From f9ed6debca45dd9bcc02d77c98822d50aba342f4 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 9 Aug 2018 22:42:53 -0700 Subject: [PATCH] xfs: repair the AGF Regenerate the AGF from the rmap data. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster --- fs/xfs/scrub/agheader_repair.c | 379 +++++++++++++++++++++++++++++++++ fs/xfs/scrub/repair.c | 27 ++- fs/xfs/scrub/repair.h | 2 + fs/xfs/scrub/scrub.c | 2 +- 4 files changed, 400 insertions(+), 10 deletions(-) diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c index 1e96621ece3a..aa180492a4a5 100644 --- a/fs/xfs/scrub/agheader_repair.c +++ b/fs/xfs/scrub/agheader_repair.c @@ -17,12 +17,19 @@ #include "xfs_sb.h" #include "xfs_inode.h" #include "xfs_alloc.h" +#include "xfs_alloc_btree.h" #include "xfs_ialloc.h" +#include "xfs_ialloc_btree.h" #include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "xfs_refcount.h" +#include "xfs_refcount_btree.h" #include "scrub/xfs_scrub.h" #include "scrub/scrub.h" #include "scrub/common.h" #include "scrub/trace.h" +#include "scrub/repair.h" +#include "scrub/bitmap.h" /* Superblock */ @@ -54,3 +61,375 @@ xrep_superblock( xfs_trans_log_buf(sc->tp, bp, 0, BBTOB(bp->b_length) - 1); return error; } + +/* AGF */ + +struct xrep_agf_allocbt { + struct xfs_scrub *sc; + xfs_agblock_t freeblks; + xfs_agblock_t longest; +}; + +/* Record free space shape information. */ +STATIC int +xrep_agf_walk_allocbt( + struct xfs_btree_cur *cur, + struct xfs_alloc_rec_incore *rec, + void *priv) +{ + struct xrep_agf_allocbt *raa = priv; + int error = 0; + + if (xchk_should_terminate(raa->sc, &error)) + return error; + + raa->freeblks += rec->ar_blockcount; + if (rec->ar_blockcount > raa->longest) + raa->longest = rec->ar_blockcount; + return error; +} + +/* Does this AGFL block look sane? */ +STATIC int +xrep_agf_check_agfl_block( + struct xfs_mount *mp, + xfs_agblock_t agbno, + void *priv) +{ + struct xfs_scrub *sc = priv; + + if (!xfs_verify_agbno(mp, sc->sa.agno, agbno)) + return -EFSCORRUPTED; + return 0; +} + +/* + * Offset within the xrep_find_ag_btree array for each btree type. Avoid the + * XFS_BTNUM_ names here to avoid creating a sparse array. + */ +enum { + XREP_AGF_BNOBT = 0, + XREP_AGF_CNTBT, + XREP_AGF_RMAPBT, + XREP_AGF_REFCOUNTBT, + XREP_AGF_END, + XREP_AGF_MAX +}; + +/* Check a btree root candidate. */ +static inline bool +xrep_check_btree_root( + struct xfs_scrub *sc, + struct xrep_find_ag_btree *fab) +{ + struct xfs_mount *mp = sc->mp; + xfs_agnumber_t agno = sc->sm->sm_agno; + + return xfs_verify_agbno(mp, agno, fab->root) && + fab->height <= XFS_BTREE_MAXLEVELS; +} + +/* + * Given the btree roots described by *fab, find the roots, check them for + * sanity, and pass the root data back out via *fab. + * + * This is /also/ a chicken and egg problem because we have to use the rmapbt + * (rooted in the AGF) to find the btrees rooted in the AGF. We also have no + * idea if the btrees make any sense. If we hit obvious corruptions in those + * btrees we'll bail out. + */ +STATIC int +xrep_agf_find_btrees( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp, + struct xrep_find_ag_btree *fab, + struct xfs_buf *agfl_bp) +{ + struct xfs_agf *old_agf = XFS_BUF_TO_AGF(agf_bp); + int error; + + /* Go find the root data. */ + error = xrep_find_ag_btree_roots(sc, agf_bp, fab, agfl_bp); + if (error) + return error; + + /* We must find the bnobt, cntbt, and rmapbt roots. */ + if (!xrep_check_btree_root(sc, &fab[XREP_AGF_BNOBT]) || + !xrep_check_btree_root(sc, &fab[XREP_AGF_CNTBT]) || + !xrep_check_btree_root(sc, &fab[XREP_AGF_RMAPBT])) + return -EFSCORRUPTED; + + /* + * We relied on the rmapbt to reconstruct the AGF. If we get a + * different root then something's seriously wrong. + */ + if (fab[XREP_AGF_RMAPBT].root != + be32_to_cpu(old_agf->agf_roots[XFS_BTNUM_RMAPi])) + return -EFSCORRUPTED; + + /* We must find the refcountbt root if that feature is enabled. */ + if (xfs_sb_version_hasreflink(&sc->mp->m_sb) && + !xrep_check_btree_root(sc, &fab[XREP_AGF_REFCOUNTBT])) + return -EFSCORRUPTED; + + return 