diff options
| -rw-r--r-- | block/qcow2.c | 47 | ||||
| -rw-r--r-- | tests/qemu-iotests/154.out | 8 |
2 files changed, 27 insertions, 28 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index 105fd5e..ecac399 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -2406,26 +2406,19 @@ finish: } -static bool is_zero_cluster(BlockDriverState *bs, int64_t start) +static bool is_zero_sectors(BlockDriverState *bs, int64_t start, + uint32_t count) { - BDRVQcow2State *s = bs->opaque; int nr; BlockDriverState *file; - int64_t res = bdrv_get_block_status_above(bs, NULL, start, - s->cluster_sectors, &nr, &file); - return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == s->cluster_sectors; -} - -static bool is_zero_cluster_top_locked(BlockDriverState *bs, int64_t start) -{ - BDRVQcow2State *s = bs->opaque; - int nr = s->cluster_sectors; - uint64_t off; - int ret; + int64_t res; - ret = qcow2_get_cluster_offset(bs, start << BDRV_SECTOR_BITS, &nr, &off); - assert(nr == s->cluster_sectors); - return ret == QCOW2_CLUSTER_UNALLOCATED || ret == QCOW2_CLUSTER_ZERO; + if (!count) { + return true; + } + res = bdrv_get_block_status_above(bs, NULL, start, count, + &nr, &file); + return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == count; } static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, @@ -2434,27 +2427,33 @@ static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, int ret; BDRVQcow2State *s = bs->opaque; - int head = sector_num % s->cluster_sectors; - int tail = (sector_num + nb_sectors) % s->cluster_sectors; + uint32_t head = sector_num % s->cluster_sectors; + uint32_t tail = (sector_num + nb_sectors) % s->cluster_sectors; trace_qcow2_write_zeroes_start_req(qemu_coroutine_self(), sector_num, nb_sectors); - if (head != 0 || tail != 0) { + if (head || tail) { int64_t cl_start = sector_num - head; + uint64_t off; + int nr; assert(cl_start + s->cluster_sectors >= sector_num + nb_sectors); - sector_num = cl_start; - nb_sectors = s->cluster_sectors; - - if (!is_zero_cluster(bs, sector_num)) { + /* check whether remainder of cluster already reads as zero */ + if (!(is_zero_sectors(bs, cl_start, head) && + is_zero_sectors(bs, sector_num + nb_sectors, + -tail & (s->cluster_sectors - 1)))) { return -ENOTSUP; } qemu_co_mutex_lock(&s->lock); /* We can have new write after previous check */ - if (!is_zero_cluster_top_locked(bs, sector_num)) { + sector_num = cl_start; + nb_sectors = nr = s->cluster_sectors; + ret = qcow2_get_cluster_offset(bs, cl_start << BDRV_SECTOR_BITS, + &nr, &off); + if (ret != QCOW2_CLUSTER_UNALLOCATED && ret != QCOW2_CLUSTER_ZERO) { qemu_co_mutex_unlock(&s->lock); return -ENOTSUP; } diff --git a/tests/qemu-iotests/154.out b/tests/qemu-iotests/154.out index 531fd8c..da9eabd 100644 --- a/tests/qemu-iotests/154.out +++ b/tests/qemu-iotests/154.out @@ -102,13 +102,13 @@ wrote 2048/2048 bytes at offset 29696 read 4096/4096 bytes at offset 28672 4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) [{ "start": 0, "length": 4096, "depth": 1, "zero": true, "data": false}, -{ "start": 4096, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": 20480}, +{ "start": 4096, "length": 4096, "depth": 0, "zero": true, "data": false}, { "start": 8192, "length": 4096, "depth": 1, "zero": true, "data": false}, -{ "start": 12288, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": 24576}, +{ "start": 12288, "length": 4096, "depth": 0, "zero": true, "data": false}, { "start": 16384, "length": 4096, "depth": 1, "zero": true, "data": false}, -{ "start": 20480, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": 28672}, +{ "start": 20480, "length": 4096, "depth": 0, "zero": true, "data": false}, { "start": 24576, "length": 4096, "depth": 1, "zero": true, "data": false}, -{ "start": 28672, "length": 4096, "depth": 0, "zero": false, "data": true, "offset": 32768}, +{ "start": 28672, "length": 4096, "depth": 0, "zero": true, "data": false}, { "start": 32768, "length": 134184960, "depth": 1, "zero": true, "data": false}] == spanning two clusters, non-zero before request == |