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[Qemu-devel] [PULL 04/23] block: Remove child references from bs->{optio
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 04/23] block: Remove child references from bs->{options, explicit_options} |
Date: |
Mon, 1 Oct 2018 19:18:42 +0200 |
From: Alberto Garcia <address@hidden>
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 <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
Signed-off-by: Kevin Wolf <address@hidden>
---
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
- [Qemu-devel] [PULL 00/23] Block layer patches, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 02/23] qemu-io: Fix writethrough check in reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 01/23] file-posix: Include filename in locking error message, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 03/23] file-posix: x-check-cache-dropped should default to false on reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 04/23] block: Remove child references from bs->{options, explicit_options},
Kevin Wolf <=
- [Qemu-devel] [PULL 06/23] block: Allow child references on reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 07/23] block: Forbid trying to change unsupported options during reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 05/23] block: Don't look for child references in append_open_options(), Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 10/23] block: Allow changing 'detect-zeroes' on reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 09/23] block: Allow changing 'discard' on reopen, Kevin Wolf, 2018/10/01
- [Qemu-devel] [PULL 08/23] file-posix: Forbid trying to change unsupported options during reopen, Kevin Wolf, 2018/10/01