diff options
Diffstat (limited to 'fs/xfs/scrub/alloc_repair.c')
| -rw-r--r-- | fs/xfs/scrub/alloc_repair.c | 934 |
1 files changed, 934 insertions, 0 deletions
diff --git a/fs/xfs/scrub/alloc_repair.c b/fs/xfs/scrub/alloc_repair.c new file mode 100644 index 0000000000..45edda0968 --- /dev/null +++ b/fs/xfs/scrub/alloc_repair.c @@ -0,0 +1,934 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2018-2023 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_btree.h" +#include "xfs_btree_staging.h" +#include "xfs_bit.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_alloc.h" +#include "xfs_alloc_btree.h" +#include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "xfs_inode.h" +#include "xfs_refcount.h" +#include "xfs_extent_busy.h" +#include "xfs_health.h" +#include "xfs_bmap.h" +#include "xfs_ialloc.h" +#include "xfs_ag.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/btree.h" +#include "scrub/trace.h" +#include "scrub/repair.h" +#include "scrub/bitmap.h" +#include "scrub/agb_bitmap.h" +#include "scrub/xfile.h" +#include "scrub/xfarray.h" +#include "scrub/newbt.h" +#include "scrub/reap.h" + +/* + * Free Space Btree Repair + * ======================= + * + * The reverse mappings are supposed to record all space usage for the entire + * AG. Therefore, we can recreate the free extent records in an AG by looking + * for gaps in the physical extents recorded in the rmapbt. These records are + * staged in @free_records. Identifying the gaps is more difficult on a + * reflink filesystem because rmap records are allowed to overlap. + * + * Because the final step of building a new index is to free the space used by + * the old index, repair needs to find that space. Unfortunately, all + * structures that live in the free space (bnobt, cntbt, rmapbt, agfl) share + * the same rmapbt owner code (OWN_AG), so this is not straightforward. + * + * The scan of the reverse mapping information records the space used by OWN_AG + * in @old_allocbt_blocks, which (at this stage) is somewhat misnamed. While + * walking the rmapbt records, we create a second bitmap @not_allocbt_blocks to + * record all visited rmap btree blocks and all blocks owned by the AGFL. + * + * After that is where the definitions of old_allocbt_blocks shifts. This + * expression identifies possible former bnobt/cntbt blocks: + * + * (OWN_AG blocks) & ~(rmapbt blocks | agfl blocks); + * + * Substituting from above definitions, that becomes: + * + * old_allocbt_blocks & ~not_allocbt_blocks + * + * The OWN_AG bitmap itself isn't needed after this point, so what we really do + * instead is: + * + * old_allocbt_blocks &= ~not_allocbt_blocks; + * + * After this point, @old_allocbt_blocks is a bitmap of alleged former + * bnobt/cntbt blocks. The xagb_bitmap_disunion operation modifies its first + * parameter in place to avoid copying records around. + * + * Next, some of the space described by @free_records are diverted to the newbt + * reservation and used to format new btree blocks. The remaining records are + * written to the new btree indices. We reconstruct both bnobt and cntbt at + * the same time since we've already done all the work. + * + * We use the prefix 'xrep_abt' here because we regenerate both free space + * allocation btrees at the same time. + */ + +struct xrep_abt { + /* Blocks owned by the rmapbt or the agfl. */ + struct xagb_bitmap not_allocbt_blocks; + + /* All OWN_AG blocks. */ + struct xagb_bitmap old_allocbt_blocks; + + /* + * New bnobt information. All btree block reservations are added to + * the reservation list in new_bnobt. + */ + struct xrep_newbt new_bnobt; + + /* new cntbt information */ + struct xrep_newbt new_cntbt; + + /* Free space extents. */ + struct xfarray *free_records; + + struct xfs_scrub *sc; + + /* Number of non-null records in @free_records. */ + uint64_t nr_real_records; + + /* get_records()'s position in the free space record array. */ + xfarray_idx_t array_cur; + + /* + * Next block we anticipate seeing in the rmap records. If the next + * rmap record is greater than next_agbno, we have found unused space. + */ + xfs_agblock_t next_agbno; + + /* Number of free blocks in this AG. */ + xfs_agblock_t nr_blocks; + + /* Longest free extent we found in the AG. */ + xfs_agblock_t longest; +}; + +/* Set up to repair AG free space btrees. */ +int +xrep_setup_ag_allocbt( + struct xfs_scrub *sc) +{ + unsigned int busy_gen; + + /* + * Make sure the busy extent list is clear because we can't put extents + * on there twice. + */ + busy_gen = READ_ONCE(sc->sa.pag->pagb_gen); + if (xfs_extent_busy_list_empty(sc->sa.pag)) + return 0; + + return xfs_extent_busy_flush(sc->tp, sc->sa.pag, busy_gen, 0); +} + +/* Check for any obvious conflicts in the free extent. */ +STATIC int +xrep_abt_check_free_ext( + struct xfs_scrub *sc, + const struct xfs_alloc_rec_incore *rec) +{ + enum xbtree_recpacking outcome; + int error; + + if (xfs_alloc_check_irec(sc->sa.pag, rec) != NULL) + return -EFSCORRUPTED; + + /* Must not be an inode chunk. */ + error = xfs_ialloc_has_inodes_at_extent(sc->sa.ino_cur, + rec->ar_startblock, rec->ar_blockcount, &outcome); + if (error) + return error; + if (outcome != XBTREE_RECPACKING_EMPTY) + return -EFSCORRUPTED; + + /* Must not be shared or CoW staging. */ + if (sc->sa.refc_cur) { + error = xfs_refcount_has_records(sc->sa.refc_cur, + XFS_REFC_DOMAIN_SHARED, rec->ar_startblock, + rec->ar_blockcount, &outcome); + if (error) + return error; + if (outcome != XBTREE_RECPACKING_EMPTY) + return -EFSCORRUPTED; + + error = xfs_refcount_has_records(sc->sa.refc_cur, + XFS_REFC_DOMAIN_COW, rec->ar_startblock, + rec->ar_blockcount, &outcome); + if (error) + return error; + if (outcome != XBTREE_RECPACKING_EMPTY) + return -EFSCORRUPTED; + } + + return 0; +} + +/* + * Stash a free space record for all the space since the last bno we found + * all the way up to @end. + */ +static int +xrep_abt_stash( + struct xrep_abt *ra, + xfs_agblock_t end) +{ + struct xfs_alloc_rec_incore arec = { + .ar_startblock = ra->next_agbno, + .ar_blockcount = end - ra->next_agbno, + }; + struct xfs_scrub *sc = ra->sc; + int error = 0; + + if (xchk_should_terminate(sc, &error)) + return error; + + error = xrep_abt_check_free_ext(ra->sc, &arec); + if (error) + return error; + + trace_xrep_abt_found(sc->mp, sc->sa.pag->pag_agno, &arec); + + error = xfarray_append(ra->free_records, &arec); + if (error) + return error; + + ra->nr_blocks += arec.ar_blockcount; + return 0; +} + +/* Record extents that aren't in use from gaps in the rmap records. */ +STATIC int +xrep_abt_walk_rmap( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xrep_abt *ra = priv; + int error; + + /* Record all the OWN_AG blocks... */ + if (rec->rm_owner == XFS_RMAP_OWN_AG) { + error = xagb_bitmap_set(&ra->old_allocbt_blocks, + rec->rm_startblock, rec->rm_blockcount); + if (error) + return error; + } + + /* ...and all the rmapbt blocks... */ + error = xagb_bitmap_set_btcur_path(&ra->not_allocbt_blocks, cur); + if (error) + return error; + + /* ...and all the free space. */ + if (rec->rm_startblock > ra->next_agbno) { + error = xrep_abt_stash(ra, rec->rm_startblock); + if (error) + return error; + } + + /* + * rmap records can overlap on reflink filesystems, so project + * next_agbno as far out into the AG space as we currently know about. + */ + ra->next_agbno = max_t(xfs_agblock_t, ra->next_agbno, + rec->rm_startblock + rec->rm_blockcount); + return 0; +} + +/* Collect an AGFL block for the