0; +} + +/* + * Reinitialize the AGF header, making an in-core copy of the old contents so + * that we know which in-core state needs to be reinitialized. + */ +STATIC void +xrep_agf_init_header( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp, + struct xfs_agf *old_agf) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_agf *agf = XFS_BUF_TO_AGF(agf_bp); + + memcpy(old_agf, agf, sizeof(*old_agf)); + memset(agf, 0, BBTOB(agf_bp->b_length)); + agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC); + agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION); + agf->agf_seqno = cpu_to_be32(sc->sa.agno); + agf->agf_length = cpu_to_be32(xfs_ag_block_count(mp, sc->sa.agno)); + agf->agf_flfirst = old_agf->agf_flfirst; + agf->agf_fllast = old_agf->agf_fllast; + agf->agf_flcount = old_agf->agf_flcount; + if (xfs_sb_version_hascrc(&mp->m_sb)) + uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid); + + /* Mark the incore AGF data stale until we're done fixing things. */ + ASSERT(sc->sa.pag->pagf_init); + sc->sa.pag->pagf_init = 0; +} + +/* Set btree root information in an AGF. */ +STATIC void +xrep_agf_set_roots( + struct xfs_scrub *sc, + struct xfs_agf *agf, + struct xrep_find_ag_btree *fab) +{ + agf->agf_roots[XFS_BTNUM_BNOi] = + cpu_to_be32(fab[XREP_AGF_BNOBT].root); + agf->agf_levels[XFS_BTNUM_BNOi] = + cpu_to_be32(fab[XREP_AGF_BNOBT].height); + + agf->agf_roots[XFS_BTNUM_CNTi] = + cpu_to_be32(fab[XREP_AGF_CNTBT].root); + agf->agf_levels[XFS_BTNUM_CNTi] = + cpu_to_be32(fab[XREP_AGF_CNTBT].height); + + agf->agf_roots[XFS_BTNUM_RMAPi] = + cpu_to_be32(fab[XREP_AGF_RMAPBT].root); + agf->agf_levels[XFS_BTNUM_RMAPi] = + cpu_to_be32(fab[XREP_AGF_RMAPBT].height); + + if (xfs_sb_version_hasreflink(&sc->mp->m_sb)) { + agf->agf_refcount_root = + cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].root); + agf->agf_refcount_level = + cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].height); + } +} + +/* Update all AGF fields which derive from btree contents. */ +STATIC int +xrep_agf_calc_from_btrees( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp) +{ + struct xrep_agf_allocbt raa = { .sc = sc }; + struct xfs_btree_cur *cur = NULL; + struct xfs_agf *agf = XFS_BUF_TO_AGF(agf_bp); + struct xfs_mount *mp = sc->mp; + xfs_agblock_t btreeblks; + xfs_agblock_t blocks; + int error; + + /* Update the AGF counters from the bnobt. */ + cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno, + XFS_BTNUM_BNO); + error = xfs_alloc_query_all(cur, xrep_agf_walk_allocbt, &raa); + if (error) + goto err; + error = xfs_btree_count_blocks(cur, &blocks); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + btreeblks = blocks - 1; + agf->agf_freeblks = cpu_to_be32(raa.freeblks); + agf->agf_longest = cpu_to_be32(raa.longest); + + /* Update the AGF counters from the cntbt. */ + cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno, + XFS_BTNUM_CNT); + error = xfs_btree_count_blocks(cur, &blocks); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + btreeblks += blocks - 1; + + /* Update the AGF counters from the rmapbt. */ + cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno); + error = xfs_btree_count_blocks(cur, &blocks); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + agf->agf_rmap_blocks = cpu_to_be32(blocks); + btreeblks += blocks - 1; + + agf->agf_btreeblks = cpu_to_be32(btreeblks); + + /* Update the AGF counters from the refcountbt. */ + if (xfs_sb_version_hasreflink(&mp->m_sb)) { + cur = xfs_refcountbt_init_cursor(mp, sc->tp, agf_bp, + sc->sa.agno); + error = xfs_btree_count_blocks(cur, &blocks); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + agf->agf_refcount_blocks = cpu_to_be32(blocks); + } + + return 0; +err: + xfs_btree_del_cursor(cur, error); + return error; +} + +/* 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; + + 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 85b048b341a0..17cf48564390 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 @@ out_release: * 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, -- 2.30.2