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

[Hu Tao]

On Thu, Jun 05, 2014 at 07:48:12AM +0200, Peter Lieven wrote:
> 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 <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.
> 
> I would include the patch in the series if the series depends on this patch.

OK.