Re: [PATCH v2 5/5] btrfs: introduce rescue=all

[David Sterba <dsterba@suse.cz>]

On Mon, Sep 28, 2020 at 02:34:57PM -0400, Josef Bacik wrote:
> Now that we have the building blocks for some better recovery options
> with corrupted file systems, add a rescue=all option to enable all of
> the relevant rescue options.  This will allow distro's to simply default
> to rescue=all for the "oh dear lord the world's on fire" recovery
> without needing to know all the different options that we have and may
> add in the future.
> 
> Reviewed-by: Qu Wenruo <wqu@suse.com>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  fs/btrfs/super.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 2282f0240c1d..3412763a9a0d 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -362,6 +362,7 @@ enum {
>  	Opt_nologreplay,
>  	Opt_ignorebadroots,
>  	Opt_ignoredatacsums,
> +	Opt_all,
>  
>  	/* Deprecated options */
>  	Opt_recovery,
> @@ -459,6 +460,7 @@ static const match_table_t rescue_tokens = {
>  	{Opt_nologreplay, "nologreplay"},
>  	{Opt_ignorebadroots, "ignorebadroots"},
>  	{Opt_ignoredatacsums, "ignoredatacsums"},
> +	{Opt_all, "all"},
>  	{Opt_err, NULL},
>  };
>  
> @@ -510,6 +512,12 @@ static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
>  			btrfs_set_and_info(info, IGNOREDATACSUMS,
>  					   "ignoring data csums");
>  			break;
> +		case Opt_all:
> +			btrfs_set_opt(info->mount_opt, IGNOREDATACSUMS);
> +			btrfs_set_opt(info->mount_opt, IGNOREBADROOTS);
> +			btrfs_set_opt(info->mount_opt, NOLOGREPLAY);
> +			btrfs_info(info, "enabling all of the rescue options");

As we're going to add more options in the future, this shoud be more
specific which ones are being enabled under 'all'.

	btrfs_info(info, "enabling all default rescue options:");
	btrfs_set_opt_and_info(info->mount_opt, IGNOREDATACSUMS, "descripton...");
	btrfs_set_opt(info->mount_opt, IGNOREBADROOTS);
	btrfs_set_opt(info->mount_opt, NOLOGREPLAY);

Also in sysfs/features we should export all supported rescue options and
which are enabled by all. That's just for user convenience so we don't
have to publish version + supported options separately.

> +			break;
>  		case Opt_err:
>  			btrfs_info(info, "unrecognized rescue option '%s'", p);
>  			ret = -EINVAL;
> -- 
> 2.26.2