[Qemu-devel] [PATCH 3/7] qcow: Support .bdrv_co_create

[Kevin Wolf]

This adds the .bdrv_co_create driver callback to qcow, which
enables image creation over QMP.

Signed-off-by: Kevin Wolf <address@hidden>
---
 qapi/block-core.json |  21 +++++-
 block/qcow.c         | 196 ++++++++++++++++++++++++++++++++++-----------------
 2 files changed, 150 insertions(+), 67 deletions(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index d38058eeab..c81677c434 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3497,6 +3497,25 @@
             '*cluster-size':    'size' } }
 
 ##
+# @BlockdevCreateOptionsQcow:
+#
+# Driver specific image creation options for qcow.
+#
+# @file             Node to create the image format on
+# @size             Size of the virtual disk in bytes
+# @backing-file     File name of the backing file if a backing file
+#                   should be used
+# @encrypt          Encryption options if the image should be encrypted
+#
+# Since: 2.12
+##
+{ 'struct': 'BlockdevCreateOptionsQcow',
+  'data': { 'file':             'BlockdevRef',
+            'size':             'size',
+            '*backing-file':    'str',
+            '*encrypt':         'QCryptoBlockCreateOptions' } }
+
+##
 # @BlockdevQcow2Version:
 #
 # @v2:  The original QCOW2 format as introduced in qemu 0.10 (version 2)
@@ -3681,8 +3700,8 @@
       'null-co':        'BlockdevCreateNotSupported',
       'nvme':           'BlockdevCreateNotSupported',
       'parallels':      'BlockdevCreateOptionsParallels',
+      'qcow':           'BlockdevCreateOptionsQcow',
       'qcow2':          'BlockdevCreateOptionsQcow2',
-      'qcow':           'BlockdevCreateNotSupported',
       'qed':            'BlockdevCreateNotSupported',
       'quorum':         'BlockdevCreateNotSupported',
       'raw':            'BlockdevCreateNotSupported',
diff --git a/block/qcow.c b/block/qcow.c
index 47a18d9a3a..2e3770ca63 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -33,6 +33,8 @@
 #include <zlib.h>
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/qapi-visit-block-core.h"
 #include "crypto/block.h"
 #include "migration/blocker.h"
 #include "block/crypto.h"
@@ -86,6 +88,8 @@ typedef struct BDRVQcowState {
     Error *migration_blocker;
 } BDRVQcowState;
 
+static QemuOptsList qcow_create_opts;
+
 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 
 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
@@ -810,62 +814,50 @@ static void qcow_close(BlockDriverState *bs)
     error_free(s->migration_blocker);
 }
 
-static int coroutine_fn qcow_co_create_opts(const char *filename, QemuOpts 
*opts,
-                                            Error **errp)
+static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
+                                       Error **errp)
 {
+    BlockdevCreateOptionsQcow *qcow_opts;
     int header_size, backing_filename_len, l1_size, shift, i;
     QCowHeader header;
     uint8_t *tmp;
     int64_t total_size = 0;
-    char *backing_file = NULL;
-    Error *local_err = NULL;
     int ret;
+    BlockDriverState *bs;
     BlockBackend *qcow_blk;
-    char *encryptfmt = NULL;
-    QDict *options;
-    QDict *encryptopts = NULL;
-    QCryptoBlockCreateOptions *crypto_opts = NULL;
     QCryptoBlock *crypto = NULL;
 
-    /* Read out options */
-    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
-                          BDRV_SECTOR_SIZE);
+    assert(opts->driver == BLOCKDEV_DRIVER_QCOW);
+    qcow_opts = &opts->u.qcow;
+
+    /* Sanity checks */
+    total_size = qcow_opts->size;
     if (total_size == 0) {
         error_setg(errp, "Image size is too small, cannot be zero length");
-        ret = -EINVAL;
-        goto cleanup;
+        return -EINVAL;
     }
 
