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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2018-2023 Oracle.  All Rights Reserved.4 * Author: Darrick J. Wong <djwong@kernel.org>5 */6#include "xfs.h"7#include "xfs_fs.h"8#include "xfs_shared.h"9#include "xfs_format.h"10#include "xfs_trans_resv.h"11#include "xfs_mount.h"12#include "xfs_btree.h"13#include "xfs_log_format.h"14#include "xfs_trans.h"15#include "xfs_sb.h"16#include "xfs_alloc.h"17#include "xfs_alloc_btree.h"18#include "xfs_ialloc.h"19#include "xfs_ialloc_btree.h"20#include "xfs_rmap.h"21#include "xfs_rmap_btree.h"22#include "xfs_refcount_btree.h"23#include "xfs_ag.h"24#include "xfs_inode.h"25#include "xfs_iunlink_item.h"26#include "scrub/scrub.h"27#include "scrub/common.h"28#include "scrub/trace.h"29#include "scrub/repair.h"30#include "scrub/bitmap.h"31#include "scrub/agb_bitmap.h"32#include "scrub/agino_bitmap.h"33#include "scrub/reap.h"34#include "scrub/xfile.h"35#include "scrub/xfarray.h"36 37/* Superblock */38 39/* Repair the superblock. */40int41xrep_superblock(42	struct xfs_scrub	*sc)43{44	struct xfs_mount	*mp = sc->mp;45	struct xfs_buf		*bp;46	xfs_agnumber_t		agno;47	int			error;48 49	/* Don't try to repair AG 0's sb; let xfs_repair deal with it. */50	agno = sc->sm->sm_agno;51	if (agno == 0)52		return -EOPNOTSUPP;53 54	error = xfs_sb_get_secondary(mp, sc->tp, agno, &bp);55	if (error)56		return error;57 58	/* Last chance to abort before we start committing fixes. */59	if (xchk_should_terminate(sc, &error))60		return error;61 62	/* Copy AG 0's superblock to this one. */63	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));64	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);65 66	/*67	 * Don't write out a secondary super with NEEDSREPAIR or log incompat68	 * features set, since both are ignored when set on a secondary.69	 */70	if (xfs_has_crc(mp)) {71		struct xfs_dsb		*sb = bp->b_addr;72 73		sb->sb_features_incompat &=74				~cpu_to_be32(XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR);75		sb->sb_features_log_incompat = 0;76	}77 78	/* Write this to disk. */79	xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_SB_BUF);80	xfs_trans_log_buf(sc->tp, bp, 0, BBTOB(bp->b_length) - 1);81	return 0;82}83 84/* AGF */85 86struct xrep_agf_allocbt {87	struct xfs_scrub	*sc;88	xfs_agblock_t		freeblks;89	xfs_agblock_t		longest;90};91 92/* Record free space shape information. */93STATIC int94xrep_agf_walk_allocbt(95	struct xfs_btree_cur		*cur,96	const struct xfs_alloc_rec_incore *rec,97	void				*priv)98{99	struct xrep_agf_allocbt		*raa = priv;100	int				error = 0;101 102	if (xchk_should_terminate(raa->sc, &error))103		return error;104 105	raa->freeblks += rec->ar_blockcount;106	if (rec->ar_blockcount > raa->longest)107		raa->longest = rec->ar_blockcount;108	return error;109}110 111/* Does this AGFL block look sane? */112STATIC int113xrep_agf_check_agfl_block(114	struct xfs_mount	*mp,115	xfs_agblock_t		agbno,116	void			*priv)117{118	struct xfs_scrub	*sc = priv;119 120	if (!xfs_verify_agbno(sc->sa.pag, agbno))121		return -EFSCORRUPTED;122	return 0;123}124 125/*126 * Offset within the xrep_find_ag_btree array for each btree type.  Avoid the127 * XFS_BTNUM_ names here to avoid creating a sparse array.128 */129enum {130	XREP_AGF_BNOBT = 0,131	XREP_AGF_CNTBT,132	XREP_AGF_RMAPBT,133	XREP_AGF_REFCOUNTBT,134	XREP_AGF_END,135	XREP_AGF_MAX136};137 138/* Check a btree root candidate. */139static inline bool140xrep_check_btree_root(141	struct xfs_scrub		*sc,142	struct xrep_find_ag_btree	*fab)143{144	return xfs_verify_agbno(sc->sa.pag, fab->root) &&145	       fab->height <= fab->maxlevels;146}147 148/*149 * Given the btree roots described by *fab, find the roots, check them for150 * sanity, and pass the root data back out via *fab.151 *152 * This is /also/ a chicken and egg problem because we have to use the rmapbt153 * (rooted in the AGF) to find the btrees rooted in the AGF.  We also have no154 * idea if the btrees make any sense.  If we hit obvious corruptions in those155 * btrees we'll bail out.156 */157STATIC int158xrep_agf_find_btrees(159	struct xfs_scrub		*sc,160	struct xfs_buf			*agf_bp,161	struct xrep_find_ag_btree	*fab,162	struct xfs_buf			*agfl_bp)163{164	struct xfs_agf			*old_agf = agf_bp->b_addr;165	int				error;166 167	/* Go find the root data. */168	error = xrep_find_ag_btree_roots(sc, agf_bp, fab, agfl_bp);169	if (error)170		return error;171 172	/* We must find the bnobt, cntbt, and rmapbt roots. */173	if (!xrep_check_btree_root(sc, &fab[XREP_AGF_BNOBT]) ||174	    !xrep_check_btree_root(sc, &fab[XREP_AGF_CNTBT]) ||175	    !xrep_check_btree_root(sc, &fab[XREP_AGF_RMAPBT]))176		return -EFSCORRUPTED;177 178	/*179	 * We relied on the rmapbt to reconstruct the AGF.  If we get a180	 * different root then something's seriously wrong.181	 */182	if (fab[XREP_AGF_RMAPBT].root != be32_to_cpu(old_agf->agf_rmap_root))183		return -EFSCORRUPTED;184 185	/* We must find the refcountbt root if that feature is enabled. */186	if (xfs_has_reflink(sc->mp) &&187	    !xrep_check_btree_root(sc, &fab[XREP_AGF_REFCOUNTBT]))188		return -EFSCORRUPTED;189 190	return 0;191}192 193/*194 * Reinitialize the AGF header, making an in-core copy of the old contents so195 * that we know which in-core state needs to be reinitialized.196 */197STATIC void198xrep_agf_init_header(199	struct xfs_scrub	*sc,200	struct xfs_buf		*agf_bp,201	struct xfs_agf		*old_agf)202{203	struct xfs_mount	*mp = sc->mp;204	struct xfs_perag	*pag = sc->sa.pag;205	struct xfs_agf		*agf = agf_bp->b_addr;206 207	memcpy(old_agf, agf, sizeof(*old_agf));208	memset(agf, 0, BBTOB(agf_bp->b_length));209	agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);210	agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);211	agf->agf_seqno = cpu_to_be32(pag->pag_agno);212	agf->agf_length = cpu_to_be32(pag->block_count);213	agf->agf_flfirst = old_agf->agf_flfirst;214	agf->agf_fllast = old_agf->agf_fllast;215	agf->agf_flcount = old_agf->agf_flcount;216	if (xfs_has_crc(mp))217		uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);218 219	/* Mark the incore AGF data stale until we're done fixing things. */220	ASSERT(xfs_perag_initialised_agf(pag));221	clear_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);222}223 224/* Set btree root information in an AGF. */225STATIC void226xrep_agf_set_roots(227	struct xfs_scrub		*sc,228	struct xfs_agf			*agf,229	struct xrep_find_ag_btree	*fab)230{231	agf->agf_bno_root = cpu_to_be32(fab[XREP_AGF_BNOBT].root);232	