Re: [PATCH V4 19/20] xfsprogs: Add support for upgrading to NREXT64 feature

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Dec 14, 2021 at 02:18:10PM +0530, Chandan Babu R wrote:
> This commit adds support to xfs_repair to allow upgrading an existing
> filesystem to support per-inode large extent counters.
> 
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
> ---
>  repair/globals.c    |  1 +
>  repair/globals.h    |  1 +
>  repair/phase2.c     | 35 ++++++++++++++++++++++++++++++++++-
>  repair/xfs_repair.c | 11 +++++++++++
>  4 files changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/repair/globals.c b/repair/globals.c
> index d89507b1..2f29391a 100644
> --- a/repair/globals.c
> +++ b/repair/globals.c
> @@ -53,6 +53,7 @@ bool	add_bigtime;		/* add support for timestamps up to 2486 */
>  bool	add_finobt;		/* add free inode btrees */
>  bool	add_reflink;		/* add reference count btrees */
>  bool	add_rmapbt;		/* add reverse mapping btrees */
> +bool	add_nrext64;
>  
>  /* misc status variables */
>  
> diff --git a/repair/globals.h b/repair/globals.h
> index 53ff2532..af0bcb6b 100644
> --- a/repair/globals.h
> +++ b/repair/globals.h
> @@ -94,6 +94,7 @@ extern bool	add_bigtime;		/* add support for timestamps up to 2486 */
>  extern bool	add_finobt;		/* add free inode btrees */
>  extern bool	add_reflink;		/* add reference count btrees */
>  extern bool	add_rmapbt;		/* add reverse mapping btrees */
> +extern bool	add_nrext64;
>  
>  /* misc status variables */
>  
> diff --git a/repair/phase2.c b/repair/phase2.c
> index c811ed5d..c9db3281 100644
> --- a/repair/phase2.c
> +++ b/repair/phase2.c
> @@ -191,6 +191,7 @@ check_new_v5_geometry(
>  	struct xfs_perag	*pag;
>  	xfs_agnumber_t		agno;
>  	xfs_ino_t		rootino;
> +	uint			old_bm_maxlevels[2];
>  	int			min_logblocks;
>  	int			error;
>  
> @@ -201,6 +202,12 @@ check_new_v5_geometry(
>  	memcpy(&old_sb, &mp->m_sb, sizeof(struct xfs_sb));
>  	memcpy(&mp->m_sb, new_sb, sizeof(struct xfs_sb));
>  
> +	old_bm_maxlevels[0] = mp->m_bm_maxlevels[0];
> +	old_bm_maxlevels[1] = mp->m_bm_maxlevels[1];
> +
> +	xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
> +	xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);

Ahh... I see why you added my (evil) patch that allows upgrading a
filesystem to reflink -- you need the check_new_v5_geometry function so
that you can check if the log size is big enough to handle larger bmbt
trees.

Hmm, I guess I should work on separating this from the actual
rmap/reflink/finobt upgrade code, since I have no idea if we /ever/ want
to support that.

--D

> +
>  	/* Do we have a big enough log? */
>  	min_logblocks = libxfs_log_calc_minimum_size(mp);
>  	if (old_sb.sb_logblocks < min_logblocks) {
> @@ -288,6 +295,9 @@ check_new_v5_geometry(
>  		pag->pagi_init = 0;
>  	}
>  
> +	mp->m_bm_maxlevels[0] = old_bm_maxlevels[0];
> +	mp->m_bm_maxlevels[1] = old_bm_maxlevels[1];
> +
>  	/*
>  	 * Put back the old superblock.
>  	 */
> @@ -366,6 +376,28 @@ set_rmapbt(
>  	return true;
>  }
>  
> +static bool
> +set_nrext64(
> +	struct xfs_mount	*mp,
> +	struct xfs_sb		*new_sb)
> +{
> +	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
> +		printf(
> +	_("Nrext64 only supported on V5 filesystems.\n"));
> +		exit(0);
> +	}
> +
> +	if (xfs_sb_version_hasnrext64(&mp->m_sb)) {
> +		printf(_("Filesystem already supports nrext64.\n"));
> +		exit(0);
> +	}
> +
> +	printf(_("Adding nrext64 to filesystem.\n"));
> +	new_sb->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NREXT64;
> +	new_sb->sb_features_incompat |= XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR;
> +	return true;
> +}
> +
>  /* Perform the user's requested upgrades on filesystem. */
>  static void
>  upgrade_filesystem(
> @@ -388,7 +420,8 @@ upgrade_filesystem(
>  		dirty |= set_reflink(mp, &new_sb);
>  	if (add_rmapbt)
>  		dirty |= set_rmapbt(mp, &new_sb);
> -
> +	if (add_nrext64)
> +		dirty |= set_nrext64(mp, &new_sb);
>  	if (!dirty)
>  		return;
>  
> diff --git a/repair/xfs_repair.c b/repair/xfs_repair.c
> index e250a5bf..96c9bb56 100644
> --- a/repair/xfs_repair.c
> +++ b/repair/xfs_repair.c
> @@ -70,6 +70,7 @@ enum c_opt_nums {
>  	CONVERT_FINOBT,
>  	CONVERT_REFLINK,
>  	CONVERT_RMAPBT,
> +	CONVERT_NREXT64,
>  	C_MAX_OPTS,
>  };
>  
> @@ -80,6 +81,7 @@ static char *c_opts[] = {
>  	[CONVERT_FINOBT]	= "finobt",
>  	[CONVERT_REFLINK]	= "reflink",
>  	[CONVERT_RMAPBT]	= "rmapbt",
> +	[CONVERT_NREXT64]	= "nrext64",
>  	[C_MAX_OPTS]		= NULL,
>  };
>  
> @@ -357,6 +359,15 @@ process_args(int argc, char **argv)
>  		_("-c rmapbt only supports upgrades\n"));
>  					add_rmapbt = true;
>  					break;
> +				case CONVERT_NREXT64:
> +					if (!val)
> +						do_abort(
> +		_("-c nrext64 requires a parameter\n"));
> +					if (strtol(val, NULL, 0) != 1)
> +						do_abort(
> +		_("-c nrext64 only supports upgrades\n"));
> +					add_nrext64 = true;
> +					break;
>  				default:
>  					unknown('c', val);
>  					break;
> -- 
> 2.30.2
>