Re: [Qemu-devel] [PATCH V9 3/4] raw-posix: Add full image preallocation option

[Peter Lieven <pl@kamp.de>]

On 05.06.2014 07:39, Hu Tao wrote:
> On Thu, May 29, 2014 at 08:55:59PM +0200, Peter Lieven wrote:
>> Am 29.05.2014 03:55, schrieb Hu Tao:
>>> On Wed, May 28, 2014 at 07:36:26AM +0200, Markus Armbruster wrote:
>>>> Peter Lieven <pl@kamp.de> writes:
>>>>
>>>>> Am 27.05.2014 um 21:24 schrieb Eric Blake <eblake@redhat.com>:
>>>>>
>>>>>> On 05/27/2014 02:22 AM, Chen Fan wrote:
>>>>>>> From: Hu Tao <hutao@cn.fujitsu.com>
>>>>>>>
>>>>>>> This patch adds a new option preallocation for raw format, and implements
>>>>>>> full preallocation by writing zeros to disk.
>>>>>>>
>>>>>>> The metadata option is changed to use posix_fallocate() to ensure
>>>>>>> subsquent writes to image file won't fail because of lack of disk space.
>>>>>>>
>>>>>>> The purpose is to ensure disk space for image file. In cases
>>>>>>> posix_fallocate() is supported, metadata option can be used, otherwise
>>>>>>> (posix_fallocate() is not supported by filesystem, or in case of thin
>>>>>>> provisioning), full option has to be used. User has to choose the proper
>>>>>>> way to use.
>>>>>>>
>>>>>>> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
>>>>>>> ---
>>>>>>> block/raw-posix.c | 61
>>>>>>> ++++++++++++++++++++++++++++++++++++++++++++++++-------
>>>>>>> 1 file changed, 54 insertions(+), 7 deletions(-)
>>>>>>>
>>>>>>> @@ -1254,6 +1255,18 @@ static int raw_create(const char *filename, QEMUOptionParameter *options,
>>>>>>>          if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
>>>>>>>              total_size = (options->value.n + BDRV_SECTOR_SIZE) &
>>>>>>>                  BDRV_SECTOR_MASK;
>>>>>>> +        } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) {
>>>>>>> +            if (!options->value.s || !strcmp(options->value.s, "off")) {
>>>>>>> +                prealloc = PREALLOC_MODE_OFF;
>>>>>>> +            } else if (!strcmp(options->value.s, "metadata")) {
>>>>>>> +                prealloc = PREALLOC_MODE_METADATA;
>>>>>>> +            } else if (!strcmp(options->value.s, "full")) {
>>>>>>> +                prealloc = PREALLOC_MODE_FULL;
>>>>>>> +            } else {
>>>>>> Instead of open-coding this conversion from string to enum, can you
>>>>>> reuse Peter's pending patch?  (Hmm, that means Peter needs to export it
>>>>>> to somewhere public, not just blockdev.c)
>>>>>>
>>>>>> https://lists.gnu.org/archive/html/qemu-devel/2014-05/msg03772.html
>>>>> I don't mind if this function is made public. You can send a patch for it.
>>>>> Please don't forget to remove the static declaration. You might
>>>>> also want to remove the inline. This was just to avoid an unused
>>>>> function error. I don't know if blockdev.c is still the right
>>>>> place for this function then.
>>>> Probably not.  I'd rename to qapi_enum_parse(), and move it to qapi/.
>>>> If no existing file fits, create a new one, say qapi/qapi-util.c.
>>> Thanks. I'll use the function in next version.
>> Will you introduce a patch to move it to QAPI or shall I?
> I will include the patch in next version of this series, but if you'd
> like I can send a seperate patch.

I would include the patch in the series if the series depends on this patch.

Peter

>
> Thanks.
>


-- 

Mit freundlichen Grüßen

Peter Lieven

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