agf->agf_bno_level = cpu_to_be32(fab[XREP_AGF_BNOBT].height);233 234	agf->agf_cnt_root = cpu_to_be32(fab[XREP_AGF_CNTBT].root);235	agf->agf_cnt_level = cpu_to_be32(fab[XREP_AGF_CNTBT].height);236 237	agf->agf_rmap_root = cpu_to_be32(fab[XREP_AGF_RMAPBT].root);238	agf->agf_rmap_level = cpu_to_be32(fab[XREP_AGF_RMAPBT].height);239 240	if (xfs_has_reflink(sc->mp)) {241		agf->agf_refcount_root =242				cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].root);243		agf->agf_refcount_level =244				cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].height);245	}246}247 248/* Update all AGF fields which derive from btree contents. */249STATIC int250xrep_agf_calc_from_btrees(251	struct xfs_scrub	*sc,252	struct xfs_buf		*agf_bp)253{254	struct xrep_agf_allocbt	raa = { .sc = sc };255	struct xfs_btree_cur	*cur = NULL;256	struct xfs_agf		*agf = agf_bp->b_addr;257	struct xfs_mount	*mp = sc->mp;258	xfs_agblock_t		btreeblks;259	xfs_agblock_t		blocks;260	int			error;261 262	/* Update the AGF counters from the bnobt. */263	cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);264	error = xfs_alloc_query_all(cur, xrep_agf_walk_allocbt, &raa);265	if (error)266		goto err;267	error = xfs_btree_count_blocks(cur, &blocks);268	if (error)269		goto err;270	xfs_btree_del_cursor(cur, error);271	btreeblks = blocks - 1;272	agf->agf_freeblks = cpu_to_be32(raa.freeblks);273	agf->agf_longest = cpu_to_be32(raa.longest);274 275	/* Update the AGF counters from the cntbt. */276	cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);277	error = xfs_btree_count_blocks(cur, &blocks);278	if (error)279		goto err;280	xfs_btree_del_cursor(cur, error);281	btreeblks += blocks - 1;282 283	/* Update the AGF counters from the rmapbt. */284	cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);285	error = xfs_btree_count_blocks(cur, &blocks);286	if (error)287		goto err;288	xfs_btree_del_cursor(cur, error);289	agf->agf_rmap_blocks = cpu_to_be32(blocks);290	btreeblks += blocks - 1;291 292	agf->agf_btreeblks = cpu_to_be32(btreeblks);293 294	/* Update the AGF counters from the refcountbt. */295	if (xfs_has_reflink(mp)) {296		cur = xfs_refcountbt_init_cursor(mp, sc->tp, agf_bp,297				sc->sa.pag);298		error = xfs_btree_count_blocks(cur, &blocks);299		if (error)300			goto err;301		xfs_btree_del_cursor(cur, error);302		agf->agf_refcount_blocks = cpu_to_be32(blocks);303	}304 305	return 0;306err:307	xfs_btree_del_cursor(cur, error);308	return error;309}310 311/* Commit the new AGF and reinitialize the incore state. */312STATIC int313xrep_agf_commit_new(314	struct xfs_scrub	*sc,315	struct xfs_buf		*agf_bp)316{317	struct xfs_perag	*pag;318	struct xfs_agf		*agf = agf_bp->b_addr;319 320	/* Trigger fdblocks recalculation */321	xfs_force_summary_recalc(sc->mp);322 323	/* Write this to disk. */324	xfs_trans_buf_set_type(sc->tp, agf_bp, XFS_BLFT_AGF_BUF);325	xfs_trans_log_buf(sc->tp, agf_bp, 0, BBTOB(agf_bp->b_length) - 1);326 327	/* Now reinitialize the in-core counters we changed. */328	pag = sc->sa.pag;329	pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);330	pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);331	pag->pagf_longest = be32_to_cpu(agf->agf_longest);332	pag->pagf_bno_level = be32_to_cpu(agf->agf_bno_level);333	pag->pagf_cnt_level = be32_to_cpu(agf->agf_cnt_level);334	pag->pagf_rmap_level = be32_to_cpu(agf->agf_rmap_level);335	pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);336	set_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);337 338	return xrep_roll_ag_trans(sc);339}340 341/* Repair the AGF. v5 filesystems only. */342int343xrep_agf(344	struct xfs_scrub		*sc)345{346	struct xrep_find_ag_btree	fab[XREP_AGF_MAX] = {347		[XREP_AGF_BNOBT] = {348			.rmap_owner = XFS_RMAP_OWN_AG,349			.buf_ops = &xfs_bnobt_buf_ops,350			.maxlevels = sc->mp->m_alloc_maxlevels,351		},352		[XREP_AGF_CNTBT] = {353			.rmap_owner = XFS_RMAP_OWN_AG,354			.buf_ops = &xfs_cntbt_buf_ops,355			.maxlevels = sc->mp->m_alloc_maxlevels,356		},357		[XREP_AGF_RMAPBT] = {358			.rmap_owner = XFS_RMAP_OWN_AG,359			.buf_ops = &xfs_rmapbt_buf_ops,360			.maxlevels = sc->mp->m_rmap_maxlevels,361		},362		[XREP_AGF_REFCOUNTBT] = {363			.rmap_owner = XFS_RMAP_OWN_REFC,364			.buf_ops = &xfs_refcountbt_buf_ops,365			.maxlevels = sc->mp->m_refc_maxlevels,366		},367		[XREP_AGF_END] = {368			.buf_ops = NULL,369		},370	};371	struct xfs_agf			old_agf;372	struct xfs_mount		*mp = sc->mp;373	struct xfs_buf			*agf_bp;374	struct xfs_buf			*agfl_bp;375	struct xfs_agf			*agf;376	int				error;377 378	/* We require the rmapbt to rebuild anything. */379	if (!xfs_has_rmapbt(mp))380		return -EOPNOTSUPP;381 382	/*383	 * Make sure we have the AGF buffer, as scrub might have decided it384	 * was corrupt after xfs_alloc_read_agf failed with -EFSCORRUPTED.385	 */386	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,387			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,388						XFS_AGF_DADDR(mp)),389			XFS_FSS_TO_BB(mp, 1), 0, &agf_bp, NULL);390	if (error)391		return error;392	agf_bp->b_ops = &xfs_agf_buf_ops;393	agf = agf_bp->b_addr;394 395	/*396	 * Load the AGFL so that we can screen out OWN_AG blocks that are on397	 * the AGFL now; these blocks might have once been part of the398	 * bno/cnt/rmap btrees but are not now.  This is a chicken and egg399	 * problem: the AGF is corrupt, so we have to trust the AGFL contents400	 * because we can't do any serious cross-referencing with any of the401	 * btrees rooted in the AGF.  If the AGFL contents are obviously bad402	 * then we'll bail out.403	 */404	error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);405	if (error)406		return error;407 408	/*409	 * Spot-check the AGFL blocks; if they're obviously corrupt then410	 * there's nothing we can do but bail out.411	 */412	error = xfs_agfl_walk(sc->mp, agf_bp->b_addr, agfl_bp,413			xrep_agf_check_agfl_block, sc);414	if (error)415		return error;416 417	/*418	 * Find the AGF btree roots.  