diff options
Diffstat (limited to 'fs/xfs/scrub/rmap_repair.c')
| -rw-r--r-- | fs/xfs/scrub/rmap_repair.c | 1697 |
1 files changed, 1697 insertions, 0 deletions
diff --git a/fs/xfs/scrub/rmap_repair.c b/fs/xfs/scrub/rmap_repair.c new file mode 100644 index 0000000000..e8e07b683e --- /dev/null +++ b/fs/xfs/scrub/rmap_repair.c @@ -0,0 +1,1697 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2018-2024 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_buf_mem.h" +#include "xfs_btree_mem.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_ialloc.h" +#include "xfs_ialloc_btree.h" +#include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "xfs_inode.h" +#include "xfs_icache.h" +#include "xfs_bmap.h" +#include "xfs_bmap_btree.h" +#include "xfs_refcount.h" +#include "xfs_refcount_btree.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/iscan.h" +#include "scrub/newbt.h" +#include "scrub/reap.h" + +/* + * Reverse Mapping Btree Repair + * ============================ + * + * This is the most involved of all the AG space btree rebuilds. Everywhere + * else in XFS we lock inodes and then AG data structures, but generating the + * list of rmap records requires that we be able to scan both block mapping + * btrees of every inode in the filesystem to see if it owns any extents in + * this AG. We can't tolerate any inode updates while we do this, so we + * freeze the filesystem to lock everyone else out, and grant ourselves + * special privileges to run transactions with regular background reclamation + * turned off. + * + * We also have to be very careful not to allow inode reclaim to start a + * transaction because all transactions (other than our own) will block. + * Deferred inode inactivation helps us out there. + * + * I) Reverse mappings for all non-space metadata and file data are collected + * according to the following algorithm: + * + * 1. For each fork of each inode: + * 1.1. Create a bitmap BMBIT to track bmbt blocks if necessary. + * 1.2. If the incore extent map isn't loaded, walk the bmbt to accumulate + * bmaps into rmap records (see 1.1.4). Set bits in BMBIT for each btree + * block. + * 1.3. If the incore extent map is loaded but the fork is in btree format, + * just visit the bmbt blocks to set the corresponding BMBIT areas. + * 1.4. From the incore extent map, accumulate each bmap that falls into our + * target AG. Remember, multiple bmap records can map to a single rmap + * record, so we cannot simply emit rmap records 1:1. + * 1.5. Emit rmap records for each extent in BMBIT and free it. + * 2. Create bitmaps INOBIT and ICHUNKBIT. + * 3. For each record in the inobt, set the corresponding areas in ICHUNKBIT, + * and set bits in INOBIT for each btree block. If the inobt has no records + * at all, we must be careful to record its root in INOBIT. + * 4. For each block in the finobt, set the corresponding INOBIT area. + * 5. Emit rmap records for each extent in INOBIT and ICHUNKBIT and free them. + * 6. Create bitmaps REFCBIT and COWBIT. + * 7. For each CoW staging extent in the refcountbt, set the corresponding + * areas in COWBIT. + * 8. For each block in the refcountbt, set the corresponding REFCBIT area. + * 9. Emit rmap records for each extent in REFCBIT and COWBIT and free them. + * A. Emit rmap for the AG headers. + * B. Emit rmap for the log, if there is one. + * + * II) The rmapbt shape and space metadata rmaps are computed as follows: + * + * 1. Count the rmaps collected in the previous step. (= NR) + * 2. Estimate the number of rmapbt blocks needed to store NR records. (= RMB) + * 3. Reserve RMB blocks through the newbt using the allocator in normap mode. + * 4. Create bitmap AGBIT. + * 5. For each reservation in the newbt, set the corresponding areas in AGBIT. + * 6. For each block in the AGFL, bnobt, and cntbt, set the bits in AGBIT. + * 7. Count the extents in AGBIT. (= AGNR) + * 8. Estimate the number of rmapbt blocks needed for NR + AGNR rmaps. (= RMB') + * 9. If RMB' >= RMB, reserve RMB' - RMB more newbt blocks, set RMB = RMB', + * and clear AGBIT. Go to step 5. + * A. Emit rmaps for each extent in AGBIT. + * + * III) The rmapbt is constructed and set in place as follows: + * + * 1. Sort the rmap records. + * 2. Bulk load the rmaps. + * + * IV) Reap the old btree blocks. + * + * 1. Create a bitmap OLDRMBIT. + * 2. For each gap in the new rmapbt, set the corresponding areas of OLDRMBIT. + * 3. For each extent in the bnobt, clear the corresponding parts of OLDRMBIT. + * 4. Reap the extents corresponding to the set areas in OLDRMBIT. These are + * the parts of the AG that the rmap didn't find during its scan of the + * primary metadata and aren't known to be in the free space, which implies + * that they were the old rmapbt blocks. + * 5. Commit. + * + * We use the 'xrep_rmap' prefix for all the rmap functions. + */ + +/* Context for collecting rmaps */ +struct xrep_rmap { + /* new rmapbt information */ + struct xrep_newbt new_btree; + + /* lock for the xfbtree and xfile */ + struct mutex lock; + + /* rmap records generated from primary metadata */ + struct xfbtree rmap_btree; + + struct xfs_scrub *sc; + + /* in-memory btree cursor for the xfs_btree_bload iteration */ + struct xfs_btree_cur *mcur; + + /* Hooks into rmap update code. */ + struct xfs_rmap_hook rhook; + + /* inode scan cursor */ + struct xchk_iscan iscan; + + /* Number of non-freespace records found. */ + unsigned long long nr_records; + + /* bnobt/cntbt contribution to btreeblks */ + xfs_agblock_t freesp_btblocks; + + /* old agf_rmap_blocks counter */ + unsigned int old_rmapbt_fsbcount; +}; + +/* Set us up to repair reverse mapping btrees. */ +int +xrep_setup_ag_rmapbt( + struct xfs_scrub *sc) +{ + struct xrep_rmap *rr; + char *descr; + int error; + + xchk_fsgates_enable(sc, XCHK_FSGATES_RMAP); + + descr = xchk_xfile_ag_descr(sc, "reverse mapping records"); + error = xrep_setup_xfbtree(sc, descr); + kfree(descr); + if (error) + return error; + + rr = kzalloc(sizeof(struct xrep_rmap), XCHK_GFP_FLAGS); + if (!rr) + return -ENOMEM; + + rr->sc = sc; + sc->buf = rr; + return 0; +} + +/* Make sure there's nothing funny about this mapping. */ +STATIC int +xrep_rmap_check_mapping( + struct xfs_scrub *sc, + const struct xfs_rmap_irec *rec) +{ + enum xbtree_recpacking outcome; + int error; + + if (xfs_rmap_check_irec(sc->sa.pag, rec) != NULL) + return -EFSCORRUPTED; + + /* Make sure this isn't free space. */ + error = xfs_alloc_has_records(sc->sa.bno_cur, rec->rm_startblock, + rec->rm_blockcount, &outcome); + if (error) + return error; + if (outcome != XBTREE_RECPACKING_EMPTY) + return -EFSCORRUPTED; + + return 0; +} + +/* Store a reverse-mapping record. */ +static inline int +xrep_rmap_stash( + struct xrep_rmap *rr, + xfs_agblock_t startblock, + xfs_extlen_t blockcount, + uint64_t owner, + uint64_t offset, + unsigned int flags) +{ + struct xfs_rmap_irec rmap = { + .rm_startblock = startblock, + .rm_blockcount = blockcount, + .rm_owner = owner, + .rm_offset = offset, + .rm_flags = flags, + }; + struct xfs_scrub *sc = rr->sc; + struct xfs_btree_cur *mcur; + int error = 0; + + if (xchk_should_terminate(sc, &error)) + return error; + + if (xchk_iscan_aborted(&rr->iscan)) + return -EFSCORRUPTED; + + trace_xrep_rmap_found(sc->mp, sc->sa.pag->pag_agno, &rmap); + + mutex_lock(&rr->lock); + mcur = xfs_rmapbt_mem_cursor(sc->sa.pag, sc->tp, &rr->rmap_btree); + error = xfs_rmap_map_raw(mcur, &rmap); + xfs_btree_del_cursor(mcur, error); + if (error) + goto out_cancel; + + error = xfbtree_trans_commit(&rr->rmap_btree, sc->tp); + if (error) + goto out_abort; + + mutex_unlock(&rr->lock); + return 0; + +out_cancel: + xfbtree_trans_cancel(&rr->rmap_btree, sc->tp); +out_abort: + xchk_iscan_abort(&rr->iscan); + mutex_unlock(&rr->lock); + return error; +} + +struct xrep_rmap_stash_run { + struct xrep_rmap *rr; + uint64_t owner; + unsigned int rmap_flags; +}; + +static int +xrep_rmap_stash_run( + uint32_t start, + uint32_t len, + void *priv) +{ + struct xrep_rmap_stash_run *rsr = priv; + struct xrep_rmap *rr = rsr->rr; + + return xrep_rmap_stash(rr, start, len, rsr->owner, 0, rsr->rmap_flags); +} + +/* + * Emit rmaps for every extent of bits set in the bitmap. Caller must ensure + * that the ranges are in units of FS blocks. + */ +STATIC int +xrep_rmap_stash_bitmap( + struct xrep_rmap *rr, + struct xagb_bitmap *bitmap, + const struct xfs_owner_info *oinfo) +{ + struct xrep_rmap_stash_run rsr = { + .rr = rr, + .owner = oinfo->oi_owner, + .rmap_flags = 0, + }; + + if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK) + rsr.rmap_flags |= XFS_RMAP_ATTR_FORK; + if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK) + rsr.rmap_flags |= XFS_RMAP_BMBT_BLOCK; + + return xagb_bitmap_walk(bitmap, xrep_rmap_stash_run, &rsr); +} + +/* Section (I): Finding all file and bmbt extents. */ + +/* Context for accumulating rmaps for an inode fork. */ +struct xrep_rmap_ifork { + /* + * Accumulate rmap data here to turn multiple adjacent bmaps into a + * single rmap. + */ + struct xfs_rmap_irec accum; + + /* Bitmap of bmbt blocks in this AG. */ + struct xagb_bitmap bmbt_blocks; + + struct xrep_rmap *rr; + + /* Which inode fork? */ + int whichfork; +}; + +/* Stash an rmap that we accumulated while walking an inode fork. */ +STATIC int +xrep_rmap_stash_accumulated( + struct xrep_rmap_ifork *rf) +{ + if (rf->accum.rm_blockcount == 0) + return 0; + + return xrep_rmap_stash(rf->rr, rf->accum.rm_startblock, + rf->accum.rm_blockcount, rf->accum.rm_owner, + rf->accum.rm_offset, rf->accum.rm_flags); +} + +/* Accumulate a bmbt record. */ +STATIC int +xrep_rmap_visit_bmbt( + struct xfs_btree_cur *cur, + struct xfs_bmbt_irec *rec, + void *priv) +{ + struct xrep_rmap_ifork *rf = priv; + struct xfs_mount *mp = rf->rr->sc->mp; + struct xfs_rmap_irec *accum = &rf->accum; + xfs_agblock_t agbno; + unsigned int rmap_flags = 0; + int error; + + if (XFS_FSB_TO_AGNO(mp, rec->br_startblock) != + rf->rr->sc->sa.pag->pag_agno) + return 0; + + agbno = XFS_FSB_TO_AGBNO(mp, rec->br_startblock); + if (rf->whichfork == XFS_ATTR_FORK) + rmap_flags |= XFS_RMAP_ATTR_FORK; + if (rec->br_state == XFS_EXT_UNWRITTEN) + rmap_flags |= XFS_RMAP_UNWRITTEN; + + /* If this bmap is adjacent to the previous one, just add it. */ + if (accum->rm_blockcount > 0 && + rec->br_startoff == accum->rm_offset + accum->rm_blockcount && + agbno == accum->rm_startblock + accum->rm_blockcount && + rmap_flags == accum->rm_flags) { + accum->rm_blockcount += rec->br_blockcount; + return 0; + } + + /* Otherwise stash the old rmap and start accumulating a new one. */ + error = xrep_rmap_stash_accumulated(rf); + if (error) + return error; + + accum->rm_startblock = agbno; + accum->rm_blockcount = rec->br_blockcount; + accum->rm_offset = rec->br_startoff; + accum->rm_flags = rmap_flags; + return 0; +} + +/* Add a btree block to the bitmap. */ +STATIC int +xrep_rmap_visit_iroot_btree_block( + struct xfs_btree_cur *cur, + int level, + void *priv) +{ + struct xrep_rmap_ifork *rf = priv; + struct xfs_buf *bp; + xfs_fsblock_t fsbno; + xfs_agblock_t agbno; + + xfs_btree_get_block(cur, level, &bp); + if (!bp) + return 0; + + fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp)); + if (XFS_FSB_TO_AGNO(cur->bc_mp, fsbno) != rf->rr->sc->sa.pag->pag_agno) + return 0; + + agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno); + return xagb_bitmap_set(&rf->bmbt_blocks, agbno, 1); +} + +/* + * Iterate a metadata btree rooted in an inode to collect rmap records for + * anything in this fork that matches the AG. + */ +STATIC int +xrep_rmap_scan_iroot_btree( + struct xrep_rmap_ifork *rf, + struct xfs_btree_cur *cur) +{ + struct xfs_owner_info oinfo; + struct xrep_rmap *rr = rf->rr; + int error; + + xagb_bitmap_init(&rf->bmbt_blocks); + + /* Record all the blocks in the btree itself. */ + error = xfs_btree_visit_blocks(cur, xrep_rmap_visit_iroot_btree_block, + XFS_BTREE_VISIT_ALL, rf); + if (error) + goto out; + + /* Emit rmaps for the btree blocks. */ + xfs_rmap_ino_bmbt_owner(&oinfo, rf->accum.rm_owner, rf->whichfork); + error = xrep_rmap_stash_bitmap(rr, &rf->bmbt_blocks, &oinfo); + if (error) + goto out; + + /* Stash any remaining accumulated rmaps. */ + error = xrep_rmap_stash_accumulated(rf); +out: + xagb_bitmap_destroy(&rf->bmbt_blocks); + return error; +} + +static inline bool +is_rt_data_fork( + struct xfs_inode *ip, + int whichfork) +{ + return XFS_IS_REALTIME_INODE(ip) && whichfork == XFS_DATA_FORK; +} + +/* + * Iterate the block mapping btree to collect rmap records for anything in this + * fork that matches the AG. Sets @mappings_done to true if we've scanned the + * block mappings in this fork. + */ +STATIC int +xrep_rmap_scan_bmbt( + struct xrep_rmap_ifork *rf, + struct xfs_inode *ip, + bool *mappings_done) +{ + struct xrep_rmap *rr = rf->rr; + struct xfs_btree_cur *cur; + struct xfs_ifork *ifp; + int error; + + *mappings_done = false; + ifp = xfs_ifork_ptr(ip, rf->whichfork); + cur = xfs_bmbt_init_cursor(rr->sc->mp, rr->sc->tp, ip, rf->whichfork); + + if (!xfs_ifork_is_realtime(ip, rf->whichfork) && + xfs_need_iread_extents(ifp)) { + /* + * If the incore extent cache isn't loaded, scan the bmbt for + * mapping records. This avoids loading the incore extent + * tree, which will increase memory pressure at a time when + * we're trying to run as quickly as we possibly can. Ignore + * realtime extents. + */ + error = xfs_bmap_query_all(cur, xrep_rmap_visit_bmbt, rf); + if (error) + goto out_cur; + + *mappings_done = true; + } + + /* Scan for the bmbt blocks, which always live on the data device. */ + error = xrep_rmap_scan_iroot_btree(rf, cur); +out_cur: + xfs_btree_del_cursor(cur, error); + return error; +} + +/* + * Iterate the in-core extent cache to collect rmap records for anything in + * this fork that matches the AG. + */ +STATIC int +xrep_rmap_scan_iext( + struct xrep_rmap_ifork *rf, + struct xfs_ifork *ifp) +{ + struct xfs_bmbt_irec rec; + struct xfs_iext_cursor icur; + int error; + + for_each_xfs_iext(ifp, &icur, &rec) { + if (isnullstartblock(rec.br_startblock)) + continue; + error = xrep_rmap_visit_bmbt(NULL, &rec, rf); + if (error) + return error; + } + + return xrep_rmap_stash_accumulated(rf); +} + +/* Find all the extents from a given AG in an inode fork. */ +STATIC int +xrep_rmap_scan_ifork( + struct xrep_rmap *rr, + struct xfs_inode *ip, + int whichfork) +{ + struct xrep_rmap_ifork rf = { + .accum = { .rm_owner = ip->i_ino, }, + .rr = rr, + .whichfork = whichfork, + }; + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); + int error = 0; + + if (!ifp) + return 0; + + if (ifp->if_format == XFS_DINODE_FMT_BTREE) { + bool mappings_done; + + /* + * Scan the bmap btree for data device mappings. This includes + * the btree blocks themselves, even if this is a realtime + * file. + */ + error = xrep_rmap_scan_bmbt(&rf, ip, &mappings_done); + if (error || mappings_done) + return error; + } else if (ifp->if_format != XFS_DINODE_FMT_EXTENTS) { + return 0; + } + + /* Scan incore extent cache if this isn't a realtime file. */ + if (xfs_ifork_is_realtime(ip, whichfork)) + return 0; + + return xrep_rmap_scan_iext(&rf, ifp); +} + +/* + * Take ILOCK on a file that we want to scan. + * + * Select ILOCK_EXCL if the file has an unloaded data bmbt or has an unloaded + * attr bmbt. Otherwise, take ILOCK_SHARED. + */ +static inline unsigned int +xrep_rmap_scan_ilock( + struct xfs_inode *ip) +{ + uint lock_mode = XFS_ILOCK_SHARED; + + if (xfs_need_iread_extents(&ip->i_df)) { + lock_mode = XFS_ILOCK_EXCL; + goto lock; + } + + if (xfs_inode_has_attr_fork(ip) && xfs_need_iread_extents(&ip->i_af)) + lock_mode = XFS_ILOCK_EXCL; + +lock: + xfs_ilock(ip, lock_mode); + return lock_mode; +} + +/* Record reverse mappings for a file. */ +STATIC int +xrep_rmap_scan_inode( + struct xrep_rmap *rr, + struct xfs_inode *ip) +{ + unsigned int lock_mode = 0; + int error; + + /* + * Directory updates (create/link/unlink/rename) drop the directory's + * ILOCK before finishing any rmapbt updates associated with directory + * shape changes. For this scan to coordinate correctly with the live + * update hook, we must take the only lock (i_rwsem) that is held all + * the way to dir op completion. This will get fixed by the parent + * pointer patchset. + */ + if (S_ISDIR(VFS_I(ip)->i_mode)) { + lock_mode = XFS_IOLOCK_SHARED; + xfs_ilock(ip, lock_mode); + } + lock_mode |= xrep_rmap_scan_ilock(ip); + + /* Check the data fork. */ + error = xrep_rmap_scan_ifork(rr, ip, XFS_DATA_FORK); + if (error) + goto out_unlock; + + /* Check the attr fork. */ + error = xrep_rmap_scan_ifork(rr, ip, XFS_ATTR_FORK); + if (error) + goto out_unlock; + + /* COW fork extents are "owned" by the refcount btree. */ + + xchk_iscan_mark_visited(&rr->iscan, ip); +out_unlock: + xfs_iunlock(ip, lock_mode); + return error; +} + +/* Section (I): Find all AG metadata extents except for free space metadata. */ + +struct xrep_rmap_inodes { + struct xrep_rmap *rr; + struct xagb_bitmap inobt_blocks; /* INOBIT */ + struct xagb_bitmap ichunk_blocks; /* ICHUNKBIT */ +}; + +/* Record inode btree rmaps. */ +STATIC int +xrep_rmap_walk_inobt( + struct xfs_btree_cur *cur, + const union xfs_btree_rec *rec, + void *priv) +{ + struct xfs_inobt_rec_incore irec; + struct xrep_rmap_inodes *ri = priv; + struct xfs_mount *mp = cur->bc_mp; + xfs_agblock_t agbno; + xfs_extlen_t aglen; + xfs_agino_t agino; + xfs_agino_t iperhole; + unsigned