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Diffstat (limited to '')
| -rw-r--r-- | fs/xfs/scrub/repair.c | 956 |
1 files changed, 956 insertions, 0 deletions
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c new file mode 100644 index 000000000..25e86c71e --- /dev/null +++ b/fs/xfs/scrub/repair.c @@ -0,0 +1,956 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2018 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <darrick.wong@oracle.com> + */ +#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_btree.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_inode.h" +#include "xfs_alloc.h" +#include "xfs_alloc_btree.h" +#include "xfs_ialloc.h" +#include "xfs_ialloc_btree.h" +#include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "xfs_refcount_btree.h" +#include "xfs_extent_busy.h" +#include "xfs_ag_resv.h" +#include "xfs_quota.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" +#include "scrub/repair.h" +#include "scrub/bitmap.h" + +/* + * Attempt to repair some metadata, if the metadata is corrupt and userspace + * told us to fix it. This function returns -EAGAIN to mean "re-run scrub", + * and will set *fixed to true if it thinks it repaired anything. + */ +int +xrep_attempt( + struct xfs_inode *ip, + struct xfs_scrub *sc) +{ + int error = 0; + + trace_xrep_attempt(ip, sc->sm, error); + + xchk_ag_btcur_free(&sc->sa); + + /* Repair whatever's broken. */ + ASSERT(sc->ops->repair); + error = sc->ops->repair(sc); + trace_xrep_done(ip, sc->sm, error); + switch (error) { + case 0: + /* + * Repair succeeded. Commit the fixes and perform a second + * scrub so that we can tell userspace if we fixed the problem. + */ + sc->sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT; + sc->flags |= XREP_ALREADY_FIXED; + return -EAGAIN; + case -EDEADLOCK: + case -EAGAIN: + /* Tell the caller to try again having grabbed all the locks. */ + if (!(sc->flags & XCHK_TRY_HARDER)) { + sc->flags |= XCHK_TRY_HARDER; + return -EAGAIN; + } + /* + * We tried harder but still couldn't grab all the resources + * we needed to fix it. The corruption has not been fixed, + * so report back to userspace. + */ + return -EFSCORRUPTED; + default: + return error; + } +} + +/* + * Complain about unfixable problems in the filesystem. We don't log + * corruptions when IFLAG_REPAIR wasn't set on the assumption that the driver + * program is xfs_scrub, which will call back with IFLAG_REPAIR set if the + * administrator isn't running xfs_scrub in no-repairs mode. + * + * Use this helper function because _ratelimited silently declares a static + * structure to track rate limiting information. + */ +void +xrep_failure( + struct xfs_mount *mp) +{ + xfs_alert_ratelimited(mp, +"Corruption not fixed during online repair. Unmount and run xfs_repair."); +} + +/* + * Repair probe -- userspace uses this to probe if we're willing to repair a + * given mountpoint. + */ +int +xrep_probe( + struct xfs_scrub *sc) +{ + int error = 0; + + if (xchk_should_terminate(sc, &error)) + return error; + + return 0; +} + +/* + * Roll a transaction, keeping the AG headers locked and reinitializing + * the btree cursors. + */ +int +xrep_roll_ag_trans( + struct xfs_scrub *sc) +{ + int error; + + /* Keep the AG header buffers locked so we can keep going. */ + if (sc->sa.agi_bp) + xfs_trans_bhold(sc->tp, sc->sa.agi_bp); + if (sc->sa.agf_bp) + xfs_trans_bhold(sc->tp, sc->sa.agf_bp); + if (sc->sa.agfl_bp) + xfs_trans_bhold(sc->tp, sc->sa.agfl_bp); + + /* + * Roll the transaction. We still own the buffer and the buffer lock + * regardless of whether or not the roll succeeds. If the roll fails, + * the buffers will be released during teardown on our way out of the + * kernel. If it succeeds, we join them to the new transaction and + * move on. + */ + error = xfs_trans_roll(&sc->tp); + if (error) + return error; + + /* Join AG headers to the new transaction. */ + if (sc->sa.agi_bp) + xfs_trans_bjoin(sc->tp, sc->sa.agi_bp); + if (sc->sa.agf_bp) + xfs_trans_bjoin(sc->tp, sc->sa.agf_bp); + if (sc->sa.agfl_bp) + xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp); + + return 0; +} + +/* + * Does the given AG have enough space to rebuild a btree? Neither AG + * reservation can be critical, and we must have enough space (factoring + * in AG reservations) to construct a whole btree. + */ +bool +xrep_ag_has_space( + struct xfs_perag *pag, + xfs_extlen_t nr_blocks, + enum xfs_ag_resv_type type) +{ + return !xfs_ag_resv_critical(pag, XFS_AG_RESV_RMAPBT) && + !xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA) && + pag->pagf_freeblks > xfs_ag_resv_needed(pag, type) + nr_blocks; +} + +/* + * Figure out how many blocks to reserve for an AG repair. We calculate the + * worst case estimate for the number of blocks we'd need to rebuild one of + * any type of per-AG btree. + */ +xfs_extlen_t +xrep_calc_ag_resblks( + struct xfs_scrub *sc) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_scrub_metadata *sm = sc->sm; + struct xfs_perag *pag; + struct xfs_buf *bp; + xfs_agino_t icount = NULLAGINO; + xfs_extlen_t aglen = NULLAGBLOCK; + xfs_extlen_t usedlen; + xfs_extlen_t freelen; + xfs_extlen_t bnobt_sz; + xfs_extlen_t inobt_sz; + xfs_extlen_t rmapbt_sz; + xfs_extlen_t refcbt_sz; + int error; + + if (!(sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)) + return 0; + + pag = xfs_perag_get(mp, sm->sm_agno); + if (pag->pagi_init) { + /* Use in-core icount if possible. */ + icount = pag->pagi_count; + } else { + /* Try to get the actual counters from disk. */ + error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp); + if (!error) { + icount = pag->pagi_count; + xfs_buf_relse(bp); + } + } + + /* Now grab the block counters from the AGF. */ + error = xfs_alloc_read_agf(mp, NULL, sm->sm_agno, 0, &bp); + if (!error) { + struct xfs_agf *agf = bp->b_addr; + + aglen = be32_to_cpu(agf->agf_length); + freelen = be32_to_cpu(agf->agf_freeblks); + usedlen = aglen - freelen; + xfs_buf_relse(bp); + } + xfs_perag_put(pag); + + /* If the icount is impossible, make some worst-case assumptions. */ + if (icount == NULLAGINO || + !xfs_verify_agino(mp, sm->sm_agno, icount)) { + xfs_agino_t first, last; + + xfs_agino_range(mp, sm->sm_agno, &first, &last); + icount = last - first + 1; + } + + /* If the block counts are impossible, make worst-case assumptions. */ + if (aglen == NULLAGBLOCK || + aglen != xfs_ag_block_count(mp, sm->sm_agno) || + freelen >= aglen) { + aglen = xfs_ag_block_count(mp, sm->sm_agno); + freelen = aglen; + usedlen = aglen; + } + + trace_xrep_calc_ag_resblks(mp, sm->sm_agno, icount, aglen, + freelen, usedlen); + + /* + * Figure out how many blocks we'd need worst case to rebuild + * each type of btree. Note that we can only rebuild the + * bnobt/cntbt or inobt/finobt as pairs. + */ + bnobt_sz = 2 * xfs_allocbt_calc_size(mp, freelen); + if (xfs_sb_version_hassparseinodes(&mp->m_sb)) + inobt_sz = xfs_iallocbt_calc_size(mp, icount / + XFS_INODES_PER_HOLEMASK_BIT); + else + inobt_sz = xfs_iallocbt_calc_size(mp, icount / + XFS_INODES_PER_CHUNK); + if (xfs_sb_version_hasfinobt(&mp->m_sb)) + inobt_sz *= 2; + if (xfs_sb_version_hasreflink(&mp->m_sb)) + refcbt_sz = xfs_refcountbt_calc_size(mp, usedlen); + else + refcbt_sz = 0; + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) { + /* + * Guess how many blocks we need to rebuild the rmapbt. + * For non-reflink filesystems we can't have more records than + * used blocks. However, with reflink it's possible to have + * more than one rmap record per AG block. We don't know how + * many rmaps there could be in the AG, so we start off with + * what we hope is an generous over-estimation. + */ + if (xfs_sb_version_hasreflink(&mp->m_sb)) + rmapbt_sz = xfs_rmapbt_calc_size(mp, + (unsigned long long)aglen * 2); + else + rmapbt_sz = xfs_rmapbt_calc_size(mp, usedlen); + } else { + rmapbt_sz = 0; + } + + trace_xrep_calc_ag_resblks_btsize(mp, sm->sm_agno, bnobt_sz, + inobt_sz, rmapbt_sz, refcbt_sz); + + return max(max(bnobt_sz, inobt_sz), max(rmapbt_sz, refcbt_sz)); +} + +/* Allocate a block in an AG. */ +int +xrep_alloc_ag_block( + struct xfs_scrub *sc, + const struct xfs_owner_info *oinfo, + xfs_fsblock_t *fsbno, + enum xfs_ag_resv_type resv) +{ + struct xfs_alloc_arg args = {0}; + xfs_agblock_t bno; + int error; + + switch (resv) { + case XFS_AG_RESV_AGFL: + case XFS_AG_RESV_RMAPBT: + error = xfs_alloc_get_freelist(sc->tp, sc->sa.agf_bp, &bno, 1); + if (error) + return error; + if (bno == NULLAGBLOCK) + return -ENOSPC; + xfs_extent_busy_reuse(sc->mp, sc->sa.agno, bno, + 1, false); + *fsbno = XFS_AGB_TO_FSB(sc->mp, sc->sa.agno, bno); + if (resv == XFS_AG_RESV_RMAPBT) + xfs_ag_resv_rmapbt_alloc(sc->mp, sc->sa.agno); + return 0; + default: + break; + } + + args.tp = sc->tp; + args.mp = sc->mp; + args.oinfo = *oinfo; + args.fsbno = XFS_AGB_TO_FSB(args.mp, sc->sa.agno, 0); + args.minlen = 1; + args.maxlen = 1; + args.prod = 1; + args.type = XFS_ALLOCTYPE_THIS_AG; + args.resv = resv; + + error = xfs_alloc_vextent(&args); + if (error) + return error; + if (args.fsbno == NULLFSBLOCK) + return -ENOSPC; + ASSERT(args.len == 1); + *fsbno = args.fsbno; + + return 0; +} + +/* Initialize a new AG btree root block with zero entries. */ +int +xrep_init_btblock( + struct xfs_scrub *sc, + xfs_fsblock_t fsb, + struct xfs_buf **bpp, + xfs_btnum_t btnum, + const struct xfs_buf_ops *ops) +{ + struct xfs_trans *tp = sc->tp; + struct xfs_mount *mp = sc->mp; + struct xfs_buf *bp; + int error; + + trace_xrep_init_btblock(mp, XFS_FSB_TO_AGNO(mp, fsb), + XFS_FSB_TO_AGBNO(mp, fsb), btnum); + + ASSERT(XFS_FSB_TO_AGNO(mp, fsb) == sc->sa.agno); + error = xfs_trans_get_buf(tp, mp->m_ddev_targp, + XFS_FSB_TO_DADDR(mp, fsb), XFS_FSB_TO_BB(mp, 1), 0, + &bp); + if (error) + return error; + xfs_buf_zero(bp, 0, BBTOB(bp->b_length)); + xfs_btree_init_block(mp, bp, btnum, 0, 0, sc->sa.agno); + xfs_trans_buf_set_type(tp, bp, XFS_BLFT_BTREE_BUF); + xfs_trans_log_buf(tp, bp, 0, BBTOB(bp->b_length) - 1); + bp->b_ops = ops; + *bpp = bp; + + return 0; +} + +/* + * Reconstructing per-AG Btrees + * + * When a space btree is corrupt, we don't bother trying to fix it. Instead, + * we scan secondary space metadata to derive the records that should be in + * the damaged btree, initialize a fresh btree root, and insert the records. + * Note that for rebuilding the rmapbt we scan all the primary data to + * generate the new records. + * + * However, that leaves the matter of removing all the metadata describing the + * old broken structure. For primary metadata we use the rmap data to collect + * every extent with a matching rmap owner (bitmap); we then iterate all other + * metadata structures with the same rmap owner to collect the extents that + * cannot be removed (sublist). We then subtract sublist from bitmap to + * derive the blocks that were used by the old btree. These blocks can be + * reaped. + * + * For rmapbt reconstructions we must use different tactics for extent + * collection. First we iterate all primary metadata (this excludes the old + * rmapbt, obviously) to generate new rmap records. The gaps in the rmap + * records are collected as bitmap. The bnobt records are collected as + * sublist. As with the other btrees we subtract sublist from bitmap, and the + * result (since the rmapbt lives in the free space) are the blocks from the + * old rmapbt. + * + * Disposal of Blocks from Old per-AG Btrees + * + * Now that we've constructed a new btree to replace the damaged one, we want + * to dispose of the blocks that (we think) the old btree was using. + * Previously, we used the rmapbt to collect the extents (bitmap) with the + * rmap owner corresponding to the tree we rebuilt, collected extents for any + * blocks with the same rmap owner that are