Re: [Qemu-devel] [Qemu-block] [PATCH for-2.10 14/16] block/qcow2: falloc/full preallocating growth

2017-03-22 Thread Stefan Hajnoczi 
On Mon, Mar 20, 2017 at 04:15:59PM +0100, Max Reitz wrote:
> On 20.03.2017 12:29, Stefan Hajnoczi wrote:
> > On Mon, Mar 13, 2017 at 10:41:15PM +0100, Max Reitz wrote:
> >> Implement the preallocation modes falloc and full for growing qcow2
> >> images.
> >>
> >> Signed-off-by: Max Reitz 
> >> ---
> >>  block/qcow2.c | 36 +++-
> >>  1 file changed, 35 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/block/qcow2.c b/block/qcow2.c
> >> index 80fb815b15..b6b08d70da 100644
> >> --- a/block/qcow2.c
> >> +++ b/block/qcow2.c
> >> @@ -2604,7 +2604,9 @@ static int qcow2_truncate(BlockDriverState *bs, 
> >> int64_t offset,
> >>  int64_t new_l1_size;
> >>  int ret;
> >>  
> >> -if (prealloc != PREALLOC_MODE_OFF && prealloc != 
> >> PREALLOC_MODE_METADATA) {
> >> +if (prealloc != PREALLOC_MODE_OFF && prealloc != 
> >> PREALLOC_MODE_METADATA &&
> >> +prealloc != PREALLOC_MODE_FALLOC && prealloc != 
> >> PREALLOC_MODE_FULL)
> > 
> > Now all cases are covered so this if statement can be dropped.  If you
> > are worried about new preallocation modes being added in the future then
> > the error_setg() can be moved into the switch statement's default case.
> 
> No, because the switch comes after we have already grown the L1 table.
> That wouldn't be so nice.

Oops :)

Stefan


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Re: [Qemu-devel] [Qemu-block] [PATCH for-2.10 14/16] block/qcow2: falloc/full preallocating growth

2017-03-20 Thread Max Reitz 
On 20.03.2017 12:29, Stefan Hajnoczi wrote:
> On Mon, Mar 13, 2017 at 10:41:15PM +0100, Max Reitz wrote:
>> Implement the preallocation modes falloc and full for growing qcow2
>> images.
>>
>> Signed-off-by: Max Reitz 
>> ---
>>  block/qcow2.c | 36 +++-
>>  1 file changed, 35 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/qcow2.c b/block/qcow2.c
>> index 80fb815b15..b6b08d70da 100644
>> --- a/block/qcow2.c
>> +++ b/block/qcow2.c
>> @@ -2604,7 +2604,9 @@ static int qcow2_truncate(BlockDriverState *bs, 
>> int64_t offset,
>>  int64_t new_l1_size;
>>  int ret;
>>  
>> -if (prealloc != PREALLOC_MODE_OFF && prealloc != 
>> PREALLOC_MODE_METADATA) {
>> +if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA 
>> &&
>> +prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)
> 
> Now all cases are covered so this if statement can be dropped.  If you
> are worried about new preallocation modes being added in the future then
> the error_setg() can be moved into the switch statement's default case.

No, because the switch comes after we have already grown the L1 table.
That wouldn't be so nice.

Max



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Re: [Qemu-devel] [Qemu-block] [PATCH for-2.10 14/16] block/qcow2: falloc/full preallocating growth

2017-03-20 Thread Stefan Hajnoczi 
On Mon, Mar 13, 2017 at 10:41:15PM +0100, Max Reitz wrote:
> Implement the preallocation modes falloc and full for growing qcow2
> images.
> 
> Signed-off-by: Max Reitz 
> ---
>  block/qcow2.c | 36 +++-
>  1 file changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 80fb815b15..b6b08d70da 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -2604,7 +2604,9 @@ static int qcow2_truncate(BlockDriverState *bs, int64_t 
> offset,
>  int64_t new_l1_size;
>  int ret;
>  
> -if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA) 
> {
> +if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA 
> &&
> +prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)

Now all cases are covered so this if statement can be dropped.  If you
are worried about new preallocation modes being added in the future then
the error_setg() can be moved into the switch statement's default case.


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