This is also a chicken-and-egg situation;419	 * see the function for more details.420	 */421	error = xrep_agf_find_btrees(sc, agf_bp, fab, agfl_bp);422	if (error)423		return error;424 425	/* Last chance to abort before we start committing fixes. */426	if (xchk_should_terminate(sc, &error))427		return error;428 429	/* Start rewriting the header and implant the btrees we found. */430	xrep_agf_init_header(sc, agf_bp, &old_agf);431	xrep_agf_set_roots(sc, agf, fab);432	error = xrep_agf_calc_from_btrees(sc, agf_bp);433	if (error)434		goto out_revert;435 436	/* Commit the changes and reinitialize incore state. */437	return xrep_agf_commit_new(sc, agf_bp);438 439out_revert:440	/* Mark the incore AGF state stale and revert the AGF. */441	clear_bit(XFS_AGSTATE_AGF_INIT, &sc->sa.pag->pag_opstate);442	memcpy(agf, &old_agf, sizeof(old_agf));443	return error;444}445 446/* AGFL */447 448struct xrep_agfl {449	/* Bitmap of alleged AGFL blocks that we're not going to add. */450	struct xagb_bitmap	crossed;451 452	/* Bitmap of other OWN_AG metadata blocks. */453	struct xagb_bitmap	agmetablocks;454 455	/* Bitmap of free space. */456	struct xagb_bitmap	*freesp;457 458	/* rmapbt cursor for finding crosslinked blocks */459	struct xfs_btree_cur	*rmap_cur;460 461	struct xfs_scrub	*sc;462};463 464/* Record all OWN_AG (free space btree) information from the rmap data. */465STATIC int466xrep_agfl_walk_rmap(467	struct xfs_btree_cur	*cur,468	const struct xfs_rmap_irec *rec,469	void			*priv)470{471	struct xrep_agfl	*ra = priv;472	int			error = 0;473 474	if (xchk_should_terminate(ra->sc, &error))475		return error;476 477	/* Record all the OWN_AG blocks. */478	if (rec->rm_owner == XFS_RMAP_OWN_AG) {479		error = xagb_bitmap_set(ra->freesp, rec->rm_startblock,480				rec->rm_blockcount);481		if (error)482			return error;483	}484 485	return xagb_bitmap_set_btcur_path(&ra->agmetablocks, cur);486}487 488/* Strike out the blocks that are cross-linked according to the rmapbt. */489STATIC int490xrep_agfl_check_extent(491	uint32_t		agbno,492	uint32_t		len,493	void			*priv)494{495	struct xrep_agfl	*ra = priv;496	xfs_agblock_t		last_agbno = agbno + len - 1;497	int			error;498 499	while (agbno <= last_agbno) {500		bool		other_owners;501 502		error = xfs_rmap_has_other_keys(ra->rmap_cur, agbno, 1,503				&XFS_RMAP_OINFO_AG, &other_owners);504		if (error)505			return error;506 507		if (other_owners) {508			error = xagb_bitmap_set(&ra->crossed, agbno, 1);509			if (error)510				return error;511		}512 513		if (xchk_should_terminate(ra->sc, &error))514			return error;515		agbno++;516	}517 518	return 0;519}520 521/*522 * Map out all the non-AGFL OWN_AG space in this AG so that we can deduce523 * which blocks belong to the AGFL.524 *525 * Compute the set of old AGFL blocks by subtracting from the list of OWN_AG526 * blocks the list of blocks owned by all other OWN_AG metadata (bnobt, cntbt,527 * rmapbt).  These are the old AGFL blocks, so return that list and the number528 * of blocks we're actually going to put back on the AGFL.529 */530STATIC int531xrep_agfl_collect_blocks(532	struct xfs_scrub	*sc,533	struct xfs_buf		*agf_bp,534	struct xagb_bitmap	*agfl_extents,535	xfs_agblock_t		*flcount)536{537	struct xrep_agfl	ra;538	struct xfs_mount	*mp = sc->mp;539	struct xfs_btree_cur	*cur;540	int			error;541 542	ra.sc = sc;543	ra.freesp = agfl_extents;544	xagb_bitmap_init(&ra.agmetablocks);545	xagb_bitmap_init(&ra.crossed);546 547	/* Find all space used by the free space btrees & rmapbt. */548	cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);549	error = xfs_rmap_query_all(cur, xrep_agfl_walk_rmap, &ra);550	xfs_btree_del_cursor(cur, error);551	if (error)552		goto out_bmp;553 554	/* Find all blocks currently being used by the bnobt. */555	cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);556	error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);557	xfs_btree_del_cursor(cur, error);558	if (error)559		goto out_bmp;560 561	/* Find all blocks currently being used by the cntbt. */562	cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);563	error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);564	xfs_btree_del_cursor(cur, error);565	if (error)566		goto out_bmp;567 568	/*569	 * Drop the freesp meta blocks that are in use by btrees.570	 * The remaining blocks /should/ be AGFL blocks.571	 */572	error = xagb_bitmap_disunion(agfl_extents, &ra.agmetablocks);573	if (error)574		goto out_bmp;575 576	/* Strike out the blocks that are cross-linked. */577	ra.rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);578	error = xagb_bitmap_walk(agfl_extents, xrep_agfl_check_extent, &ra);579	xfs_btree_del_cursor(ra.rmap_cur, error);580	if (error)581		goto out_bmp;582	error = xagb_bitmap_disunion(agfl_extents, &ra.crossed);583	if (error)584		goto out_bmp;585 586	/*587	 * Calculate the new AGFL size.  If we found more blocks than fit in588	 * the AGFL we'll free them later.589	 */590	*flcount = min_t(uint64_t, xagb_bitmap_hweight(agfl_extents),591			 xfs_agfl_size(mp));592 593out_bmp:594	xagb_bitmap_destroy(&ra.crossed);595	xagb_bitmap_destroy(&ra.agmetablocks);596	return error;597}598 599/* Update the AGF and reset the in-core state. */600STATIC void601xrep_agfl_update_agf(602	struct xfs_scrub	*sc,603	struct xfs_buf		*agf_bp,604	xfs_agblock_t		flcount)605{606	struct xfs_agf		*agf = agf_bp->b_addr;607 608	ASSERT(flcount <= xfs_agfl_size(sc->mp));609 610	/* Trigger fdblocks recalculation */611	xfs_force_summary_recalc(sc->mp);612 613	/* Update the AGF counters. */614	if (xfs_perag_initialised_agf(sc->sa.pag)) {615		sc->sa.pag->pagf_flcount = flcount;616		clear_bit(XFS_AGSTATE_AGFL_NEEDS_RESET,617				&sc->sa.pag->pag_opstate);618	}619	agf->agf_flfirst = cpu_to_be32(0);620	agf->agf_flcount = cpu_to_be32(flcount);621	if (flcount)622		agf->agf_fllast = cpu_to_be32(flcount - 1);623	else624		agf->agf_fllast = cpu_to_be32(xfs_agfl_size(sc->mp) - 1);625 626	xfs_alloc_log_agf(sc->tp, agf_bp,627			XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);628}629 630struct xrep_agfl_fill {631	struct xagb_bitmap	used_extents;632	struct xfs_scrub	*sc;633	__be32			*agfl_bno;634	xfs_agblock_t		flcount;635	unsigned int		fl_off;636};637 638/* Fill the AGFL with whatever blocks are in this extent. */639static int640xrep_agfl_fill(641	uint32_t		start,642	uint32_t		len,643	void			*priv)644{645	struct xrep_agfl_fill	*af = priv;646	struct xfs_scrub	*sc = af->sc;647	xfs_agblock_t		agbno = start;648	int			error;649 650	trace_xrep_agfl_insert(sc->sa.pag, agbno, len);651 652	while (agbno < start + len && af->fl_off < af->flcount)653		af->agfl_bno[af->fl_off++] = cpu_to_be32(agbno++);654 655	error = xagb_bitmap_set(&af->used_extents, start, agbno - 1);656	if (error)657		return error;658 659	if (af->fl_off == af->flcount)660		return -ECANCELED;661 662	return 0;663}664 665/* Write out a totally new AGFL. */666STATIC int667xrep_agfl_init_header(668	struct xfs_scrub	*sc,669	struct xfs_buf		*agfl_bp,670	struct xagb_bitmap	*agfl_extents,671	xfs_agblock_t		flcount)672{673	struct xrep_agfl_fill	af = {674		.sc		= sc,675		.flcount	= flcount,676	};677	struct xfs_mount	*mp = sc->mp;678	struct xfs_agfl		*agfl;679	int			error;680 681	ASSERT(flcount <= xfs_agfl_size(mp));682 683	/*684	 * Start rewriting the header by setting the bno[] array to685	 * NULLAGBLOCK, then setting AGFL header fields.686	 */687	agfl = XFS_BUF_TO_AGFL(agfl_bp);688	memset(agfl, 0xFF, BBTOB(agfl_bp->b_length));689	agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);690	agfl->agfl_seqno = cpu_to_be32(sc->sa.pag->pag_agno);691	uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);692 693	/*694	 * Fill the AGFL with the remaining blocks.  