From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51623) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ecvJv-0004aO-5S for qemu-devel@nongnu.org; Sat, 20 Jan 2018 10:44:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ecvJr-0000C1-Ts for qemu-devel@nongnu.org; Sat, 20 Jan 2018 10:44:39 -0500 From: Max Reitz Date: Sat, 20 Jan 2018 16:44:11 +0100 Message-Id: <20180120154412.9990-6-mreitz@redhat.com> In-Reply-To: <20180120154412.9990-1-mreitz@redhat.com> References: <20180120154412.9990-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v2 5/6] block: Handle null backing link List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Markus Armbruster , Eric Blake , Alberto Garcia , Kevin Wolf Instead of converting all "backing": null instances into "backing": "", handle a null value directly in bdrv_open_inherit(). This enables explicitly null backing links for json:{} filenames. Signed-off-by: Max Reitz --- block.c | 4 +++- blockdev.c | 14 -------------- tests/qemu-iotests/089 | 20 ++++++++++++++++++++ tests/qemu-iotests/089.out | 8 ++++++++ 4 files changed, 31 insertions(+), 15 deletions(-) diff --git a/block.c b/block.c index 909cf076b7..32b7887651 100644 --- a/block.c +++ b/block.c @@ -2597,7 +2597,9 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, /* See cautionary note on accessing @options above */ backing = qdict_get_try_str(options, "backing"); - if (backing && *backing == '\0') { + if (qobject_to(qdict_get(options, "backing"), QNull) != NULL || + (backing && *backing == '\0')) + { flags |= BDRV_O_NO_BACKING; qdict_del(options, "backing"); } diff --git a/blockdev.c b/blockdev.c index 2dce231c98..5aac920eae 100644 --- a/blockdev.c +++ b/blockdev.c @@ -3969,7 +3969,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp) QObject *obj; Visitor *v = qobject_output_visitor_new(&obj); QDict *qdict; - const QDictEntry *ent; Error *local_err = NULL; visit_type_BlockdevOptions(v, NULL, &options, &local_err); @@ -3983,19 +3982,6 @@ void qmp_blockdev_add(BlockdevOptions *options, Error **errp) qdict_flatten(qdict); - /* - * Rewrite "backing": null to "backing": "" - * TODO Rewrite "" to null instead, and perhaps not even here - */ - for (ent = qdict_first(qdict); ent; ent = qdict_next(qdict, ent)) { - char *dot = strrchr(ent->key, '.'); - - if (!strcmp(dot ? dot + 1 : ent->key, "backing") - && qobject_type(ent->value) == QTYPE_QNULL) { - qdict_put(qdict, ent->key, qstring_new()); - } - } - if (!qdict_get_try_str(qdict, "node-name")) { error_setg(errp, "'node-name' must be specified for the root node"); goto fail; diff --git a/tests/qemu-iotests/089 b/tests/qemu-iotests/089 index 0b059aba90..aa1ba4a98e 100755 --- a/tests/qemu-iotests/089 +++ b/tests/qemu-iotests/089 @@ -82,6 +82,26 @@ $QEMU_IO_PROG --cache $CACHEMODE \ $QEMU_IO -c 'read -P 42 0 512' "$TEST_IMG" | _filter_qemu_io +echo +echo "=== Testing correct handling of 'backing':null ===" +echo + +_make_test_img -b "$TEST_IMG.base" $IMG_SIZE + +# This should read 42 +$QEMU_IO -c 'read -P 42 0 512' "$TEST_IMG" | _filter_qemu_io + +# This should read 0 +$QEMU_IO -c 'read -P 0 0 512' "json:{\ + 'driver': '$IMGFMT', + 'file': { + 'driver': 'file', + 'filename': '$TEST_IMG' + }, + 'backing': null +}" | _filter_qemu_io + + # Taken from test 071 echo echo "=== Testing blkdebug ===" diff --git a/tests/qemu-iotests/089.out b/tests/qemu-iotests/089.out index 0bf5a13ec1..89e3e4340a 100644 --- a/tests/qemu-iotests/089.out +++ b/tests/qemu-iotests/089.out @@ -19,6 +19,14 @@ Pattern verification failed at offset 0, 512 bytes read 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +=== Testing correct handling of 'backing':null === + +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base +read 512/512 bytes at offset 0 +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +read 512/512 bytes at offset 0 +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) + === Testing blkdebug === Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 -- 2.14.3