diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/block.c b/block.c index 64e7d220c6..1e53b3dffd 100644 --- a/block.c +++ b/block.c @@ -858,9 +858,10 @@ free_and_fail: * dictionary, it needs to use QINCREF() before calling bdrv_file_open. */ int bdrv_file_open(BlockDriverState **pbs, const char *filename, - QDict *options, int flags, Error **errp) + const char *reference, QDict *options, int flags, + Error **errp) { - BlockDriverState *bs; + BlockDriverState *bs = NULL; BlockDriver *drv; const char *drvname; bool allow_protocol_prefix = false; @@ -872,6 +873,24 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, options = qdict_new(); } + if (reference) { + if (filename || qdict_size(options)) { + error_setg(errp, "Cannot reference an existing block device with " + "additional options or a new filename"); + return -EINVAL; + } + QDECREF(options); + + bs = bdrv_find(reference); + if (!bs) { + error_setg(errp, "Cannot find block device '%s'", reference); + return -ENODEV; + } + bdrv_ref(bs); + *pbs = bs; + return 0; + } + bs = bdrv_new(""); bs->options = options; options = qdict_clone_shallow(options); @@ -1124,7 +1143,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, qdict_extract_subqdict(options, &file_options, "file."); - ret = bdrv_file_open(&file, filename, file_options, + ret = bdrv_file_open(&file, filename, NULL, file_options, bdrv_open_flags(bs, flags | BDRV_O_UNMAP), &local_err); if (ret < 0) { goto fail; |