diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/qcow2-cluster.c | 110 |
1 files changed, 53 insertions, 57 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 8ed1f7dd2a..11414830ec 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -886,7 +886,6 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, unsigned int nb_clusters; int ret; - uint64_t alloc_offset; uint64_t alloc_cluster_offset; trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset, @@ -928,72 +927,69 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, return 0; } - /* Calculate start and size of allocation */ - alloc_offset = guest_offset; - alloc_cluster_offset = *host_offset; - /* Allocate, if necessary at a given offset in the image file */ - ret = do_alloc_cluster_offset(bs, alloc_offset, &alloc_cluster_offset, + alloc_cluster_offset = *host_offset; + ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset, &nb_clusters); if (ret < 0) { goto fail; } - /* save info needed for meta data update */ - if (nb_clusters > 0) { - /* - * requested_sectors: Number of sectors from the start of the first - * newly allocated cluster to the end of the (possibly shortened - * before) write request. - * - * avail_sectors: Number of sectors from the start of the first - * newly allocated to the end of the last newly allocated cluster. - * - * nb_sectors: The number of sectors from the start of the first - * newly allocated cluster to the end of the aread that the write - * request actually writes to (excluding COW at the end) - */ - int requested_sectors = - (*bytes + offset_into_cluster(s, guest_offset)) - >> BDRV_SECTOR_BITS; - int avail_sectors = nb_clusters - << (s->cluster_bits - BDRV_SECTOR_BITS); - int alloc_n_start = offset_into_cluster(s, guest_offset) - >> BDRV_SECTOR_BITS; - int nb_sectors = MIN(requested_sectors, avail_sectors); - - if (*host_offset == 0) { - *host_offset = alloc_cluster_offset; - } - - *m = g_malloc0(sizeof(**m)); - - **m = (QCowL2Meta) { - .alloc_offset = alloc_cluster_offset, - .offset = alloc_offset & ~(s->cluster_size - 1), - .nb_clusters = nb_clusters, - .nb_available = nb_sectors, - - .cow_start = { - .offset = 0, - .nb_sectors = alloc_n_start, - }, - .cow_end = { - .offset = nb_sectors * BDRV_SECTOR_SIZE, - .nb_sectors = avail_sectors - nb_sectors, - }, - }; - qemu_co_queue_init(&(*m)->dependent_requests); - QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); - - *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE) - - offset_into_cluster(s, guest_offset)); - assert(*bytes != 0); - } else { + /* Can't extend contiguous allocation */ + if (nb_clusters == 0) { *bytes = 0; return 0; } + /* + * Save info needed for meta data update. + * + * requested_sectors: Number of sectors from the start of the first + * newly allocated cluster to the end of the (possibly shortened + * before) write request. + * + * avail_sectors: Number of sectors from the start of the first + * newly allocated to the end of the last newly allocated cluster. + * + * nb_sectors: The number of sectors from the start of the first + * newly allocated cluster to the end of the area that the write + * request actually writes to (excluding COW at the end) + */ + int requested_sectors = + (*bytes + offset_into_cluster(s, guest_offset)) + >> BDRV_SECTOR_BITS; + int avail_sectors = nb_clusters + << (s->cluster_bits - BDRV_SECTOR_BITS); + int alloc_n_start = offset_into_cluster(s, guest_offset) + >> BDRV_SECTOR_BITS; + int nb_sectors = MIN(requested_sectors, avail_sectors); + + *host_offset = alloc_cluster_offset; + + *m = g_malloc0(sizeof(**m)); + + **m = (QCowL2Meta) { + .alloc_offset = *host_offset, + .offset = start_of_cluster(s, guest_offset), + .nb_clusters = nb_clusters, + .nb_available = nb_sectors, + + .cow_start = { + .offset = 0, + .nb_sectors = alloc_n_start, + }, + .cow_end = { + .offset = nb_sectors * BDRV_SECTOR_SIZE, + .nb_sectors = avail_sectors - nb_sectors, + }, + }; + qemu_co_queue_init(&(*m)->dependent_requests); + QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); + + *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE) + - offset_into_cluster(s, guest_offset)); + assert(*bytes != 0); + return 1; fail: |