Re: [Qemu-devel] [Qemu-block] [PATCH 1/2] qcow2: Do not mark inactive images corrupt

[Max Reitz <mreitz@redhat.com>]

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On 2018-06-04 22:06, Jeff Cody wrote:
> On Mon, Jun 04, 2018 at 04:14:36PM +0200, Max Reitz wrote:
>> When signaling a corruption on a read-only image, qcow2 already makes
>> fatal events non-fatal (i.e., they will not result in the image being
>> closed, and the image header's corrupt flag will not be set).  This is
>> necessary because we cannot set the corrupt flag on read-only images,
>> and it is possible because further corruption of read-only images is
>> impossible.
>>
>> Inactive images are effectively read-only, too, so we should do the same
>> for them.
>>
>> (Otherwise, the assert(!(bs->open_flags & BDRV_O_INACTIVE)) in
>> bdrv_co_pwritev() will fail, crashing qemu.)
>>
>> Cc: qemu-stable@nongnu.org
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>  block/qcow2.c | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/qcow2.c b/block/qcow2.c
>> index 59a38b9cd3..8b5f7386f7 100644
>> --- a/block/qcow2.c
>> +++ b/block/qcow2.c
>> @@ -4402,7 +4402,9 @@ void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
>>      char *message;
>>      va_list ap;
>>  
>> -    fatal = fatal && !bs->read_only;
>> +    if ((bs->open_flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) != BDRV_O_RDWR) {
> 
> Hmm, this is pretty much exactly what the bdrv_is_writable() helper function
> does in block.c; too bad it's scope is limited to block.c.  Maybe worth it
> to make it a more widely available helper and use it here?

You know what, I copied it from there but for some reason never thought
of making it global.

Will do.

Max

>> +        fatal = false;
>> +    }
>>  
>>      if (s->signaled_corruption &&
>>          (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
>> -- 
>> 2.17.0
>>
>>



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