Bug#661580: mkfs.xfs fails to detect correct sector size

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

On 2/28/12 3:11 AM, Christoph Hellwig wrote:
> Carlos, didn't you plan to look into this issue?
> 
> Goswin, how do you determin that mkfs is still doing unaligned I/O
> when forcing the large sevtor size?  Once we set the sector size XFS
> can't do I/O smaller than it.

I did think this was supposed to be working already:

        get_topology(&xi, &ft);

        if (ft.sectoralign) {
                /*
                 * Older Linux software RAID versions want the sector size
                 * to match the block size to avoid switching I/O sizes.
                 * For the legacy libdisk case we thus set the sector size to
                 * match the block size.  For systems using libblkid we assume
                 * that the kernel is recent enough to not require this and
                 * ft.sectoralign will never be set.
                 */
                sectorsize = blocksize;
        } else if (!ssflag) {
                /*
                 * Unless specified manually on the command line use the
                 * advertised sector size of the device.
                 */
                sectorsize = ft.sectorsize ? ft.sectorsize : XFS_MIN_SECTORSIZE;
        }

but it may depend on whether or not it is being built with libblkid support or 
not...?

I'll try to test it when I have some time, unless Carlos beats me to it.

-Eric