[v2,08/11] block/crypto: implement blockdev-amend
diff mbox series

Message ID 20190912223028.18496-9-mlevitsk@redhat.com
State New
Headers show
Series
  • RFC crypto/luks: encryption key managment using amend interface
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Commit Message

Maxim Levitsky Sept. 12, 2019, 10:30 p.m. UTC
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
 block/crypto.c       | 85 ++++++++++++++++++++++++++++++++++----------
 qapi/block-core.json |  7 ++--
 2 files changed, 71 insertions(+), 21 deletions(-)

Comments

Markus Armbruster Oct. 7, 2019, 7:58 a.m. UTC | #1
Maxim Levitsky <mlevitsk@redhat.com> writes:

> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
[...]
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index 7900914506..4a6db98938 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -4211,8 +4211,11 @@
>  # Driver specific image creation options for LUKS.
>  #
>  # @file             Node to create the image format on
> +#                   Mandatory for create
>  # @size             Size of the virtual disk in bytes
> +#                   Mandatory for create
>  # @preallocation    Preallocation mode for the new image
> +#                   Only for create
>  #                   (since: 4.2)
>  #                   (default: off; allowed values: off, metadata, falloc, full)
>  #
> @@ -4220,8 +4223,8 @@
>  ##
>  { 'struct': 'BlockdevCreateOptionsLUKS',
>    'base': 'QCryptoBlockCreateOptionsLUKS',
> -  'data': { 'file':             'BlockdevRef',
> -            'size':             'size',
> +  'data': { '*file':             'BlockdevRef',
> +            '*size':             'size',
>              '*preallocation':   'PreallocMode' } }
>  
>  ##

Why is this change needed?

When the commit message says "implement FOO" and nothing else, then I
don't expect QAPI schema changes.  Working the answer to my question
into the commit message might avoid the surprise.

Patch
diff mbox series

diff --git a/block/crypto.c b/block/crypto.c
index f42fa057e6..5905f7f520 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -534,6 +534,17 @@  block_crypto_co_create_luks(BlockdevCreateOptions *create_options, Error **errp)
     assert(create_options->driver == BLOCKDEV_DRIVER_LUKS);
     luks_opts = &create_options->u.luks;
 
+    if (!luks_opts->has_size) {
+        error_setg(errp, "'size' is manadatory for image creation");
+        return -EINVAL;
+    }
+
+    if (!luks_opts->has_file) {
+        error_setg(errp, "'file' is manadatory for image creation");
+        return -EINVAL;
+    }
+
+
     bs = bdrv_open_blockdev_ref(luks_opts->file, errp);
     if (bs == NULL) {
         return -EIO;
@@ -667,6 +678,39 @@  block_crypto_get_specific_info_luks(BlockDriverState *bs, Error **errp)
 }
 
 
+static int
+block_crypto_amend_options_generic(BlockDriverState *bs,
+                                   QCryptoBlockCreateOptions *amend_options,
+                                   bool force,
+                                   Error **errp)
+{
+    BlockCrypto *crypto = bs->opaque;
+    int ret = -1;
+
+    assert(crypto);
+    assert(crypto->block);
+
+    /* apply for exclusive write permissions to the underlying file*/
+    crypto->updating_keys = true;
+    ret = bdrv_child_refresh_perms(bs, bs->file, errp);
+    if (ret) {
+        goto cleanup;
+    }
+
+    ret = qcrypto_block_amend_options(crypto->block,
+                                      block_crypto_read_func,
+                                      block_crypto_write_func,
+                                      bs,
+                                      amend_options,
+                                      force,
+                                      errp);
+cleanup:
+    /* release exclusive write permissions to the underlying file*/
+    crypto->updating_keys = false;
+    bdrv_child_refresh_perms(bs, bs->file, errp);
+    return ret;
+}
+
 static int
 block_crypto_amend_options(BlockDriverState *bs,
                            QemuOpts *opts,
@@ -678,44 +722,45 @@  block_crypto_amend_options(BlockDriverState *bs,
     BlockCrypto *crypto = bs->opaque;
     QDict *cryptoopts = NULL;
     QCryptoBlockCreateOptions *amend_options = NULL;
-    int ret;
+    int ret = -EINVAL;
 
     assert(crypto);
     assert(crypto->block);
 
