From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57495) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g71r2-0002ND-Uh for qemu-devel@nongnu.org; Mon, 01 Oct 2018 13:19:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g71qz-00075L-3J for qemu-devel@nongnu.org; Mon, 01 Oct 2018 13:19:31 -0400 From: Kevin Wolf Date: Mon, 1 Oct 2018 19:18:42 +0200 Message-Id: <20181001171901.11004-5-kwolf@redhat.com> In-Reply-To: <20181001171901.11004-1-kwolf@redhat.com> References: <20181001171901.11004-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 04/23] block: Remove child references from bs->{options, explicit_options} 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: Alberto Garcia Block drivers allow opening their children using a reference to an existing BlockDriverState. These references remain stored in the 'options' and 'explicit_options' QDicts, but we don't need to keep them once everything is open. What is more important, these values can become wrong if the children change: $ qemu-img create -f qcow2 hd0.qcow2 10M $ qemu-img create -f qcow2 hd1.qcow2 10M $ qemu-img create -f qcow2 hd2.qcow2 10M $ $QEMU -drive if=none,file=hd0.qcow2,node-name=hd0 \ -drive if=none,file=hd1.qcow2,node-name=hd1,backing=hd0 \ -drive file=hd2.qcow2,node-name=hd2,backing=hd1 After this hd2 has hd1 as its backing file. Now let's remove it using block_stream: (qemu) block_stream hd2 0 hd0.qcow2 Now hd0 is the backing file of hd2, but hd2's options QDicts still contain backing=hd1. Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- block.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index c298ca6a19..db71ea5b9a 100644 --- a/block.c +++ b/block.c @@ -2763,12 +2763,15 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, } } - /* Remove all children options from bs->options and bs->explicit_options */ + /* Remove all children options and references + * from bs->options and bs->explicit_options */ QLIST_FOREACH(child, &bs->children, next) { char *child_key_dot; child_key_dot = g_strdup_printf("%s.", child->name); qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot); qdict_extract_subqdict(bs->options, NULL, child_key_dot); + qdict_del(bs->explicit_options, child->name); + qdict_del(bs->options, child->name); g_free(child_key_dot); } @@ -3290,6 +3293,7 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state) { BlockDriver *drv; BlockDriverState *bs; + BdrvChild *child; bool old_can_write, new_can_write; assert(reopen_state != NULL); @@ -3314,6 +3318,13 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state) bs->open_flags = reopen_state->flags; bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); + /* Remove child references from bs->options and bs->explicit_options. + * Child options were already removed in bdrv_reopen_queue_child() */ + QLIST_FOREACH(child, &bs->children, next) { + qdict_del(bs->explicit_options, child->name); + qdict_del(bs->options, child->name); + } + bdrv_refresh_limits(bs, NULL); bdrv_set_perm(reopen_state->bs, reopen_state->perm, -- 2.13.6