owned by another data structure + * (sublist), and subtracted sublist from bitmap. In theory the extents + * remaining in bitmap are the old btree's blocks. + * + * Unfortunately, it's possible that the btree was crosslinked with other + * blocks on disk. The rmap data can tell us if there are multiple owners, so + * if the rmapbt says there is an owner of this block other than @oinfo, then + * the block is crosslinked. Remove the reverse mapping and continue. + * + * If there is one rmap record, we can free the block, which removes the + * reverse mapping but doesn't add the block to the free space. Our repair + * strategy is to hope the other metadata objects crosslinked on this block + * will be rebuilt (atop different blocks), thereby removing all the cross + * links. + * + * If there are no rmap records at all, we also free the block. If the btree + * being rebuilt lives in the free space (bnobt/cntbt/rmapbt) then there isn't + * supposed to be a rmap record and everything is ok. For other btrees there + * had to have been an rmap entry for the block to have ended up on @bitmap, + * so if it's gone now there's something wrong and the fs will shut down. + * + * Note: If there are multiple rmap records with only the same rmap owner as + * the btree we're trying to rebuild and the block is indeed owned by another + * data structure with the same rmap owner, then the block will be in sublist + * and therefore doesn't need disposal. If there are multiple rmap records + * with only the same rmap owner but the block is not owned by something with + * the same rmap owner, the block will be freed. + * + * The caller is responsible for locking the AG headers for the entire rebuild + * operation so that nothing else can sneak in and change the AG state while + * we're not looking. We also assume that the caller already invalidated any + * buffers associated with @bitmap. + */ + +/* + * Invalidate buffers for per-AG btree blocks we're dumping. This function + * is not intended for use with file data repairs; we have bunmapi for that. + */ +int +xrep_invalidate_blocks( + struct xfs_scrub *sc, + struct xbitmap *bitmap) +{ + struct xbitmap_range *bmr; + struct xbitmap_range *n; + struct xfs_buf *bp; + xfs_fsblock_t fsbno; + + /* + * For each block in each extent, see if there's an incore buffer for + * exactly that block; if so, invalidate it. The buffer cache only + * lets us look for one buffer at a time, so we have to look one block + * at a time. Avoid invalidating AG headers and post-EOFS blocks + * because we never own those; and if we can't TRYLOCK the buffer we + * assume it's owned by someone else. + */ + for_each_xbitmap_block(fsbno, bmr, n, bitmap) { + /* Skip AG headers and post-EOFS blocks */ + if (!xfs_verify_fsbno(sc->mp, fsbno)) + continue; + bp = xfs_buf_incore(sc->mp->m_ddev_targp, + XFS_FSB_TO_DADDR(sc->mp, fsbno), + XFS_FSB_TO_BB(sc->mp, 1), XBF_TRYLOCK); + if (bp) { + xfs_trans_bjoin(sc->tp, bp); + xfs_trans_binval(sc->tp, bp); + } + } + + return 0; +} + +/* Ensure the freelist is the correct size. */ +int +xrep_fix_freelist( + struct xfs_scrub *sc, + bool can_shrink) +{ + struct xfs_alloc_arg args = {0}; + + args.mp = sc->mp; + args.tp = sc->tp; + args.agno = sc->sa.agno; + args.alignment = 1; + args.pag = sc->sa.pag; + + return xfs_alloc_fix_freelist(&args, + can_shrink ? 