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

[Max Reitz]

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 <address@hidden>
> > ---
> >   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