[v2] qcow2: space preallocation and COW improvements

[Qemu-devel] [PATCH v2 03/15] blkdebug: support BDRV_REQ_ALLOCATE

Posted by Anton Nefedov 8 years, 8 months ago

Support the flag if the underlying BDS supports it

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
---
 block/blkdebug.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index a5196e8..8b1401b 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -415,7 +415,8 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
 
     bs->supported_write_flags = BDRV_REQ_FUA &
         bs->file->bs->supported_write_flags;
-    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
+    bs->supported_zero_flags =
+        (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_ALLOCATE) &
         bs->file->bs->supported_zero_flags;
     ret = -EINVAL;
 
-- 
2.7.4

Re: [Qemu-devel] [PATCH v2 03/15] blkdebug: support BDRV_REQ_ALLOCATE

Posted by Eric Blake 8 years, 8 months ago

On 06/01/2017 10:14 AM, Anton Nefedov wrote:
> Support the flag if the underlying BDS supports it
> 
> Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
> ---
>  block/blkdebug.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Shouldn't other passthrough drivers (like raw-format.c) make this change
as well?

> 
> diff --git a/block/blkdebug.c b/block/blkdebug.c
> index a5196e8..8b1401b 100644
> --- a/block/blkdebug.c
> +++ b/block/blkdebug.c
> @@ -415,7 +415,8 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
>  
>      bs->supported_write_flags = BDRV_REQ_FUA &
>          bs->file->bs->supported_write_flags;
> -    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
> +    bs->supported_zero_flags =
> +        (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_ALLOCATE) &
>          bs->file->bs->supported_zero_flags;
>      ret = -EINVAL;
>  
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v2 03/15] blkdebug: support BDRV_REQ_ALLOCATE

Posted by Anton Nefedov 8 years, 8 months ago


On 06/01/2017 10:50 PM, Eric Blake wrote:
> On 06/01/2017 10:14 AM, Anton Nefedov wrote:
>> Support the flag if the underlying BDS supports it
>>
>> Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
>> ---
>>   block/blkdebug.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> Shouldn't other passthrough drivers (like raw-format.c) make this change
> as well?
> 

Right.

Wonder why they even enumerate those instead of just

bs->supported_zero_flags = bs->file->bs->supported_zero_flags;

>>
>> diff --git a/block/blkdebug.c b/block/blkdebug.c
>> index a5196e8..8b1401b 100644
>> --- a/block/blkdebug.c
>> +++ b/block/blkdebug.c
>> @@ -415,7 +415,8 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
>>   
>>       bs->supported_write_flags = BDRV_REQ_FUA &
>>           bs->file->bs->supported_write_flags;
>> -    bs->supported_zero_flags = (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP) &
>> +    bs->supported_zero_flags =
>> +        (BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_ALLOCATE) &
>>           bs->file->bs->supported_zero_flags;
>>       ret = -EINVAL;
>>   
>>
> 

/Anton