Re: [Qemu-devel] [PATCH] block/raw-posix: use a character device if a block device is given

[Kevin Wolf <kwolf@redhat.com>]

Am 24.05.2011 11:30, schrieb Christoph Egger:
> 
> On NetBSD a userland process is better with the character device
> interface. In addition, a block device can't be opened twice; if a Xen
> backend opens it, qemu can't and vice-versa.

If you provide a Signed-off-by, I think this patch is ready to be committed.

Kevin

> 
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 6b72470..64dceb1 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -136,12 +143,55 @@ static int64_t raw_getlength(BlockDriverState *bs);
>   static int cdrom_reopen(BlockDriverState *bs);
>   #endif
> 
> +#if defined(__NetBSD__)
> +static int raw_normalize_devicepath(const char **filename)
> +{
> +    static char namebuf[PATH_MAX];
> +    const char *dp, *fname;
> +    struct stat sb;
> +
> +    fname = *filename;
> +    dp = strrchr(fname, '/');
> +    if (lstat(fname, &sb) < 0) {
> +        fprintf(stderr, "%s: stat failed: %s\n",
> +            fname, strerror(errno));
> +        return -errno;
> +    }
> +
> +    if (!S_ISBLK(sb.st_mode)) {
> +        return 0;
> +    }
> +
> +    if (dp == NULL) {
> +        snprintf(namebuf, PATH_MAX, "r%s", fname);
> +    } else {
> +        snprintf(namebuf, PATH_MAX, "%.*s/r%s",
> +            (int)(dp - fname), fname, dp + 1);
> +    }
> +    fprintf(stderr, "%s is a block device", fname);
> +    *filename = namebuf;
> +    fprintf(stderr, ", using %s\n", *filename);
> +
> +    return 0;
> +}
> +#else
> +static int raw_normalize_devicepath(const char **filename)
> +{
> +    return 0;
> +}
> +#endif
> +
>   static int raw_open_common(BlockDriverState *bs, const char *filename,
>                              int bdrv_flags, int open_flags)
>   {
>       BDRVRawState *s = bs->opaque;
>       int fd, ret;
> 
> +    ret = raw_normalize_devicepath(&filename);
> +    if (ret != 0) {
> +        return ret;
> +    }
> +
>       s->open_flags = open_flags | O_BINARY;
>       s->open_flags &= ~O_ACCMODE;
>       if (bdrv_flags & BDRV_O_RDWR) {
> 
>