0 : XFS_ALLOC_FLAG_NOSHRINK); +} + +/* + * Put a block back on the AGFL. + */ +STATIC int +xrep_put_freelist( + struct xfs_scrub *sc, + xfs_agblock_t agbno) +{ + int error; + + /* Make sure there's space on the freelist. */ + error = xrep_fix_freelist(sc, true); + if (error) + return error; + + /* + * Since we're "freeing" a lost block onto the AGFL, we have to + * create an rmap for the block prior to merging it or else other + * parts will break. + */ + error = xfs_rmap_alloc(sc->tp, sc->sa.agf_bp, sc->sa.agno, agbno, 1, + &XFS_RMAP_OINFO_AG); + if (error) + return error; + + /* Put the block on the AGFL. */ + error = xfs_alloc_put_freelist(sc->tp, sc->sa.agf_bp, sc->sa.agfl_bp, + agbno, 0); + if (error) + return error; + xfs_extent_busy_insert(sc->tp, sc->sa.agno, agbno, 1, + XFS_EXTENT_BUSY_SKIP_DISCARD); + + return 0; +} + +/* Dispose of a single block. */ +STATIC int +xrep_reap_block( + struct xfs_scrub *sc, + xfs_fsblock_t fsbno, + const struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type resv) +{ + struct xfs_btree_cur *cur; + struct xfs_buf *agf_bp = NULL; + xfs_agnumber_t agno; + xfs_agblock_t agbno; + bool has_other_rmap; + int error; + + agno = XFS_FSB_TO_AGNO(sc->mp, fsbno); + agbno = XFS_FSB_TO_AGBNO(sc->mp, fsbno); + + /* + * If we are repairing per-inode metadata, we need to read in the AGF + * buffer. Otherwise, we're repairing a per-AG structure, so reuse + * the AGF buffer that the setup functions already grabbed. + */ + if (sc->ip) { + error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf_bp); + if (error) + return error; + } else { + agf_bp = sc->sa.agf_bp; + } + cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf_bp, agno); + + /* Can we find any other rmappings? */ + error = xfs_rmap_has_other_keys(cur, agbno, 1, oinfo, &has_other_rmap); + xfs_btree_del_cursor(cur, error); + if (error) + goto out_free; + + /* + * If there are other rmappings, this block is cross linked and must + * not be freed. Remove the reverse mapping and move on. Otherwise, + * we were the only owner of the block, so free the extent, which will + * also remove the rmap. + * + * XXX: XFS doesn't support detecting the case where a single block + * metadata structure is crosslinked with a multi-block structure + * because the buffer cache doesn't detect aliasing problems, so we + * can't fix 100% of crosslinking problems (yet). The verifiers will + * blow on writeout, the filesystem will shut down, and the admin gets + * to run xfs_repair. + */ + if (has_other_rmap) + error = xfs_rmap_free(sc->tp, agf_bp, agno, agbno, 1, oinfo); + else if (resv == XFS_AG_RESV_AGFL) + error = xrep_put_freelist(sc, agbno); + else + error = xfs_free_extent(sc->tp, fsbno, 1, oinfo, resv); + if (agf_bp != sc->sa.agf_bp) + xfs_trans_brelse(sc->tp, agf_bp); + if (error) + return error; + + if (sc->ip) + return xfs_trans_roll_inode(&sc->tp, sc->ip); + return xrep_roll_ag_trans(sc); + +out_free: + if (agf_bp != sc->sa.agf_bp) + xfs_trans_brelse(sc->tp, agf_bp); + return error; +} + +/* Dispose of every block of every extent in the bitmap. */ +int +xrep_reap_extents( + struct xfs_scrub *sc, + struct xbitmap *bitmap, + const struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type type) +{ + struct xbitmap_range *bmr; + struct xbitmap_range *n; + xfs_fsblock_t fsbno; + int error = 0; + + ASSERT(xfs_sb_version_hasrmapbt(&sc->mp->m_sb)); + + for_each_xbitmap_block(fsbno, bmr, n, bitmap) { + ASSERT(sc->ip != NULL || + XFS_FSB_TO_AGNO(sc->mp, fsbno) == sc->sa.agno); + trace_xrep_dispose_btree_extent(sc->mp, + XFS_FSB_TO_AGNO(sc->mp, fsbno), + XFS_FSB_TO_AGBNO(sc->mp, fsbno), 1); + + error = xrep_reap_block(sc, fsbno, oinfo, type); + if (error) + break; + } + + return error; +} + +/* + * Finding per-AG Btree Roots for AGF/AGI Reconstruction + * + * If the AGF or AGI become slightly corrupted, it may be necessary to rebuild + * the AG headers by using the rmap data to rummage through the AG looking for + * btree roots. This is not guaranteed to work if the AG is heavily damaged + * or the rmap data are corrupt. + * + * Callers of xrep_find_ag_btree_roots must lock the AGF and AGFL + * buffers if the AGF is being rebuilt; or the AGF and AGI buffers if the + * AGI is being rebuilt. It must maintain these locks until it's safe for + * other threads to change the btrees' shapes. The caller provides + * information about the btrees to look for by passing in an array of + * xrep_find_ag_btree with the (rmap