From a9da6e49d8281e65d172ed843807a613651d4ef3 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Fri, 21 Feb 2020 11:25:20 +0000 Subject: luks: implement .bdrv_measure() Add qemu-img measure support in the "luks" block driver. Signed-off-by: Stefan Hajnoczi Reviewed-by: Max Reitz Message-Id: <20200221112522.1497712-3-stefanha@redhat.com> Signed-off-by: Max Reitz --- block/crypto.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'block/crypto.c') diff --git a/block/crypto.c b/block/crypto.c index 2482383..23e9c74 100644 --- a/block/crypto.c +++ b/block/crypto.c @@ -484,6 +484,67 @@ static int64_t block_crypto_getlength(BlockDriverState *bs) } +static BlockMeasureInfo *block_crypto_measure(QemuOpts *opts, + BlockDriverState *in_bs, + Error **errp) +{ + g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL; + Error *local_err = NULL; + BlockMeasureInfo *info; + uint64_t size; + size_t luks_payload_size; + QDict *cryptoopts; + + /* + * Preallocation mode doesn't affect size requirements but we must consume + * the option. + */ + g_free(qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC)); + + size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); + + if (in_bs) { + int64_t ssize = bdrv_getlength(in_bs); + + if (ssize < 0) { + error_setg_errno(&local_err, -ssize, + "Unable to get image virtual_size"); + goto err; + } + + size = ssize; + } + + cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL, + &block_crypto_create_opts_luks, true); + qdict_put_str(cryptoopts, "format", "luks"); + create_opts = block_crypto_create_opts_init(cryptoopts, &local_err); + qobject_unref(cryptoopts); + if (!create_opts) { + goto err; + } + + if (!qcrypto_block_calculate_payload_offset(create_opts, NULL, + &luks_payload_size, + &local_err)) { + goto err; + } + + /* + * Unallocated blocks are still encrypted so allocation status makes no + * difference to the file size. + */ + info = g_new(BlockMeasureInfo, 1); + info->fully_allocated = luks_payload_size + size; + info->required = luks_payload_size + size; + return info; + +err: + error_propagate(errp, local_err); + return NULL; +} + + static int block_crypto_probe_luks(const uint8_t *buf, int buf_size, const char *filename) { @@ -670,6 +731,7 @@ static BlockDriver bdrv_crypto_luks = { .bdrv_co_preadv = block_crypto_co_preadv, .bdrv_co_pwritev = block_crypto_co_pwritev, .bdrv_getlength = block_crypto_getlength, + .bdrv_measure = block_crypto_measure, .bdrv_get_info = block_crypto_get_info_luks, .bdrv_get_specific_info = block_crypto_get_specific_info_luks, -- cgit v1.1