diff options
| -rw-r--r-- | block.c | 73 | ||||
| -rw-r--r-- | include/block/block.h | 3 |
2 files changed, 76 insertions, 0 deletions
@@ -1041,6 +1041,79 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) } /* + * Opens a disk image whose options are given as BlockdevRef in another block + * device's options. + * + * If force_raw is true, bdrv_file_open() will be used, thereby preventing any + * image format auto-detection. If it is false and a filename is given, + * bdrv_open() will be used for auto-detection. + * + * If allow_none is true, no image will be opened if filename is false and no + * BlockdevRef is given. *pbs will remain unchanged and 0 will be returned. + * + * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. + * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict + * itself, all options starting with "${bdref_key}." are considered part of the + * BlockdevRef. + * + * The BlockdevRef will be removed from the options QDict. + */ +int bdrv_open_image(BlockDriverState **pbs, const char *filename, + QDict *options, const char *bdref_key, int flags, + bool force_raw, bool allow_none, Error **errp) +{ + QDict *image_options; + int ret; + char *bdref_key_dot; + const char *reference; + + bdref_key_dot = g_strdup_printf("%s.", bdref_key); + qdict_extract_subqdict(options, &image_options, bdref_key_dot); + g_free(bdref_key_dot); + + reference = qdict_get_try_str(options, bdref_key); + if (!filename && !reference && !qdict_size(image_options)) { + if (allow_none) { + ret = 0; + } else { + error_setg(errp, "A block device must be specified for \"%s\"", + bdref_key); + ret = -EINVAL; + } + goto done; + } + + if (filename && !force_raw) { + /* If a filename is given and the block driver should be detected + automatically (instead of using none), use bdrv_open() in order to do + that auto-detection. */ + BlockDriverState *bs; + + if (reference) { + error_setg(errp, "Cannot reference an existing block device while " + "giving a filename"); + ret = -EINVAL; + goto done; + } + + bs = bdrv_new(""); + ret = bdrv_open(bs, filename, image_options, flags, NULL, errp); + if (ret < 0) { + bdrv_unref(bs); + } else { + *pbs = bs; + } + } else { + ret = bdrv_file_open(pbs, filename, reference, image_options, flags, + errp); + } + +done: + qdict_del(options, bdref_key); + return ret; +} + +/* * Opens a disk image (raw, qcow2, vmdk, ...) * * options is a QDict of options to pass to the block drivers, or NULL for an diff --git a/include/block/block.h b/include/block/block.h index e2b2a15..a47f3d4 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -186,6 +186,9 @@ int bdrv_parse_discard_flags(const char *mode, int *flags); int bdrv_file_open(BlockDriverState **pbs, const char *filename, const char *reference, QDict *options, int flags, Error **errp); +int bdrv_open_image(BlockDriverState **pbs, const char *filename, + QDict *options, const char *bdref_key, int flags, + bool force_raw, bool allow_none, Error **errp); int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp); int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, int flags, BlockDriver *drv, Error **errp); |