owner, buf_ops, magic) fields set. + * The (root, height) fields will be set on return if anything is found. The + * last element of the array should have a NULL buf_ops to mark the end of the + * array. + * + * For every rmapbt record matching any of the rmap owners in btree_info, + * read each block referenced by the rmap record. If the block is a btree + * block from this filesystem matching any of the magic numbers and has a + * level higher than what we've already seen, remember the block and the + * height of the tree required to have such a block. When the call completes, + * we return the highest block we've found for each btree description; those + * should be the roots. + */ + +struct xrep_findroot { + struct xfs_scrub *sc; + struct xfs_buf *agfl_bp; + struct xfs_agf *agf; + struct xrep_find_ag_btree *btree_info; +}; + +/* See if our block is in the AGFL. */ +STATIC int +xrep_findroot_agfl_walk( + struct xfs_mount *mp, + xfs_agblock_t bno, + void *priv) +{ + xfs_agblock_t *agbno = priv; + + return (*agbno == bno) ? -ECANCELED : 0; +} + +/* Does this block match the btree information passed in? */ +STATIC int +xrep_findroot_block( + struct xrep_findroot *ri, + struct xrep_find_ag_btree *fab, + uint64_t owner, + xfs_agblock_t agbno, + bool *done_with_block) +{ + struct xfs_mount *mp = ri->sc->mp; + struct xfs_buf *bp; + struct xfs_btree_block *btblock; + xfs_daddr_t daddr; + int block_level; + int error = 0; + + daddr = XFS_AGB_TO_DADDR(mp, ri->sc->sa.agno, agbno); + + /* + * Blocks in the AGFL have stale contents that might just happen to + * have a matching magic and uuid. We don't want to pull these blocks + * in as part of a tree root, so we have to filter out the AGFL stuff + * here. If the AGFL looks insane we'll just refuse to repair. + */ + if (owner == XFS_RMAP_OWN_AG) { + error = xfs_agfl_walk(mp, ri->agf, ri->agfl_bp, + xrep_findroot_agfl_walk, &agbno); + if (error == -ECANCELED) + return 0; + if (error) + return error; + } + + /* + * Read the buffer into memory so that we can see if it's a match for + * our btree type. We have no clue if it is beforehand, and we want to + * avoid xfs_trans_read_buf's behavior of dumping the DONE state (which + * will cause needless disk reads in subsequent calls to this function) + * and logging metadata verifier failures. + * + * Therefore, pass in NULL buffer ops. If the buffer was already in + * memory from some other caller it will already have b_ops assigned. + * If it was in memory from a previous unsuccessful findroot_block + * call, the buffer won't have b_ops but it should be clean and ready + * for us to try to verify if the read call succeeds. The same applies + * if the buffer wasn't in memory at all. + * + * Note: If we never match a btree type with this buffer, it will be + * left in memory with NULL b_ops. This shouldn't be a problem unless + * the buffer gets written. + */ + error = xfs_trans_read_buf(mp, ri->sc->tp, mp->m_ddev_targp, daddr, + mp->m_bsize, 0, &bp, NULL); + if (error) + return error; + + /* Ensure the block magic matches the btree type we're looking for. */ + btblock = XFS_BUF_TO_BLOCK(bp); + ASSERT(fab->buf_ops->magic[1] != 0); + if (btblock->bb_magic != fab->buf_ops->magic[1]) + goto out; + + /* + * If the buffer already has ops applied and they're not the ones for + * this btree type, we know this block doesn't match the btree and we + * can bail out. + * + * If the buffer ops match ours, someone else has already validated + * the block for us, so we can move on to checking if this is a root + * block candidate. + * + * If the buffer does not have ops, nobody has successfully validated + * the contents and the buffer cannot be dirty. If the magic, uuid, + * and structure match this btree type then we'll move on to checking + * if it's a root block candidate. If there is no match, bail out. + */ + if (bp->b_ops) { + if (bp->b_ops != fab->buf_ops) + goto