Am 15.11.2018 um 03:03 hat Eric Blake geschrieben:
> No need to reimplement fragmentation to BLOCK_CRYPTO_MAX_IO_SIZE
> ourselves when we can ask the block layer to do it for us.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
>
> ---
> Question - is this patch for 'crypto' acceptable, or should we stick
> with just the previous one that marks things as 64-bit clean?
I don't know what Dan thinks, but I like it.
Kevin
> block/crypto.c | 80 +++++++++++++++++++-------------------------------
> 1 file changed, 30 insertions(+), 50 deletions(-)
>
> diff --git a/block/crypto.c b/block/crypto.c
> index 259ef2649e1..b004cef22c2 100644
> --- a/block/crypto.c
> +++ b/block/crypto.c
> @@ -328,8 +328,6 @@ block_crypto_co_preadv(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> QEMUIOVector *qiov, int flags)
> {
> BlockCrypto *crypto = bs->opaque;
> - uint64_t cur_bytes; /* number of bytes in current iteration */
> - uint64_t bytes_done = 0;
> uint8_t *cipher_data = NULL;
> QEMUIOVector hd_qiov;
> int ret = 0;
> @@ -346,38 +344,30 @@ block_crypto_co_preadv(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> /* Bounce buffer because we don't wish to expose cipher text
> * in qiov which points to guest memory.
> */
> - cipher_data =
> - qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
> - qiov->size));
> + assert(qiov->size <= BLOCK_CRYPTO_MAX_IO_SIZE);
> + cipher_data = qemu_try_blockalign(bs->file->bs, qiov->size);
> if (cipher_data == NULL) {
> ret = -ENOMEM;
> goto cleanup;
> }
>
> - while (bytes) {
> - cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
> + qemu_iovec_reset(&hd_qiov);
> + qemu_iovec_add(&hd_qiov, cipher_data, bytes);
>
> - qemu_iovec_reset(&hd_qiov);
> - qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
> -
> - ret = bdrv_co_preadv(bs->file, payload_offset + offset + bytes_done,
> - cur_bytes, &hd_qiov, 0);
> - if (ret < 0) {
> - goto cleanup;
> - }
> -
> - if (qcrypto_block_decrypt(crypto->block, offset + bytes_done,
> - cipher_data, cur_bytes, NULL) < 0) {
> - ret = -EIO;
> - goto cleanup;
> - }
> -
> - qemu_iovec_from_buf(qiov, bytes_done, cipher_data, cur_bytes);
> + ret = bdrv_co_preadv(bs->file, payload_offset + offset, bytes,
> + &hd_qiov, 0);
> + if (ret < 0) {
> + goto cleanup;
> + }
>
> - bytes -= cur_bytes;
> - bytes_done += cur_bytes;
> + if (qcrypto_block_decrypt(crypto->block, offset,
> + cipher_data, bytes, NULL) < 0) {
> + ret = -EIO;
> + goto cleanup;
> }
>
> + qemu_iovec_from_buf(qiov, 0, cipher_data, bytes);
> +
> cleanup:
> qemu_iovec_destroy(&hd_qiov);
> qemu_vfree(cipher_data);
> @@ -391,8 +381,6 @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> QEMUIOVector *qiov, int flags)
> {
> BlockCrypto *crypto = bs->opaque;
> - uint64_t cur_bytes; /* number of bytes in current iteration */
> - uint64_t bytes_done = 0;
> uint8_t *cipher_data = NULL;
> QEMUIOVector hd_qiov;
> int ret = 0;
> @@ -409,36 +397,28 @@ block_crypto_co_pwritev(BlockDriverState *bs, uint64_t
> offset, uint64_t bytes,
> /* Bounce buffer because we're not permitted to touch
> * contents of qiov - it points to guest memory.
> */
> - cipher_data =
> - qemu_try_blockalign(bs->file->bs, MIN(BLOCK_CRYPTO_MAX_IO_SIZE,
> - qiov->size));
> + assert(qiov->size <= BLOCK_CRYPTO_MAX_IO_SIZE);
> + cipher_data = qemu_try_blockalign(bs->file->bs, qiov->size);
> if (cipher_data == NULL) {
> ret = -ENOMEM;
> goto cleanup;
> }
>
> - while (bytes) {
> - cur_bytes = MIN(bytes, BLOCK_CRYPTO_MAX_IO_SIZE);
> + qemu_iovec_to_buf(qiov, 0, cipher_data, bytes);
>
> - qemu_iovec_to_buf(qiov, bytes_done, cipher_data, cur_bytes);
> + if (qcrypto_block_encrypt(crypto->block, offset,
> + cipher_data, bytes, NULL) < 0) {
> + ret = -EIO;
> + goto cleanup;
> + }
>
> - if (qcrypto_block_encrypt(crypto->block, offset + bytes_done,
> - cipher_data, cur_bytes, NULL) < 0) {
> - ret = -EIO;
> - goto cleanup;
> - }
> + qemu_iovec_reset(&hd_qiov);
> + qemu_iovec_add(&hd_qiov, cipher_data, bytes);
>
> - qemu_iovec_reset(&hd_qiov);
> - qemu_iovec_add(&hd_qiov, cipher_data, cur_bytes);
> -
> - ret = bdrv_co_pwritev(bs->file, payload_offset + offset + bytes_done,
> - cur_bytes, &hd_qiov, flags);
> - if (ret < 0) {
> - goto cleanup;
> - }
> -
> - bytes -= cur_bytes;
> - bytes_done += cur_bytes;
> + ret = bdrv_co_pwritev(bs->file, payload_offset + offset,
> + bytes, &hd_qiov, flags);
> + if (ret < 0) {
> + goto cleanup;
> }
>
> cleanup:
> @@ -453,7 +433,7 @@ static void block_crypto_refresh_limits(BlockDriverState
> *bs, Error **errp)
> BlockCrypto *crypto = bs->opaque;
> uint64_t sector_size = qcrypto_block_get_sector_size(crypto->block);
> bs->bl.request_alignment = sector_size; /* No sub-sector I/O */
> - bs->bl.max_transfer = INT64_MAX;
> + bs->bl.max_transfer = BLOCK_CRYPTO_MAX_IO_SIZE;
> }
>
>
> --
> 2.17.2
>