If agfl_extents has more695	 * blocks than fit in the AGFL, they will be freed in a subsequent696	 * step.697	 */698	xagb_bitmap_init(&af.used_extents);699	af.agfl_bno = xfs_buf_to_agfl_bno(agfl_bp);700	xagb_bitmap_walk(agfl_extents, xrep_agfl_fill, &af);701	error = xagb_bitmap_disunion(agfl_extents, &af.used_extents);702	if (error)703		return error;704 705	/* Write new AGFL to disk. */706	xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF);707	xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1);708	xagb_bitmap_destroy(&af.used_extents);709	return 0;710}711 712/* Repair the AGFL. */713int714xrep_agfl(715	struct xfs_scrub	*sc)716{717	struct xagb_bitmap	agfl_extents;718	struct xfs_mount	*mp = sc->mp;719	struct xfs_buf		*agf_bp;720	struct xfs_buf		*agfl_bp;721	xfs_agblock_t		flcount;722	int			error;723 724	/* We require the rmapbt to rebuild anything. */725	if (!xfs_has_rmapbt(mp))726		return -EOPNOTSUPP;727 728	xagb_bitmap_init(&agfl_extents);729 730	/*731	 * Read the AGF so that we can query the rmapbt.  We hope that there's732	 * nothing wrong with the AGF, but all the AG header repair functions733	 * have this chicken-and-egg problem.734	 */735	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);736	if (error)737		return error;738 739	/*740	 * Make sure we have the AGFL buffer, as scrub might have decided it741	 * was corrupt after xfs_alloc_read_agfl failed with -EFSCORRUPTED.742	 */743	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,744			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,745						XFS_AGFL_DADDR(mp)),746			XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL);747	if (error)748		return error;749	agfl_bp->b_ops = &xfs_agfl_buf_ops;750 751	/* Gather all the extents we're going to put on the new AGFL. */752	error = xrep_agfl_collect_blocks(sc, agf_bp, &agfl_extents, &flcount);753	if (error)754		goto err;755 756	/* Last chance to abort before we start committing fixes. */757	if (xchk_should_terminate(sc, &error))758		goto err;759 760	/*761	 * Update AGF and AGFL.  We reset the global free block counter when762	 * we adjust the AGF flcount (which can fail) so avoid updating any763	 * buffers until we know that part works.764	 */765	xrep_agfl_update_agf(sc, agf_bp, flcount);766	error = xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount);767	if (error)768		goto err;769 770	/*771	 * Ok, the AGFL should be ready to go now.  Roll the transaction to772	 * make the new AGFL permanent before we start using it to return773	 * freespace overflow to the freespace btrees.774	 */775	sc->sa.agf_bp = agf_bp;776	error = xrep_roll_ag_trans(sc);777	if (error)778		goto err;779 780	/* Dump any AGFL overflow. */781	error = xrep_reap_agblocks(sc, &agfl_extents, &XFS_RMAP_OINFO_AG,782			XFS_AG_RESV_AGFL);783	if (error)784		goto err;785 786err:787	xagb_bitmap_destroy(&agfl_extents);788	return error;789}790 791/* AGI */792 793/*794 * Offset within the xrep_find_ag_btree array for each btree type.  Avoid the795 * XFS_BTNUM_ names here to avoid creating a sparse array.796 */797enum {798	XREP_AGI_INOBT = 0,799	XREP_AGI_FINOBT,800	XREP_AGI_END,801	XREP_AGI_MAX802};803 804#define XREP_AGI_LOOKUP_BATCH		32805 806struct xrep_agi {807	struct xfs_scrub		*sc;808 809	/* AGI buffer, tracked separately */810	struct xfs_buf			*agi_bp;811 812	/* context for finding btree roots */813	struct xrep_find_ag_btree	fab[XREP_AGI_MAX];814 815	/* old AGI contents in case we have to revert */816	struct xfs_agi			old_agi;817 818	/* bitmap of which inodes are unlinked */819	struct xagino_bitmap		iunlink_bmp;820 821	/* heads of the unlinked inode bucket lists */822	xfs_agino_t			iunlink_heads[XFS_AGI_UNLINKED_BUCKETS];823 824	/* scratchpad for batched lookups of the radix tree */825	struct xfs_inode		*lookup_batch[XREP_AGI_LOOKUP_BATCH];826 827	/* Map of ino -> next_ino for unlinked inode processing. */828	struct xfarray			*iunlink_next;829 830	/* Map of ino -> prev_ino for unlinked inode processing. */831	struct xfarray			*iunlink_prev;832};833 834static void835xrep_agi_buf_cleanup(836	void		*buf)837{838	struct xrep_agi	*ragi = buf;839 840	xfarray_destroy(ragi->iunlink_prev);841	xfarray_destroy(ragi->iunlink_next);842	xagino_bitmap_destroy(&ragi->iunlink_bmp);843}844 845/*846 * Given the inode btree roots described by *fab, find the roots, check them847 * for sanity, and pass the root data back out via *fab.848 */849STATIC int850xrep_agi_find_btrees(851	struct xrep_agi			*ragi)852{853	struct xfs_scrub		*sc = ragi->sc;854	struct xrep_find_ag_btree	*fab = ragi->fab;855	struct xfs_buf			*agf_bp;856	struct xfs_mount		*mp = sc->mp;857	int				error;858 859	/* Read the AGF. */860	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);861	if (error)862		return error;863 864	/* Find the btree roots. */865	error = xrep_find_ag_btree_roots(sc, agf_bp, fab, NULL);866	if (error)867		return error;868 869	/* We must find the inobt root. */870	if (!xrep_check_btree_root(sc, &fab[XREP_AGI_INOBT]))871		return -EFSCORRUPTED;872 873	/* We must find the finobt root if that feature is enabled. */874	if (xfs_has_finobt(mp) &&875	    !xrep_check_btree_root(sc, &fab[XREP_AGI_FINOBT]))876		return -EFSCORRUPTED;877 878	return 0;879}880 881/*882 * Reinitialize the AGI header, making an in-core copy of the old contents so883 * that we know which in-core state needs to be reinitialized.884 */885STATIC void886xrep_agi_init_header(887	struct xrep_agi		*ragi)888{889	struct xfs_scrub	*sc = ragi->sc;890	struct xfs_buf		*agi_bp = ragi->agi_bp;891	struct xfs_agi		*old_agi = &ragi->old_agi;892	struct xfs_agi		*agi = agi_bp->b_addr;893	struct xfs_perag	*pag = sc->sa.pag;894	struct xfs_mount	*mp = sc->mp;895 896	memcpy(old_agi, agi, sizeof(*old_agi));897	memset(agi, 0, BBTOB(agi_bp->b_length));898	agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);899	agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);900	