From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:38469) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyI5m-0001Gz-KH for qemu-devel@nongnu.org; Mon, 25 Feb 2019 10:22:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gyI5j-0001lx-OB for qemu-devel@nongnu.org; Mon, 25 Feb 2019 10:22:54 -0500 From: Kevin Wolf Date: Mon, 25 Feb 2019 16:20:32 +0100 Message-Id: <20190225152053.15976-51-kwolf@redhat.com> In-Reply-To: <20190225152053.15976-1-kwolf@redhat.com> References: <20190225152053.15976-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 50/71] block: Purify .bdrv_refresh_filename() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org From: Max Reitz Currently, BlockDriver.bdrv_refresh_filename() is supposed to both refresh the filename (BDS.exact_filename) and set BDS.full_open_options. Now that we have generic code in the central bdrv_refresh_filename() for creating BDS.full_open_options, we can drop the latter part from all BlockDriver.bdrv_refresh_filename() implementations. This also means that we can drop all of the existing default code for this from the global bdrv_refresh_filename() itself. Furthermore, we now have to call BlockDriver.bdrv_refresh_filename() after having set BDS.full_open_options, because the block driver's implementation should now be allowed to depend on BDS.full_open_options being set correctly. Finally, with this patch we can drop the @options parameter from BlockDriver.bdrv_refresh_filename(); also, add a comment on this function's purpose in block/block_int.h while touching its interface. This completely obsoletes blklogwrite's implementation of .bdrv_refresh_filename(). Signed-off-by: Max Reitz Message-id: 20190201192935.18394-25-mreitz@redhat.com Signed-off-by: Max Reitz --- include/block/block_int.h | 6 +- block.c | 131 +++++++------------------------------ block/blkdebug.c | 54 ++++++--------- block/blklogwrites.c | 22 ------- block/blkverify.c | 16 +---- block/commit.c | 2 +- block/mirror.c | 2 +- block/nbd.c | 23 +------ block/nfs.c | 36 +--------- block/null.c | 22 ++++--- block/nvme.c | 22 ++++--- block/quorum.c | 30 --------- tests/qemu-iotests/228 | 4 -- tests/qemu-iotests/228.out | 2 +- 14 files changed, 81 insertions(+), 291 deletions(-) diff --git a/include/block/block_int.h b/include/block/block_int.h index ab4cf2df07..836d67c1ae 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -139,7 +139,11 @@ struct BlockDriver { Error **errp); int (*bdrv_make_empty)(BlockDriverState *bs); =20 - void (*bdrv_refresh_filename)(BlockDriverState *bs, QDict *options); + /* + * Refreshes the bs->exact_filename field. If that is impossible, + * bs->exact_filename has to be left empty. + */ + void (*bdrv_refresh_filename)(BlockDriverState *bs); =20 /* * Gathers the open options for all children into @target. diff --git a/block.c b/block.c index a6e523059d..23869623ea 100644 --- a/block.c +++ b/block.c @@ -5621,33 +5621,6 @@ static bool append_strong_runtime_options(QDict *d= , BlockDriverState *bs) return found_any; } =20 -static bool append_open_options(QDict *d, BlockDriverState *bs) -{ - const QDictEntry *entry; - QemuOptDesc *desc; - bool found_any =3D false; - - for (entry =3D qdict_first(bs->options); entry; - entry =3D qdict_next(bs->options, entry)) - { - /* Exclude all non-driver-specific options */ - for (desc =3D bdrv_runtime_opts.desc; desc->name; desc++) { - if (!strcmp(qdict_entry_key(entry), desc->name)) { - break; - } - } - if (desc->name) { - continue; - } - - qdict_put_obj(d, qdict_entry_key(entry), - qobject_ref(qdict_entry_value(entry))); - found_any =3D true; - } - - return found_any; -} - /* Note: This function may return