diff options
| -rw-r--r-- | block/qcow2-cluster.c | 81 | ||||
| -rw-r--r-- | block/qcow2.c | 33 | ||||
| -rw-r--r-- | block/qcow2.h | 4 |
3 files changed, 94 insertions, 24 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 1e84bd8e2e..9d349d61c6 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -2016,12 +2016,59 @@ static int zero_in_l2_slice(BlockDriverState *bs, uint64_t offset, return nb_clusters; } -int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, int flags) +static int zero_l2_subclusters(BlockDriverState *bs, uint64_t offset, + unsigned nb_subclusters) +{ + BDRVQcow2State *s = bs->opaque; + uint64_t *l2_slice; + uint64_t old_l2_bitmap, l2_bitmap; + int l2_index, ret, sc = offset_to_sc_index(s, offset); + + /* For full clusters use zero_in_l2_slice() instead */ + assert(nb_subclusters > 0 && nb_subclusters < s->subclusters_per_cluster); + assert(sc + nb_subclusters <= s->subclusters_per_cluster); + assert(offset_into_subcluster(s, offset) == 0); + + ret = get_cluster_table(bs, offset, &l2_slice, &l2_index); + if (ret < 0) { + return ret; + } + + switch (qcow2_get_cluster_type(bs, get_l2_entry(s, l2_slice, l2_index))) { + case QCOW2_CLUSTER_COMPRESSED: + ret = -ENOTSUP; /* We cannot partially zeroize compressed clusters */ + goto out; + case QCOW2_CLUSTER_NORMAL: + case QCOW2_CLUSTER_UNALLOCATED: + break; + default: + g_assert_not_reached(); + } + + old_l2_bitmap = l2_bitmap = get_l2_bitmap(s, l2_slice, l2_index); + + l2_bitmap |= QCOW_OFLAG_SUB_ZERO_RANGE(sc, sc + nb_subclusters); + l2_bitmap &= ~QCOW_OFLAG_SUB_ALLOC_RANGE(sc, sc + nb_subclusters); + + if (old_l2_bitmap != l2_bitmap) { + set_l2_bitmap(s, l2_slice, l2_index, l2_bitmap); + qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice); + } + + ret = 0; +out: + qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice); + + return ret; +} + +int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, int flags) { BDRVQcow2State *s = bs->opaque; uint64_t end_offset = offset + bytes; uint64_t nb_clusters; + unsigned head, tail; int64_t cleared; int ret; @@ -2036,8 +2083,8 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, } /* Caller must pass aligned values, except at image end */ - assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); - assert(QEMU_IS_ALIGNED(end_offset, s->cluster_size) || + assert(offset_into_subcluster(s, offset) == 0); + assert(offset_into_subcluster(s, end_offset) == 0 || end_offset >= bs->total_sectors << BDRV_SECTOR_BITS); /* @@ -2052,11 +2099,26 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, return -ENOTSUP; } - /* Each L2 slice is handled by its own loop iteration */ - nb_clusters = size_to_clusters(s, bytes); + head = MIN(end_offset, ROUND_UP(offset, s->cluster_size)) - offset; + offset += head; + + tail = (end_offset >= bs->total_sectors << BDRV_SECTOR_BITS) ? 0 : + end_offset - MAX(offset, start_of_cluster(s, end_offset)); + end_offset -= tail; s->cache_discards = true; + if (head) { + ret = zero_l2_subclusters(bs, offset - head, + size_to_subclusters(s, head)); + if (ret < 0) { + goto fail; + } + } + + /* Each L2 slice is handled by its own loop iteration */ + nb_clusters = size_to_clusters(s, end_offset - offset); + while (nb_clusters > 0) { cleared = zero_in_l2_slice(bs, offset, nb_clusters, flags); if (cleared < 0) { @@ -2068,6 +2130,13 @@ int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, offset += (cleared * s->cluster_size); } + if (tail) { + ret = zero_l2_subclusters(bs, end_offset, size_to_subclusters(s, tail)); + if (ret < 0) { + goto fail; + } + } + ret = 0; fail: s->cache_discards = false; diff --git a/block/qcow2.c b/block/qcow2.c index 9990535c46..0cf0b0a9fb 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1913,7 +1913,7 @@ static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) /* Encryption works on a sector granularity */ bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); } - bs->bl.pwrite_zeroes_alignment = s->cluster_size; + bs->bl.pwrite_zeroes_alignment = s->subcluster_size; bs->bl.pdiscard_alignment = s->cluster_size; } @@ -3833,8 +3833,9 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, int ret; BDRVQcow2State *s = bs->opaque; - uint32_t head = offset % s->cluster_size; - uint32_t tail = (offset + bytes) % s->cluster_size; + uint32_t head = offset_into_subcluster(s, offset); + uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) - + (offset + bytes); trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes); if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) { @@ -3846,20 +3847,19 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, unsigned int nr; QCow2SubclusterType type; - assert(head + bytes <= s->cluster_size); + assert(head + bytes + tail <= s->subcluster_size); /* check whether remainder of cluster already reads as zero */ if (!(is_zero(bs, offset - head, head) && - is_zero(bs, offset + bytes, - tail ? s->cluster_size - tail : 0))) { + is_zero(bs, offset + bytes, tail))) { return -ENOTSUP; } qemu_co_mutex_lock(&s->lock); /* We can have new write after previous check */ - offset = QEMU_ALIGN_DOWN(offset, s->cluster_size); - bytes = s->cluster_size; - nr = s->cluster_size; + offset -= head; + bytes = s->subcluster_size; + nr = s->subcluster_size; ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type); if (ret < 0 || (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && @@ -3875,8 +3875,8 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); - /* Whatever is left can use real zero clusters */ - ret = qcow2_cluster_zeroize(bs, offset, bytes, flags); + /* Whatever is left can use real zero subclusters */ + ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags); qemu_co_mutex_unlock(&s->lock); return ret; @@ -4357,15 +4357,16 @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, } if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) { - uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->cluster_size); + uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size); /* - * Use zero clusters as much as we can. qcow2_cluster_zeroize() - * requires a cluster-aligned start. The end may be unaligned if it is - * at the end of the image (which it is here). + * Use zero clusters as much as we can. qcow2_subcluster_zeroize() + * requires a subcluster-aligned start. The end may be unaligned if + * it is at the end of the image (which it is here). */ if (offset > zero_start) { - ret = qcow2_cluster_zeroize(bs, zero_start, offset - zero_start, 0); + ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start, + 0); if (ret < 0) { error_setg_errno(errp, -ret, "Failed to zero out new clusters"); goto fail; diff --git a/block/qcow2.h b/block/qcow2.h index 4fad40b96b..4ef4ae4ab0 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -898,8 +898,8 @@ void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m); int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, uint64_t bytes, enum qcow2_discard_type type, bool full_discard); -int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset, - uint64_t bytes, int flags); +int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, int flags); int qcow2_expand_zero_clusters(BlockDriverState *bs, BlockDriverAmendStatusCB *status_cb, |