int i; + int error; + + /* Record the inobt blocks. */ + error = xagb_bitmap_set_btcur_path(&ri->inobt_blocks, cur); + if (error) + return error; + + xfs_inobt_btrec_to_irec(mp, rec, &irec); + if (xfs_inobt_check_irec(cur->bc_ag.pag, &irec) != NULL) + return -EFSCORRUPTED; + + agino = irec.ir_startino; + + /* Record a non-sparse inode chunk. */ + if (!xfs_inobt_issparse(irec.ir_holemask)) { + agbno = XFS_AGINO_TO_AGBNO(mp, agino); + aglen = max_t(xfs_extlen_t, 1, + XFS_INODES_PER_CHUNK / mp->m_sb.sb_inopblock); + + return xagb_bitmap_set(&ri->ichunk_blocks, agbno, aglen); + } + + /* Iterate each chunk. */ + iperhole = max_t(xfs_agino_t, mp->m_sb.sb_inopblock, + XFS_INODES_PER_HOLEMASK_BIT); + aglen = iperhole / mp->m_sb.sb_inopblock; + for (i = 0, agino = irec.ir_startino; + i < XFS_INOBT_HOLEMASK_BITS; + i += iperhole / XFS_INODES_PER_HOLEMASK_BIT, agino += iperhole) { + /* Skip holes. */ + if (irec.ir_holemask & (1 << i)) + continue; + + /* Record the inode chunk otherwise. */ + agbno = XFS_AGINO_TO_AGBNO(mp, agino); + error = xagb_bitmap_set(&ri->ichunk_blocks, agbno, aglen); + if (error) + return error; + } + + return 0; +} + +/* Collect rmaps for the blocks containing inode btrees and the inode chunks. */ +STATIC int +xrep_rmap_find_inode_rmaps( + struct xrep_rmap *rr) +{ + struct xrep_rmap_inodes ri = { + .rr = rr, + }; + struct xfs_scrub *sc = rr->sc; + int error; + + xagb_bitmap_init(&ri.inobt_blocks); + xagb_bitmap_init(&ri.ichunk_blocks); + + /* + * Iterate every record in the inobt so we can capture all the inode + * chunks and the blocks in the inobt itself. + */ + error = xfs_btree_query_all(sc->sa.ino_cur, xrep_rmap_walk_inobt, &ri); + if (error) + goto out_bitmap; + + /* + * Note that if there are zero records in the inobt then query_all does + * nothing and we have to account the empty inobt root manually. + */ + if (xagb_bitmap_empty(&ri.ichunk_blocks)) { + struct xfs_agi *agi = sc->sa.agi_bp->b_addr; + + error = xagb_bitmap_set(&ri.inobt_blocks, + be32_to_cpu(agi->agi_root), 1); + if (error) + goto out_bitmap; + } + + /* Scan the finobt too. */ + if (xfs_has_finobt(sc->mp)) { + error = xagb_bitmap_set_btblocks(&ri.inobt_blocks, + sc->sa.fino_cur); + if (error) + goto out_bitmap; + } + + /* Generate rmaps for everything. */ + error = xrep_rmap_stash_bitmap(rr, &ri.inobt_blocks, + &XFS_RMAP_OINFO_INOBT); + if (error) + goto out_bitmap; + error = xrep_rmap_stash_bitmap(rr, &ri.ichunk_blocks, + &XFS_RMAP_OINFO_INODES); + +out_bitmap: + xagb_bitmap_destroy(&ri.inobt_blocks); + xagb_bitmap_destroy(&ri.ichunk_blocks); + return error; +} + +/* Record a CoW staging extent. */ +STATIC int +xrep_rmap_walk_cowblocks( + struct xfs_btree_cur *cur, + const struct xfs_refcount_irec *irec, + void *priv) +{ + struct xagb_bitmap *bitmap = priv; + + if (!xfs_refcount_check_domain(irec) || + irec->rc_domain != XFS_REFC_DOMAIN_COW) + return -EFSCORRUPTED; + + return xagb_bitmap_set(bitmap, irec->rc_startblock, irec->rc_blockcount); +} + +/* + * Collect rmaps for the blocks containing the refcount btree, and all CoW + * staging extents. + */ +STATIC int +xrep_rmap_find_refcount_rmaps( + struct xrep_rmap *rr) +{ + struct xagb_bitmap refcountbt_blocks; /* REFCBIT */ + struct xagb_bitmap cow_blocks; /* COWBIT */ + struct xfs_refcount_irec low = { + .rc_startblock = 0, + .rc_domain = XFS_REFC_DOMAIN_COW, + }; + struct xfs_refcount_irec high = { + .rc_startblock = -1U, + .rc_domain = XFS_REFC_DOMAIN_COW, + }; + struct xfs_scrub *sc = rr->sc; + int error; + + if (!xfs_has_reflink(sc->mp)) + return 0; + + xagb_bitmap_init(&refcountbt_blocks); + xagb_bitmap_init(&cow_blocks); + + /* refcountbt */ + error = xagb_bitmap_set_btblocks(&refcountbt_blocks, sc->sa.refc_cur); + if (error) + goto out_bitmap; + + /* Collect rmaps for CoW staging extents. */ + error = xfs_refcount_query_range(sc->sa.refc_cur, &low, &high, + xrep_rmap_walk_cowblocks, &cow_blocks); + if (error) + goto out_bitmap; + + /* Generate rmaps for everything. */ + error = xrep_rmap_stash_bitmap(rr, &cow_blocks, &XFS_RMAP_OINFO_COW); + if (error) + goto out_bitmap; + error = xrep_rmap_stash_bitmap(rr, &refcountbt_blocks, + &XFS_RMAP_OINFO_REFC); + +out_bitmap: + xagb_bitmap_destroy(&cow_blocks); + xagb_bitmap_destroy(&refcountbt_blocks); + return error; +} + +/* Generate rmaps for the AG headers (AGI/AGF/AGFL) */ +STATIC int +xrep_rmap_find_agheader_rmaps( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + + /* Create a record for the AG sb->agfl. */ + return xrep_rmap_stash(rr, XFS_SB_BLOCK(sc->mp), + XFS_AGFL_BLOCK(sc->mp) - XFS_SB_BLOCK(sc->mp) + 1, + XFS_RMAP_OWN_FS, 0, 0); +} + +/* Generate rmaps for the log, if it's in this AG. */ +STATIC int +xrep_rmap_find_log_rmaps( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + + if (!xfs_ag_contains_log(sc->mp, sc->sa.pag->pag_agno)) + return 0; + + return xrep_rmap_stash(rr, + XFS_FSB_TO_AGBNO(sc->mp, sc->mp->m_sb.sb_logstart), + sc->mp->m_sb.sb_logblocks, XFS_RMAP_OWN_LOG, 0, 0); +} + +/* Check and count all the records that we gathered. */ +STATIC int +xrep_rmap_check_record( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xrep_rmap *rr = priv; + int error; + + error = xrep_rmap_check_mapping(rr->sc, rec); + if (error) + return error; + + rr->nr_records++; + return 0; +} + +/* + * Generate all the reverse-mappings for this AG, a list of the old rmapbt + * blocks, and the new btreeblks count. Figure out if we have enough free + * space to reconstruct the inode btrees. The caller must clean up the lists + * if anything goes wrong. This implements section (I) above. + */ +STATIC int +xrep_rmap_find_rmaps( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + struct xchk_ag *sa = &sc->sa; + struct xfs_inode *ip; + struct xfs_btree_cur *mcur; + int error; + + /* Find all