Re: [Qemu-devel] [PATCH 1/4] qcow2: Add qcow2_signal_corruption()

[Max Reitz <mreitz@redhat.com>]

On 20.08.2014 12:10, Kevin Wolf wrote:
> Am 16.08.2014 um 23:16 hat Max Reitz geschrieben:
>> Add a helper function for easily marking an image corrupt while
>> outputting an informative message to stderr and via QAPI.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>   block/qcow2.c | 28 ++++++++++++++++++++++++++++
>>   block/qcow2.h |  4 ++++
>>   2 files changed, 32 insertions(+)
>>
>> diff --git a/block/qcow2.c b/block/qcow2.c
>> index 435e0e1..ef2c931 100644
>> --- a/block/qcow2.c
>> +++ b/block/qcow2.c
>> @@ -30,6 +30,8 @@
>>   #include "qemu/error-report.h"
>>   #include "qapi/qmp/qerror.h"
>>   #include "qapi/qmp/qbool.h"
>> +#include "qapi/qmp/types.h"
>> +#include "qapi-event.h"
>>   #include "trace.h"
>>   #include "qemu/option_int.h"
>>   
>> @@ -2378,6 +2380,32 @@ static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts)
>>       return 0;
>>   }
>>   
>> +void qcow2_signal_corruption(BlockDriverState *bs, int64_t offset, int64_t size,
>> +                             const char *message_format, ...)
>> +{
>> +    char *message;
>> +    va_list ap;
>> +
>> +    va_start(ap, message_format);
>> +    message = g_strdup_vprintf(message_format, ap);
>> +    va_end(ap);
>> +
>> +    if (bs->read_only) {
>> +        fprintf(stderr, "qcow2: Image is corrupt: %s\n", message);
> The BDS isn't made unusable in read-only mode, so we can produce quite a
> lot of these messages and fill up the log. Perhaps it would be better to
> print the message only the first time (or the first n times) and then
> tell the user that further errors won't be logged.
>
> Also, including the block device or file name (or both) wouldn't hurt.

I'll include both in v2.

Max

>> +    } else {
>> +        fprintf(stderr, "qcow2: Marking image as corrupt: %s\n", message);
>> +        qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), message,
>> +                                              offset >= 0, offset,
>> +                                              size >= 0, size, &error_abort);
>> +    }
>> +    g_free(message);
>> +
>> +    if (!bs->read_only) {
>> +        qcow2_mark_corrupt(bs);
>> +        bs->drv = NULL; /* make BDS unusable */
>> +    }
>> +}
> Kevin