From 0e93d3f43ec7d3308bff25ce1be81d46330168c9 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 9 Aug 2018 22:43:02 -0700 Subject: [PATCH] xfs: repair the AGFL Repair the AGFL from the rmap data. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster --- fs/xfs/scrub/agheader_repair.c | 281 +++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/bitmap.c | 92 ++++++++++++++ fs/xfs/scrub/bitmap.h | 4 + fs/xfs/scrub/repair.h | 2 + fs/xfs/scrub/scrub.c | 2 +- 5 files changed, 380 insertions(+), 1 deletion(-) diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c index aa18049..9ce3023 100644 --- a/fs/xfs/scrub/agheader_repair.c +++ b/fs/xfs/scrub/agheader_repair.c @@ -433,3 +433,284 @@ out_revert: memcpy(agf, &old_agf, sizeof(old_agf)); return error; } + +/* AGFL */ + +struct xrep_agfl { + /* Bitmap of other OWN_AG metadata blocks. */ + struct xfs_bitmap agmetablocks; + + /* Bitmap of free space. */ + struct xfs_bitmap *freesp; + + struct xfs_scrub *sc; +}; + +/* Record all OWN_AG (free space btree) information from the rmap data. */ +STATIC int +xrep_agfl_walk_rmap( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xrep_agfl *ra = priv; + xfs_fsblock_t fsb; + int error = 0; + + if (xchk_should_terminate(ra->sc, &error)) + return error; + + /* Record all the OWN_AG blocks. */ + if (rec->rm_owner == XFS_RMAP_OWN_AG) { + fsb = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno, + rec->rm_startblock); + error = xfs_bitmap_set(ra->freesp, fsb, rec->rm_blockcount); + if (error) + return error; + } + + return xfs_bitmap_set_btcur_path(&ra->agmetablocks, cur); +} + +/* + * Map out all the non-AGFL OWN_AG space in this AG so that we can deduce + * which blocks belong to the AGFL. + * + * Compute the set of old AGFL blocks by subtracting from the list of OWN_AG + * blocks the list of blocks owned by all other OWN_AG metadata (bnobt, cntbt, + * rmapbt). These are the old AGFL blocks, so return that list and the number + * of blocks we're actually going to put back on the AGFL. + */ +STATIC int +xrep_agfl_collect_blocks( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp, + struct xfs_bitmap *agfl_extents, + xfs_agblock_t *flcount) +{ + struct xrep_agfl ra; + struct xfs_mount *mp = sc->mp; + struct xfs_btree_cur *cur; + struct xfs_bitmap_range *br; + struct xfs_bitmap_range *n; + int error; + + ra.sc = sc; + ra.freesp = agfl_extents; + xfs_bitmap_init(&ra.agmetablocks); + + /* Find all space used by the free space btrees & rmapbt. */ + cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno); + error = xfs_rmap_query_all(cur, xrep_agfl_walk_rmap, &ra); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + + /* Find all blocks currently being used by the bnobt. */ + cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno, + XFS_BTNUM_BNO); + error = xfs_bitmap_set_btblocks(&ra.agmetablocks, cur); + if (error) + goto err; + xfs_btree_del_cursor(cur, error); + + /* Find all blocks currently being used by the cntbt. */ + cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno, + XFS_BTNUM_CNT); + error = xfs_bitmap_set_btblocks(&ra.agmetablocks, cur); + if (error) + goto err; + + xfs_btree_del_cursor(cur, error); + + /* + * Drop the freesp meta blocks that are in use by btrees. + * The remaining blocks /should/ be AGFL blocks. + */ + error = xfs_bitmap_disunion(agfl_extents, &ra.agmetablocks); + xfs_bitmap_destroy(&ra.agmetablocks); + if (error) + return error; + + /* + * Calculate the new AGFL size. If we found more blocks than fit in + * the AGFL we'll free them later. + */ + *flcount = 0; + for_each_xfs_bitmap_extent(br, n, agfl_extents) { + *flcount += br->len; + if (*flcount > xfs_agfl_size(mp)) + break; + } + if (*flcount > xfs_agfl_size(mp)) + *flcount = xfs_agfl_size(mp); + return 0; + +err: + xfs_bitmap_destroy(&ra.agmetablocks); + xfs_btree_del_cursor(cur, error); + return error; +} + +/* Update the AGF and reset the in-core state. */ +STATIC void +xrep_agfl_update_agf( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp, + xfs_agblock_t flcount) +{ + struct xfs_agf *agf = XFS_BUF_TO_AGF(agf_bp); + + ASSERT(flcount <= xfs_agfl_size(sc->mp)); + + /* Trigger fdblocks recalculation */ + xfs_force_summary_recalc(sc->mp); + + /* Update the AGF counters. */ + if (sc->sa.pag->pagf_init) + sc->sa.pag->pagf_flcount = flcount; + agf->agf_flfirst = cpu_to_be32(0); + agf->agf_flcount = cpu_to_be32(flcount); + agf->agf_fllast = cpu_to_be32(flcount - 1); + + xfs_alloc_log_agf(sc->tp, agf_bp, + XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT); +} + +/* Write out a totally new AGFL. */ +STATIC void +xrep_agfl_init_header( + struct xfs_scrub *sc, + struct xfs_buf *agfl_bp, + struct xfs_bitmap *agfl_extents, + xfs_agblock_t flcount) +{ + struct xfs_mount *mp = sc->mp; + __be32 *agfl_bno; + struct xfs_bitmap_range *br; + struct xfs_bitmap_range *n; + struct xfs_agfl *agfl; + xfs_agblock_t agbno; + unsigned int fl_off; + + ASSERT(flcount <= xfs_agfl_size(mp)); + + /* + * Start rewriting the header by setting the bno[] array to + * NULLAGBLOCK, then setting AGFL header fields. + */ + agfl = XFS_BUF_TO_AGFL(agfl_bp); + memset(agfl, 0xFF, BBTOB(agfl_bp->b_length)); + agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC); + agfl->agfl_seqno = cpu_to_be32(sc->sa.agno); + uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid); + + /* + * Fill the AGFL with the remaining blocks. If agfl_extents has more + * blocks than fit in the AGFL, they will be freed in a subsequent + * step. + */ + fl_off = 0; + agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agfl_bp); + for_each_xfs_bitmap_extent(br, n, agfl_extents) { + agbno = XFS_FSB_TO_AGBNO(mp, br->start); + + trace_xrep_agfl_insert(mp, sc->sa.agno, agbno, br->len); + + while (br->len > 0 && fl_off < flcount) { + agfl_bno[fl_off] = cpu_to_be32(agbno); + fl_off++; + agbno++; + + /* + * We've now used br->start by putting it in the AGFL, + * so bump br so that we don't reap the block later. + */ + br->start++; + br->len--; + } + + if (br->len) + break; + list_del(&br->list); + kmem_free(br); + } + + /* Write new AGFL to disk. */ + xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF); + xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1); +} + +/* Repair the AGFL. */ +int +xrep_agfl( + struct xfs_scrub *sc) +{ + struct xfs_owner_info oinfo; + struct xfs_bitmap agfl_extents; + struct xfs_mount *mp = sc->mp; + struct xfs_buf *agf_bp; + struct xfs_buf *agfl_bp; + xfs_agblock_t flcount; + 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); + xfs_bitmap_init(&agfl_extents); + + /* + * Read the AGF so that we can query the rmapbt. We hope that there's + * nothing wrong with the AGF, but all the AG header repair functions + * have this chicken-and-egg problem. + */ + error = xfs_alloc_read_agf(mp, sc->tp, sc->sa.agno, 0, &agf_bp); + if (error) + return error; + if (!agf_bp) + return -ENOMEM; + + /* + * Make sure we have the AGFL buffer, as scrub might have decided it + * was corrupt after xfs_alloc_read_agfl failed with -EFSCORRUPTED. + */ + error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp, + XFS_AG_DADDR(mp, sc->sa.agno, XFS_AGFL_DADDR(mp)), + XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL); + if (error) + return error; + agfl_bp->b_ops = &xfs_agfl_buf_ops; + + /* Gather all the extents we're going to put on the new AGFL. */ + error = xrep_agfl_collect_blocks(sc, agf_bp, &agfl_extents, &flcount); + if (error) + goto err; + + /* + * Update AGF and AGFL. We reset the global free block counter when + * we adjust the AGF flcount (which can fail) so avoid updating any + * buffers until we know that part works. + */ + xrep_agfl_update_agf(sc, agf_bp, flcount); + xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount); + + /* + * Ok, the AGFL should be ready to go now. Roll the transaction to + * make the new AGFL permanent before we start using it to return + * freespace overflow to the freespace btrees. + */ + sc->sa.agf_bp = agf_bp; + sc->sa.agfl_bp = agfl_bp; + error = xrep_roll_ag_trans(sc); + if (error) + goto err; + + /* Dump any AGFL overflow. */ + xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG); + return xrep_reap_extents(sc, &agfl_extents, &oinfo, XFS_AG_RESV_AGFL); +err: + xfs_bitmap_destroy(&agfl_extents); + return error; +} diff --git a/fs/xfs/scrub/bitmap.c b/fs/xfs/scrub/bitmap.c index c770e2d..fdadc9e1 100644 --- a/fs/xfs/scrub/bitmap.c +++ b/fs/xfs/scrub/bitmap.c @@ -9,6 +9,7 @@ #include "xfs_format.h" #include "xfs_trans_resv.h" #include "xfs_mount.h" +#include "xfs_btree.h" #include "scrub/xfs_scrub.h" #include "scrub/scrub.h" #include "scrub/common.h" @@ -209,3 +210,94 @@ out: } #undef LEFT_ALIGNED #undef RIGHT_ALIGNED + +/* + * Record all btree blocks seen while iterating all records of a btree. + * + * We know that the btree query_all function starts at the left edge and walks + * towards the right edge of the tree. Therefore, we know that we can walk up + * the btree cursor towards the root; if the pointer for a given level points + * to the first record/key in that block, we haven't seen this block before; + * and therefore we need to remember that we saw this block in the btree. + * + * So if our btree is: + * + * 4 + * / | \ + * 1 2 3 + * + * Pretend for this example that each leaf block has 100 btree records. For + * the first btree record, we'll observe that bc_ptrs[0] == 1, so we record + * that we saw block 1. Then we observe that bc_ptrs[1] == 1, so we record + * block 4. The list is [1, 4]. + * + * For the second btree record, we see that bc_ptrs[0] == 2, so we exit the + * loop. The list remains [1, 4]. + * + * For the 101st btree record, we've moved onto leaf block 2. Now + * bc_ptrs[0] == 1 again, so we record that we saw block 2. We see that + * bc_ptrs[1] == 2, so we exit the loop. The list is now [1, 4, 2]. + * + * For the 102nd record, bc_ptrs[0] == 2, so we continue. + * + * For the 201st record, we've moved on to leaf block 3. bc_ptrs[0] == 1, so + * we add 3 to the list. Now it is [1, 4, 2, 3]. + * + * For the 300th record we just exit, with the list being [1, 4, 2, 3]. + */ + +/* + * Record all the buffers pointed to by the btree cursor. Callers already + * engaged in a btree walk should call this function to capture the list of + * blocks going from the leaf towards the root. + */ +int +xfs_bitmap_set_btcur_path( + struct xfs_bitmap *bitmap, + struct xfs_btree_cur *cur) +{ + struct xfs_buf *bp; + xfs_fsblock_t fsb; + int i; + int error; + + for (i = 0; i < cur->bc_nlevels && cur->bc_ptrs[i] == 1; i++) { + xfs_btree_get_block(cur, i, &bp); + if (!bp) + continue; + fsb = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn); + error = xfs_bitmap_set(bitmap, fsb, 1); + if (error) + return error; + } + + return 0; +} + +/* Collect a btree's block in the bitmap. */ +STATIC int +xfs_bitmap_collect_btblock( + struct xfs_btree_cur *cur, + int level, + void *priv) +{ + struct xfs_bitmap *bitmap = priv; + struct xfs_buf *bp; + xfs_fsblock_t fsbno; + + xfs_btree_get_block(cur, level, &bp); + if (!bp) + return 0; + + fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn); + return xfs_bitmap_set(bitmap, fsbno, 1); +} + +/* Walk the btree and mark the bitmap wherever a btree block is found. */ +int +xfs_bitmap_set_btblocks( + struct xfs_bitmap *bitmap, + struct xfs_btree_cur *cur) +{ + return xfs_btree_visit_blocks(cur, xfs_bitmap_collect_btblock, bitmap); +} diff --git a/fs/xfs/scrub/bitmap.h b/fs/xfs/scrub/bitmap.h index dad652e..ae8ecbc 100644 --- a/fs/xfs/scrub/bitmap.h +++ b/fs/xfs/scrub/bitmap.h @@ -28,5 +28,9 @@ void xfs_bitmap_destroy(struct xfs_bitmap *bitmap); int xfs_bitmap_set(struct xfs_bitmap *bitmap, uint64_t start, uint64_t len); int xfs_bitmap_disunion(struct xfs_bitmap *bitmap, struct xfs_bitmap *sub); +int xfs_bitmap_set_btcur_path(struct xfs_bitmap *bitmap, + struct xfs_btree_cur *cur); +int xfs_bitmap_set_btblocks(struct xfs_bitmap *bitmap, + struct xfs_btree_cur *cur); #endif /* __XFS_SCRUB_BITMAP_H__ */ diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h index 6f0903c..1d28336 100644 --- a/fs/xfs/scrub/repair.h +++ b/fs/xfs/scrub/repair.h @@ -59,6 +59,7 @@ 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); +int xrep_agfl(struct xfs_scrub *sc); #else @@ -83,6 +84,7 @@ xrep_calc_ag_resblks( #define xrep_probe xrep_notsupported #define xrep_superblock xrep_notsupported #define xrep_agf xrep_notsupported +#define xrep_agfl xrep_notsupported #endif /* CONFIG_XFS_ONLINE_REPAIR */ diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index 1e8a17c..2670f4c 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -220,7 +220,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = { .type = ST_PERAG, .setup = xchk_setup_fs, .scrub = xchk_agfl, - .repair = xrep_notsupported, + .repair = xrep_agfl, }, [XFS_SCRUB_TYPE_AGI] = { /* agi */ .type = ST_PERAG, -- 2.7.4