[Qemu-devel] [PATCH v2 0/2] block/replication fixes

[Qemu-devel] [PATCH v2 0/2] block/replication fixes

[Changlong Xie]

V2:
1. fix typo

Changlong Xie (2):
  block/replication: prefect the logic to acquire 'top_id'
  block/replication: Clarify 'top-id' parameter usage

 block/replication.c  | 9 +++++++--
 qapi/block-core.json | 3 ++-
 2 files changed, 9 insertions(+), 3 deletions(-)

-- 
1.9.3

[Qemu-devel] [PATCH v2 1/2] block/replication: prefect the logic to acquire 'top_id'

[Changlong Xie]

Only g_strdup(top_id) if 'top_id' is not NULL, although there
is no memory leak here

Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
 block/replication.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/replication.c b/block/replication.c
index 3bd1cf1..5b432d9 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -104,11 +104,11 @@ static int replication_open(BlockDriverState *bs, QDict *options,
     } else if (!strcmp(mode, "secondary")) {
         s->mode = REPLICATION_MODE_SECONDARY;
         top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
-        s->top_id = g_strdup(top_id);
-        if (!s->top_id) {
+        if (!top_id) {
             error_setg(&local_err, "Missing the option top-id");
             goto fail;
         }
+        s->top_id = g_strdup(top_id);
     } else {
         error_setg(&local_err,
                    "The option mode's value should be primary or secondary");
-- 
1.9.3

Re: [Qemu-devel] [PATCH v2 1/2] block/replication: prefect the logic to acquire 'top_id'

[Eric Blake]

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On 10/11/2016 05:46 AM, Changlong Xie wrote:
> Only g_strdup(top_id) if 'top_id' is not NULL, although there
> is no memory leak here
> 
> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
> ---
>  block/replication.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/block/replication.c b/block/replication.c
> index 3bd1cf1..5b432d9 100644
> --- a/block/replication.c
> +++ b/block/replication.c
> @@ -104,11 +104,11 @@ static int replication_open(BlockDriverState *bs, QDict *options,
>      } else if (!strcmp(mode, "secondary")) {
>          s->mode = REPLICATION_MODE_SECONDARY;
>          top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
> -        s->top_id = g_strdup(top_id);

g_strdup(NULL) is safe; it returns NULL in that case.

> -        if (!s->top_id) {
> +        if (!top_id) {
>              error_setg(&local_err, "Missing the option top-id");
>              goto fail;
>          }
> +        s->top_id = g_strdup(top_id);

I see no point to this patch, rather than churn.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v2 1/2] block/replication: prefect the logic to acquire 'top_id'

[Changlong Xie]

On 10/11/2016 10:52 PM, Eric Blake wrote:
> On 10/11/2016 05:46 AM, Changlong Xie wrote:
>> Only g_strdup(top_id) if 'top_id' is not NULL, although there
>> is no memory leak here
>>
>> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
>> ---
>>   block/replication.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/replication.c b/block/replication.c
>> index 3bd1cf1..5b432d9 100644
>> --- a/block/replication.c
>> +++ b/block/replication.c
>> @@ -104,11 +104,11 @@ static int replication_open(BlockDriverState *bs, QDict *options,
>>       } else if (!strcmp(mode, "secondary")) {
>>           s->mode = REPLICATION_MODE_SECONDARY;
>>           top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
>> -        s->top_id = g_strdup(top_id);
>
> g_strdup(NULL) is safe; it returns NULL in that case.

Yes, that's why i said 'there is no memory leak here' in the commit 
message.

>
>> -        if (!s->top_id) {
>> +        if (!top_id) {
>>               error_setg(&local_err, "Missing the option top-id");
>>               goto fail;
>>           }
>> +        s->top_id = g_strdup(top_id);
>
> I see no point to this patch, rather than churn.

It just reduce on execution path. Maybe i'm too academic :)
Will remove it in the next series.

Thanks
	-Xie

>

[Qemu-devel] [PATCH v2 2/2] block/replication: Clarify 'top-id' parameter usage

[Changlong Xie]

Replication driver only support 'top-id' parameter in secondary side,
and it must not be supplied in primary side

Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
---
 block/replication.c  | 5 +++++
 qapi/block-core.json | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/replication.c b/block/replication.c
index 5b432d9..1d0f115 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -101,6 +101,11 @@ static int replication_open(BlockDriverState *bs, QDict *options,
 
     if (!strcmp(mode, "primary")) {
         s->mode = REPLICATION_MODE_PRIMARY;
+        top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
+        if (top_id) {
+            error_setg(&local_err, "The primary side does not support option top-id");
+            goto fail;
+        }
     } else if (!strcmp(mode, "secondary")) {
         s->mode = REPLICATION_MODE_SECONDARY;
         top_id = qemu_opt_get(opts, REPLICATION_TOP_ID);
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 4badb97..ec92df4 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2197,7 +2197,8 @@
 # @mode: the replication mode
 #
 # @top-id: #optional In secondary mode, node name or device ID of the root
-#          node who owns the replication node chain. Ignored in primary mode.
+#          node who owns the replication node chain. Must not be given in
+#          primary mode.
 #
 # Since: 2.8
 ##
-- 
1.9.3

Re: [Qemu-devel] [PATCH v2 2/2] block/replication: Clarify 'top-id' parameter usage

[Eric Blake]

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On 10/11/2016 05:46 AM, Changlong Xie wrote:
> Replication driver only support 'top-id' parameter in secondary side,
> and it must not be supplied in primary side

Grammar suggestion:

The replication driver only supports the 'top-id' parameter for the
secondary side; it must not be supplied for the primary side.

> 
> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
> ---
>  block/replication.c  | 5 +++++
>  qapi/block-core.json | 3 ++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v2 2/2] block/replication: Clarify 'top-id' parameter usage

[Changlong Xie]

On 10/11/2016 10:54 PM, Eric Blake wrote:
> The replication driver only supports the 'top-id' parameter for the
> secondary side; it must not be supplied for the primary side.

Will apply in next version.

Thanks
	-Xie