false positives; it may return true * even if opening the backing file specified by bs's image header * would result in exactly bs->backing. */ @@ -5681,6 +5654,8 @@ void bdrv_refresh_filename(BlockDriverState *bs) BdrvChild *child; QDict *opts; bool backing_overridden; + bool generate_json_filename; /* Whether our default implementation s= hould + fill exact_filename (false) or not (= true) */ =20 if (!drv) { return; @@ -5716,90 +5691,10 @@ void bdrv_refresh_filename(BlockDriverState *bs) backing_overridden =3D false; } =20 - if (drv->bdrv_refresh_filename) { - /* Obsolete information is of no use here, so drop the old file = name - * information before refreshing it */ - bs->exact_filename[0] =3D '\0'; - if (bs->full_open_options) { - qobject_unref(bs->full_open_options); - bs->full_open_options =3D NULL; - } - - opts =3D qdict_new(); - append_open_options(opts, bs); - drv->bdrv_refresh_filename(bs, opts); - qobject_unref(opts); - } else if (bs->file) { - /* Try to reconstruct valid information from the underlying file= */ - bool has_open_options; - - bs->exact_filename[0] =3D '\0'; - if (bs->full_open_options) { - qobject_unref(bs->full_open_options); - bs->full_open_options =3D NULL; - } - - opts =3D qdict_new(); - has_open_options =3D append_open_options(opts, bs); - has_open_options |=3D backing_overridden; - - /* If no specific options have been given for this BDS, the file= name of - * the underlying file should suffice for this one as well */ - if (bs->file->bs->exact_filename[0] && !has_open_options) { - strcpy(bs->exact_filename, bs->file->bs->exact_filename); - } - /* Reconstructing the full options QDict is simple for most form= at block - * drivers, as long as the full options are known for the underl= ying - * file BDS. The full options QDict of that file BDS should some= how - * contain a representation of the filename, therefore the follo= wing - * suffices without querying the (exact_)filename of this BDS. *= / - if (bs->file->bs->full_open_options && - (!bs->backing || bs->backing->bs->full_open_options)) - { - qdict_put_str(opts, "driver", drv->format_name); - qdict_put(opts, "file", - qobject_ref(bs->file->bs->full_open_options)); - - if (bs->backing) { - qdict_put(opts, "backing", - qobject_ref(bs->backing->bs->full_open_options= )); - } else if (backing_overridden) { - qdict_put_null(opts, "backing"); - } - - bs->full_open_options =3D opts; - } else { - qobject_unref(opts); - } - } else if (!bs->full_open_options && qdict_size(bs->options)) { - /* There is no underlying file BDS (at least referenced by BDS.f= ile), - * so the full options QDict should be equal to the options give= n - * specifically for this block device when it was opened (plus t= he - * driver specification). - * Because those options don't change, there is no need to updat= e - * full_open_options when it's already set. */ - - opts =3D qdict_new(); - append_open_options(opts, bs); - qdict_put_str(opts, "driver", drv->format_name); - - if (bs->exact_filename[0]) { - /* This may not work for all block protocol drivers (some ma= y - * require this filename to be parsed), but we have to find = some - * default solution here, so just include it. If some block = driver - * does not support pure options without any filename at all= or - * needs some special format of the options QDict, it needs = to - * implement the driver-specific bdrv_refresh_filename() fun= ction. - */ - qdict_put_str(opts, "filename", bs->exact_filename); - } - - bs->full_open_options =3D opts; - } - /* Gather the options QDict */ opts =3D qdict_new(); - append_strong_runtime_options(opts, bs); + generate_json_filename =3D