Re: [PATCH 07/22] xfs: scrub AGF and AGFL

[Allison Henderson <allison.henderson@oracle.com>]

Looks good.  Similar the other scrub routines.
Reviewed by: Allison Henderson <allison.henderson@oracle.com>

On 7/20/2017 9:39 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Check the block references in the AGF and AGFL headers to make sure
> they make sense.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_fs.h  |    4 +
>  fs/xfs/scrub/agheader.c |  227 +++++++++++++++++++++++++++++++++++++++++++++++
>  fs/xfs/scrub/common.c   |   68 ++++++++++++++
>  fs/xfs/scrub/common.h   |    8 ++
>  fs/xfs/xfs_trace.h      |    4 +
>  5 files changed, 309 insertions(+), 2 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
> index 2f12fb1..cc35b7d 100644
> --- a/fs/xfs/libxfs/xfs_fs.h
> +++ b/fs/xfs/libxfs/xfs_fs.h
> @@ -484,7 +484,9 @@ struct xfs_scrub_metadata {
>  #define XFS_SCRUB_TYPE_TEST	0	/* dummy to test ioctl */
>  #define XFS_SCRUB_TYPE_METABUFS	1	/* in-core metadata buffers */
>  #define XFS_SCRUB_TYPE_SB	2	/* superblock */
> -#define XFS_SCRUB_TYPE_MAX	2
> +#define XFS_SCRUB_TYPE_AGF	3	/* AG free header */
> +#define XFS_SCRUB_TYPE_AGFL	4	/* AG free list */
> +#define XFS_SCRUB_TYPE_MAX	4
>
>  /* i: repair this metadata */
>  #define XFS_SCRUB_FLAG_REPAIR		(1 << 0)
> diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
> index 3bca60d..48e276c 100644
> --- a/fs/xfs/scrub/agheader.c
> +++ b/fs/xfs/scrub/agheader.c
> @@ -47,6 +47,72 @@ xfs_scrub_setup_ag_header(
>  	return xfs_scrub_setup_fs(sc, ip);
>  }
>
> +/* Find the size of the AG, in blocks. */
> +static inline xfs_agblock_t
> +xfs_scrub_ag_blocks(
> +	struct xfs_mount	*mp,
> +	xfs_agnumber_t		agno)
> +{
> +	ASSERT(agno < mp->m_sb.sb_agcount);
> +
> +	if (agno < mp->m_sb.sb_agcount - 1)
> +		return mp->m_sb.sb_agblocks;
> +	return mp->m_sb.sb_dblocks - (agno * mp->m_sb.sb_agblocks);
> +}
> +
> +/* Walk all the blocks in the AGFL. */
> +int
> +xfs_scrub_walk_agfl(
> +	struct xfs_scrub_context	*sc,
> +	int				(*fn)(struct xfs_scrub_context *,
> +					      xfs_agblock_t bno, void *),
> +	void				*priv)
> +{
> +	struct xfs_agf			*agf;
> +	__be32				*agfl_bno;
> +	struct xfs_mount		*mp = sc->mp;
> +	unsigned int			flfirst;
> +	unsigned int			fllast;
> +	int				i;
> +	int				error;
> +
> +	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
> +	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, sc->sa.agfl_bp);
> +	flfirst = be32_to_cpu(agf->agf_flfirst);
> +	fllast = be32_to_cpu(agf->agf_fllast);
> +
> +	/* Skip an empty AGFL. */
> +	if (agf->agf_flcount == cpu_to_be32(0))
> +		return 0;
> +
> +	/* first to last is a consecutive list. */
> +	if (fllast >= flfirst) {
> +		for (i = flfirst; i <= fllast; i++) {
> +			error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
> +			if (error)
> +				return error;
> +		}
> +
> +		return 0;
> +	}
> +
> +	/* first to the end */
> +	for (i = flfirst; i < XFS_AGFL_SIZE(mp); i++) {
> +		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
> +		if (error)
> +			return error;
> +	}
> +
> +	/* the start to last. */
> +	for (i = 0; i <= fllast; i++) {
> +		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
> +		if (error)
> +			return error;
> +	}
> +
> +	return 0;
> +}
> +
>  /* Superblock */
