Re: Re: [PATCH v2] btrfs: introduce sync_csum_mode to tweak sync checksum behavior

[David Sterba <dsterba@suse.cz>]

On Thu, Feb 01, 2024 at 01:28:49AM +0000, Naohiro Aota wrote:
> On Wed, Jan 31, 2024 at 08:04:59PM +0100, David Sterba wrote:
> > On Wed, Jan 31, 2024 at 04:13:45PM +0900, Naohiro Aota wrote:
> > > +#ifdef CONFIG_BTRFS_DEBUG
> > > +static ssize_t btrfs_sync_csum_show(struct kobject *kobj,
> > > +				    struct kobj_attribute *a, char *buf)
> > > +{
> > > +	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
> > > +
> > > +	switch (fs_devices->sync_csum_mode) {
> > > +	case BTRFS_SYNC_CSUM_AUTO:
> > > +		return sysfs_emit(buf, "auto\n");
> > > +	case BTRFS_SYNC_CSUM_FORCE_ON:
> > > +		return sysfs_emit(buf, "on\n");
> > > +	case BTRFS_SYNC_CSUM_FORCE_OFF:
> > > +		return sysfs_emit(buf, "off\n");
> > 
> > We're using numeric indicators for on/off in other sysfs files, though
> > here it's a bit more readable.
> 
> But, numeric indicators (0/1) cannot indicate tripe values well. Should I
> represent it as e.g, "auto" => 0, "on" => 1, "off" => -1?

We can do 0, 1, auto, the same values should work as the input. The
parsing will do a special case for auto.