append_strong_runtime_options(opts, bs); + generate_json_filename |=3D backing_overridden; =20 if (drv->bdrv_gather_child_options) { /* Some block drivers may not want to present all of their child= ren's @@ -5825,6 +5720,24 @@ void bdrv_refresh_filename(BlockDriverState *bs) qobject_unref(bs->full_open_options); bs->full_open_options =3D opts; =20 + if (drv->bdrv_refresh_filename) { + /* Obsolete information is of no use here, so drop the old file = name + * information before refreshing it */ + bs->exact_filename[0] =3D '\0'; + + drv->bdrv_refresh_filename(bs); + } else if (bs->file) { + /* Try to reconstruct valid information from the underlying file= */ + + bs->exact_filename[0] =3D '\0'; + + /* If no specific options have been given for this BDS, the file= name of + * the underlying file should suffice for this one as well */ + if (bs->file->bs->exact_filename[0] && !generate_json_filename) = { + strcpy(bs->exact_filename, bs->file->bs->exact_filename); + } + } + if (bs->exact_filename[0]) { pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); } else { diff --git a/block/blkdebug.c b/block/blkdebug.c index 71b4275b98..1ea835c2b9 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -811,51 +811,37 @@ static int64_t blkdebug_getlength(BlockDriverState = *bs) return bdrv_getlength(bs->file->bs); } =20 -static void blkdebug_refresh_filename(BlockDriverState *bs, QDict *optio= ns) +static void blkdebug_refresh_filename(BlockDriverState *bs) { BDRVBlkdebugState *s =3D bs->opaque; - QDict *opts; const QDictEntry *e; - bool force_json =3D false; - - for (e =3D qdict_first(options); e; e =3D qdict_next(options, e)) { - if (strcmp(qdict_entry_key(e), "config") && - strcmp(qdict_entry_key(e), "x-image")) - { - force_json =3D true; - break; - } - } + int ret; =20 - if (force_json && !bs->file->bs->full_open_options) { - /* The config file cannot be recreated, so creating a plain file= name - * is impossible */ + if (!bs->file->bs->exact_filename[0]) { return; } =20 - if (!force_json && bs->file->bs->exact_filename[0]) { - int ret =3D snprintf(bs->exact_filename, sizeof(bs->exact_filena= me), - "blkdebug:%s:%s", s->config_file ?: "", - bs->file->bs->exact_filename); - if (ret >=3D sizeof(bs->exact_filename)) { - /* An overflow makes the filename unusable, so do not report= any */ - bs->exact_filename[0] =3D 0; + for (e =3D qdict_first(bs->full_open_options); e; + e =3D qdict_next(bs->full_open_options, e)) + { + /* Real child options are under "image", but "x-image" may + * contain a filename */ + if (strcmp(qdict_entry_key(e), "config") && + strcmp(qdict_entry_key(e), "image") && + strcmp(qdict_entry_key(e), "x-image") && + strcmp(qdict_entry_key(e), "driver")) + { + return; } } =20 - opts =3D qdict_new(); - qdict_put_str(opts, "driver", "blkdebug"); - - qdict_put(opts, "image", qobject_ref(bs->file->bs->full_open_options= )); - - for (e =3D qdict_first(options); e; e =3D qdict_next(options, e)) { - if (strcmp(qdict_entry_key(e), "x-image")) { - qdict_put_obj(opts, qdict_entry_key(e), - qobject_ref(qdict_entry_value(e))); - } + ret =3D snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "blkdebug:%s:%s", + s->config_file ?: "", bs->file->bs->exact_filename); + if (ret >=3D sizeof(bs->exact_filename)) { + /* An overflow makes the filename unusable, so do not report any= */ + bs->exact_filename[0] =3D 0; } - - bs->full_open_options =3D opts; } =20 static void blkdebug_refresh_limits(BlockDriverState *bs, Error **errp) diff --git a/block/blklogwrites.c b/block/blklogwrites.c index 5da5df112d..eb2b4901a5 100644 --- a/block/blklogwrites.c +++ b/block/blklogwrites.c @@ -280,27 +280,6 @@ static int64_t