not-to-release list. */ +static int +xrep_abt_walk_agfl( + struct xfs_mount *mp, + xfs_agblock_t agbno, + void *priv) +{ + struct xrep_abt *ra = priv; + + return xagb_bitmap_set(&ra->not_allocbt_blocks, agbno, 1); +} + +/* + * Compare two free space extents by block number. We want to sort in order of + * increasing block number. + */ +static int +xrep_bnobt_extent_cmp( + const void *a, + const void *b) +{ + const struct xfs_alloc_rec_incore *ap = a; + const struct xfs_alloc_rec_incore *bp = b; + + if (ap->ar_startblock > bp->ar_startblock) + return 1; + else if (ap->ar_startblock < bp->ar_startblock) + return -1; + return 0; +} + +/* + * Re-sort the free extents by block number so that we can put the records into + * the bnobt in the correct order. Make sure the records do not overlap in + * physical space. + */ +STATIC int +xrep_bnobt_sort_records( + struct xrep_abt *ra) +{ + struct xfs_alloc_rec_incore arec; + xfarray_idx_t cur = XFARRAY_CURSOR_INIT; + xfs_agblock_t next_agbno = 0; + int error; + + error = xfarray_sort(ra->free_records, xrep_bnobt_extent_cmp, 0); + if (error) + return error; + + while ((error = xfarray_iter(ra->free_records, &cur, &arec)) == 1) { + if (arec.ar_startblock < next_agbno) + return -EFSCORRUPTED; + + next_agbno = arec.ar_startblock + arec.ar_blockcount; + } + + return error; +} + +/* + * Compare two free space extents by length and then block number. We want + * to sort first in order of increasing length and then in order of increasing + * block number. + */ +static int +xrep_cntbt_extent_cmp( + const void *a, + const void *b) +{ + const struct xfs_alloc_rec_incore *ap = a; + const struct xfs_alloc_rec_incore *bp = b; + + if (ap->ar_blockcount > bp->ar_blockcount) + return 1; + else if (ap->ar_blockcount < bp->ar_blockcount) + return -1; + return xrep_bnobt_extent_cmp(a, b); +} + +/* + * Sort the free extents by length so so that we can put the records into the + * cntbt in the correct order. Don't let userspace kill us if we're resorting + * after allocating btree blocks. + */ +STATIC int +xrep_cntbt_sort_records( + struct xrep_abt *ra, + bool is_resort) +{ + return xfarray_sort(ra->free_records, xrep_cntbt_extent_cmp, + is_resort ? 0 : XFARRAY_SORT_KILLABLE); +} + +/* + * Iterate all reverse mappings to find (1) the gaps between rmap records (all + * unowned space), (2) the OWN_AG extents (which encompass the free space + * btrees, the rmapbt, and the agfl), (3) the rmapbt blocks, and (4) the AGFL + * blocks. The free space is (1) + (2) - (3) - (4). + */ +STATIC int +xrep_abt_find_freespace( + struct xrep_abt *ra) +{ + struct xfs_scrub *sc = ra->sc; + struct xfs_mount *mp = sc->mp; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + struct xfs_buf *agfl_bp; + xfs_agblock_t agend; + int error; + + xagb_bitmap_init(&ra->not_allocbt_blocks); + + xrep_ag_btcur_init(sc, &sc->sa); + + /* + * Iterate all the reverse mappings to find gaps in the physical + * mappings, all the OWN_AG blocks, and all the rmapbt extents. + */ + error = xfs_rmap_query_all(sc->sa.rmap_cur, xrep_abt_walk_rmap, ra); + if (error) + goto err; + + /* Insert a record for space between the last rmap and EOAG. */ + agend = be32_to_cpu(agf->agf_length); + if (ra->next_agbno < agend) { + error = xrep_abt_stash(ra, agend); + if (error) + goto err; + } + + /* Collect all the AGFL blocks. */ + error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp); + if (error) + goto err; + + error = xfs_agfl_walk(mp, agf, agfl_bp, xrep_abt_walk_agfl, ra); + if (error) + goto err_agfl; + + /* Compute the old bnobt/cntbt blocks. */ + error = xagb_bitmap_disunion(&ra->old_allocbt_blocks, + &ra->not_allocbt_blocks); + if (error) + goto err_agfl; + + ra->nr_real_records = xfarray_length(ra->free_records); +err_agfl: + xfs_trans_brelse(sc->tp, agfl_bp); +err: + xchk_ag_btcur_free(&sc->sa); + xagb_bitmap_destroy(&ra->not_allocbt_blocks); + return error; +} + +/* + * We're going to use the observed free space records to reserve blocks for the + * new free space btrees, so we play an iterative game where we try to converge + * on the number of blocks we need: + * + * 1. Estimate how many blocks we'll need to store the records. + * 2. If the first free record has more blocks than we need, we're done. + * We will have to re-sort the records prior to building the cntbt. + * 3. If that record has exactly the number of blocks we need, null out the + * record. We're done. + * 4. Otherwise, we still need more blocks. Null out the record, subtract its + * length from the number of blocks we need, and go back to step 1. + * + * Fortunately, we don't have to do any transaction work to play this game, so + * we don't have to tear down the staging cursors. + */ +STATIC int +xrep_abt_reserve_space( + struct xrep_abt *ra, + struct xfs_btree_cur *bno_cur, + struct xfs_btree_cur *cnt_cur, + bool *needs_resort) +{ + struct xfs_scrub *sc = ra->sc; + xfarray_idx_t record_nr; + unsigned int allocated = 0; + int error = 0; + + record_nr = xfarray_length(ra->free_records) - 1; + do { + struct xfs_alloc_rec_incore arec; + uint64_t required; + unsigned int desired; + unsigned int len; + + /* Compute how many blocks we'll need. */ + error = xfs_btree_bload_compute_geometry(cnt_cur, + &ra->new_cntbt.bload, ra->nr_real_records); + if (error) + break; + + error = xfs_btree_bload_compute_geometry(bno_cur, + &ra->new_bnobt.bload, ra->nr_real_records); + if (error) + break; + + /* How many btree blocks do we need to store all records? */ + required = ra->new_bnobt.bload.nr_blocks + + ra->new_cntbt.bload.nr_blocks; + ASSERT(required < INT_MAX); + + /* If we've reserved enough blocks, we're done. */ + if (allocated >= required) + break; + + desired = required - allocated; + + /* We need space but there's none left; bye! */ + if (ra->nr_real_records == 0) { + error = -ENOSPC; + break; + } + + /* Grab the first record from the list. */ + error = xfarray_load(ra->free_records, record_nr, &arec); + if (error) + break; + + ASSERT(arec.ar_blockcount <= UINT_MAX); + len = min_t(unsigned int, arec.ar_blockcount, desired); + + trace_xrep_newbt_alloc_ag_blocks(sc->mp, sc->sa.pag->pag_agno, + arec.ar_startblock, len, XFS_RMAP_OWN_AG); + + error = xrep_newbt_add_extent(&ra->new_bnobt, sc->sa.pag, + arec.ar_startblock, len); + if (error) + break; + allocated += len; + ra->nr_blocks -= len; + + if (arec.ar_blockcount > desired) { + /* + * Record has more space than we need. The number of + * free records doesn't change, so shrink the free + * record, inform the caller that the records are no + * longer sorted by length, and exit. + */ + arec.ar_startblock += desired; + arec.ar_blockcount -= desired; + error = xfarray_store(ra->free_records, record_nr, + &arec); + if (error) + break; + + *needs_resort = true; + return 0; + } + + /* + * We're going to use up the entire record, so unset it and + * move on to the next one. This changes the number of free + * records (but doesn't break the sorting order), so we must + * go around the loop once more to re-run _bload_init. + */ + error = xfarray_unset(ra->free_records, record_nr); + if (error) + break; + ra->nr_real_records--; + record_nr--; + } while (1); + + return error; +} + +STATIC int +xrep_abt_dispose_one( + struct xrep_abt *ra, + struct xrep_newbt_resv *resv) +{ + struct xfs_scrub *sc = ra->sc; + struct xfs_perag *pag = sc->sa.pag; + xfs_agblock_t free_agbno = resv->agbno + resv->used; + xfs_extlen_t free_aglen = resv->len - resv->used; + int