Re: divergence of ffs flags

[David Brownlee <abs%netbsd.org@localhost>]

On 3 September 2013 03:04, David Holland <dholland-tech%netbsd.org@localhost> 
wrote:
> It seems that FreeBSD's and NetBSD's ffs superblock flags have been
> allowed to diverge:
[...]
> -#define FS_SUJ         0x008   /* Filesystem using softupdate journal */
> +#define FS_INDEXDIRS   0x008   /* kernel supports indexed directories */
[...]
> -#define FS_NFS4ACLS    0x100   /* file system has NFSv4 ACLs enabled */
> -#define FS_INDEXDIRS   0x200   /* kernel supports indexed directories */
> -#define FS_TRIM        0x400   /* issue BIO_DELETE for deleted blocks */
> +#define FS_DOWAPBL     0x100   /* Write ahead physical block logging */
> +#define FS_DOQUOTA2    0x200   /* in-filesystem quotas */

What are the options?

I assume we can version something in the superblock so new NetBSD &
FreeBSD code could resolve the overlaps but that doesn't help old
code...

Pick new conflicting flags for the overlaps, ask FreeBSD to reserve
them, add code to support both versions to all branches, and then in a
release or so migrate across to them?