blk_log_writes_getlength(BlockDriverS= tate *bs) return bdrv_getlength(bs->file->bs); } =20 -static void blk_log_writes_refresh_filename(BlockDriverState *bs, - QDict *options) -{ - BDRVBlkLogWritesState *s =3D bs->opaque; - - if (bs->file->bs->full_open_options - && s->log_file->bs->full_open_options) - { - QDict *opts =3D qdict_new(); - qdict_put_str(opts, "driver", "blklogwrites"); - - qobject_ref(bs->file->bs->full_open_options); - qdict_put(opts, "file", bs->file->bs->full_open_options); - qobject_ref(s->log_file->bs->full_open_options); - qdict_put(opts, "log", s->log_file->bs->full_open_options); - qdict_put_int(opts, "log-sector-size", s->sectorsize); - - bs->full_open_options =3D opts; - } -} - static void blk_log_writes_child_perm(BlockDriverState *bs, BdrvChild *c= , const BdrvChildRole *role, BlockReopenQueue *ro_q, @@ -531,7 +510,6 @@ static BlockDriver bdrv_blk_log_writes =3D { .bdrv_open =3D blk_log_writes_open, .bdrv_close =3D blk_log_writes_close, .bdrv_getlength =3D blk_log_writes_getlength, - .bdrv_refresh_filename =3D blk_log_writes_refresh_filename, .bdrv_child_perm =3D blk_log_writes_child_perm, .bdrv_refresh_limits =3D blk_log_writes_refresh_limits, =20 diff --git a/block/blkverify.c b/block/blkverify.c index 3c7d4c8729..3ff77ff49a 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -281,24 +281,10 @@ static bool blkverify_recurse_is_first_non_filter(B= lockDriverState *bs, return bdrv_recurse_is_first_non_filter(s->test_file->bs, candidate)= ; } =20 -static void blkverify_refresh_filename(BlockDriverState *bs, QDict *opti= ons) +static void blkverify_refresh_filename(BlockDriverState *bs) { BDRVBlkverifyState *s =3D bs->opaque; =20 - if (bs->file->bs->full_open_options - && s->test_file->bs->full_open_options) - { - QDict *opts =3D qdict_new(); - qdict_put_str(opts, "driver", "blkverify"); - - qdict_put(opts, "raw", - qobject_ref(bs->file->bs->full_open_options)); - qdict_put(opts, "test", - qobject_ref(s->test_file->bs->full_open_options)); - - bs->full_open_options =3D opts; - } - if (bs->file->bs->exact_filename[0] && s->test_file->bs->exact_filename[0]) { diff --git a/block/commit.c b/block/commit.c index 614a8ca374..385fb98527 100644 --- a/block/commit.c +++ b/block/commit.c @@ -230,7 +230,7 @@ static int coroutine_fn bdrv_commit_top_preadv(BlockD= riverState *bs, return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags); } =20 -static void bdrv_commit_top_refresh_filename(BlockDriverState *bs, QDict= *opts) +static void bdrv_commit_top_refresh_filename(BlockDriverState *bs) { pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->backing->bs->filename); diff --git a/block/mirror.c b/block/mirror.c index 031c1aeaeb..726d3c27fb 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1431,7 +1431,7 @@ static int coroutine_fn bdrv_mirror_top_pdiscard(Bl= ockDriverState *bs, NULL, 0); } =20 -static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs, QDict= *opts) +static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs) { if (bs->backing =3D=3D NULL) { /* we can be here after failed bdrv_attach_child in diff --git a/block/nbd.c b/block/nbd.c index 318a58776c..2e72df528a 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -477,12 +477,9 @@ static void nbd_attach_aio_context(BlockDriverState = *bs, nbd_client_attach_aio_context(bs, new_context); } =20 -static void nbd_refresh_filename(BlockDriverState *bs, QDict *options) +static void nbd_refresh_filename(BlockDriverState *bs) { BDRVNBDState *s =3D bs->opaque; - QDict *opts =3D qdict_new(); - QObject *saddr_qdict; - Visitor *ov; const char *host =3D NULL, *port =3D NULL, *path =3D NULL; =20 if (s->saddr->type =3D=3D SOCKET_ADDRESS_TYPE_INET) { @@ -495,8 +492,6 @@ static void nbd_refresh_filename(BlockDriverState *bs= , QDict *options) path =3D s->saddr->u.q_unix.path; } /* else can't represent as pseudo-filename */ =20 - qdict_put_str(opts, "driver", "nbd"); - if (path && s->export) { snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nbd+unix:///%s?socket=3D%s", s->export, path); @@ -510,22 +505,6 @@ static void nbd_refresh_filename(BlockDriverState *b= s, QDict *options) snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nbd://%s:%s", host, port); } - - ov =3D qobject_output_visitor_new(&saddr_qdict); - visit_type_SocketAddress(ov, NULL, &s->saddr, &error_abort); - visit_complete(ov, &saddr_qdict); - visit_free(ov); - qdict_put_obj(opts, "server", saddr_qdict); - - if (s->export) { - qdict_put_str(opts, "export", s->export); - } - if (s->tlscredsid) { - qdict_put_str(opts, "tls-creds", s->tlscredsid); - } - - qdict_flatten(opts); - bs->full_open_options =3D opts; } =20 static char *nbd_dirname(BlockDriverState *bs, Error **errp) diff --git a/block/nfs.c b/block/nfs.c index 6985a44b89..531903610b 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -799,14 +799,9 @@ static int nfs_reopen_prepare(BDRVReopenState *state= , return 0; } =20 -static void nfs_refresh_filename(BlockDriverState *bs, QDict *options) +static void nfs_refresh_filename(BlockDriverState *bs) { NFSClient *client =3D bs->opaque; - QDict *opts =3D qdict_new(); - QObject *server_qdict; - Visitor *ov; - - qdict_put_str(opts, "driver", "nfs"); =20 if (client->uid && !client->gid) { snprintf(bs->exact_filename, sizeof(bs->exact_filename), @@ -824,35 +819,6 @@ static void nfs_refresh_filename(BlockDriverState *b= s, QDict *options) snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nfs://%s%s", client->server->host, client->path); } - - ov =3D qobject_output_visitor_new(&server_qdict); - visit_type_NFSServer(ov, NULL, &client->server, &error_abort); - visit_complete(ov, &server_qdict); - qdict_put_obj(opts, "server", server_qdict); - qdict_put_str(opts, "path", client->path); - - if (client->uid) { - qdict_put_int(opts, "user", client->uid); - } - if (client->gid) { - qdict_put_int(opts, "group", client->gid); - } - if (client->tcp_syncnt) { - qdict_put_int(opts, "tcp-syn-cnt", client->tcp_syncnt); - } - if (client->readahead) { - qdict_put_int(opts, "readahead-size", client->readahead); - } - if (client->pagecache) { - qdict_put_int(opts, "page-cache-size", client->pagecache); - } - if (client->debug) { - qdict_put_int(opts, "debug", client->debug); - } - - visit_free(ov); - qdict_flatten(opts); - bs->full_open_options =3D opts; } =20 static char *nfs_dirname(BlockDriverState *bs, Error **errp) diff --git a/block/null.c b/block/null.c index 858892f0c4..1c56a0ef01 100644 --- a/block/null.c +++ b/block/null.c @@ -239,17 +239,23 @@ static int coroutine_fn null_co_block_status(BlockD= riverState *bs, return ret; } =20 -static void null_refresh_filename(BlockDriverState *bs, QDict *opts) +static void null_refresh_filename(BlockDriverState *bs) { - qdict_del(opts, "filename"); - - if (!qdict_size(opts)) { - snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://"= , - bs->drv->format_name); + const QDictEntry *e; + + for (e =3D qdict_first(bs->full_open_options); e; + e =3D qdict_next(bs->full_open_options, e)) + { + /* These options can be ignored */ + if (strcmp(qdict_entry_key(e), "filename") && + strcmp(qdict_entry_key(e), "driver")) + { + return; + } } =20 - qdict_put_str(opts, "driver", bs->drv->format_name); - bs->full_open_options =3D qobject_ref(opts); + snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://", + bs->drv->format_name); } =20 