs->opaque; QEMUIOVector qiov; struct iovec iov; - int n, ret; - - n = n_end - n_start; - if (n <= 0) { - return 0; - } + int ret; - iov.iov_len = n * BDRV_SECTOR_SIZE; + iov.iov_len = bytes; iov.iov_base = qemu_try_blockalign(bs, iov.iov_len); if (iov.iov_base == NULL) { return -ENOMEM; @@ -424,18 +420,21 @@ static int coroutine_fn copy_sectors(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, (start_sect + n_start) * BDRV_SECTOR_SIZE, - n * BDRV_SECTOR_SIZE, &qiov, 0); + ret = bs->drv->bdrv_co_preadv(bs, src_cluster_offset + offset_in_cluster, + bytes, &qiov, 0); if (ret < 0) { goto out; } if (bs->encrypted) { Error *err = NULL; + int64_t sector = (cluster_offset + offset_in_cluster) + >> BDRV_SECTOR_BITS; assert(s->cipher); - if (qcow2_encrypt_sectors(s, start_sect + n_start, - iov.iov_base, iov.iov_base, n, - true, &err) < 0) { + assert((offset_in_cluster & ~BDRV_SECTOR_MASK) == 0); + assert((bytes & ~BDRV_SECTOR_MASK) == 0); + if (qcow2_encrypt_sectors(s, sector, iov.iov_base, iov.iov_base, + bytes >> BDRV_SECTOR_BITS, true, &err) < 0) { ret = -EIO; error_free(err); goto out; @@ -443,14 +442,14 @@ static int coroutine_fn copy_sectors(BlockDriverState *bs, } ret = qcow2_pre_write_overlap_check(bs, 0, - cluster_offset + n_start * BDRV_SECTOR_SIZE, n * BDRV_SECTOR_SIZE); + cluster_offset + offset_in_cluster, bytes); if (ret < 0) { goto out; } BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE); - ret = bdrv_co_writev(bs->file->bs, (cluster_offset >> 9) + n_start, n, - &qiov); + ret = bdrv_co_pwritev(bs->file->bs, cluster_offset + offset_in_cluster, + bytes, &qiov, 0); if (ret < 0) { goto out; } @@ -745,9 +744,8 @@ static int perform_cow(BlockDriverState *bs, QCowL2Meta *m, Qcow2COWRegion *r) } qemu_co_mutex_unlock(&s->lock); - ret = copy_sectors(bs, m->offset / BDRV_SECTOR_SIZE, m->alloc_offset, - r->offset / BDRV_SECTOR_SIZE, - r->offset / BDRV_SECTOR_SIZE + r->nb_sectors); + ret = do_perform_cow(bs, m->offset, m->alloc_offset, + r->offset, r->nb_sectors * BDRV_SECTOR_SIZE); qemu_co_mutex_lock(&s->lock); if (ret < 0) { @@ -809,13 +807,14 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m) assert(l2_index + m->nb_clusters <= s->l2_size); for (i = 0; i < m->nb_clusters; i++) { /* if two concurrent writes happen to the same unallocated cluster - * each write allocates separate cluster and writes data concurrently. - * The first one to complete updates l2 table with pointer to its - * cluster the second one has to do RMW (which is done above by - * copy_sectors()), update l2 table with its cluster pointer and free - * old cluster. This is what this loop does */ - if(l2_table[l2_index + i] != 0) + * each write allocates separate cluster and writes data concurrently. + * The first one to complete updates l2 table with pointer to its + * cluster the second one has to do RMW (which is done above by + * perform_cow()), update l2 table with its cluster pointer and free + * old cluster. This is what this loop does */ + if (l2_table[l2_index + i] != 0) { old_cluster[j++] = l2_table[l2_index + i]; + } l2_table[l2_index + i] = cpu_to_be64((cluster_offset + (i << s->cluster_bits)) | QCOW_OFLAG_COPIED); |