On Tue, Aug 07, 2018 at 08:57:12PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Regenerate the AGF from the rmap data.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/scrub/agheader_repair.c | 370 ++++++++++++++++++++++++++++++++++++++++
> fs/xfs/scrub/repair.c | 27 ++-
> fs/xfs/scrub/repair.h | 2
> fs/xfs/scrub/scrub.c | 2
> 4 files changed, 391 insertions(+), 10 deletions(-)
>
>
> diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
> index 1e96621ece3a..4842fc598c9b 100644
> --- a/fs/xfs/scrub/agheader_repair.c
> +++ b/fs/xfs/scrub/agheader_repair.c
...
> @@ -54,3 +61,366 @@ xrep_superblock(
...
> +/* Commit the new AGF and reinitialize the incore state. */
> +STATIC int
> +xrep_agf_commit_new(
> + struct xfs_scrub *sc,
> + struct xfs_buf *agf_bp)
> +{
> + struct xfs_perag *pag;
> + struct xfs_agf *agf = XFS_BUF_TO_AGF(agf_bp);
> +
> + /* Trigger fdblocks recalculation */
> + xfs_force_summary_recalc(sc->mp);
> +
> + /* Write this to disk. */
> + xfs_trans_buf_set_type(sc->tp, agf_bp, XFS_BLFT_AGF_BUF);
> + xfs_trans_log_buf(sc->tp, agf_bp, 0, BBTOB(agf_bp->b_length) - 1);
> +
> + /* Now reinitialize the in-core counters we changed. */
> + pag = sc->sa.pag;
> + pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
> + pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
> + pag->pagf_longest = be32_to_cpu(agf->agf_longest);
> + pag->pagf_levels[XFS_BTNUM_BNOi] =
> + be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
> + pag->pagf_levels[XFS_BTNUM_CNTi] =
> + be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
> + pag->pagf_levels[XFS_BTNUM_RMAPi] =
> + be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
> + pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
> + pag->pagf_init = 1;
I still think the above could be factored into a helper since it looks
like a copy of the associated xfs_alloc_read_agf() code. That aside,
this looks fine now that the ->pagf_init thing is fixed:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> +
> + return 0;
> +}
> +
> +/* Repair the AGF. v5 filesystems only. */
> +int
> +xrep_agf(
> + struct xfs_scrub *sc)
> +{
> + struct xrep_find_ag_btree fab[XREP_AGF_MAX] = {
> + [XREP_AGF_BNOBT] = {
> + .rmap_owner = XFS_RMAP_OWN_AG,
> + .buf_ops = &xfs_allocbt_buf_ops,
> + .magic = XFS_ABTB_CRC_MAGIC,
> + },
> + [XREP_AGF_CNTBT] = {
> + .rmap_owner = XFS_RMAP_OWN_AG,
> + .buf_ops = &xfs_allocbt_buf_ops,
> + .magic = XFS_ABTC_CRC_MAGIC,
> + },
> + [XREP_AGF_RMAPBT] = {
> + .rmap_owner = XFS_RMAP_OWN_AG,
> + .buf_ops = &xfs_rmapbt_buf_ops,
> + .magic = XFS_RMAP_CRC_MAGIC,
> + },
> + [XREP_AGF_REFCOUNTBT] = {
> + .rmap_owner = XFS_RMAP_OWN_REFC,
> + .buf_ops = &xfs_refcountbt_buf_ops,
> + .magic = XFS_REFC_CRC_MAGIC,
> + },
> + [XREP_AGF_END] = {
> + .buf_ops = NULL,
> + },
> + };
> + struct xfs_agf old_agf;
> + struct xfs_mount *mp = sc->mp;
> + struct xfs_buf *agf_bp;
> + struct xfs_buf *agfl_bp;
> + struct xfs_agf *agf;
> + int error;
> +
> + /* We require the rmapbt to rebuild anything. */
> + if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
> + return -EOPNOTSUPP;
> +
> + xchk_perag_get(sc->mp, &sc->sa);
> + /*
> + * Make sure we have the AGF buffer, as scrub might have decided it
> + * was corrupt after xfs_alloc_read_agf failed with -EFSCORRUPTED.
> + */
> + error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
> + XFS_AG_DADDR(mp, sc->sa.agno, XFS_AGF_DADDR(mp)),
> + XFS_FSS_TO_BB(mp, 1), 0, &agf_bp, NULL);
> + if (error)
> + return error;
> + agf_bp->b_ops = &xfs_agf_buf_ops;
> + agf = XFS_BUF_TO_AGF(agf_bp);
> +
> + /*
> + * Load the AGFL so that we can screen out OWN_AG blocks that are on
> + * the AGFL now; these blocks might have once been part of the
> + * bno/cnt/rmap btrees but are not now. This is a chicken and egg
> + * problem: the AGF is corrupt, so we have to trust the AGFL contents
> + * because we can't do any serious cross-referencing with any of the
> + * btrees rooted in the AGF. If the AGFL contents are obviously bad
> + * then we'll bail out.
> + */
> + error = xfs_alloc_read_agfl(mp, sc->tp, sc->sa.agno, &agfl_bp);
> + if (error)
> + return error;
> +
> + /*
> + * Spot-check the AGFL blocks; if they're obviously corrupt then
> + * there's nothing we can do but bail out.