error; + + ASSERT(pag == resv->pag); + + /* Add a deferred rmap for each extent we used. */ + if (resv->used > 0) + xfs_rmap_alloc_extent(sc->tp, pag->pag_agno, resv->agbno, + resv->used, XFS_RMAP_OWN_AG); + + /* + * For each reserved btree block we didn't use, add it to the free + * space btree. We didn't touch fdblocks when we reserved them, so + * we don't touch it now. + */ + if (free_aglen == 0) + return 0; + + trace_xrep_newbt_free_blocks(sc->mp, resv->pag->pag_agno, free_agbno, + free_aglen, ra->new_bnobt.oinfo.oi_owner); + + error = __xfs_free_extent(sc->tp, resv->pag, free_agbno, free_aglen, + &ra->new_bnobt.oinfo, XFS_AG_RESV_IGNORE, true); + if (error) + return error; + + return xrep_defer_finish(sc); +} + +/* + * Deal with all the space we reserved. Blocks that were allocated for the + * free space btrees need to have a (deferred) rmap added for the OWN_AG + * allocation, and blocks that didn't get used can be freed via the usual + * (deferred) means. + */ +STATIC void +xrep_abt_dispose_reservations( + struct xrep_abt *ra, + int error) +{ + struct xrep_newbt_resv *resv, *n; + + if (error) + goto junkit; + + list_for_each_entry_safe(resv, n, &ra->new_bnobt.resv_list, list) { + error = xrep_abt_dispose_one(ra, resv); + if (error) + goto junkit; + } + +junkit: + list_for_each_entry_safe(resv, n, &ra->new_bnobt.resv_list, list) { + xfs_perag_put(resv->pag); + list_del(&resv->list); + kfree(resv); + } + + xrep_newbt_cancel(&ra->new_bnobt); + xrep_newbt_cancel(&ra->new_cntbt); +} + +/* Retrieve free space data for bulk load. */ +STATIC int +xrep_abt_get_records( + struct xfs_btree_cur *cur, + unsigned int idx, + struct xfs_btree_block *block, + unsigned int nr_wanted, + void *priv) +{ + struct xfs_alloc_rec_incore *arec = &cur->bc_rec.a; + struct xrep_abt *ra = priv; + union xfs_btree_rec *block_rec; + unsigned int loaded; + int error; + + for (loaded = 0; loaded < nr_wanted; loaded++, idx++) { + error = xfarray_load_next(ra->free_records, &ra->array_cur, + arec); + if (error) + return error; + + ra->longest = max(ra->longest, arec->ar_blockcount); + + block_rec = xfs_btree_rec_addr(cur, idx, block); + cur->bc_ops->init_rec_from_cur(cur, block_rec); + } + + return loaded; +} + +/* Feed one of the new btree blocks to the bulk loader. */ +STATIC int +xrep_abt_claim_block( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr, + void *priv) +{ + struct xrep_abt *ra = priv; + + return xrep_newbt_claim_block(cur, &ra->new_bnobt, ptr); +} + +/* + * Reset the AGF counters to reflect the free space btrees that we just + * rebuilt, then reinitialize the per-AG data. + */ +STATIC int +xrep_abt_reset_counters( + struct xrep_abt *ra) +{ + struct xfs_scrub *sc = ra->sc; + struct xfs_perag *pag = sc->sa.pag; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + unsigned int freesp_btreeblks = 0; + + /* + * Compute the contribution to agf_btreeblks for the new free space + * btrees. This is the computed btree size minus anything we didn't + * use. + */ + freesp_btreeblks += ra->new_bnobt.bload.nr_blocks - 1; + freesp_btreeblks += ra->new_cntbt.bload.nr_blocks - 1; + + freesp_btreeblks -= xrep_newbt_unused_blocks(&ra->new_bnobt); + freesp_btreeblks -= xrep_newbt_unused_blocks(&ra->new_cntbt); + + /* + * The AGF header contains extra information related to the free space + * btrees, so we must update those fields here. + */ + agf->agf_btreeblks = cpu_to_be32(freesp_btreeblks + + (be32_to_cpu(agf->agf_rmap_blocks) - 1)); + agf->agf_freeblks = cpu_to_be32(ra->nr_blocks); + agf->agf_longest = cpu_to_be32(ra->longest); + xfs_alloc_log_agf(sc->tp, sc->sa.agf_bp, XFS_AGF_BTREEBLKS | + XFS_AGF_LONGEST | + XFS_AGF_FREEBLKS); + + /* + * After we commit the new btree to disk, it is