>
>  #define XFS_SCRUB_SB_CHECK(fs_ok) \
> @@ -195,3 +261,164 @@ xfs_scrub_superblock(
>  }
>  #undef XFS_SCRUB_SB_OP_ERROR_GOTO
>  #undef XFS_SCRUB_SB_CHECK
> +
> +/* AGF */
> +
> +#define XFS_SCRUB_AGF_CHECK(fs_ok) \
> +	XFS_SCRUB_CHECK(sc, sc->sa.agf_bp, "AGF", fs_ok)
> +#define XFS_SCRUB_AGF_OP_ERROR_GOTO(error, label) \
> +	XFS_SCRUB_OP_ERROR_GOTO(sc, sc->sm->sm_agno, \
> +			XFS_AGF_BLOCK(sc->mp), "AGF", error, label)
> +/* Scrub the AGF. */
> +int
> +xfs_scrub_agf(
> +	struct xfs_scrub_context	*sc)
> +{
> +	struct xfs_mount		*mp = sc->mp;
> +	struct xfs_agf			*agf;
> +	xfs_daddr_t			daddr;
> +	xfs_daddr_t			eofs;
> +	xfs_agnumber_t			agno;
> +	xfs_agblock_t			agbno;
> +	xfs_agblock_t			eoag;
> +	xfs_agblock_t			agfl_first;
> +	xfs_agblock_t			agfl_last;
> +	xfs_agblock_t			agfl_count;
> +	xfs_agblock_t			fl_count;
> +	int				level;
> +	int				error = 0;
> +
> +	agno = sc->sm->sm_agno;
> +	error = xfs_scrub_load_ag_headers(sc, agno, XFS_SCRUB_TYPE_AGF);
> +	XFS_SCRUB_AGF_OP_ERROR_GOTO(&error, out);
> +
> +	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
> +	eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
> +
> +	/* Check the AG length */
> +	eoag = be32_to_cpu(agf->agf_length);
> +	XFS_SCRUB_AGF_CHECK(eoag == xfs_scrub_ag_blocks(mp, agno));
> +
> +	/* Check the AGF btree roots and levels */
> +	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNO]);
> +	daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
> +	XFS_SCRUB_AGF_CHECK(agbno > XFS_AGI_BLOCK(mp));
> +	XFS_SCRUB_AGF_CHECK(agbno < mp->m_sb.sb_agblocks);
> +	XFS_SCRUB_AGF_CHECK(agbno < eoag);
> +	XFS_SCRUB_AGF_CHECK(daddr < eofs);
> +
> +	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNT]);
> +	daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
> +	XFS_SCRUB_AGF_CHECK(agbno > XFS_AGI_BLOCK(mp));
> +	XFS_SCRUB_AGF_CHECK(agbno < mp->m_sb.sb_agblocks);
> +	XFS_SCRUB_AGF_CHECK(agbno < eoag);
> +	XFS_SCRUB_AGF_CHECK(daddr < eofs);
> +
> +	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
> +	XFS_SCRUB_AGF_CHECK(level > 0);
> +	XFS_SCRUB_AGF_CHECK(level <= XFS_BTREE_MAXLEVELS);
> +
> +	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
> +	XFS_SCRUB_AGF_CHECK(level > 0);
> +	XFS_SCRUB_AGF_CHECK(level <= XFS_BTREE_MAXLEVELS);
> +
> +	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
> +		agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_RMAP]);
> +		daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
> +		XFS_SCRUB_AGF_CHECK(agbno > XFS_AGI_BLOCK(mp));
> +		XFS_SCRUB_AGF_CHECK(agbno < mp->m_sb.sb_agblocks);
> +		XFS_SCRUB_AGF_CHECK(agbno < eoag);
> +		XFS_SCRUB_AGF_CHECK(daddr < eofs);
> +
> +		level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
> +		XFS_SCRUB_AGF_CHECK(level > 0);
> +		XFS_SCRUB_AGF_CHECK(level <= XFS_BTREE_MAXLEVELS);
> +	}
> +
> +	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
> +		agbno = be32_to_cpu(agf->agf_refcount_root);
> +		daddr = XFS_AGB_TO_DADDR(mp, agno, agbno);
> +		XFS_SCRUB_AGF_CHECK(agbno > XFS_AGI_BLOCK(mp));
> +		XFS_SCRUB_AGF_CHECK(agbno < mp->m_sb.sb_agblocks);
> +		XFS_SCRUB_AGF_CHECK(agbno < eoag);
> +		XFS_SCRUB_AGF_CHECK(daddr < eofs);
> +
> +		level = be32_to_cpu(agf->agf_refcount_level);
> +		XFS_SCRUB_AGF_CHECK(level > 0);
