Am 15.12.2012 15:09, schrieb Stefan Weil:
> The block drivers normally return -errno for typical errors.
> There is no appropriate error code for "wrong format", so
> use a special error code which does not conflict with system
> error codes.
>
> Signed-off-by: Stefan Weil <s...@weilnetz.de>
> ---
> block.h | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/block.h b/block.h
> index 893448a..829e18b 100644
> --- a/block.h
> +++ b/block.h
> @@ -90,6 +90,13 @@ typedef struct BlockDevOps {
> #define BDRV_SECTOR_SIZE (1ULL << BDRV_SECTOR_BITS)
> #define BDRV_SECTOR_MASK ~(BDRV_SECTOR_SIZE - 1)
>
> +/* The block drivers normally return -errno for typical errors.
> + * There is no appropriate error code for "wrong format", so
> + * use a special error code which does not conflict with system
> + * error codes.
> + */
> +#define BDRV_WRONG_FORMAT INT_MIN
I think it would be better to use the E* format and a positive number so
that it's obvious that it's meant to be used in -errno returns.
Also, I would consider moving it to qemu-common.h where other errno
values are defined that may be missing on some systems, so that
everything stays in one place and we won't define overlapping codes:
#if !defined(ENOTSUP)
#define ENOTSUP 4096
#endif
#if !defined(ECANCELED)
#define ECANCELED 4097
#endif
This sounds like a good addition in the same place would be:
#define EBDRV_WRONG_FORMAT 4098
Or just use EINVAL or ENOTTY like Stefan suggested.
Kevin