the per-AG metadata. */ + xrep_ag_btcur_init(sc, &sc->sa); + + error = xrep_rmap_find_inode_rmaps(rr); + if (error) + goto end_agscan; + + error = xrep_rmap_find_refcount_rmaps(rr); + if (error) + goto end_agscan; + + error = xrep_rmap_find_agheader_rmaps(rr); + if (error) + goto end_agscan; + + error = xrep_rmap_find_log_rmaps(rr); +end_agscan: + xchk_ag_btcur_free(&sc->sa); + if (error) + return error; + + /* + * Set up for a potentially lengthy filesystem scan by reducing our + * transaction resource usage for the duration. Specifically: + * + * Unlock the AG header buffers and cancel the transaction to release + * the log grant space while we scan the filesystem. + * + * Create a new empty transaction to eliminate the possibility of the + * inode scan deadlocking on cyclical metadata. + * + * We pass the empty transaction to the file scanning function to avoid + * repeatedly cycling empty transactions. This can be done even though + * we take the IOLOCK to quiesce the file because empty transactions + * do not take sb_internal. + */ + sa->agf_bp = NULL; + sa->agi_bp = NULL; + xchk_trans_cancel(sc); + error = xchk_trans_alloc_empty(sc); + if (error) + return error; + + /* Iterate all AGs for inodes rmaps. */ + while ((error = xchk_iscan_iter(&rr->iscan, &ip)) == 1) { + error = xrep_rmap_scan_inode(rr, ip); + xchk_irele(sc, ip); + if (error) + break; + + if (xchk_should_terminate(sc, &error)) + break; + } + xchk_iscan_iter_finish(&rr->iscan); + if (error) + return error; + + /* + * Switch out for a real transaction and lock the AG headers in + * preparation for building a new tree. + */ + xchk_trans_cancel(sc); + error = xchk_setup_fs(sc); + if (error) + return error; + error = xchk_perag_drain_and_lock(sc); + if (error) + return error; + + /* + * If a hook failed to update the in-memory btree, we lack the data to + * continue the repair. + */ + if (xchk_iscan_aborted(&rr->iscan)) + return -EFSCORRUPTED; + + /* + * Now that we have everything locked again, we need to count the + * number of rmap records stashed in the btree. This should reflect + * all actively-owned space in the filesystem. At the same time, check + * all our records before we start building a new btree, which requires + * a bnobt cursor. + */ + mcur = xfs_rmapbt_mem_cursor(rr->sc->sa.pag, NULL, &rr->rmap_btree); + sc->sa.bno_cur = xfs_bnobt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp, + sc->sa.pag); + + rr->nr_records = 0; + error = xfs_rmap_query_all(mcur, xrep_rmap_check_record, rr); + + xfs_btree_del_cursor(sc->sa.bno_cur, error); + sc->sa.bno_cur = NULL; + xfs_btree_del_cursor(mcur, error); + + return error; +} + +/* Section (II): Reserving space for new rmapbt and setting free space bitmap */ + +struct xrep_rmap_agfl { + struct xagb_bitmap *bitmap; + xfs_agnumber_t agno; +}; + +/* Add an AGFL block to the rmap list. */ +STATIC int +xrep_rmap_walk_agfl( + struct xfs_mount *mp, + xfs_agblock_t agbno, + void *priv) +{ + struct xrep_rmap_agfl *ra = priv; + + return xagb_bitmap_set(ra->bitmap, agbno, 1); +} + +/* + * Run one round of reserving space for the new rmapbt and recomputing the + * number of blocks needed to store the previously observed rmapbt records and + * the ones we'll create for the free space metadata. When we don't need more + * blocks, return a bitmap of OWN_AG extents in @freesp_blocks and set @done to + * true. + */ +STATIC int +xrep_rmap_try_reserve( + struct xrep_rmap *rr, + struct xfs_btree_cur *rmap_cur, + struct xagb_bitmap *freesp_blocks, + uint64_t *blocks_reserved, + bool *done) +{ + struct xrep_rmap_agfl ra = { + .bitmap = freesp_blocks, + .agno = rr->sc->sa.pag->pag_agno, + }; + struct xfs_scrub *sc = rr->sc; + struct xrep_newbt_resv *resv, *n; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + struct xfs_buf *agfl_bp; + uint64_t nr_blocks; /* RMB */ + uint64_t freesp_records; + int error; + + /* + * We're going to recompute new_btree.bload.nr_blocks at the end of + * this function to reflect however many btree blocks we need to store + * all the rmap records (including the ones that reflect the changes we + * made to support the new rmapbt blocks), so we save the old value + * here so we can decide if we've reserved enough blocks. + */ + nr_blocks = rr->new_btree.bload.nr_blocks; + + /* + * Make sure we've reserved enough space for the new btree. This can + * change the shape of the free space btrees, which can cause secondary + * interactions with the rmap records because all three space btrees + * have the same rmap owner. We'll account for all that below. + */ + error = xrep_newbt_alloc_blocks(&rr->new_btree, + nr_blocks - *blocks_reserved); + if (error) + return error; + + *blocks_reserved = rr->new_btree.bload.nr_blocks; + + /* Clear everything in the bitmap. */ + xagb_bitmap_destroy(freesp_blocks); + + /* Set all the bnobt blocks in the bitmap. */ + sc->sa.bno_cur = xfs_bnobt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp, + sc->sa.pag); + error = xagb_bitmap_set_btblocks(freesp_blocks, sc->sa.bno_cur); + xfs_btree_del_cursor(sc->sa.bno_cur, error); + sc->sa.bno_cur = NULL; + if (error) + return error; + + /* Set all the cntbt blocks in the bitmap. */ + sc->sa.cnt_cur = xfs_cntbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp, + sc->sa.pag); + error = xagb_bitmap_set_btblocks(freesp_blocks, sc->sa.cnt_cur); + xfs_btree_del_cursor(sc->sa.cnt_cur, error); + sc->sa.cnt_cur = NULL; + if (error) + return error; + + /* Record our new btreeblks value. */ + rr->freesp_btblocks = xagb_bitmap_hweight(freesp_blocks) - 2; + + /* Set all the new rmapbt blocks in the bitmap. */ + list_for_each_entry_safe(resv, n, &rr->new_btree.resv_list, list) { + error = xagb_bitmap_set(freesp_blocks, resv->agbno, resv->len); + if (error) + return error; + } + + /* Set all