diff options
| -rw-r--r-- | block/qcow2-cluster.c | 17 | ||||
| -rw-r--r-- | block/qcow2.c | 12 |
2 files changed, 17 insertions, 12 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index f06c08f64c..8538533102 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1516,6 +1516,23 @@ int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1; sector_offset = coffset & 511; csize = nb_csectors * 512 - sector_offset; + + /* Allocate buffers on first decompress operation, most images are + * uncompressed and the memory overhead can be avoided. The buffers + * are freed in .bdrv_close(). + */ + if (!s->cluster_data) { + /* one more sector for decompressed data alignment */ + s->cluster_data = qemu_try_blockalign(bs->file->bs, + QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size + 512); + if (!s->cluster_data) { + return -ENOMEM; + } + } + if (!s->cluster_cache) { + s->cluster_cache = g_malloc(s->cluster_size); + } + BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED); ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data, nb_csectors); diff --git a/block/qcow2.c b/block/qcow2.c index fbfffadc76..a3679c69e8 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1360,16 +1360,6 @@ static int qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - s->cluster_cache = g_malloc(s->cluster_size); - /* one more sector for decompressed data alignment */ - s->cluster_data = qemu_try_blockalign(bs->file->bs, QCOW_MAX_CRYPT_CLUSTERS - * s->cluster_size + 512); - if (s->cluster_data == NULL) { - error_setg(errp, "Could not allocate temporary cluster buffer"); - ret = -ENOMEM; - goto fail; - } - s->cluster_cache_offset = -1; s->flags = flags; @@ -1507,8 +1497,6 @@ static int qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, if (s->refcount_block_cache) { qcow2_cache_destroy(bs, s->refcount_block_cache); } - g_free(s->cluster_cache); - qemu_vfree(s->cluster_data); qcrypto_block_free(s->crypto); qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); return ret; |