Re: [PATCH 2/5] xfs_repair: allow upgrades to v5 filesystems

[Brian Foster <bfoster@redhat.com>]

On Fri, Feb 12, 2021 at 09:47:14PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Add some helper functions so that we can allow users to upgrade V5
> filesystems in a sane manner.  This just lands the boilerplate; the
> actual feature validation and whatnot will land in the next patches.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

>  repair/phase2.c |   40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> 
> diff --git a/repair/phase2.c b/repair/phase2.c
> index 952ac4a5..f654edcc 100644
> --- a/repair/phase2.c
> +++ b/repair/phase2.c
> @@ -131,6 +131,40 @@ zero_log(
>  		libxfs_max_lsn = log->l_last_sync_lsn;
>  }
>  
> +/* Perform the user's requested upgrades on filesystem. */
> +static void
> +upgrade_filesystem(
> +	struct xfs_mount	*mp)
> +{
> +	struct xfs_buf		*bp;
> +	bool			dirty = false;
> +	int			error;
> +
> +        if (no_modify || !dirty)
> +                return;
> +
> +        bp = libxfs_getsb(mp);
> +        if (!bp || bp->b_error) {
> +                do_error(
> +	_("couldn't get superblock for feature upgrade, err=%d\n"),
> +                                bp ? bp->b_error : ENOMEM);
> +        } else {
> +                libxfs_sb_to_disk(bp->b_addr, &mp->m_sb);
> +
> +                /*
> +		 * Write the primary super to disk immediately so that
> +		 * needsrepair will be set if repair doesn't complete.
> +		 */
> +                error = -libxfs_bwrite(bp);
> +                if (error)
> +                        do_error(
> +	_("filesystem feature upgrade failed, err=%d\n"),
> +                                        error);
> +        }
> +        if (bp)
> +                libxfs_buf_relse(bp);
> +}
> +
>  /*
>   * ok, at this point, the fs is mounted but the root inode may be
>   * trashed and the ag headers haven't been checked.  So we have
> @@ -235,4 +269,10 @@ phase2(
>  				do_warn(_("would correct\n"));
>  		}
>  	}
> +
> +	/*
> +	 * Upgrade the filesystem now that we've done a preliminary check of
> +	 * the superblocks, the AGs, the log, and the metadata inodes.
> +	 */
> +	upgrade_filesystem(mp);
>  }
>