[Qemu-devel] Re: [PATCH] block: Use error codes from lower levels for error message

[Stefan Weil]

Am 19.07.2010 14:26, schrieb Kevin Wolf:
> Am 18.07.2010 21:42, schrieb Stefan Weil:
>    
> > "No such file or directory" is a misleading error message
> > when a user tries to open a file with wrong permissions.
> >
> > Cc: Kevin Wolf<address@hidden>
> > Signed-off-by: Stefan Weil<address@hidden>
> > ---
> >   block.c |   12 ++++++++----
> >   1 files changed, 8 insertions(+), 4 deletions(-)
> >
> > diff --git a/block.c b/block.c
> > index f837876..2f80540 100644
> > --- a/block.c
> > +++ b/block.c
> > @@ -330,16 +330,20 @@ BlockDriver *bdrv_find_protocol(const char *filename)
> >       return NULL;
> >   }
> >
> > -static BlockDriver *find_image_format(const char *filename)
> > +static BlockDriver *find_image_format(const char *filename, int *error)
> >      
> Wouldn't it be a more natural interface to return an 0/-errno int and
> pass the BlockDriver* by reference? I think we already have some
> function that work this way in the block code, but I can't remember any
> that get an int *error.
>    

... nor did I find a function which takes a BlockDriver**.
But if you prefer it like that, I can send a new version of the patch.

>    
> >   {
> >       int ret, score, score_max;
> >       BlockDriver *drv1, *drv;
> >       uint8_t buf[2048];
> >       BlockDriverState *bs;
> >
> > +    *error = -ENOENT;
> >      
> Why -ENOENT is the default would be clearer if you moved it down next to
> the drv = NULL before the loop that searches for the driver.
>
>    

What about the "return bdrv_find_format" lines?
They need a default value, too.

And I did not want to change too much because I cannot
run a complete test for all cases.

So setting *error at the beginning should be the safest
modification.

> Apart from these minor nitpicks it looks good.
>
> Kevin
>
>    
Thanks.

Stefan