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

[Hu Tao]

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 <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?

I will include the patch in next version of this series, but if you'd
like I can send a seperate patch.

Thanks.