agi->agi_seqno = cpu_to_be32(pag->pag_agno);901	agi->agi_length = cpu_to_be32(pag->block_count);902	agi->agi_newino = cpu_to_be32(NULLAGINO);903	agi->agi_dirino = cpu_to_be32(NULLAGINO);904	if (xfs_has_crc(mp))905		uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);906 907	/* Mark the incore AGF data stale until we're done fixing things. */908	ASSERT(xfs_perag_initialised_agi(pag));909	clear_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);910}911 912/* Set btree root information in an AGI. */913STATIC void914xrep_agi_set_roots(915	struct xrep_agi			*ragi)916{917	struct xfs_scrub		*sc = ragi->sc;918	struct xfs_agi			*agi = ragi->agi_bp->b_addr;919	struct xrep_find_ag_btree	*fab = ragi->fab;920 921	agi->agi_root = cpu_to_be32(fab[XREP_AGI_INOBT].root);922	agi->agi_level = cpu_to_be32(fab[XREP_AGI_INOBT].height);923 924	if (xfs_has_finobt(sc->mp)) {925		agi->agi_free_root = cpu_to_be32(fab[XREP_AGI_FINOBT].root);926		agi->agi_free_level = cpu_to_be32(fab[XREP_AGI_FINOBT].height);927	}928}929 930/* Update the AGI counters. */931STATIC int932xrep_agi_calc_from_btrees(933	struct xrep_agi		*ragi)934{935	struct xfs_scrub	*sc = ragi->sc;936	struct xfs_buf		*agi_bp = ragi->agi_bp;937	struct xfs_btree_cur	*cur;938	struct xfs_agi		*agi = agi_bp->b_addr;939	struct xfs_mount	*mp = sc->mp;940	xfs_agino_t		count;941	xfs_agino_t		freecount;942	int			error;943 944	cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);945	error = xfs_ialloc_count_inodes(cur, &count, &freecount);946	if (error)947		goto err;948	if (xfs_has_inobtcounts(mp)) {949		xfs_agblock_t	blocks;950 951		error = xfs_btree_count_blocks(cur, &blocks);952		if (error)953			goto err;954		agi->agi_iblocks = cpu_to_be32(blocks);955	}956	xfs_btree_del_cursor(cur, error);957 958	agi->agi_count = cpu_to_be32(count);959	agi->agi_freecount = cpu_to_be32(freecount);960 961	if (xfs_has_finobt(mp) && xfs_has_inobtcounts(mp)) {962		xfs_agblock_t	blocks;963 964		cur = xfs_finobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);965		error = xfs_btree_count_blocks(cur, &blocks);966		if (error)967			goto err;968		xfs_btree_del_cursor(cur, error);969		agi->agi_fblocks = cpu_to_be32(blocks);970	}971 972	return 0;973err:974	xfs_btree_del_cursor(cur, error);975	return error;976}977 978/*979 * Record a forwards unlinked chain pointer from agino -> next_agino in our980 * staging information.981 */982static inline int983xrep_iunlink_store_next(984	struct xrep_agi		*ragi,985	xfs_agino_t		agino,986	xfs_agino_t		next_agino)987{988	ASSERT(next_agino != 0);989 990	return xfarray_store(ragi->iunlink_next, agino, &next_agino);991}992 993/*994 * Record a backwards unlinked chain pointer from prev_ino <- agino in our995 * staging information.996 */997static inline int998xrep_iunlink_store_prev(999	struct xrep_agi		*ragi,1000	xfs_agino_t		agino,1001	xfs_agino_t		prev_agino)1002{1003	ASSERT(prev_agino != 0);1004 1005	return xfarray_store(ragi->iunlink_prev, agino, &prev_agino);1006}1007 1008/*1009 * Given an @agino, look up the next inode in the iunlink bucket.  Returns1010 * NULLAGINO if we're at the end of the chain, 0 if @agino is not in memory1011 * like it should be, or a per-AG inode number.1012 */1013static inline xfs_agino_t1014xrep_iunlink_next(1015	struct xfs_scrub	*sc,1016	xfs_agino_t		agino)1017{1018	struct xfs_inode	*ip;1019 1020	ip = xfs_iunlink_lookup(sc->sa.pag, agino);1021	if (!ip)1022		return 0;1023 1024	return ip->i_next_unlinked;1025}1026 1027/*1028 * Load the inode @agino into memory, set its i_prev_unlinked, and drop the1029 * inode so it can be inactivated.  Returns NULLAGINO if we're at the end of1030 * the chain or if we should stop walking the chain due to corruption; or a1031 * per-AG inode number.1032 */1033STATIC xfs_agino_t1034xrep_iunlink_reload_next(1035	struct xrep_agi		*ragi,1036	xfs_agino_t		prev_agino,1037	xfs_agino_t		agino)1038{1039	struct xfs_scrub	*sc = ragi->sc;1040	struct xfs_inode	*ip;1041	xfs_ino_t		ino;1042	xfs_agino_t		ret = NULLAGINO;1043	int			error;1044 1045	ino = XFS_AGINO_TO_INO(sc->mp, sc->sa.pag->pag_agno, agino);1046	error = xchk_iget(ragi->sc, ino, &ip);1047	if (error)1048		return ret;1049 1050	trace_xrep_iunlink_reload_next(ip, prev_agino);1051 1052	/* If this is a linked inode, stop processing the chain. */1053	if (VFS_I(ip)->i_nlink != 0) {1054		xrep_iunlink_store_next(ragi, agino, NULLAGINO);1055		goto rele;1056	}1057 1058	ip->i_prev_unlinked = prev_agino;1059	ret = ip->i_next_unlinked;1060 1061	/*1062	 * Drop the inode reference that we just took.  We hold the AGI, so1063	 * this inode cannot move off the unlinked list and hence cannot be1064	 * reclaimed.1065	 */1066rele:1067	xchk_irele(sc, ip);1068	return ret;1069}1070 1071/*1072 * Walk an AGI unlinked bucket's list to load incore any unlinked inodes that1073 * still existed at mount time.  This can happen if iunlink processing fails1074 * during log recovery.1075 */1076STATIC int1077xrep_iunlink_walk_ondisk_bucket(1078	struct xrep_agi		*ragi,1079	unsigned int		bucket)1080{1081	struct xfs_scrub	*sc = ragi->sc;1082	struct xfs_agi		*agi = sc->sa.agi_bp->b_addr;1083	xfs_agino_t		prev_agino = NULLAGINO;1084	xfs_agino_t		next_agino;1085	int			error = 0;1086 1087	next_agino = be32_to_cpu(agi->agi_unlinked[bucket]);1088	while (next_agino != NULLAGINO) {1089		xfs_agino_t	agino = next_agino;1090 1091		if (xchk_should_terminate(ragi->sc, &error))1092			return error;1093 1094		trace_xrep_iunlink_walk_ondisk_bucket(sc->sa.pag, bucket,1095				prev_agino, agino);1096 1097		if (bucket != agino % XFS_AGI_UNLINKED_BUCKETS)1098			break;1099 1100		next_agino = xrep_iunlink_next(sc, agino);1101		if (!next_agino)1102			next_agino = xrep_iunlink_reload_next(ragi, prev_agino,1103					agino);1104 1105		prev_agino = agino;1106	}1107 1108	return 0;1109}1110 1111/* Decide if this is an unlinked inode in this AG. */1112STATIC bool1113xrep_iunlink_igrab(1114	struct xfs_perag	*pag,1115	struct xfs_inode	*ip)1116{1117	struct xfs_mount	*mp = pag->pag_mount;1118 1119	if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)1120		return false;1121 1122	if (!xfs_inode_on_unlinked_list(ip))1123		return false;1124 1125	return true;1126}1127 1128/*1129 * Mark the given inode in the lookup batch in our unlinked inode bitmap, and1130 * remember if this inode is the start of the unlinked chain.1131 */1132STATIC int1133xrep_iunlink_visit(1134	struct xrep_agi		*ragi,1135	unsigned int		batch_idx)1136{1137	struct xfs_mount	*mp = ragi->sc->mp;1138	struct xfs_inode	*ip = ragi->lookup_batch[batch_idx];1139	xfs_agino_t		agino;1140	unsigned int		bucket;1141	int			error;1142 1143	ASSERT(XFS_INO_TO_AGNO(mp, ip->i_ino) == ragi->sc->sa.pag->pag_agno);1144	ASSERT(xfs_inode_on_unlinked_list(ip));1145 1146	agino = XFS_INO_TO_AGINO(mp, ip->i_ino);1147	bucket = agino % XFS_AGI_UNLINKED_BUCKETS;1148 1149	trace_xrep_iunlink_visit(ragi->sc->sa.pag, bucket,1150			ragi->iunlink_heads[bucket], ip);1151 1152	error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);1153	if (error)1154		return error;1155 1156	if (ip->i_prev_unlinked == NULLAGINO) {1157		if (ragi->iunlink_heads[bucket] == NULLAGINO)1158			ragi->iunlink_heads[bucket] = agino;1159	}1160 1161	return 0;1162}1163 1164/*1165 * Find all incore unlinked inodes so that we can rebuild the unlinked buckets.1166 * We hold the AGI so there should not be any modifications to the unlinked1167 * list.1168 */1169STATIC int1170xrep_iunlink_mark_incore(1171	struct xrep_agi		*ragi)1172{1173	struct xfs_perag	*pag = ragi->sc->sa.pag;1174	struct xfs_mount	*mp = pag->pag_mount;1175	uint32_t		first_index = 0;1176	bool			done = false;1177	unsigned int		nr_found = 0;1178 1179	do {1180		unsigned int	i;1181		int		error = 0;1182 1183		if (xchk_should_terminate(ragi->sc, &error))1184			return error;1185 1186		rcu_read_lock();1187 1188		nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,1189				(void **)&ragi->lookup_batch, first_index,1190				XREP_AGI_LOOKUP_BATCH);1191		if (!nr_found) {1192			rcu_read_unlock();1193			return 0;1194		}1195 1196		for (i = 0; i < nr_found; i++) {1197			struct xfs_inode *ip = ragi->lookup_batch[i];1198 1199			if (done || !xrep_iunlink_igrab(pag, ip))1200				ragi->lookup_batch[i] = NULL;1201 1202			/*1203			 * Update the index for the next lookup. Catch1204			 * overflows into the next AG range which can occur if1205			 * we have inodes in the last block of the AG and we1206			 * are currently pointing to the last inode.1207			 *1208			 * Because we may see inodes that are from the wrong AG1209			 * due to RCU freeing and reallocation, only update the1210			 * index if it lies in this AG. It was a race that lead1211			 * us to see this inode, so another lookup from the1212			 * same index will not find it again.1213			 */1214			if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)1215				continue;1216			first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);1217			if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))1218				done = true;1219		}1220 1221		/* unlock now we've grabbed the inodes. */1222		rcu_read_unlock();1223 1224		for (i = 0; i < nr_found; i++) {1225			if (!ragi->lookup_batch[i])1226				continue;1227			error = xrep_iunlink_visit(ragi, i);1228			if (error)1229				return error;1230		}1231	} while (!done);1232 1233	return 0;1234}1235 1236/* Mark all the unlinked ondisk inodes in this inobt record in iunlink_bmp. */1237STATIC int1238xrep_iunlink_mark_ondisk_rec(1239	struct xfs_btree_cur		*cur,1240	const union xfs_btree_rec	*rec,1241	void				*priv)1242{1243	struct xfs_inobt_rec_incore	irec;1244	struct xrep_agi			*ragi = priv;1245	struct xfs_scrub		*sc = ragi->sc;1246	struct xfs_mount		*mp = cur->bc_mp;1247	xfs_agino_t			agino;1248	unsigned int			i;1249	int				error = 0;1250 1251	xfs_inobt_btrec_to_irec(mp, rec, &irec);1252 1253	for (i = 0, agino = irec.ir_startino;1254	     i < XFS_INODES_PER_CHUNK;1255	     i++, agino++) {1256		struct xfs_inode	*ip;1257		unsigned int		len = 1;1258 1259		/* Skip free inodes */1260		if (XFS_INOBT_MASK(i) & irec.ir_free)1261			continue;1262		/* Skip inodes we've seen before */1263		if (xagino_bitmap_test(&ragi->iunlink_bmp, agino, &len))1264			continue;1265 1266		/*1267		 * Skip incore inodes; these were already picked up by1268		 * the _mark_incore step.1269		 */1270		rcu_read_lock();1271		ip = radix_tree_lookup(&sc->sa.pag->pag_ici_root, agino);1272		rcu_read_unlock();1273		if (ip)1274			continue;1275 1276		/*1277		 * Try to look up this inode.  If we can't get it, just move1278		 * on because we haven't actually scrubbed the inobt or the1279		 * inodes yet.1280		 */1281		error = xchk_iget(ragi->sc,1282				XFS_AGINO_TO_INO(mp, sc->sa.pag->pag_agno,1283						 agino),1284				&ip);1285		if (error)1286			continue;1287 1288		trace_xrep_iunlink_reload_ondisk(ip);1289 1290		if (VFS_I(ip)->i_nlink == 0)1291			error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);1292		xchk_irele(sc, ip);1293		if (error)1294			break;1295	}1296 1297	return error;1298}1299 1300/*1301 * Find ondisk inodes that are unlinked and not in cache, and mark them in1302 * iunlink_bmp.   We haven't checked the inobt yet, so we don't error out if1303 * the btree is corrupt.1304 */1305STATIC void1306xrep_iunlink_mark_ondisk(1307	struct xrep_agi		*ragi)1308{1309	struct xfs_scrub	*sc = ragi->sc;1310	struct xfs_buf		*agi_bp = ragi->agi_bp;1311	struct xfs_btree_cur	*cur;1312	int			error;1313 1314	cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);1315	error = xfs_btree_query_all(cur, xrep_iunlink_mark_ondisk_rec, ragi);1316	xfs_btree_del_cursor(cur, error);1317}1318 1319/*1320 * Walk an iunlink bucket's inode list.  For each inode that should be on this1321 * chain, clear its entry in in iunlink_bmp because it's ok and we don't need1322 * to touch it further.1323 */1324STATIC int1325xrep_iunlink_resolve_bucket(1326	struct xrep_agi		*ragi,1327	unsigned int		bucket)1328{1329	struct xfs_scrub	*sc = ragi->sc;1330	struct xfs_inode	*ip;1331	xfs_agino_t		prev_agino = NULLAGINO;1332	xfs_agino_t		next_agino = ragi->iunlink_heads[bucket];1333	int			error = 0;1334 1335	while (next_agino != NULLAGINO) {1336		if (xchk_should_terminate(ragi->sc, &error))1337			return error;1338 1339		/* Find the next inode in the chain. */1340		ip = xfs_iunlink_lookup(sc->sa.pag, next_agino);1341		if (!ip) {1342			/* Inode not incore?  Terminate the chain. */1343			trace_xrep_iunlink_resolve_uncached(sc->sa.pag,1344					bucket, prev_agino, next_agino);1345 1346			next_agino = NULLAGINO;1347			break;1348		}1349 1350		if (next_agino % XFS_AGI_UNLINKED_BUCKETS != bucket) {1351			/*1352			 * Inode is in the wrong bucket.  Advance the list,1353			 * but pretend we didn't see this inode.1354			 */1355			trace_xrep_iunlink_resolve_wronglist(sc->sa.pag,1356					bucket, prev_agino, next_agino);1357 1358			next_agino = ip->i_next_unlinked;1359			continue;1360		}1361 1362		if (!xfs_inode_on_unlinked_list(ip)) {1363			/*1364			 * Incore inode doesn't think this inode is on an1365			 * unlinked list.  