-    crypto->updating_keys = true;
-
-    ret = bdrv_child_refresh_perms(bs, bs->file, errp);
-    if (ret < 0) {
-        goto cleanup;
-    }
-
     cryptoopts = qemu_opts_to_qdict_filtered(opts, NULL,
                                              &block_crypto_create_opts_luks,
                                              true);
 
     qdict_put_str(cryptoopts, "format", "luks");
     amend_options = block_crypto_create_opts_init(cryptoopts, errp);
+
     if (!amend_options) {
-        ret = -EINVAL;
         goto cleanup;
     }
 
-    ret = qcrypto_block_amend_options(crypto->block,
-                                      block_crypto_read_func,
-                                      block_crypto_write_func,
-                                      bs,
-                                      amend_options,
-                                      force,
-                                      errp);
+    ret = block_crypto_amend_options_generic(bs, amend_options, force, errp);
 cleanup:
-    crypto->updating_keys = false;
-    bdrv_child_refresh_perms(bs, bs->file, errp);
     qapi_free_QCryptoBlockCreateOptions(amend_options);
     qobject_unref(cryptoopts);
     return ret;
 }
 
+static int
+coroutine_fn block_crypto_co_amend(BlockDriverState *bs,
+                                   BlockdevCreateOptions *opts,
+                                   bool force,
+                                   Error **errp)
+{
+    QCryptoBlockCreateOptions amend_opts;
+
+    amend_opts = (QCryptoBlockCreateOptions) {
+        .format = Q_CRYPTO_BLOCK_FORMAT_LUKS,
+        .u.luks = *qapi_BlockdevCreateOptionsLUKS_base(&opts->u.luks),
+    };
+
+    return block_crypto_amend_options_generic(bs, &amend_opts, force, errp);
+}
+
 
 static void
 block_crypto_child_perms(BlockDriverState *bs, BdrvChild *c,
@@ -750,7 +795,8 @@  block_crypto_child_perms(BlockDriverState *bs, BdrvChild *c,
      */
 
     if (crypto->updating_keys) {
-        /*need exclusive write access for header update  */
+        assert(!(bs->open_flags & BDRV_O_NO_IO));
+        /*need exclusive read and write access for header update  */
         perm |= BLK_PERM_WRITE;
         shared &= ~(BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE);
     }
@@ -786,6 +832,7 @@  static BlockDriver bdrv_crypto_luks = {
     .bdrv_get_info      = block_crypto_get_info_luks,
     .bdrv_get_specific_info = block_crypto_get_specific_info_luks,
     .bdrv_amend_options = block_crypto_amend_options,
+    .bdrv_co_amend      = block_crypto_co_amend,
 
     .strong_runtime_opts = block_crypto_strong_runtime_opts,
 };
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 7900914506..4a6db98938 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4211,8 +4211,11 @@ 
 # Driver specific image creation options for LUKS.
 #
 # @file             Node to create the image format on
+#                   Mandatory for create
 # @size             Size of the virtual disk in bytes
+#                   Mandatory for create
 # @preallocation    Preallocation mode for the new image
+#                   Only for create
 #                   (since: 4.2)
 #                   (default: off; allowed values: off, metadata, falloc, full)
 #
@@ -4220,8 +4223,8 @@ 
 ##
 { 'struct': 'BlockdevCreateOptionsLUKS',
   'base': 'QCryptoBlockCreateOptionsLUKS',
-  'data': { 'file':             'BlockdevRef',
-            'size':             'size',
+  'data': { '*file':             'BlockdevRef',
+            '*size':             'size',
             '*preallocation':   'PreallocMode' } }
 
 ##