diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 19 |
1 files changed, 19 insertions, 0 deletions
@@ -2361,6 +2361,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, char *bdref_key_dot; const char *reference = NULL; int ret = 0; + bool implicit_backing = false; BlockDriverState *backing_hd; QDict *options; QDict *tmp_parent_options = NULL; @@ -2396,6 +2397,16 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qobject_unref(options); goto free_exit; } else { + if (qdict_size(options) == 0) { + /* If the user specifies options that do not modify the + * backing file's behavior, we might still consider it the + * implicit backing file. But it's easier this way, and + * just specifying some of the backing BDS's options is + * only possible with -drive anyway (otherwise the QAPI + * schema forces the user to specify everything). */ + implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file); + } + bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, &local_err); if (local_err) { @@ -2429,6 +2440,12 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, } bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs)); + if (implicit_backing) { + bdrv_refresh_filename(backing_hd); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_hd->filename); + } + /* Hook up the backing file link; drop our reference, bs owns the * backing_hd reference now */ bdrv_set_backing_hd(bs, backing_hd, &local_err); @@ -3848,6 +3865,8 @@ int bdrv_change_backing_file(BlockDriverState *bs, if (ret == 0) { pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); + pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), + backing_file ?: ""); } return ret; } |