possible that the + * process to reap the old btree blocks will race with the AIL trying + * to checkpoint the old btree blocks into the filesystem. If the new + * tree is shorter than the old one, the allocbt write verifier will + * fail and the AIL will shut down the filesystem. + * + * To avoid this, save the old incore btree height values as the alt + * height values before re-initializing the perag info from the updated + * AGF to capture all the new values. + */ + pag->pagf_repair_levels[XFS_BTNUM_BNOi] = pag->pagf_levels[XFS_BTNUM_BNOi]; + pag->pagf_repair_levels[XFS_BTNUM_CNTi] = pag->pagf_levels[XFS_BTNUM_CNTi]; + + /* Reinitialize with the values we just logged. */ + return xrep_reinit_pagf(sc); +} + +/* + * Use the collected free space information to stage new free space btrees. + * If this is successful we'll return with the new btree root + * information logged to the repair transaction but not yet committed. + */ +STATIC int +xrep_abt_build_new_trees( + struct xrep_abt *ra) +{ + struct xfs_scrub *sc = ra->sc; + struct xfs_btree_cur *bno_cur; + struct xfs_btree_cur *cnt_cur; + struct xfs_perag *pag = sc->sa.pag; + bool needs_resort = false; + int error; + + /* + * Sort the free extents by length so that we can set up the free space + * btrees in as few extents as possible. This reduces the amount of + * deferred rmap / free work we have to do at the end. + */ + error = xrep_cntbt_sort_records(ra, false); + if (error) + return error; + + /* + * Prepare to construct the new btree by reserving disk space for the + * new btree and setting up all the accounting information we'll need + * to root the new btree while it's under construction and before we + * attach it to the AG header. + */ + xrep_newbt_init_bare(&ra->new_bnobt, sc); + xrep_newbt_init_bare(&ra->new_cntbt, sc); + + ra->new_bnobt.bload.get_records = xrep_abt_get_records; + ra->new_cntbt.bload.get_records = xrep_abt_get_records; + + ra->new_bnobt.bload.claim_block = xrep_abt_claim_block; + ra->new_cntbt.bload.claim_block = xrep_abt_claim_block; + + /* Allocate cursors for the staged btrees. */ + bno_cur = xfs_allocbt_stage_cursor(sc->mp, &ra->new_bnobt.afake, + pag, XFS_BTNUM_BNO); + cnt_cur = xfs_allocbt_stage_cursor(sc->mp, &ra->new_cntbt.afake, + pag, XFS_BTNUM_CNT); + + /* Last chance to abort before we start committing fixes. */ + if (xchk_should_terminate(sc, &error)) + goto err_cur; + + /* Reserve the space we'll need for the new btrees. */ + error = xrep_abt_reserve_space(ra, bno_cur, cnt_cur, &needs_resort); + if (error) + goto err_cur; + + /* + * If we need to re-sort the free extents by length, do so so that we + * can put the records into the cntbt in the correct order. + */ + if (needs_resort) { + error = xrep_cntbt_sort_records(ra, needs_resort); + if (error) + goto err_cur; + } + + /* + * Due to btree slack factors, it's possible for a new btree to be one + * level taller than the old btree. Update the alternate incore btree + * height so that we don't trip the verifiers when writing the new + * btree blocks to disk. + */ + pag->pagf_repair_levels[XFS_BTNUM_BNOi] = + ra->new_bnobt.bload.btree_height; + pag->pagf_repair_levels[XFS_BTNUM_CNTi] = + ra->new_cntbt.bload.btree_height; + + /* Load the free space by length tree. */ + ra->array_cur = XFARRAY_CURSOR_INIT; + ra->longest = 0; + error = xfs_btree_bload(cnt_cur, &ra->new_cntbt.bload, ra); + if (error) + goto err_levels; + + error = xrep_bnobt_sort_records(ra); + if (error) + return error; + + /* Load the free space by block number tree. */ + ra->array_cur = XFARRAY_CURSOR_INIT; + error = xfs_btree_bload(bno_cur, &ra->new_bnobt.bload, ra); + if (error) + goto err_levels; + + /* + * Install the new btrees in the AG header. After this