> + */
> + error = xfs_agfl_walk(sc->mp, XFS_BUF_TO_AGF(agf_bp), agfl_bp,
> + xrep_agf_check_agfl_block, sc);
> + if (error)
> + return error;
> +
> + /*
> + * Find the AGF btree roots. This is also a chicken-and-egg situation;
> + * see the function for more details.
> + */
> + error = xrep_agf_find_btrees(sc, agf_bp, fab, agfl_bp);
> + if (error)
> + return error;
> +
> + /* Start rewriting the header and implant the btrees we found. */
> + xrep_agf_init_header(sc, agf_bp, &old_agf);
> + xrep_agf_set_roots(sc, agf, fab);
> + error = xrep_agf_calc_from_btrees(sc, agf_bp);
> + if (error)
> + goto out_revert;
> +
> + /* Commit the changes and reinitialize incore state. */
> + return xrep_agf_commit_new(sc, agf_bp);
> +
> +out_revert:
> + /* Mark the incore AGF state stale and revert the AGF. */
> + sc->sa.pag->pagf_init = 0;
> + memcpy(agf, &old_agf, sizeof(old_agf));
> + return error;
> +}
> diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
> index 6c199e2ebb81..183d9e84c7e5 100644
> --- a/fs/xfs/scrub/repair.c
> +++ b/fs/xfs/scrub/repair.c
> @@ -128,9 +128,12 @@ xrep_roll_ag_trans(
> int error;
>
> /* Keep the AG header buffers locked so we can keep going. */
> - xfs_trans_bhold(sc->tp, sc->sa.agi_bp);
> - xfs_trans_bhold(sc->tp, sc->sa.agf_bp);
> - xfs_trans_bhold(sc->tp, sc->sa.agfl_bp);
> + if (sc->sa.agi_bp)
> + xfs_trans_bhold(sc->tp, sc->sa.agi_bp);
> + if (sc->sa.agf_bp)
> + xfs_trans_bhold(sc->tp, sc->sa.agf_bp);
> + if (sc->sa.agfl_bp)
> + xfs_trans_bhold(sc->tp, sc->sa.agfl_bp);
>
> /* Roll the transaction. */
> error = xfs_trans_roll(&sc->tp);
> @@ -138,9 +141,12 @@ xrep_roll_ag_trans(
> goto out_release;
>
> /* Join AG headers to the new transaction. */
> - xfs_trans_bjoin(sc->tp, sc->sa.agi_bp);
> - xfs_trans_bjoin(sc->tp, sc->sa.agf_bp);
> - xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp);
> + if (sc->sa.agi_bp)
> + xfs_trans_bjoin(sc->tp, sc->sa.agi_bp);
> + if (sc->sa.agf_bp)
> + xfs_trans_bjoin(sc->tp, sc->sa.agf_bp);
> + if (sc->sa.agfl_bp)
> + xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp);
>
> return 0;
>
> @@ -150,9 +156,12 @@ xrep_roll_ag_trans(
> * buffers will be released during teardown on our way out
> * of the kernel.
> */
> - xfs_trans_bhold_release(sc->tp, sc->sa.agi_bp);
> - xfs_trans_bhold_release(sc->tp, sc->sa.agf_bp);
> - xfs_trans_bhold_release(sc->tp, sc->sa.agfl_bp);
> + if (sc->sa.agi_bp)
> + xfs_trans_bhold_release(sc->tp, sc->sa.agi_bp);
> + if (sc->sa.agf_bp)
> + xfs_trans_bhold_release(sc->tp, sc->sa.agf_bp);
> + if (sc->sa.agfl_bp)
> + xfs_trans_bhold_release(sc->tp, sc->sa.agfl_bp);
>
> return error;
> }
> diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
> index 5a4e92221916..6f0903c51a47 100644
> --- a/fs/xfs/scrub/repair.h
> +++ b/fs/xfs/scrub/repair.h
> @@ -58,6 +58,7 @@ int xrep_ino_dqattach(struct xfs_scrub *sc);
>
> int xrep_probe(struct xfs_scrub *sc);
> int xrep_superblock(struct xfs_scrub *sc);
> +int xrep_agf(struct xfs_scrub *sc);
>
> #else
>
> @@ -81,6 +82,7 @@ xrep_calc_ag_resblks(
>
> #define xrep_probe xrep_notsupported
> #define xrep_superblock xrep_notsupported
> +#define xrep_agf xrep_notsupported
>
> #endif /* CONFIG_XFS_ONLINE_REPAIR */
>
> diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
> index 6efb926f3cf8..1e8a17c8e2b9 100644
> --- a/fs/xfs/scrub/scrub.c
> +++ b/fs/xfs/scrub/scrub.c
> @@ -214,7 +214,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
> .type = ST_PERAG,
> .setup = xchk_setup_fs,
> .scrub = xchk_agf,
> - .repair = xrep_notsupported,
> + .repair = xrep_agf,
> },
> [XFS_SCRUB_TYPE_AGFL]= { /* agfl */
> .type = ST_PERAG,
>
> --
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