This is probably because we reloaded1366			 * it from disk.  Advance the list, but pretend we1367			 * didn't see this inode; we'll fix that later.1368			 */1369			trace_xrep_iunlink_resolve_nolist(sc->sa.pag,1370					bucket, prev_agino, next_agino);1371			next_agino = ip->i_next_unlinked;1372			continue;1373		}1374 1375		trace_xrep_iunlink_resolve_ok(sc->sa.pag, bucket, prev_agino,1376				next_agino);1377 1378		/*1379		 * Otherwise, this inode's unlinked pointers are ok.  Clear it1380		 * from the unlinked bitmap since we're done with it, and make1381		 * sure the chain is still correct.1382		 */1383		error = xagino_bitmap_clear(&ragi->iunlink_bmp, next_agino, 1);1384		if (error)1385			return error;1386 1387		/* Remember the previous inode's next pointer. */1388		if (prev_agino != NULLAGINO) {1389			error = xrep_iunlink_store_next(ragi, prev_agino,1390					next_agino);1391			if (error)1392				return error;1393		}1394 1395		/* Remember this inode's previous pointer. */1396		error = xrep_iunlink_store_prev(ragi, next_agino, prev_agino);1397		if (error)1398			return error;1399 1400		/* Advance the list and remember this inode. */1401		prev_agino = next_agino;1402		next_agino = ip->i_next_unlinked;1403	}1404 1405	/* Update the previous inode's next pointer. */1406	if (prev_agino != NULLAGINO) {1407		error = xrep_iunlink_store_next(ragi, prev_agino, next_agino);1408		if (error)1409			return error;1410	}1411 1412	return 0;1413}1414 1415/* Reinsert this unlinked inode into the head of the staged bucket list. */1416STATIC int1417xrep_iunlink_add_to_bucket(1418	struct xrep_agi		*ragi,1419	xfs_agino_t		agino)1420{1421	xfs_agino_t		current_head;1422	unsigned int		bucket;1423	int			error;1424 1425	bucket = agino % XFS_AGI_UNLINKED_BUCKETS;1426 1427	/* Point this inode at the current head of the bucket list. */1428	current_head = ragi->iunlink_heads[bucket];1429 1430	trace_xrep_iunlink_add_to_bucket(ragi->sc->sa.pag, bucket, agino,1431			current_head);1432 1433	error = xrep_iunlink_store_next(ragi, agino, current_head);1434	if (error)1435		return error;1436 1437	/* Remember the head inode's previous pointer. */1438	if (current_head != NULLAGINO) {1439		error = xrep_iunlink_store_prev(ragi, current_head, agino);1440		if (error)1441			return error;1442	}1443 1444	ragi->iunlink_heads[bucket] = agino;1445	return 0;1446}1447 1448/* Reinsert unlinked inodes into the staged iunlink buckets. */1449STATIC int1450xrep_iunlink_add_lost_inodes(1451	uint32_t		start,1452	uint32_t		len,1453	void			*priv)1454{1455	struct xrep_agi		*ragi = priv;1456	int			error;1457 1458	for (; len > 0; start++, len--) {1459		error = xrep_iunlink_add_to_bucket(ragi, start);1460		if (error)1461			return error;1462	}1463 1464	return 0;1465}1466 1467/*1468 * Figure out the iunlink bucket values and find inodes that need to be1469 * reinserted into the list.1470 */1471STATIC int1472xrep_iunlink_rebuild_buckets(1473	struct xrep_agi		*ragi)1474{1475	unsigned int		i;1476	int			error;1477 1478	/*1479	 * Walk the ondisk AGI unlinked list to find inodes that are on the1480	 * list but aren't in memory.  This can happen if a past log recovery1481	 * tried to clear the iunlinked list but failed.  Our scan rebuilds the1482	 * unlinked list using incore inodes, so we must load and link them1483	 * properly.1484	 */1485	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {1486		error = xrep_iunlink_walk_ondisk_bucket(ragi, i);1487		if (error)1488			return error;1489	}1490 1491	/*1492	 * Record all the incore unlinked inodes in iunlink_bmp that we didn't1493	 * find by walking the ondisk iunlink buckets.  This shouldn't happen,1494	 * but we can't risk forgetting an inode somewhere.1495	 */1496	error = xrep_iunlink_mark_incore(ragi);1497	if (error)1498		return error;1499 1500	/*1501	 * If there are ondisk inodes that are unlinked and are not been loaded1502	 * into cache, record them in iunlink_bmp.1503	 */1504	xrep_iunlink_mark_ondisk(ragi);1505 1506	/*1507	 * Walk each iunlink bucket to (re)construct as much of the incore list1508	 * as would be correct.  For each inode that survives this step, mark1509	 * it clear in iunlink_bmp; we're done with those inodes.1510	 */1511	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {1512		error = xrep_iunlink_resolve_bucket(ragi, i);1513		if (error)1514			return error;1515	}1516 1517	/*1518	 * Any unlinked inodes that we didn't find through the bucket list1519	 * walk (or was ignored by the walk) must be inserted into the bucket1520	 * list.  Stage this in memory for now.1521	 */1522	return xagino_bitmap_walk(&ragi->iunlink_bmp,1523			xrep_iunlink_add_lost_inodes, ragi);1524}1525 1526/* Update i_next_iunlinked for the inode @agino. */1527STATIC int1528xrep_iunlink_relink_next(1529	struct xrep_agi		*ragi,1530	xfarray_idx_t		idx,1531	xfs_agino_t		next_agino)1532{1533	struct xfs_scrub	*sc = ragi->sc;1534	struct xfs_perag	*pag = sc->sa.pag;1535	struct xfs_inode	*ip;1536	xfarray_idx_t		agino = idx - 1;1537	bool			want_rele = false;1538	int			error = 0;1539 1540	ip = xfs_iunlink_lookup(pag, agino);1541	if (!ip) {1542		xfs_ino_t	ino;1543		xfs_agino_t	prev_agino;1544 1545		/*1546		 * No inode exists in cache.  Load it off the disk so that we1547		 * can reinsert it into the incore unlinked list.1548		 */1549		ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);1550		error = xchk_iget(sc, ino, &ip);1551		if (error)1552			return -EFSCORRUPTED;1553 1554		want_rele = true;1555 1556		/* Set the backward pointer since this just came off disk. */1557		error = xfarray_load(ragi->iunlink_prev, agino, &prev_agino);1558		if (error)1559			goto out_rele;1560 1561		trace_xrep_iunlink_relink_prev(ip, prev_agino);1562		ip->i_prev_unlinked = prev_agino;1563	}1564 1565	/* Update the forward pointer. */1566	if (ip->i_next_unlinked != next_agino) {1567		error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);1568		if (error)1569			goto out_rele;1570 1571		trace_xrep_iunlink_relink_next(ip, next_agino);1572		ip->i_next_unlinked = next_agino;1573	}1574 1575out_rele:1576	/*1577	 * The iunlink lookup doesn't igrab because we hold the AGI buffer lock1578	 * and the inode cannot be reclaimed.  