static const char *const null_strong_runtime_opts[] =3D { diff --git a/block/nvme.c b/block/nvme.c index bf656b2bba..6b5845644b 100644 --- a/block/nvme.c +++ b/block/nvme.c @@ -1053,17 +1053,23 @@ static int nvme_reopen_prepare(BDRVReopenState *r= eopen_state, return 0; } =20 -static void nvme_refresh_filename(BlockDriverState *bs, QDict *opts) +static void nvme_refresh_filename(BlockDriverState *bs) { - qdict_del(opts, "filename"); - - if (!qdict_size(opts)) { - snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://"= , - bs->drv->format_name); + const QDictEntry *e; + + for (e =3D qdict_first(bs->full_open_options); e; + e =3D qdict_next(bs->full_open_options, e)) + { + /* These options can be ignored */ + if (strcmp(qdict_entry_key(e), "filename") && + strcmp(qdict_entry_key(e), "driver")) + { + return; + } } =20 - qdict_put_str(opts, "driver", bs->drv->format_name); - bs->full_open_options =3D qobject_ref(opts); + snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://", + bs->drv->format_name); } =20 static void nvme_refresh_limits(BlockDriverState *bs, Error **errp) diff --git a/block/quorum.c b/block/quorum.c index 3984f0aa4f..352f729136 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -1065,35 +1065,6 @@ static void quorum_del_child(BlockDriverState *bs,= BdrvChild *child, bdrv_drained_end(bs); } =20 -static void quorum_refresh_filename(BlockDriverState *bs, QDict *options= ) -{ - BDRVQuorumState *s =3D bs->opaque; - QDict *opts; - QList *children; - int i; - - for (i =3D 0; i < s->num_children; i++) { - if (!s->children[i]->bs->full_open_options) { - return; - } - } - - children =3D qlist_new(); - for (i =3D 0; i < s->num_children; i++) { - qlist_append(children, - qobject_ref(s->children[i]->bs->full_open_options))= ; - } - - opts =3D qdict_new(); - qdict_put_str(opts, "driver", "quorum"); - qdict_put_int(opts, QUORUM_OPT_VOTE_THRESHOLD, s->threshold); - qdict_put_bool(opts, QUORUM_OPT_BLKVERIFY, s->is_blkverify); - qdict_put_bool(opts, QUORUM_OPT_REWRITE, s->rewrite_corrupted); - qdict_put(opts, "children", children); - - bs->full_open_options =3D opts; -} - static void quorum_gather_child_options(BlockDriverState *bs, QDict *tar= get, bool backing_overridden) { @@ -1159,7 +1130,6 @@ static BlockDriver bdrv_quorum =3D { =20 .bdrv_open =3D quorum_open, .bdrv_close =3D quorum_close, - .bdrv_refresh_filename =3D quorum_refresh_filename, .bdrv_gather_child_options =3D quorum_gather_child_options, .bdrv_dirname =3D quorum_dirname, =20 diff --git a/tests/qemu-iotests/228 b/tests/qemu-iotests/228 index 7a57c41e29..9a50afd205 100755 --- a/tests/qemu-iotests/228 +++ b/tests/qemu-iotests/228 @@ -230,10 +230,6 @@ with iotests.FilePath('base.img') as base_img_path, = \ overlay=3D'node0') =20 # This should give us the original plain result - # FIXME: Currently, it yields a json:{} filename even though it - # only contains a @driver and a @file entry, so a plain - # filename would obviously suffice. This is fixed by a - # future patch. =20 log_node_info(vm.node_info('node0')) =20 diff --git a/tests/qemu-iotests/228.out b/tests/qemu-iotests/228.out index 393ab09164..4217df24fe 100644 --- a/tests/qemu-iotests/228.out +++ b/tests/qemu-iotests/228.out @@ -74,7 +74,7 @@ bs->backing: (none) {"execute": "blockdev-snapshot", "arguments": {"node": "original-backing= ", "overlay": "node0"}} {"return": {}} =20 -bs->filename: json:{"driver": "IMGFMT", "file": {"driver": "file", "file= name": "TEST_DIR/PID-top.img"}} +bs->filename: TEST_DIR/PID-top.img bs->backing_file: TEST_DIR/PID-base.img bs->backing->bs->filename: TEST_DIR/PID-base.img =20 --=20 2.20.1