use util-linux-ng's libblkid instead of libvolume_id

[Karel Zak]

 Good work, the patch looks good. Few nits:

On Thu, Mar 26, 2009 at 05:10:57PM +0100, Kay Sievers wrote:
> +blkid_module="blkid >= 1.99"

 I'm not sure if this is really the final blkid version number for
 util-linux-v2.15. I need to talk about it with Ted -- unfortunately
 he is probably too busy now... (The current version in e2fsprogs is 1.41
 and I hope this version will be freezed -- in such case we can use
 something better than 1.99 -- for example 1.43 or so.)

> +#include <blkid/blkid.h>

 This is correct, but I'd suggest to use <blkid.h> and proper "-I" gcc
 option (pkg-config blkid --cflags).

> +				if (blkid_probe_lookup_value (pr, "USAGE", &usage, &len) == 0 &&

 the "len" is optional, you can use NULL.

> +			blkid_probe_set_device (pr, fd, vol_probe_offset, vol_size);

 Please, test return code. This function reads 512 bytes from the
 device and the read() can fail.
 
 Note that you needn't to set volume size, that's optional, the
 library can internally ask for BLKGETSIZE64.

    Karel

-- 
 Karel Zak  <kzak at redhat.com>