Re: [PATCH] ufs: convert ufs to the new mount API

[Al Viro <viro@zeniv.linux.org.uk>]

On Thu, Jan 16, 2025 at 04:07:44PM -0600, Eric Sandeen wrote:
> On 1/16/25 1:08 PM, Al Viro wrote:
> > On Thu, Jan 16, 2025 at 12:49:32PM -0600, Eric Sandeen wrote:
> > 
> >> +	switch (opt) {
> >> +	case Opt_type:
> >> +		if (reconfigure &&
> >> +		    (ctx->mount_options & UFS_MOUNT_UFSTYPE) != result.uint_32) {
> >> +			pr_err("ufstype can't be changed during remount\n");
> >> +			return -EINVAL;
> >>  		}
> >> +		ufs_clear_opt(ctx->mount_options, UFS_MOUNT_UFSTYPE);
> >> +		ufs_set_opt(ctx->mount_options, result.uint_32);
> >> +		break;
> > 
> > Do we really want to support ufstype=foo,ufstype=bar?
> 
> well, we already do that today. Old code was:
> 
>                 switch (token) {
>                 case Opt_type_old:
>                         ufs_clear_opt (*mount_options, UFSTYPE);
>                         ufs_set_opt (*mount_options, UFSTYPE_OLD);
>                         break; 
>                 case Opt_type_sunx86:
>                         ufs_clear_opt (*mount_options, UFSTYPE);
>                         ufs_set_opt (*mount_options, UFSTYPE_SUNx86);
>                         break;
> ...
> 
> so I was going for a straight conversion for now so that the behavior
> was exactly the same (i.e. keep the last-specified type. I know, it's
> weird, who would do that? Still. Don't break userspace? And we've been
> burned before.)

FWIW, see viro/vfs.git #work.ufs - separating ufs flavour and on-error
flags, dealing with -o ufstype conflicts, then your patch ported on
top of that.