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

Allison Henderson
2017-07-23T16:59:46Z

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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