vmdk: Implement .bdrv_co_create callback

This makes VMDK support blockdev-create. The implementation reuses the
image creation code in vmdk_co_create_opts which now acceptes a callback
pointer to "retrieve" BlockBackend pointers from the caller. This way we
separate the logic between file/extent acquisition and initialization.

The QAPI command parameters are mostly the same as the old create_opts
except the dropped legacy @compat6 switch, which is redundant with
@hwversion.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 321 insertions, 127 deletions

diff --git a/block/vmdk.c b/block/vmdk.c
index 32fc2c84b3..5a162ee85c 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -1932,33 +1932,56 @@ static int filename_decompose(const char *filename, char *path, char *prefix,
     return VMDK_OK;
 }
 
-static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts,
-                                            Error **errp)
+/*
+ * idx == 0: get or create the descriptor file (also the image file if in a
+ *           non-split format.
+ * idx >= 1: get the n-th extent if in a split subformat
+ */
+typedef BlockBackend *(*vmdk_create_extent_fn)(int64_t size,
+                                               int idx,
+                                               bool flat,
+                                               bool split,
+                                               bool compress,
+                                               bool zeroed_grain,
+                                               void *opaque,
+                                               Error **errp);
+
+static void vmdk_desc_add_extent(GString *desc,
+                                 const char *extent_line_fmt,
+                                 int64_t size, const char *filename)
+{
+    char *basename = g_path_get_basename(filename);
+
+    g_string_append_printf(desc, extent_line_fmt,
+                           DIV_ROUND_UP(size, BDRV_SECTOR_SIZE), basename);
+    g_free(basename);
+}
+
+static int coroutine_fn vmdk_co_do_create(int64_t size,
+                                          BlockdevVmdkSubformat subformat,
+                                          BlockdevVmdkAdapterType adapter_type,
+                                          const char *backing_file,
+                                          const char *hw_version,
+                                          bool compat6,
+                                          bool zeroed_grain,
+                                          vmdk_create_extent_fn extent_fn,
+                                          void *opaque,
+                                          Error **errp)
 {
-    int idx = 0;
-    BlockBackend *new_blk = NULL;
+    int extent_idx;
+    BlockBackend *blk = NULL;
     Error *local_err = NULL;
     char *desc = NULL;
-    int64_t total_size = 0, filesize;
-    char *adapter_type = NULL;
-    char *backing_file = NULL;
-    char *hw_version = NULL;
-    char *fmt = NULL;
     int ret = 0;
     bool flat, split, compress;
     GString *ext_desc_lines;
-    char *path = g_malloc0(PATH_MAX);
-    char *prefix = g_malloc0(PATH_MAX);
-    char *postfix = g_malloc0(PATH_MAX);
-    char *desc_line = g_malloc0(BUF_SIZE);
-    char *ext_filename = g_malloc0(PATH_MAX);
-    char *desc_filename = g_malloc0(PATH_MAX);
     const int64_t split_size = 0x80000000;  /* VMDK has constant split size */
-    const char *desc_extent_line;
+    int64_t extent_size;
+    int64_t created_size = 0;
+    const char *extent_line_fmt;
     char *parent_desc_line = g_malloc0(BUF_SIZE);
     uint32_t parent_cid = 0xffffffff;
     uint32_t number_heads = 16;
-    bool zeroed_grain = false;
     uint32_t desc_offset = 0, desc_len;
     const char desc_template[] =
         "# Disk DescriptorFile\n"
@@ -1982,71 +2005,35 @@ static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts
 
     ext_desc_lines = g_string_new(NULL);
 
-    if (filename_decompose(filename, path, prefix, postfix, PATH_MAX, errp)) {
-        ret = -EINVAL;
-        goto exit;
-    }
     /* Read out options */
-    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
-                          BDRV_SECTOR_SIZE);
-    adapter_type = qemu_opt_get_del(opts, BLOCK_OPT_ADAPTER_TYPE);
-    backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
-    hw_version = qemu_opt_get_del(opts, BLOCK_OPT_HWVERSION);
-    if (qemu_opt_get_bool_del(opts, BLOCK_OPT_COMPAT6, false)) {
-        if (strcmp(hw_version, "undefined")) {
+    if (compat6) {
+        if (hw_version) {
             error_setg(errp,
                        "compat6 cannot be enabled with hwversion set");
             ret = -EINVAL;
             goto exit;
         }
-        g_free(hw_version);
-        hw_version = g_strdup("6");
-    }
-    if (strcmp(hw_version, "undefined") == 0) {
-        g_free(hw_version);
-        hw_version = g_strdup("4");
+        hw_version = "6";
     }
-    fmt = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
-    if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ZEROED_GRAIN, false)) {
-        zeroed_grain = true;
+    if (!hw_version) {
+        hw_version = "4";
     }
 