-    backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
-    encryptfmt = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
-    if (encryptfmt) {
-        if (qemu_opt_get(opts, BLOCK_OPT_ENCRYPT)) {
-            error_setg(errp, "Options " BLOCK_OPT_ENCRYPT " and "
-                       BLOCK_OPT_ENCRYPT_FORMAT " are mutually exclusive");
-            ret = -EINVAL;
-            goto cleanup;
-        }
-    } else if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
-        encryptfmt = g_strdup("aes");
+    if (qcow_opts->has_encrypt &&
+        qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW)
+    {
+        error_setg(errp, "Unsupported encryption format");
+        return -EINVAL;
     }
 
-    ret = bdrv_create_file(filename, opts, &local_err);
-    if (ret < 0) {
-        error_propagate(errp, local_err);
-        goto cleanup;
+    /* Create BlockBackend to write to the image */
+    bs = bdrv_open_blockdev_ref(qcow_opts->file, errp);
+    if (bs == NULL) {
+        return -EIO;
     }
 
-    qcow_blk = blk_new_open(filename, NULL, NULL,
-                            BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
-                            &local_err);
-    if (qcow_blk == NULL) {
-        error_propagate(errp, local_err);
-        ret = -EIO;
-        goto cleanup;
+    qcow_blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
+    ret = blk_insert_bs(qcow_blk, bs, errp);
+    if (ret < 0) {
+        goto exit;
     }
-
     blk_set_allow_write_beyond_eof(qcow_blk, true);
 
+    /* Create image format */
     ret = blk_truncate(qcow_blk, 0, PREALLOC_MODE_OFF, errp);
     if (ret < 0) {
         goto exit;
@@ -877,16 +869,15 @@ static int coroutine_fn qcow_co_create_opts(const char 
*filename, QemuOpts *opts
     header.size = cpu_to_be64(total_size);
     header_size = sizeof(header);
     backing_filename_len = 0;
-    if (backing_file) {
-        if (strcmp(backing_file, "fat:")) {
+    if (qcow_opts->has_backing_file) {
+        if (strcmp(qcow_opts->backing_file, "fat:")) {
             header.backing_file_offset = cpu_to_be64(header_size);
-            backing_filename_len = strlen(backing_file);
+            backing_filename_len = strlen(qcow_opts->backing_file);
             header.backing_file_size = cpu_to_be32(backing_filename_len);
             header_size += backing_filename_len;
         } else {
             /* special backing file for vvfat */
-            g_free(backing_file);
-            backing_file = NULL;
+            qcow_opts->has_backing_file = false;
         }
         header.cluster_bits = 9; /* 512 byte cluster to avoid copying
                                     unmodified sectors */
@@ -901,26 +892,10 @@ static int coroutine_fn qcow_co_create_opts(const char 
*filename, QemuOpts *opts
 
     header.l1_table_offset = cpu_to_be64(header_size);
 
-    options = qemu_opts_to_qdict(opts, NULL);
-    qdict_extract_subqdict(options, &encryptopts, "encrypt.");
-    QDECREF(options);
-    if (encryptfmt) {
-        if (!g_str_equal(encryptfmt, "aes")) {
-            error_setg(errp, "Unknown encryption format '%s', expected 'aes'",
-                       encryptfmt);
-            ret = -EINVAL;
-            goto exit;
-        }
+    if (qcow_opts->has_encrypt) {
         header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
 
-        crypto_opts = block_crypto_create_opts_init(
-            Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp);
-        if (!crypto_opts) {
-            ret = -EINVAL;
-            goto exit;
-        }
-
-        crypto = qcrypto_block_create(crypto_opts, "encrypt.",
+        crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.",
                                       NULL, NULL, NULL, errp);
         if (!crypto) {
             ret = -EINVAL;
@@ -936,9 +911,9 @@ static int coroutine_fn qcow_co_create_opts(const char 
*filename, QemuOpts *opts
         goto exit;
     }
 
