Re: [Qemu-block] [PATCH v2 02/21] block: Fix reopen with semantically overlapping options

[Alberto Garcia]

On Mon 23 Nov 2015 04:59:41 PM CET, Kevin Wolf wrote:
> This fixes bdrv_reopen() calls like the following one:
>
> qemu-io -c 'open -o overlap-check.template=all /tmp/test.qcow2' \
> -c 'reopen -o overlap-check=none'
>
> The approach taken so far would result in an options QDict that has both
> "overlap-check.template=all" and "overlap-check=none", which obviously
> conflicts. In this case, the old option should be overridden by the
> newly specified option.
>
> Signed-off-by: Kevin Wolf 

Reviewed-by: Alberto Garcia 

Berto

Re: [Qemu-block] [PATCH v2 02/21] block: Fix reopen with semantically overlapping options

[Max Reitz]

On 23.11.2015 16:59, Kevin Wolf wrote:
> This fixes bdrv_reopen() calls like the following one:
> 
> qemu-io -c 'open -o overlap-check.template=all /tmp/test.qcow2' \
> -c 'reopen -o overlap-check=none'
> 
> The approach taken so far would result in an options QDict that has both
> "overlap-check.template=all" and "overlap-check=none", which obviously
> conflicts. In this case, the old option should be overridden by the
> newly specified option.
> 
> Signed-off-by: Kevin Wolf 
> ---
>  block.c | 16 +++-
>  1 file changed, 15 insertions(+), 1 deletion(-)

Reviewed-by: Max Reitz 



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[Qemu-block] [PATCH v2 02/21] block: Fix reopen with semantically overlapping options

[Kevin Wolf]

This fixes bdrv_reopen() calls like the following one:

qemu-io -c 'open -o overlap-check.template=all /tmp/test.qcow2' \
-c 'reopen -o overlap-check=none'

The approach taken so far would result in an options QDict that has both
"overlap-check.template=all" and "overlap-check=none", which obviously
conflicts. In this case, the old option should be overridden by the
newly specified option.

Signed-off-by: Kevin Wolf 
---
 block.c | 16 +++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index 3a7324b..675e5a8 100644
--- a/block.c
+++ b/block.c
@@ -624,6 +624,20 @@ static int refresh_total_sectors(BlockDriverState *bs, 
int64_t hint)
 }
 
 /**
+ * Combines a QDict of new block driver @options with any missing options taken
+ * from @old_options, so that leaving out an option defaults to its old value.
+ */
+static void bdrv_join_options(BlockDriverState *bs, QDict *options,
+  QDict *old_options)
+{
+if (bs->drv && bs->drv->bdrv_join_options) {
+bs->drv->bdrv_join_options(options, old_options);
+} else {
+qdict_join(options, old_options, false);
+}
+}
+
+/**
  * Set open flags for a given discard mode
  *
  * Return 0 on success, -1 if the discard mode was invalid.
@@ -1663,7 +1677,7 @@ BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue 
*bs_queue,
 }
 
 old_options = qdict_clone_shallow(bs->options);
-qdict_join(options, old_options, false);
+bdrv_join_options(bs, options, old_options);
 QDECREF(old_options);
 
 /* bdrv_open() masks this flag out */
-- 
1.8.3.1