-    if (!adapter_type) {
-        adapter_type = g_strdup("ide");
-    } else if (strcmp(adapter_type, "ide") &&
-               strcmp(adapter_type, "buslogic") &&
-               strcmp(adapter_type, "lsilogic") &&
-               strcmp(adapter_type, "legacyESX")) {
-        error_setg(errp, "Unknown adapter type: '%s'", adapter_type);
-        ret = -EINVAL;
-        goto exit;
-    }
-    if (strcmp(adapter_type, "ide") != 0) {
+    if (adapter_type != BLOCKDEV_VMDK_ADAPTER_TYPE_IDE) {
         /* that's the number of heads with which vmware operates when
            creating, exporting, etc. vmdk files with a non-ide adapter type */
         number_heads = 255;
     }
-    if (!fmt) {
-        /* Default format to monolithicSparse */
-        fmt = g_strdup("monolithicSparse");
-    } else if (strcmp(fmt, "monolithicFlat") &&
-               strcmp(fmt, "monolithicSparse") &&
-               strcmp(fmt, "twoGbMaxExtentSparse") &&
-               strcmp(fmt, "twoGbMaxExtentFlat") &&
-               strcmp(fmt, "streamOptimized")) {
-        error_setg(errp, "Unknown subformat: '%s'", fmt);
-        ret = -EINVAL;
-        goto exit;
-    }
-    split = !(strcmp(fmt, "twoGbMaxExtentFlat") &&
-              strcmp(fmt, "twoGbMaxExtentSparse"));
-    flat = !(strcmp(fmt, "monolithicFlat") &&
-             strcmp(fmt, "twoGbMaxExtentFlat"));
-    compress = !strcmp(fmt, "streamOptimized");
+    split = (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTFLAT) ||
+            (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTSPARSE);
+    flat = (subformat == BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICFLAT) ||
+           (subformat == BLOCKDEV_VMDK_SUBFORMAT_TWOGBMAXEXTENTFLAT);
+    compress = subformat == BLOCKDEV_VMDK_SUBFORMAT_STREAMOPTIMIZED;
+
     if (flat) {
-        desc_extent_line = "RW %" PRId64 " FLAT \"%s\" 0\n";
+        extent_line_fmt = "RW %" PRId64 " FLAT \"%s\" 0\n";
     } else {
-        desc_extent_line = "RW %" PRId64 " SPARSE \"%s\"\n";
+        extent_line_fmt = "RW %" PRId64 " SPARSE \"%s\"\n";
     }
     if (flat && backing_file) {
         error_setg(errp, "Flat image can't have backing file");
@@ -2058,10 +2045,34 @@ static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts
         ret = -ENOTSUP;
         goto exit;
     }
+
+    /* Create extents */
+    if (split) {
+        extent_size = split_size;
+    } else {
+        extent_size = size;
+    }
+    if (!split && !flat) {
+        created_size = extent_size;
+    } else {
+        created_size = 0;
+    }
+    /* Get the descriptor file BDS */
+    blk = extent_fn(created_size, 0, flat, split, compress, zeroed_grain,
+                    opaque, errp);
+    if (!blk) {
+        ret = -EIO;
+        goto exit;
+    }
+    if (!split && !flat) {
+        vmdk_desc_add_extent(ext_desc_lines, extent_line_fmt, created_size,
+                             blk_bs(blk)->filename);
+    }
+
     if (backing_file) {
-        BlockBackend *blk;
+        BlockBackend *backing;
         char *full_backing = g_new0(char, PATH_MAX);
-        bdrv_get_full_backing_filename_from_filename(filename, backing_file,
+        bdrv_get_full_backing_filename_from_filename(blk_bs(blk)->filename, backing_file,
                                                      full_backing, PATH_MAX,
                                                      &local_err);
         if (local_err) {
@@ -2071,106 +2082,211 @@ static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts
             goto exit;
         }
 