However, if we used iget to load1579	 * a missing inode, we must irele it here.1580	 */1581	if (want_rele)1582		xchk_irele(sc, ip);1583	return error;1584}1585 1586/* Update i_prev_iunlinked for the inode @agino. */1587STATIC int1588xrep_iunlink_relink_prev(1589	struct xrep_agi		*ragi,1590	xfarray_idx_t		idx,1591	xfs_agino_t		prev_agino)1592{1593	struct xfs_scrub	*sc = ragi->sc;1594	struct xfs_perag	*pag = sc->sa.pag;1595	struct xfs_inode	*ip;1596	xfarray_idx_t		agino = idx - 1;1597	bool			want_rele = false;1598	int			error = 0;1599 1600	ASSERT(prev_agino != 0);1601 1602	ip = xfs_iunlink_lookup(pag, agino);1603	if (!ip) {1604		xfs_ino_t	ino;1605		xfs_agino_t	next_agino;1606 1607		/*1608		 * No inode exists in cache.  Load it off the disk so that we1609		 * can reinsert it into the incore unlinked list.1610		 */1611		ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);1612		error = xchk_iget(sc, ino, &ip);1613		if (error)1614			return -EFSCORRUPTED;1615 1616		want_rele = true;1617 1618		/* Set the forward pointer since this just came off disk. */1619		error = xfarray_load(ragi->iunlink_prev, agino, &next_agino);1620		if (error)1621			goto out_rele;1622 1623		error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);1624		if (error)1625			goto out_rele;1626 1627		trace_xrep_iunlink_relink_next(ip, next_agino);1628		ip->i_next_unlinked = next_agino;1629	}1630 1631	/* Update the backward pointer. */1632	if (ip->i_prev_unlinked != prev_agino) {1633		trace_xrep_iunlink_relink_prev(ip, prev_agino);1634		ip->i_prev_unlinked = prev_agino;1635	}1636 1637out_rele:1638	/*1639	 * The iunlink lookup doesn't igrab because we hold the AGI buffer lock1640	 * and the inode cannot be reclaimed.  However, if we used iget to load1641	 * a missing inode, we must irele it here.1642	 */1643	if (want_rele)1644		xchk_irele(sc, ip);1645	return error;1646}1647 1648/* Log all the iunlink updates we need to finish regenerating the AGI. */1649STATIC int1650xrep_iunlink_commit(1651	struct xrep_agi		*ragi)1652{1653	struct xfs_agi		*agi = ragi->agi_bp->b_addr;1654	xfarray_idx_t		idx = XFARRAY_CURSOR_INIT;1655	xfs_agino_t		agino;1656	unsigned int		i;1657	int			error;1658 1659	/* Fix all the forward links */1660	while ((error = xfarray_iter(ragi->iunlink_next, &idx, &agino)) == 1) {1661		error = xrep_iunlink_relink_next(ragi, idx, agino);1662		if (error)1663			return error;1664	}1665 1666	/* Fix all the back links */1667	idx = XFARRAY_CURSOR_INIT;1668	while ((error = xfarray_iter(ragi->iunlink_prev, &idx, &agino)) == 1) {1669		error = xrep_iunlink_relink_prev(ragi, idx, agino);1670		if (error)1671			return error;1672	}1673 1674	/* Copy the staged iunlink buckets to the new AGI. */1675	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {1676		trace_xrep_iunlink_commit_bucket(ragi->sc->sa.pag, i,1677				be32_to_cpu(ragi->old_agi.agi_unlinked[i]),1678				ragi->iunlink_heads[i]);1679 1680		agi->agi_unlinked[i] = cpu_to_be32(ragi->iunlink_heads[i]);1681	}1682 1683	return 0;1684}1685 1686/* Trigger reinitialization of the in-core data. */1687STATIC int1688xrep_agi_commit_new(1689	struct xrep_agi		*ragi)1690{1691	struct xfs_scrub	*sc = ragi->sc;1692	struct xfs_buf		*agi_bp = ragi->agi_bp;1693	struct xfs_perag	*pag;1694	struct xfs_agi		*agi = agi_bp->b_addr;1695 1696	/* Trigger inode count recalculation */1697	xfs_force_summary_recalc(sc->mp);1698 1699	/* Write this to disk. */1700	xfs_trans_buf_set_type(sc->tp, agi_bp, XFS_BLFT_AGI_BUF);1701	xfs_trans_log_buf(sc->tp, agi_bp, 0, BBTOB(agi_bp->b_length) - 1);1702 1703	/* Now reinitialize the in-core counters if necessary. */1704	pag = sc->sa.pag;1705	pag->pagi_count = be32_to_cpu(agi->agi_count);1706	pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);1707	set_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);1708 1709	return xrep_roll_ag_trans(sc);1710}1711 1712/* Repair the AGI. */1713int1714xrep_agi(1715	struct xfs_scrub	*sc)1716{1717	struct xrep_agi		*ragi;1718	struct xfs_mount	*mp = sc->mp;1719	char			*descr;1720	unsigned int		i;1721	int			error;1722 1723	/* We require the rmapbt to rebuild anything. */1724	if (!xfs_has_rmapbt(mp))1725		return -EOPNOTSUPP;1726 1727	sc->buf = kzalloc(sizeof(struct xrep_agi), XCHK_GFP_FLAGS);1728	if (!sc->buf)1729		return -ENOMEM;1730	ragi = sc->buf;1731	ragi->sc = sc;1732 1733	ragi->fab[XREP_AGI_INOBT] = (struct xrep_find_ag_btree){1734		.rmap_owner	= XFS_RMAP_OWN_INOBT,1735		.buf_ops	= &xfs_inobt_buf_ops,1736		.maxlevels	= M_IGEO(sc->mp)->inobt_maxlevels,1737	};1738	ragi->fab[XREP_AGI_FINOBT] = (struct xrep_find_ag_btree){1739		.rmap_owner	= XFS_RMAP_OWN_INOBT,1740		.buf_ops	= &xfs_finobt_buf_ops,1741		.maxlevels	= M_IGEO(sc->mp)->inobt_maxlevels,1742	};1743	ragi->fab[XREP_AGI_END] = (struct xrep_find_ag_btree){1744		.buf_ops	= NULL,1745	};1746 1747	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)1748		ragi->iunlink_heads[i] = NULLAGINO;1749 1750	xagino_bitmap_init(&ragi->iunlink_bmp);1751	sc->buf_cleanup = xrep_agi_buf_cleanup;1752 1753	descr = xchk_xfile_ag_descr(sc, "iunlinked next pointers");1754	error = xfarray_create(descr, 0, sizeof(xfs_agino_t),1755			&ragi->iunlink_next);1756	kfree(descr);1757	if (error)1758		return error;1759 1760	descr = xchk_xfile_ag_descr(sc, "iunlinked prev pointers");1761	error = xfarray_create(descr, 0, sizeof(xfs_agino_t),1762			&ragi->iunlink_prev);1763	kfree(descr);1764	if (error)1765		return error;1766 1767	/*1768	 * Make sure we have the AGI buffer, as scrub might have decided it1769	 * was corrupt after xfs_ialloc_read_agi failed with -EFSCORRUPTED.1770	 */1771	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,1772			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,1773						XFS_AGI_DADDR(mp)),1774			XFS_FSS_TO_BB(mp, 1), 0, &ragi->agi_bp, NULL);1775	if (error)1776		return error;1777	ragi->agi_bp->b_ops = &xfs_agi_buf_ops;1778 1779	/* Find the AGI btree roots. */1780	error = xrep_agi_find_btrees(ragi);1781	if (error)1782		return error;1783 1784	error = xrep_iunlink_rebuild_buckets(ragi);1785	if (error)1786		return error;1787 1788	/* Last chance to abort before we start committing fixes. */1789	if (xchk_should_terminate(sc, &error))1790		return error;1791 1792	/* Start rewriting the header and implant the btrees we found. */1793	xrep_agi_init_header(ragi);1794	xrep_agi_set_roots(ragi);1795	error = xrep_agi_calc_from_btrees(ragi);1796	if (error)1797		goto out_revert;1798	error = xrep_iunlink_commit(ragi);1799	if (error)1800		goto out_revert;1801 1802	/* Reinitialize in-core state. */1803	return xrep_agi_commit_new(ragi);1804 1805out_revert:1806	/* Mark the incore AGI state stale and revert the AGI. */1807	clear_bit(XFS_AGSTATE_AGI_INIT, &sc->sa.pag->pag_opstate);1808	memcpy(ragi->agi_bp->b_addr, &ragi->old_agi, sizeof(struct xfs_agi));1809	return error;1810}1811