point the old + * btrees are no longer accessible and the new trees are live. + */ + xfs_allocbt_commit_staged_btree(bno_cur, sc->tp, sc->sa.agf_bp); + xfs_btree_del_cursor(bno_cur, 0); + xfs_allocbt_commit_staged_btree(cnt_cur, sc->tp, sc->sa.agf_bp); + xfs_btree_del_cursor(cnt_cur, 0); + + /* Reset the AGF counters now that we've changed the btree shape. */ + error = xrep_abt_reset_counters(ra); + if (error) + goto err_newbt; + + /* Dispose of any unused blocks and the accounting information. */ + xrep_abt_dispose_reservations(ra, error); + + return xrep_roll_ag_trans(sc); + +err_levels: + pag->pagf_repair_levels[XFS_BTNUM_BNOi] = 0; + pag->pagf_repair_levels[XFS_BTNUM_CNTi] = 0; +err_cur: + xfs_btree_del_cursor(cnt_cur, error); + xfs_btree_del_cursor(bno_cur, error); +err_newbt: + xrep_abt_dispose_reservations(ra, error); + return error; +} + +/* + * Now that we've logged the roots of the new btrees, invalidate all of the + * old blocks and free them. + */ +STATIC int +xrep_abt_remove_old_trees( + struct xrep_abt *ra) +{ + struct xfs_perag *pag = ra->sc->sa.pag; + int error; + + /* Free the old btree blocks if they're not in use. */ + error = xrep_reap_agblocks(ra->sc, &ra->old_allocbt_blocks, + &XFS_RMAP_OINFO_AG, XFS_AG_RESV_IGNORE); + if (error) + return error; + + /* + * Now that we've zapped all the old allocbt blocks we can turn off + * the alternate height mechanism. + */ + pag->pagf_repair_levels[XFS_BTNUM_BNOi] = 0; + pag->pagf_repair_levels[XFS_BTNUM_CNTi] = 0; + return 0; +} + +/* Repair the freespace btrees for some AG. */ +int +xrep_allocbt( + struct xfs_scrub *sc) +{ + struct xrep_abt *ra; + struct xfs_mount *mp = sc->mp; + char *descr; + int error; + + /* We require the rmapbt to rebuild anything. */ + if (!xfs_has_rmapbt(mp)) + return -EOPNOTSUPP; + + ra = kzalloc(sizeof(struct xrep_abt), XCHK_GFP_FLAGS); + if (!ra) + return -ENOMEM; + ra->sc = sc; + + /* We rebuild both data structures. */ + sc->sick_mask = XFS_SICK_AG_BNOBT | XFS_SICK_AG_CNTBT; + + /* + * Make sure the busy extent list is clear because we can't put extents + * on there twice. In theory we cleared this before we started, but + * let's not risk the filesystem. + */ + if (!xfs_extent_busy_list_empty(sc->sa.pag)) { + error = -EDEADLOCK; + goto out_ra; + } + + /* Set up enough storage to handle maximally fragmented free space. */ + descr = xchk_xfile_ag_descr(sc, "free space records"); + error = xfarray_create(descr, mp->m_sb.sb_agblocks / 2, + sizeof(struct xfs_alloc_rec_incore), + &ra->free_records); + kfree(descr); + if (error) + goto out_ra; + + /* Collect the free space data and find the old btree blocks. */ + xagb_bitmap_init(&ra->old_allocbt_blocks); + error = xrep_abt_find_freespace(ra); + if (error) + goto out_bitmap; + + /* Rebuild the free space information. */ + error = xrep_abt_build_new_trees(ra); + if (error) + goto out_bitmap; + + /* Kill the old trees. */ + error = xrep_abt_remove_old_trees(ra); + if (error) + goto out_bitmap; + +out_bitmap: + xagb_bitmap_destroy(&ra->old_allocbt_blocks); + xfarray_destroy(ra->free_records); +out_ra: + kfree(ra); + return error; +} + +/* Make sure both btrees are ok after we've rebuilt them. */ +int +xrep_revalidate_allocbt( + struct xfs_scrub *sc) +{ + __u32 old_type = sc->sm->sm_type; + int error; + + /* + * We must update sm_type temporarily so that the tree-to-tree cross + * reference checks will work in the correct direction, and also so + * that tracing will report correctly if there are more errors. + */ + sc->sm->sm_type = XFS_SCRUB_TYPE_BNOBT; + error = xchk_allocbt(sc); + if (error) + goto out; + + sc->sm->sm_type = XFS_SCRUB_TYPE_CNTBT; + error = xchk_allocbt(sc); +out: + sc->sm->sm_type = old_type; + return error; +} |