-        blk = blk_new_open(full_backing, NULL, NULL,
-                           BDRV_O_NO_BACKING, errp);
+        backing = blk_new_open(full_backing, NULL, NULL,
+                               BDRV_O_NO_BACKING, errp);
         g_free(full_backing);
-        if (blk == NULL) {
+        if (backing == NULL) {
             ret = -EIO;
             goto exit;
         }
-        if (strcmp(blk_bs(blk)->drv->format_name, "vmdk")) {
-            blk_unref(blk);
+        if (strcmp(blk_bs(backing)->drv->format_name, "vmdk")) {
+            error_setg(errp, "Invalid backing file format: %s. Must be vmdk",
+                       blk_bs(backing)->drv->format_name);
+            blk_unref(backing);
             ret = -EINVAL;
             goto exit;
         }
-        ret = vmdk_read_cid(blk_bs(blk), 0, &parent_cid);
-        blk_unref(blk);
+        ret = vmdk_read_cid(blk_bs(backing), 0, &parent_cid);
+        blk_unref(backing);
         if (ret) {
+            error_setg(errp, "Failed to read parent CID");
             goto exit;
         }
         snprintf(parent_desc_line, BUF_SIZE,
                 "parentFileNameHint=\"%s\"", backing_file);
     }
-
-    /* Create extents */
-    filesize = total_size;
-    while (filesize > 0) {
-        int64_t size = filesize;
-
-        if (split && size > split_size) {
-            size = split_size;
-        }
-        if (split) {
-            snprintf(desc_filename, PATH_MAX, "%s-%c%03d%s",
-                    prefix, flat ? 'f' : 's', ++idx, postfix);
-        } else if (flat) {
-            snprintf(desc_filename, PATH_MAX, "%s-flat%s", prefix, postfix);
-        } else {
-            snprintf(desc_filename, PATH_MAX, "%s%s", prefix, postfix);
-        }
-        snprintf(ext_filename, PATH_MAX, "%s%s", path, desc_filename);
-
-        if (vmdk_create_extent(ext_filename, size,
-                               flat, compress, zeroed_grain, NULL, opts, errp)) {
+    extent_idx = 1;
+    while (created_size < size) {
+        BlockBackend *extent_blk;
+        int64_t cur_size = MIN(size - created_size, extent_size);
+        extent_blk = extent_fn(cur_size, extent_idx, flat, split, compress,
+                               zeroed_grain, opaque, errp);
+        if (!extent_blk) {
             ret = -EINVAL;
             goto exit;
         }
-        filesize -= size;
-
-        /* Format description line */
-        snprintf(desc_line, BUF_SIZE,
-                    desc_extent_line, size / BDRV_SECTOR_SIZE, desc_filename);
-        g_string_append(ext_desc_lines, desc_line);
+        vmdk_desc_add_extent(ext_desc_lines, extent_line_fmt, cur_size,
+                             blk_bs(extent_blk)->filename);
+        created_size += cur_size;
+        extent_idx++;
+        blk_unref(extent_blk);
     }
     /* generate descriptor file */
     desc = g_strdup_printf(desc_template,
                            g_random_int(),
                            parent_cid,
-                           fmt,
+                           BlockdevVmdkSubformat_str(subformat),
                            parent_desc_line,
                            ext_desc_lines->str,
                            hw_version,
-                           total_size /
+                           size /
                                (int64_t)(63 * number_heads * BDRV_SECTOR_SIZE),
                            number_heads,
-                           adapter_type);
+                           BlockdevVmdkAdapterType_str(adapter_type));
     desc_len = strlen(desc);
     /* the descriptor offset = 0x200 */
     if (!split && !flat) {
         desc_offset = 0x200;
-    } else {
-        ret = bdrv_create_file(filename, opts, &local_err);
+    }
+
+    ret = blk_pwrite(blk, desc_offset, desc, desc_len, 0);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not write description");
+        goto exit;
+    }
+    /* bdrv_pwrite write padding zeros to align to sector, we don't need that
+     * for description file */
+    if (desc_offset == 0) {
+        ret = blk_truncate(blk, desc_len, PREALLOC_MODE_OFF, errp);
         if (ret < 0) {
-            error_propagate(errp, local_err);
             goto exit;
         }
     }
+    ret = 0;
+exit:
+    if (blk) {
+        blk_unref(blk);
+    }
+    g_free(desc);
+    g_free(parent_desc_line);
+    g_string_free(ext_desc_lines, true);
+    return ret;
+}
 
