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

[Peter Lieven]

Am 29.05.2014 03:55, schrieb Hu Tao:
> On Wed, May 28, 2014 at 07:36:26AM +0200, Markus Armbruster wrote:
>> Peter Lieven <address@hidden> writes:
>>
>>> Am 27.05.2014 um 21:24 schrieb Eric Blake <address@hidden>:
>>>
>>>> On 05/27/2014 02:22 AM, Chen Fan wrote:
>>>>> From: Hu Tao <address@hidden>
>>>>>
>>>>> 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 <address@hidden>
>>>>> ---
>>>>> 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?

Peter