-    if (backing_file) {
+    if (qcow_opts->has_backing_file) {
         ret = blk_pwrite(qcow_blk, sizeof(header),
-                         backing_file, backing_filename_len, 0);
+                         qcow_opts->backing_file, backing_filename_len, 0);
         if (ret != backing_filename_len) {
             goto exit;
         }
@@ -959,12 +934,100 @@ static int coroutine_fn qcow_co_create_opts(const char 
*filename, QemuOpts *opts
     ret = 0;
 exit:
     blk_unref(qcow_blk);
-cleanup:
-    QDECREF(encryptopts);
-    g_free(encryptfmt);
     qcrypto_block_free(crypto);
-    qapi_free_QCryptoBlockCreateOptions(crypto_opts);
-    g_free(backing_file);
+    return ret;
+}
+
+static int coroutine_fn qcow_co_create_opts(const char *filename,
+                                            QemuOpts *opts, Error **errp)
+{
+    BlockdevCreateOptions *create_options = NULL;
+    BlockDriverState *bs = NULL;
+    QDict *qdict = NULL;
+    QObject *qobj;
+    Visitor *v;
+    const char *val;
+    Error *local_err = NULL;
+    int ret;
+
+    static const QDictRenames opt_renames[] = {
+        { BLOCK_OPT_BACKING_FILE,       "backing-file" },
+        { BLOCK_OPT_ENCRYPT,            BLOCK_OPT_ENCRYPT_FORMAT },
+        { NULL, NULL },
+    };
+
+    /* Parse options and convert legacy syntax */
+    qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
+
+    val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
+    if (val && !strcmp(val, "on")) {
+        qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
+    } else if (val && !strcmp(val, "off")) {
+        qdict_del(qdict, BLOCK_OPT_ENCRYPT);
+    }
+
+    val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
+    if (val && !strcmp(val, "aes")) {
+        qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
+    }
+
+    if (!qdict_rename_keys(qdict, opt_renames, errp)) {
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    /* Create and open the file (protocol layer) */
+    ret = bdrv_create_file(filename, opts, &local_err);
+    if (ret < 0) {
+        error_propagate(errp, local_err);
+        goto fail;
+    }
+
+    bs = bdrv_open(filename, NULL, NULL,
+                   BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
+    if (bs == NULL) {
+        ret = -EIO;
+        goto fail;
+    }
+
+    /* Now get the QAPI type BlockdevCreateOptions */
+    qdict_put_str(qdict, "driver", "qcow");
+    qdict_put_str(qdict, "file", bs->node_name);
+
+    qobj = qdict_crumple(qdict, errp);
+    QDECREF(qdict);
+    qdict = qobject_to_qdict(qobj);
+    if (qdict == NULL) {
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    v = qobject_input_visitor_new_keyval(QOBJECT(qdict));
+    visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
+    visit_free(v);
+
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    /* Silently round up size */
+    assert(create_options->driver == BLOCKDEV_DRIVER_QCOW);
+    create_options->u.qcow.size =
+        ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE);
+
+    /* Create the qcow image (format layer) */
+    ret = qcow_co_create(create_options, errp);
+    if (ret < 0) {
+        goto fail;
+    }
+
+    ret = 0;
+fail:
+    QDECREF(qdict);
+    bdrv_unref(bs);
+    qapi_free_BlockdevCreateOptions(create_options);
     return ret;
 }
 
@@ -1128,6 +1191,7 @@ static BlockDriver bdrv_qcow = {
     .bdrv_close                = qcow_close,
     .bdrv_child_perm        = bdrv_format_default_perms,
     .bdrv_reopen_prepare    = qcow_reopen_prepare,
+    .bdrv_co_create         = qcow_co_create,
     .bdrv_co_create_opts    = qcow_co_create_opts,
     .bdrv_has_zero_init     = bdrv_has_zero_init_1,
     .supports_backing       = true,
-- 
2.13.6