* [Qemu-devel] [PATCH v2 1/2] qcow2: include LUKS payload overhead in qemu-img measure
2019-01-23 10:33 [Qemu-devel] [PATCH v2 0/2] qcow2: include LUKS payload overhead in qemu-img measure Stefan Hajnoczi
@ 2019-01-23 10:33 ` Stefan Hajnoczi
2019-02-15 19:11 ` Max Reitz
2019-01-23 10:33 ` [Qemu-devel] [PATCH v2 2/2] iotests: add LUKS payload overhead to 178 qemu-img measure test Stefan Hajnoczi
1 sibling, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2019-01-23 10:33 UTC (permalink / raw)
To: qemu-devel
Cc: Kevin Wolf, Max Reitz, Daniel Berrange, qemu-block,
Philippe Mathieu-Daudé, Stefan Hajnoczi
LUKS encryption reserves clusters for its own payload data. The size of
this area must be included in the qemu-img measure calculation so that
we arrive at the correct minimum required image size.
(Ab)use the qcrypto_block_create() API to determine the payload
overhead. We discard the payload data that qcrypto thinks will be
written to the image.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
block/qcow2.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 71 insertions(+), 1 deletion(-)
diff --git a/block/qcow2.c b/block/qcow2.c
index 4897abae5e..e6f7685706 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -4231,6 +4231,60 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
return ret;
}
+static ssize_t qcow2_measure_crypto_hdr_init_func(QCryptoBlock *block,
+ size_t headerlen, void *opaque, Error **errp)
+{
+ size_t *headerlenp = opaque;
+
+ /* Stash away the payload size */
+ *headerlenp = headerlen;
+ return 0;
+}
+
+static ssize_t qcow2_measure_crypto_hdr_write_func(QCryptoBlock *block,
+ size_t offset, const uint8_t *buf, size_t buflen,
+ void *opaque, Error **errp)
+{
+ /* Discard the bytes, we're not actually writing to an image */
+ return buflen;
+}
+
+/* Determine the number of bytes for the LUKS payload */
+static bool qcow2_measure_luks_headerlen(QemuOpts *opts, size_t *len,
+ Error **errp)
+{
+ QDict *opts_qdict;
+ QDict *cryptoopts_qdict;
+ QCryptoBlockCreateOptions *cryptoopts;
+ QCryptoBlock *crypto;
+
+ /* Extract "encrypt." options into a qdict */
+ opts_qdict = qemu_opts_to_qdict(opts, NULL);
+ qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt.");
+ qobject_unref(opts_qdict);
+
+ /* Build QCryptoBlockCreateOptions object from qdict */
+ qdict_put_str(cryptoopts_qdict, "format", "luks");
+ cryptoopts = block_crypto_create_opts_init(cryptoopts_qdict, errp);
+ qobject_unref(cryptoopts_qdict);
+ if (!cryptoopts) {
+ return false;
+ }
+
+ /* Fake LUKS creation in order to determine the payload size */
+ crypto = qcrypto_block_create(cryptoopts, "encrypt.",
+ qcow2_measure_crypto_hdr_init_func,
+ qcow2_measure_crypto_hdr_write_func,
+ len, errp);
+ qapi_free_QCryptoBlockCreateOptions(cryptoopts);
+ if (!crypto) {
+ return false;
+ }
+
+ qcrypto_block_free(crypto);
+ return true;
+}
+
static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
Error **errp)
{
@@ -4240,11 +4294,13 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
uint64_t virtual_size; /* disk size as seen by guest */
uint64_t refcount_bits;
uint64_t l2_tables;
+ uint64_t luks_payload_size = 0;
size_t cluster_size;
int version;
char *optstr;
PreallocMode prealloc;
bool has_backing_file;
+ bool has_luks;
/* Parse image creation options */
cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
@@ -4274,6 +4330,20 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
has_backing_file = !!optstr;
g_free(optstr);
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
+ has_luks = optstr && strcmp(optstr, "luks") == 0;
+ g_free(optstr);
+