-    new_blk = blk_new_open(filename, NULL, NULL,
-                           BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
-                           &local_err);
-    if (new_blk == NULL) {
-        error_propagate(errp, local_err);
-        ret = -EIO;
+typedef struct {
+    char *path;
+    char *prefix;
+    char *postfix;
+    QemuOpts *opts;
+} VMDKCreateOptsData;
+
+static BlockBackend *vmdk_co_create_opts_cb(int64_t size, int idx,
+                                            bool flat, bool split, bool compress,
+                                            bool zeroed_grain, void *opaque,
+                                            Error **errp)
+{
+    BlockBackend *blk = NULL;
+    BlockDriverState *bs = NULL;
+    VMDKCreateOptsData *data = opaque;
+    char *ext_filename = NULL;
+    char *rel_filename = NULL;
+
+    if (idx == 0) {
+        rel_filename = g_strdup_printf("%s%s", data->prefix, data->postfix);
+    } else if (split) {
+        rel_filename = g_strdup_printf("%s-%c%03d%s",
+                                       data->prefix,
+                                       flat ? 'f' : 's', idx, data->postfix);
+    } else {
+        assert(idx == 1);
+        rel_filename = g_strdup_printf("%s-flat%s", data->prefix, data->postfix);
+    }
+
+    ext_filename = g_strdup_printf("%s%s", data->path, rel_filename);
+    g_free(rel_filename);
+
+    if (vmdk_create_extent(ext_filename, size,
+                           flat, compress, zeroed_grain, &blk, data->opts,
+                           errp)) {
         goto exit;
     }
+    bdrv_unref(bs);
+exit:
+    g_free(ext_filename);
+    return blk;
+}
 
-    blk_set_allow_write_beyond_eof(new_blk, true);
+static int coroutine_fn vmdk_co_create_opts(const char *filename, QemuOpts *opts,
+                                            Error **errp)
+{
+    Error *local_err = NULL;
+    char *desc = NULL;
+    int64_t total_size = 0;
+    char *adapter_type = NULL;
+    BlockdevVmdkAdapterType adapter_type_enum;
+    char *backing_file = NULL;
+    char *hw_version = NULL;
+    char *fmt = NULL;
+    BlockdevVmdkSubformat subformat;
+    int ret = 0;
+    char *path = g_malloc0(PATH_MAX);
+    char *prefix = g_malloc0(PATH_MAX);
+    char *postfix = g_malloc0(PATH_MAX);
+    char *desc_line = g_malloc0(BUF_SIZE);
+    char *ext_filename = g_malloc0(PATH_MAX);
+    char *desc_filename = g_malloc0(PATH_MAX);
+    char *parent_desc_line = g_malloc0(BUF_SIZE);
+    bool zeroed_grain;
+    bool compat6;
+    VMDKCreateOptsData data;
 