> +		XFS_SCRUB_AGF_CHECK(level <= XFS_BTREE_MAXLEVELS);
> +	}
> +
> +	/* Check the AGFL counters */
> +	agfl_first = be32_to_cpu(agf->agf_flfirst);
> +	agfl_last = be32_to_cpu(agf->agf_fllast);
> +	agfl_count = be32_to_cpu(agf->agf_flcount);
> +	if (agfl_last > agfl_first)
> +		fl_count = agfl_last - agfl_first + 1;
> +	else
> +		fl_count = XFS_AGFL_SIZE(mp) - agfl_first + agfl_last + 1;
> +	XFS_SCRUB_AGF_CHECK(agfl_count == 0 || fl_count == agfl_count);
> +
> +out:
> +	return error;
> +}
> +#undef XFS_SCRUB_AGF_OP_ERROR_GOTO
> +#undef XFS_SCRUB_AGF_CHECK
> +
> +/* AGFL */
> +
> +#define XFS_SCRUB_AGFL_CHECK(fs_ok) \
> +	XFS_SCRUB_CHECK(sc, sc->sa.agfl_bp, "AGFL", fs_ok)
> +struct xfs_scrub_agfl {
> +	xfs_agblock_t			eoag;
> +	xfs_daddr_t			eofs;
> +};
> +
> +/* Scrub an AGFL block. */
> +STATIC int
> +xfs_scrub_agfl_block(
> +	struct xfs_scrub_context	*sc,
> +	xfs_agblock_t			agbno,
> +	void				*priv)
> +{
> +	struct xfs_mount		*mp = sc->mp;
> +	xfs_agnumber_t			agno = sc->sa.agno;
> +	struct xfs_scrub_agfl		*sagfl = priv;
> +
> +	XFS_SCRUB_AGFL_CHECK(agbno > XFS_AGI_BLOCK(mp));
> +	XFS_SCRUB_AGFL_CHECK(XFS_AGB_TO_DADDR(mp, agno, agbno) < sagfl->eofs);
> +	XFS_SCRUB_AGFL_CHECK(agbno < mp->m_sb.sb_agblocks);
> +	XFS_SCRUB_AGFL_CHECK(agbno < sagfl->eoag);
> +
> +	return 0;
> +}
> +
> +#define XFS_SCRUB_AGFL_OP_ERROR_GOTO(error, label) \
> +	XFS_SCRUB_OP_ERROR_GOTO(sc, sc->sm->sm_agno, \
> +			XFS_AGFL_BLOCK(sc->mp), "AGFL", error, label)
> +/* Scrub the AGFL. */
> +int
> +xfs_scrub_agfl(
> +	struct xfs_scrub_context	*sc)
> +{
> +	struct xfs_scrub_agfl		sagfl;
> +	struct xfs_mount		*mp = sc->mp;
> +	struct xfs_agf			*agf;
> +	int				error;
> +
> +	error = xfs_scrub_load_ag_headers(sc, sc->sm->sm_agno,
> +			XFS_SCRUB_TYPE_AGFL);
> +	XFS_SCRUB_AGFL_OP_ERROR_GOTO(&error, out);
> +	if (!sc->sa.agf_bp)
> +		return -EFSCORRUPTED;
> +
> +	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
> +	sagfl.eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
> +	sagfl.eoag = be32_to_cpu(agf->agf_length);
> +
> +	/* Check the blocks in the AGFL. */
> +	return xfs_scrub_walk_agfl(sc, xfs_scrub_agfl_block, &sagfl);
> +out:
> +	return error;
> +}
> +#undef XFS_SCRUB_AGFL_OP_ERROR_GOTO
> +#undef XFS_SCRUB_AGFL_CHECK
> diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
> index 9285107..d1ef722 100644
> --- a/fs/xfs/scrub/common.c
> +++ b/fs/xfs/scrub/common.c
> @@ -603,6 +603,66 @@ xfs_scrub_setup(
>  	return sc->fns->setup(sc, ip);
>  }
>
> +/*
> + * Load and verify an AG header for further AG header examination.
> + * If this header is not the target of the examination, don't return
> + * the buffer if a runtime or verifier error occurs.
> + */
> +STATIC int
> +xfs_scrub_load_ag_header(
> +	struct xfs_scrub_context	*sc,
> +	xfs_daddr_t			daddr,
> +	struct xfs_buf			**bpp,
> +	const struct xfs_buf_ops	*ops,
> +	bool				is_target)
> +{
> +	struct xfs_mount		*mp = sc->mp;
> +	int				error;
> +
> +	*bpp = NULL;
> +	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
> +			XFS_AG_DADDR(mp, sc->sa.agno, daddr),
> +			XFS_FSS_TO_BB(mp, 1), 0, bpp, ops);
> +	return is_target ? error : 0;
> +}
> +
> +/*
> + * Load as many of the AG headers and btree cursors as we can for an
> + * examination and cross-reference of an AG header.
