Re: [PATCH 08/11] xfs_repair: allow setting the needsrepair flag

[Eric Sandeen <sandeen@sandeen.net>]

On 2/11/21 4:59 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Quietly set up the ability to tell xfs_repair to set NEEDSREPAIR at
> program start and (presumably) clear it by the end of the run.  This
> code isn't terribly useful to users; it's mainly here so that fstests
> can exercise the functionality.  We don't document this flag in the
> manual pages at all because repair clears needsrepair at exit, which
> means the knobs only exist for fstests to exercise the functionality.
> 
> Note that we can't do any of these upgrades until we've at least done a
> preliminary scan of the primary super and the log.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Brian Foster <bfoster@redhat.com>


I'm still a little on the fence about the cmdline option for crashing repair at a certain point from the POV that Brian kind of pointed out that this doesn't exactly scale as we need more hooks.

but

ehhhh it's a test-only undocumented option and I guess we could change it later if desired

we do have other debug options on the commandline already as well....


> ---
>  repair/globals.c    |    2 ++
>  repair/globals.h    |    2 ++
>  repair/phase2.c     |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  repair/xfs_repair.c |    9 +++++++
>  4 files changed, 76 insertions(+)
> 
> 
> diff --git a/repair/globals.c b/repair/globals.c
> index 110d98b6..699a96ee 100644
> --- a/repair/globals.c
> +++ b/repair/globals.c
> @@ -49,6 +49,8 @@ int	rt_spec;		/* Realtime dev specified as option */
>  int	convert_lazy_count;	/* Convert lazy-count mode on/off */
>  int	lazy_count;		/* What to set if to if converting */
>  
> +bool	add_needsrepair;	/* forcibly set needsrepair while repairing */
> +
>  /* misc status variables */
>  
>  int	primary_sb_modified;
> diff --git a/repair/globals.h b/repair/globals.h
> index 1d397b35..043b3e8e 100644
> --- a/repair/globals.h
> +++ b/repair/globals.h
> @@ -90,6 +90,8 @@ extern int	rt_spec;		/* Realtime dev specified as option */
>  extern int	convert_lazy_count;	/* Convert lazy-count mode on/off */
>  extern int	lazy_count;		/* What to set if to if converting */
>  
> +extern bool	add_needsrepair;
> +
>  /* misc status variables */
>  
>  extern int		primary_sb_modified;
> diff --git a/repair/phase2.c b/repair/phase2.c
> index 952ac4a5..9a8d42e1 100644
> --- a/repair/phase2.c
> +++ b/repair/phase2.c
> @@ -131,6 +131,63 @@ zero_log(
>  		libxfs_max_lsn = log->l_last_sync_lsn;
>  }
>  
> +static bool
> +set_needsrepair(
> +	struct xfs_mount	*mp)
> +{
> +	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
> +		printf(
> +	_("needsrepair flag only supported on V5 filesystems.\n"));
> +		exit(0);
> +	}
> +
> +	if (xfs_sb_version_needsrepair(&mp->m_sb)) {
> +		printf(_("Filesystem already marked as needing repair.\n"));
> +		exit(0);
> +	}
> +
> +	printf(_("Marking filesystem in need of repair.\n"));
> +	mp->m_sb.sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR;
> +	return true;
> +}
> +
> +/* 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 (add_needsrepair)
> +		dirty |= set_needsrepair(mp);
> +
> +        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 +292,10 @@ 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);
>  }
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index 90d1a95a..a613505f 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -65,11 +65,13 @@ static char *o_opts[] = {
>   */
>  enum c_opt_nums {
>  	CONVERT_LAZY_COUNT = 0,
> +	CONVERT_NEEDSREPAIR,
>  	C_MAX_OPTS,
>  };
>  
>  static char *c_opts[] = {
>  	[CONVERT_LAZY_COUNT]	= "lazycount",
> +	[CONVERT_NEEDSREPAIR]	= "needsrepair",
>  	[C_MAX_OPTS]		= NULL,
>  };
>  
> @@ -302,6 +304,13 @@ process_args(int argc, char **argv)
>  					lazy_count = (int)strtol(val, NULL, 0);
>  					convert_lazy_count = 1;
>  					break;
> +				case CONVERT_NEEDSREPAIR:
> +					if (!val)
> +						do_abort(
> +		_("-c needsrepair requires a parameter\n"));
> +					if (strtol(val, NULL, 0) == 1)
> +						add_needsrepair = true;
> +					break;
>  				default:
>  					unknown('c', val);
>  					break;
>