-    ret = blk_pwrite(new_blk, desc_offset, desc, desc_len, 0);
-    if (ret < 0) {
-        error_setg_errno(errp, -ret, "Could not write description");
+    if (filename_decompose(filename, path, prefix, postfix, PATH_MAX, errp)) {
+        ret = -EINVAL;
         goto exit;
     }
-    /* bdrv_pwrite write padding zeros to align to sector, we don't need that
-     * for description file */
-    if (desc_offset == 0) {
-        ret = blk_truncate(new_blk, desc_len, PREALLOC_MODE_OFF, errp);
+    /* Read out options */
+    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                          BDRV_SECTOR_SIZE);
+    adapter_type = qemu_opt_get_del(opts, BLOCK_OPT_ADAPTER_TYPE);
+    backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
+    hw_version = qemu_opt_get_del(opts, BLOCK_OPT_HWVERSION);
+    compat6 = qemu_opt_get_bool_del(opts, BLOCK_OPT_COMPAT6, false);
+    if (strcmp(hw_version, "undefined") == 0) {
+        g_free(hw_version);
+        hw_version = g_strdup("4");
     }
-exit:
-    if (new_blk) {
-        blk_unref(new_blk);
+    fmt = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);
+    zeroed_grain = qemu_opt_get_bool_del(opts, BLOCK_OPT_ZEROED_GRAIN, false);
+
+    if (adapter_type) {
+        adapter_type_enum = qapi_enum_parse(&BlockdevVmdkAdapterType_lookup,
+                                            adapter_type,
+                                            BLOCKDEV_VMDK_ADAPTER_TYPE_IDE,
+                                            &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            ret = -EINVAL;
+            goto exit;
+        }
+    } else {
+        adapter_type_enum = BLOCKDEV_VMDK_ADAPTER_TYPE_IDE;
     }
+
+    if (!fmt) {
+        /* Default format to monolithicSparse */
+        subformat = BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICSPARSE;
+    } else {
+        subformat = qapi_enum_parse(&BlockdevVmdkSubformat_lookup,
+                                    fmt,
+                                    BLOCKDEV_VMDK_SUBFORMAT_MONOLITHICSPARSE,
+                                    &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            ret = -EINVAL;
+            goto exit;
+        }
+    }
+    data = (VMDKCreateOptsData){
+        .prefix = prefix,
+        .postfix = postfix,
+        .path = path,
+        .opts = opts,
+    };
+    ret = vmdk_co_do_create(total_size, subformat, adapter_type_enum,
+                            backing_file, hw_version, compat6, zeroed_grain,
+                            vmdk_co_create_opts_cb, &data, errp);
+
+exit:
     g_free(adapter_type);
     g_free(backing_file);
     g_free(hw_version);
@@ -2183,7 +2299,84 @@ exit:
     g_free(ext_filename);
     g_free(desc_filename);
     g_free(parent_desc_line);
-    g_string_free(ext_desc_lines, true);
+    return ret;
+}
+
+static BlockBackend *vmdk_co_create_cb(int64_t size, int idx,
+                                       bool flat, bool split, bool compress,
+                                       bool zeroed_grain, void *opaque,
+                                       Error **errp)
+{
+    int ret;
+    BlockDriverState *bs;
+    BlockBackend *blk;
+    BlockdevCreateOptionsVmdk *opts = opaque;
+
+    if (idx == 0) {
+        bs = bdrv_open_blockdev_ref(opts->file, errp);
+    } else {
+        int i;
+        BlockdevRefList *list = opts->extents;
+        for (i = 1; i < idx; i++) {
+            if (!list || !list->next) {
+                error_setg(errp, "Extent [%d] not specified", i);
+                return NULL;
+            }
+            list = list->next;
+        }
+        if (!list) {
+            error_setg(errp, "Extent [%d] not specified", idx - 1);
+            return NULL;
+        }
+        bs = bdrv_open_blockdev_ref(list->value, errp);
+    }
+    if (!bs) {
+        return NULL;
+    }
+    blk = blk_new(BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE | BLK_PERM_RESIZE,
+                  BLK_PERM_ALL);
+    if (blk_insert_bs(blk, bs, errp)) {
+        bdrv_unref(bs);
+        return NULL;
+    }
+    blk_set_allow_write_beyond_eof(blk, true);
+    bdrv_unref(bs);
+
+    ret = vmdk_init_extent(blk, size, flat, compress, zeroed_grain, errp);
+    if (ret) {
+        blk_unref(blk);
+        blk = NULL;
+    }
+    return blk;
+}
+
+static int coroutine_fn vmdk_co_create(BlockdevCreateOptions *create_options,
+                                       Error **errp)
+{
+    int ret;
+    BlockdevCreateOptionsVmdk *opts;
+
+    opts = &create_options->u.vmdk;
+
+    /* Validate options */
+    if (!QEMU_IS_ALIGNED(opts->size, BDRV_SECTOR_SIZE)) {
+        error_setg(errp, "Image size must be a multiple of 512 bytes");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    ret = vmdk_co_do_create(opts->size,
+                            opts->subformat,
+                            opts->adapter_type,
+                            opts->backing_file,
+                            opts->hwversion,
+                            false,
+                            opts->zeroed_grain,
+                            vmdk_co_create_cb,
+                            opts, errp);
+    return ret;
+
+out:
     return ret;
 }
 
@@ -2451,6 +2644,7 @@ static BlockDriver bdrv_vmdk = {
     .bdrv_co_pwrite_zeroes        = vmdk_co_pwrite_zeroes,
     .bdrv_close                   = vmdk_close,
     .bdrv_co_create_opts          = vmdk_co_create_opts,
+    .bdrv_co_create               = vmdk_co_create,
     .bdrv_co_flush_to_disk        = vmdk_co_flush,
     .bdrv_co_block_status         = vmdk_co_block_status,
     .bdrv_get_allocated_file_size = vmdk_get_allocated_file_size,