the AGFL blocks in the bitmap. */ + error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp); + if (error) + return error; + + error = xfs_agfl_walk(sc->mp, agf, agfl_bp, xrep_rmap_walk_agfl, &ra); + if (error) + return error; + + /* Count the extents in the bitmap. */ + freesp_records = xagb_bitmap_count_set_regions(freesp_blocks); + + /* Compute how many blocks we'll need for all the rmaps. */ + error = xfs_btree_bload_compute_geometry(rmap_cur, + &rr->new_btree.bload, rr->nr_records + freesp_records); + if (error) + return error; + + /* We're done when we don't need more blocks. */ + *done = nr_blocks >= rr->new_btree.bload.nr_blocks; + return 0; +} + +/* + * Iteratively reserve space for rmap btree while recording OWN_AG rmaps for + * the free space metadata. This implements section (II) above. + */ +STATIC int +xrep_rmap_reserve_space( + struct xrep_rmap *rr, + struct xfs_btree_cur *rmap_cur) +{ + struct xagb_bitmap freesp_blocks; /* AGBIT */ + uint64_t blocks_reserved = 0; + bool done = false; + int error; + + /* Compute how many blocks we'll need for the rmaps collected so far. */ + error = xfs_btree_bload_compute_geometry(rmap_cur, + &rr->new_btree.bload, rr->nr_records); + if (error) + return error; + + /* Last chance to abort before we start committing fixes. */ + if (xchk_should_terminate(rr->sc, &error)) + return error; + + xagb_bitmap_init(&freesp_blocks); + + /* + * Iteratively reserve space for the new rmapbt and recompute the + * number of blocks needed to store the previously observed rmapbt + * records and the ones we'll create for the free space metadata. + * Finish when we don't need more blocks. + */ + do { + error = xrep_rmap_try_reserve(rr, rmap_cur, &freesp_blocks, + &blocks_reserved, &done); + if (error) + goto out_bitmap; + } while (!done); + + /* Emit rmaps for everything in the free space bitmap. */ + xrep_ag_btcur_init(rr->sc, &rr->sc->sa); + error = xrep_rmap_stash_bitmap(rr, &freesp_blocks, &XFS_RMAP_OINFO_AG); + xchk_ag_btcur_free(&rr->sc->sa); + +out_bitmap: + xagb_bitmap_destroy(&freesp_blocks); + return error; +} + +/* Section (III): Building the new rmap btree. */ + +/* Update the AGF counters. */ +STATIC int +xrep_rmap_reset_counters( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + struct xfs_perag *pag = sc->sa.pag; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + xfs_agblock_t rmap_btblocks; + + /* + * The AGF header contains extra information related to the reverse + * mapping btree, so we must update those fields here. + */ + rmap_btblocks = rr->new_btree.afake.af_blocks - 1; + agf->agf_btreeblks = cpu_to_be32(rr->freesp_btblocks + rmap_btblocks); + xfs_alloc_log_agf(sc->tp, sc->sa.agf_bp, XFS_AGF_BTREEBLKS); + + /* + * 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 rmapbt 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_rmap_level = pag->pagf_rmap_level; + + /* Reinitialize with the values we just logged. */ + return xrep_reinit_pagf(sc); +} + +/* Retrieve rmapbt data for bulk load. */ +STATIC int +xrep_rmap_get_records( + struct xfs_btree_cur *cur, + unsigned int idx, + struct xfs_btree_block *block, + unsigned int nr_wanted, + void *priv) +{ + struct xrep_rmap *rr = priv; + union xfs_btree_rec *block_rec; + unsigned int loaded; + int error; + + for (loaded = 0; loaded < nr_wanted; loaded++, idx++) { + int stat = 0; + + error = xfs_btree_increment(rr->mcur, 0, &stat); + if (error) + return error; + if (!stat) + return -EFSCORRUPTED; + + error = xfs_rmap_get_rec(rr->mcur, &cur->bc_rec.r, &stat); + if (error) + return error; + if (!stat) + return -EFSCORRUPTED; + + 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_rmap_claim_block( + struct xfs_btree_cur *cur, + union xfs_btree_ptr *ptr, + void *priv) +{ + struct xrep_rmap *rr = priv; + + return xrep_newbt_claim_block(cur, &rr->new_btree, ptr); +} + +/* Custom allocation function for new rmap btrees. */ +STATIC int +xrep_rmap_alloc_vextent( + struct xfs_scrub *sc, + struct xfs_alloc_arg *args, + xfs_fsblock_t alloc_hint) +{ + int error; + + /* + * We don't want an rmap update on the allocation, since we iteratively + * compute the OWN_AG records /after/ allocating blocks for the records + * that we already know we need to store. Therefore, fix the freelist + * with the NORMAP flag set so that we don't also try to create an rmap + * for new AGFL blocks. + */ + error = xrep_fix_freelist(sc, XFS_ALLOC_FLAG_NORMAP); + if (error) + return error; + + /* + * If xrep_fix_freelist fixed the freelist by moving blocks from the + * free space btrees or by removing blocks from the AGFL and queueing + * an EFI to free the block, the transaction will be dirty. This + * second case is of interest to us. + * + * Later on, we will need to compare gaps in the new recordset against + * the block usage of all OWN_AG owners in order to free the old + * btree's blocks, which means that we can't have EFIs for former AGFL + * blocks attached to the repair transaction when we commit the new + * btree. + * + * xrep_newbt_alloc_blocks guarantees this for us by calling + * xrep_defer_finish to commit anything that fix_freelist may have + * added to the transaction. + */ + return xfs_alloc_vextent_near_bno(args, alloc_hint); +} + + +/* Count the records in this btree. */ +STATIC int +xrep_rmap_count_records( + struct xfs_btree_cur *cur, + unsigned long long *nr) +{ + int running = 1; + int error; + + *nr = 0; + + error = xfs_btree_goto_left_edge(cur); + if (error) + return error; + + while (running && !