> + */
> +int
> +xfs_scrub_load_ag_headers(
> +	struct xfs_scrub_context	*sc,
> +	xfs_agnumber_t			agno,
> +	unsigned int			type)
> +{
> +	struct xfs_mount		*mp = sc->mp;
> +	int				error;
> +
> +	ASSERT(type == XFS_SCRUB_TYPE_AGF || type == XFS_SCRUB_TYPE_AGFL);
> +	memset(&sc->sa, 0, sizeof(sc->sa));
> +	sc->sa.agno = agno;
> +
> +	error = xfs_scrub_load_ag_header(sc, XFS_AGI_DADDR(mp),
> +			&sc->sa.agi_bp, &xfs_agi_buf_ops, false);
> +	if (error)
> +		return error;
> +
> +	error = xfs_scrub_load_ag_header(sc, XFS_AGF_DADDR(mp),
> +			&sc->sa.agf_bp, &xfs_agf_buf_ops,
> +			type == XFS_SCRUB_TYPE_AGF);
> +	if (error)
> +		return error;
> +
> +	error = xfs_scrub_load_ag_header(sc, XFS_AGFL_DADDR(mp),
> +			&sc->sa.agfl_bp, &xfs_agfl_buf_ops,
> +			type == XFS_SCRUB_TYPE_AGFL);
> +	if (error)
> +		return error;
> +
> +	return 0;
> +}
> +
>  /* Scrubbing dispatch. */
>
>  static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
> @@ -618,6 +678,14 @@ static const struct xfs_scrub_meta_fns meta_scrub_fns[] = {
>  		.setup	= xfs_scrub_setup_ag_header,
>  		.scrub	= xfs_scrub_superblock,
>  	},
> +	{ /* agf */
> +		.setup	= xfs_scrub_setup_ag_header,
> +		.scrub	= xfs_scrub_agf,
> +	},
> +	{ /* agfl */
> +		.setup	= xfs_scrub_setup_ag_header,
> +		.scrub	= xfs_scrub_agfl,
> +	},
>  };
>
>  /* Dispatch metadata scrubbing. */
> diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
> index 094a708..5c4893d 100644
> --- a/fs/xfs/scrub/common.h
> +++ b/fs/xfs/scrub/common.h
> @@ -193,6 +193,12 @@ int xfs_scrub_ag_read_headers(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
>  			      struct xfs_buf **agfl);
>  int xfs_scrub_ag_btcur_init(struct xfs_scrub_context *sc,
>  			    struct xfs_scrub_ag *sa);
> +int xfs_scrub_load_ag_headers(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
> +			      unsigned int type);
> +int xfs_scrub_walk_agfl(struct xfs_scrub_context *sc,
> +			int (*fn)(struct xfs_scrub_context *, xfs_agblock_t bno,
> +				  void *),
> +			void *priv);
>
>  /* Setup functions */
>
> @@ -208,6 +214,8 @@ SETUP_FN(xfs_scrub_setup_ag_header);
>  SCRUB_FN(xfs_scrub_dummy);
>  SCRUB_FN(xfs_scrub_metabufs);
>  SCRUB_FN(xfs_scrub_superblock);
> +SCRUB_FN(xfs_scrub_agf);
> +SCRUB_FN(xfs_scrub_agfl);
>  #undef SCRUB_FN
>
>  #endif	/* __XFS_REPAIR_COMMON_H__ */
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index 483008a..ebf6045 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -3314,7 +3314,9 @@ DEFINE_GETFSMAP_EVENT(xfs_getfsmap_mapping);
>  #define XFS_SCRUB_TYPE_DESC \
>  	{ XFS_SCRUB_TYPE_TEST,		"dummy" }, \
>  	{ XFS_SCRUB_TYPE_METABUFS,	"metabufs" }, \
> -	{ XFS_SCRUB_TYPE_SB,		"superblock" }
> +	{ XFS_SCRUB_TYPE_SB,		"superblock" }, \
> +	{ XFS_SCRUB_TYPE_AGF,		"AGF" }, \
> +	{ XFS_SCRUB_TYPE_AGFL,		"AGFL" }
>  DECLARE_EVENT_CLASS(xfs_scrub_class,
>  	TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm,
>  		 int error),
>
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