+ if (has_luks) {
+ size_t headerlen;
+
+ if (!qcow2_measure_luks_headerlen(opts, &headerlen, &local_err)) {
+ goto err;
+ }
+
+ luks_payload_size = ROUND_UP(headerlen, cluster_size);
+ }
+
virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
virtual_size = ROUND_UP(virtual_size, cluster_size);
@@ -4344,7 +4414,7 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
info = g_new(BlockMeasureInfo, 1);
info->fully_allocated =
qcow2_calc_prealloc_size(virtual_size, cluster_size,
- ctz32(refcount_bits));
+ ctz32(refcount_bits)) + luks_payload_size;
/* Remove data clusters that are not required. This overestimates the
* required size because metadata needed for the fully allocated file is
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* [Qemu-devel] [PATCH v2 2/2] iotests: add LUKS payload overhead to 178 qemu-img measure test
2019-01-23 10:33 [Qemu-devel] [PATCH v2 0/2] qcow2: include LUKS payload overhead in qemu-img measure Stefan Hajnoczi
2019-01-23 10:33 ` [Qemu-devel] [PATCH v2 1/2] " Stefan Hajnoczi
@ 2019-01-23 10:33 ` Stefan Hajnoczi
2019-02-15 19:14 ` Max Reitz
1 sibling, 1 reply; 6+ messages in thread
From: Stefan Hajnoczi @ 2019-01-23 10:33 UTC (permalink / raw)
To: qemu-devel
Cc: Kevin Wolf, Max Reitz, Daniel Berrange, qemu-block,
Philippe Mathieu-Daudé, Stefan Hajnoczi
The previous patch includes the LUKS payload overhead into the qemu-img
measure calculation for qcow2. Update qemu-iotests 178 to exercise this
new code path.
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
tests/qemu-iotests/178 | 8 ++++++++
tests/qemu-iotests/178.out.qcow2 | 24 ++++++++++++++++++++++++
2 files changed, 32 insertions(+)
diff --git a/tests/qemu-iotests/178 b/tests/qemu-iotests/178
index 3f4b4a4564..23eb017ea1 100755
--- a/tests/qemu-iotests/178
+++ b/tests/qemu-iotests/178
@@ -142,6 +142,14 @@ for ofmt in human json; do
# The backing file doesn't need to exist :)
$QEMU_IMG measure --output=$ofmt -o backing_file=x \
-f "$fmt" -O "$IMGFMT" "$TEST_IMG"
+
+ echo
+ echo "== $fmt input image and LUKS encryption =="
+ echo
+ $QEMU_IMG measure --output=$ofmt \
+ --object secret,id=sec0,data=base \
+ -o encrypt.format=luks,encrypt.key-secret=sec0 \
+ -f "$fmt" -O "$IMGFMT" "$TEST_IMG"
fi
echo
diff --git a/tests/qemu-iotests/178.out.qcow2 b/tests/qemu-iotests/178.out.qcow2
index d42d4a4597..55a8dc926f 100644
--- a/tests/qemu-iotests/178.out.qcow2
+++ b/tests/qemu-iotests/178.out.qcow2
@@ -68,6 +68,11 @@ converted image file size in bytes: 458752
required size: 1074135040
fully allocated size: 1074135040
+== qcow2 input image and LUKS encryption ==
+
+required size: 2686976
+fully allocated size: 1076232192
+
== qcow2 input image and preallocation (human) ==
required size: 1074135040
@@ -114,6 +119,11 @@ converted image file size in bytes: 524288
required size: 1074135040
fully allocated size: 1074135040
+== raw input image and LUKS encryption ==
+
+required size: 2686976
+fully allocated size: 1076232192
+
== raw input image and preallocation (human) ==
required size: 1074135040
@@ -205,6 +215,13 @@ converted image file size in bytes: 458752
"fully-allocated": 1074135040
}
+== qcow2 input image and LUKS encryption ==
+
+{
+ "required": 2686976,
+ "fully-allocated": 1076232192
+}
+
== qcow2 input image and preallocation (json) ==
{
@@ -263,6 +280,13 @@ converted image file size in bytes: 524288
"fully-allocated": 1074135040
}
+== raw input image and LUKS encryption ==
+
+{
+ "required": 2686976,
+ "fully-allocated": 1076232192
+}
+
== raw input image and preallocation (json) ==
{
--
2.20.1
^ permalink raw reply related [flat|nested] 6+ messages in thread