(error = xfs_btree_increment(cur, 0, &running))) { + if (running) + (*nr)++; + } + + return error; +} +/* + * Use the collected rmap information to stage a new rmap btree. If this is + * successful we'll return with the new btree root information logged to the + * repair transaction but not yet committed. This implements section (III) + * above. + */ +STATIC int +xrep_rmap_build_new_tree( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + struct xfs_perag *pag = sc->sa.pag; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + struct xfs_btree_cur *rmap_cur; + xfs_fsblock_t fsbno; + int error; + + /* + * Preserve the old rmapbt block count so that we can adjust the + * per-AG rmapbt reservation after we commit the new btree root and + * want to dispose of the old btree blocks. + */ + rr->old_rmapbt_fsbcount = be32_to_cpu(agf->agf_rmap_blocks); + + /* + * 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. The new blocks are accounted to the + * rmapbt per-AG reservation, which we will adjust further after + * committing the new btree. + */ + fsbno = XFS_AGB_TO_FSB(sc->mp, pag->pag_agno, XFS_RMAP_BLOCK(sc->mp)); + xrep_newbt_init_ag(&rr->new_btree, sc, &XFS_RMAP_OINFO_SKIP_UPDATE, + fsbno, XFS_AG_RESV_RMAPBT); + rr->new_btree.bload.get_records = xrep_rmap_get_records; + rr->new_btree.bload.claim_block = xrep_rmap_claim_block; + rr->new_btree.alloc_vextent = xrep_rmap_alloc_vextent; + rmap_cur = xfs_rmapbt_init_cursor(sc->mp, NULL, NULL, pag); + xfs_btree_stage_afakeroot(rmap_cur, &rr->new_btree.afake); + + /* + * Initialize @rr->new_btree, reserve space for the new rmapbt, + * and compute OWN_AG rmaps. + */ + error = xrep_rmap_reserve_space(rr, rmap_cur); + if (error) + goto err_cur; + + /* + * Count the rmapbt records again, because the space reservation + * for the rmapbt itself probably added more records to the btree. + */ + rr->mcur = xfs_rmapbt_mem_cursor(rr->sc->sa.pag, NULL, + &rr->rmap_btree); + + error = xrep_rmap_count_records(rr->mcur, &rr->nr_records); + if (error) + goto err_mcur; + + /* + * Due to btree slack factors, it's possible for a new btree to be one + * level taller than the old btree. Update the incore btree height so + * that we don't trip the verifiers when writing the new btree blocks + * to disk. + */ + pag->pagf_repair_rmap_level = rr->new_btree.bload.btree_height; + + /* + * Move the cursor to the left edge of the tree so that the first + * increment in ->get_records positions us at the first record. + */ + error = xfs_btree_goto_left_edge(rr->mcur); + if (error) + goto err_level; + + /* Add all observed rmap records. */ + error = xfs_btree_bload(rmap_cur, &rr->new_btree.bload, rr); + if (error) + goto err_level; + + /* + * Install the new btree in the AG header. After this point the old + * btree is no longer accessible and the new tree is live. + */ + xfs_rmapbt_commit_staged_btree(rmap_cur, sc->tp, sc->sa.agf_bp); + xfs_btree_del_cursor(rmap_cur, 0); + xfs_btree_del_cursor(rr->mcur, 0); + rr->mcur = NULL; + + /* + * Now that we've written the new btree to disk, we don't need to keep + * updating the in-memory btree. Abort the scan to stop live updates. + */ + xchk_iscan_abort(&rr->iscan); + + /* + * The newly committed rmap recordset includes mappings for the blocks + * that we reserved to build the new btree. If there is excess space + * reservation to be freed, the corresponding rmap records must also be + * removed. + */ + rr->new_btree.oinfo = XFS_RMAP_OINFO_AG; + + /* Reset the AGF counters now that we've changed the btree shape. */ + error = xrep_rmap_reset_counters(rr); + if (error) + goto err_newbt; + + /* Dispose of any unused blocks and the accounting information. */ + error = xrep_newbt_commit(&rr->new_btree); + if (error) + return error; + + return xrep_roll_ag_trans(sc); + +err_level: + pag->pagf_repair_rmap_level = 0; +err_mcur: + xfs_btree_del_cursor(rr->mcur, error); +err_cur: + xfs_btree_del_cursor(rmap_cur, error); +err_newbt: + xrep_newbt_cancel(&rr->new_btree); + return error; +} + +/* Section (IV): Reaping the old btree. */ + +struct xrep_rmap_find_gaps { + struct xagb_bitmap rmap_gaps; + xfs_agblock_t next_agbno; +}; + +/* Subtract each free extent in the bnobt from the rmap gaps. */ +STATIC int +xrep_rmap_find_freesp( + struct xfs_btree_cur *cur, + const struct xfs_alloc_rec_incore *rec, + void *priv) +{ + struct xrep_rmap_find_gaps *rfg = priv; + + return xagb_bitmap_clear(&rfg->rmap_gaps, rec->ar_startblock, + rec->ar_blockcount); +} + +/* Record the free space we find, as part of cleaning out the btree. */ +STATIC int +xrep_rmap_find_gaps( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xrep_rmap_find_gaps *rfg = priv; + int error; + + if (rec->rm_startblock > rfg->next_agbno) { + error = xagb_bitmap_set(&rfg->rmap_gaps, rfg->next_agbno, + rec->rm_startblock - rfg->next_agbno); + if (error) + return error; + } + + rfg->next_agbno = max_t(xfs_agblock_t, rfg->next_agbno, + rec->rm_startblock + rec->rm_blockcount); + return 0; +} + +/* + * Reap the old rmapbt blocks. Now that the rmapbt is fully rebuilt, we make + * a list of gaps in the rmap records and a list of the extents mentioned in + * the bnobt. Any block that's in the new rmapbt gap list but not mentioned + * in the bnobt is a block from the old rmapbt and can be removed. + */ +STATIC int +xrep_rmap_remove_old_tree( + struct xrep_rmap *rr) +{ + struct xrep_rmap_find_gaps rfg = { + .next_agbno = 0, + }; + struct xfs_scrub *sc = rr->sc; + struct xfs_agf *agf = sc->sa.agf_bp->b_addr; + struct xfs_perag *pag = sc->sa.pag; + struct xfs_btree_cur *mcur; + xfs_agblock_t agend; + int error; + + xagb_bitmap_init(&rfg.rmap_gaps); + + /* Compute free space from the new rmapbt. */ + mcur = xfs_rmapbt_mem_cursor(rr->sc->sa.pag, NULL, &rr->rmap_btree); + + error = xfs_rmap_query_all(mcur, xrep_rmap_find_gaps, &rfg); + xfs_btree_del_cursor(mcur, error); + if (error) + goto out_bitmap; + + /* Insert a record for space between the last rmap and EOAG. */ + agend = be32_to_cpu(agf->agf_length); + if (rfg.next_agbno < agend) { + error = xagb_bitmap_set(&rfg.rmap_gaps, rfg.next_agbno, + agend - rfg.next_agbno); + if (error) + goto out_bitmap; + } + + /* Compute free space from the existing bnobt. */ + sc->sa.bno_cur = xfs_bnobt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp, + sc->sa.pag); + error = xfs_alloc_query_all(sc->sa.bno_cur, xrep_rmap_find_freesp, + &rfg); + xfs_btree_del_cursor(sc->sa.bno_cur, error); + sc->sa.bno_cur = NULL; + if (error) + goto out_bitmap; + + /* + * Free the "free" blocks that the new rmapbt knows about but the bnobt + * doesn't--these are the old rmapbt blocks. Credit the old rmapbt + * block usage count back to the per-AG rmapbt reservation (and not + * fdblocks, since the rmap btree lives in free space) to keep the + * reservation and free space accounting correct. + */ + error = xrep_reap_agblocks(sc, &rfg.rmap_gaps, + &XFS_RMAP_OINFO_ANY_OWNER, XFS_AG_RESV_RMAPBT); + if (error) + goto out_bitmap; + + /* + * Now that we've zapped all the old rmapbt blocks we can turn off + * the alternate height mechanism and reset the per-AG space + * reservation. + */ + pag->pagf_repair_rmap_level = 0; + sc->flags |= XREP_RESET_PERAG_RESV; +out_bitmap: + xagb_bitmap_destroy(&rfg.rmap_gaps); + return error; +} + +static inline bool +xrep_rmapbt_want_live_update( + struct xchk_iscan *iscan, + const struct xfs_owner_info *oi) +{ + if (xchk_iscan_aborted(iscan)) + return false; + + /* + * Before unlocking the AG header to perform the inode scan, we + * recorded reverse mappings for all AG metadata except for the OWN_AG + * metadata. IOWs, the in-memory btree knows about the AG headers, the + * two inode btrees, the CoW staging extents, and the refcount btrees. + * For these types of metadata, we need to record the live updates in + * the in-memory rmap btree. + * + * However, we do not scan the free space btrees or the AGFL until we + * have re-locked the AGF and are ready to reserve space for the new + * rmap btree, so we do not want live updates for OWN_AG metadata. + */ + if (XFS_RMAP_NON_INODE_OWNER(oi->oi_owner)) + return oi->oi_owner != XFS_RMAP_OWN_AG; + + /* Ignore updates to files that the scanner hasn't visited yet. */ + return xchk_iscan_want_live_update(iscan, oi->oi_owner); +} + +/* + * Apply a rmapbt update from the regular filesystem into our shadow btree. + * We're running from the thread that owns the AGF buffer and is generating + * the update, so we must be careful about which parts of the struct xrep_rmap + * that we change. + */ +static int +xrep_rmapbt_live_update( + struct notifier_block *nb, + unsigned long action, + void *data) +{ + struct xfs_rmap_update_params *p = data; + struct xrep_rmap *rr; + struct xfs_mount *mp; + struct xfs_btree_cur *mcur; + struct xfs_trans *tp; + void *txcookie; + int error; + + rr = container_of(nb, struct xrep_rmap, rhook.rmap_hook.nb); + mp = rr->sc->mp; + + if (!xrep_rmapbt_want_live_update(&rr->iscan, &p->oinfo)) + goto out_unlock; + + trace_xrep_rmap_live_update(mp, rr->sc->sa.pag->pag_agno, action, p); + + error = xrep_trans_alloc_hook_dummy(mp, &txcookie, &tp); + if (error) + goto out_abort; + + mutex_lock(&rr->lock); + mcur = xfs_rmapbt_mem_cursor(rr->sc->sa.pag, tp, &rr->rmap_btree); + error = __xfs_rmap_finish_intent(mcur, action, p->startblock, + p->blockcount, &p->oinfo, p->unwritten); + xfs_btree_del_cursor(mcur, error); + if (error) + goto out_cancel; + + error = xfbtree_trans_commit(&rr->rmap_btree, tp); + if (error) + goto out_cancel; + + xrep_trans_cancel_hook_dummy(&txcookie, tp); + mutex_unlock(&rr->lock); + return NOTIFY_DONE; + +out_cancel: + xfbtree_trans_cancel(&rr->rmap_btree, tp); + xrep_trans_cancel_hook_dummy(&txcookie, tp); +out_abort: + mutex_unlock(&rr->lock); + xchk_iscan_abort(&rr->iscan); +out_unlock: + return NOTIFY_DONE; +} + +/* Set up the filesystem scan components. */ +STATIC int +xrep_rmap_setup_scan( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + int error; + + mutex_init(&rr->lock); + + /* Set up in-memory rmap btree */ + error = xfs_rmapbt_mem_init(sc->mp, &rr->rmap_btree, sc->xmbtp, + sc->sa.pag->pag_agno); + if (error) + goto out_mutex; + + /* Retry iget every tenth of a second for up to 30 seconds. */ + xchk_iscan_start(sc, 30000, 100, &rr->iscan); + + /* + * Hook into live rmap operations so that we can update our in-memory + * btree to reflect live changes on the filesystem. Since we drop the + * AGF buffer to scan all the inodes, we need this piece to avoid + * installing a stale btree. + */ + ASSERT(sc->flags & XCHK_FSGATES_RMAP); + xfs_rmap_hook_setup(&rr->rhook, xrep_rmapbt_live_update); + error = xfs_rmap_hook_add(sc->sa.pag, &rr->rhook); + if (error) + goto out_iscan; + return 0; + +out_iscan: + xchk_iscan_teardown(&rr->iscan); + xfbtree_destroy(&rr->rmap_btree); +out_mutex: + mutex_destroy(&rr->lock); + return error; +} + +/* Tear down scan components. */ +STATIC void +xrep_rmap_teardown( + struct xrep_rmap *rr) +{ + struct xfs_scrub *sc = rr->sc; + + xchk_iscan_abort(&rr->iscan); + xfs_rmap_hook_del(sc->sa.pag, &rr->rhook); + xchk_iscan_teardown(&rr->iscan); + xfbtree_destroy(&rr->rmap_btree); + mutex_destroy(&rr->lock); +} + +/* Repair the rmap btree for some AG. */ +int +xrep_rmapbt( + struct xfs_scrub *sc) +{ + struct xrep_rmap *rr = sc->buf; + int error; + + error = xrep_rmap_setup_scan(rr); + if (error) + return error; + + /* + * Collect rmaps for everything in this AG that isn't space metadata. + * These rmaps won't change even as we try to allocate blocks. + */ + error = xrep_rmap_find_rmaps(rr); + if (error) + goto out_records; + + /* Rebuild the rmap information. */ + error = xrep_rmap_build_new_tree(rr); + if (error) + goto out_records; + + /* Kill the old tree. */ + error = xrep_rmap_remove_old_tree(rr); + if (error) + goto out_records; + +out_records: + xrep_rmap_teardown(rr); + return error; +} |