out; + } else { + ASSERT(!xfs_trans_buf_is_dirty(bp)); + if (!uuid_equal(&btblock->bb_u.s.bb_uuid, + &mp->m_sb.sb_meta_uuid)) + goto out; + /* + * Read verifiers can reference b_ops, so we set the pointer + * here. If the verifier fails we'll reset the buffer state + * to what it was before we touched the buffer. + */ + bp->b_ops = fab->buf_ops; + fab->buf_ops->verify_read(bp); + if (bp->b_error) { + bp->b_ops = NULL; + bp->b_error = 0; + goto out; + } + + /* + * Some read verifiers will (re)set b_ops, so we must be + * careful not to change b_ops after running the verifier. + */ + } + + /* + * This block passes the magic/uuid and verifier tests for this btree + * type. We don't need the caller to try the other tree types. + */ + *done_with_block = true; + + /* + * Compare this btree block's level to the height of the current + * candidate root block. + * + * If the level matches the root we found previously, throw away both + * blocks because there can't be two candidate roots. + * + * If level is lower in the tree than the root we found previously, + * ignore this block. + */ + block_level = xfs_btree_get_level(btblock); + if (block_level + 1 == fab->height) { + fab->root = NULLAGBLOCK; + goto out; + } else if (block_level < fab->height) { + goto out; + } + + /* + * This is the highest block in the tree that we've found so far. + * Update the btree height to reflect what we've learned from this + * block. + */ + fab->height = block_level + 1; + + /* + * If this block doesn't have sibling pointers, then it's the new root + * block candidate. Otherwise, the root will be found farther up the + * tree. + */ + if (btblock->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) && + btblock->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK)) + fab->root = agbno; + else + fab->root = NULLAGBLOCK; + + trace_xrep_findroot_block(mp, ri->sc->sa.agno, agbno, + be32_to_cpu(btblock->bb_magic), fab->height - 1); +out: + xfs_trans_brelse(ri->sc->tp, bp); + return error; +} + +/* + * Do any of the blocks in this rmap record match one of the btrees we're + * looking for? + */ +STATIC int +xrep_findroot_rmap( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xrep_findroot *ri = priv; + struct xrep_find_ag_btree *fab; + xfs_agblock_t b; + bool done; + int error = 0; + + /* Ignore anything that isn't AG metadata. */ + if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner)) + return 0; + + /* Otherwise scan each block + btree type. */ + for (b = 0; b < rec->rm_blockcount; b++) { + done = false; + for (fab = ri->btree_info; fab->buf_ops; fab++) { + if (rec->rm_owner != fab->rmap_owner) + continue; + error = xrep_findroot_block(ri, fab, + rec->rm_owner, rec->rm_startblock + b, + &done); + if (error) + return error; + if (done) + break; + } + } + + return 0; +} + +/* Find the roots of the per-AG btrees described in btree_info. */ +int +xrep_find_ag_btree_roots( + struct xfs_scrub *sc, + struct xfs_buf *agf_bp, + struct xrep_find_ag_btree *btree_info, + struct xfs_buf *agfl_bp) +{ + struct xfs_mount *mp = sc->mp; + struct xrep_findroot ri; + struct xrep_find_ag_btree *fab; + struct xfs_btree_cur *cur; + int error; + + ASSERT(xfs_buf_islocked(agf_bp)); + ASSERT(agfl_bp == NULL || xfs_buf_islocked(agfl_bp)); + + ri.sc = sc; + ri.btree_info = btree_info; + ri.agf = agf_bp->b_addr; + ri.agfl_bp = agfl_bp; + for (fab = btree_info; fab->buf_ops; fab++) { + ASSERT(agfl_bp || fab->rmap_owner != XFS_RMAP_OWN_AG); + ASSERT(XFS_RMAP_NON_INODE_OWNER(fab->rmap_owner)); + fab->root = NULLAGBLOCK; + fab->height = 0; + } + + cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno); + error = xfs_rmap_query_all(cur, xrep_findroot_rmap, &ri); + xfs_btree_del_cursor(cur, error); + + return error; +} + +/* Force a quotacheck the next time we mount. */ +void +xrep_force_quotacheck( + struct xfs_scrub *sc, + xfs_dqtype_t type) +{ + uint flag; + + flag = xfs_quota_chkd_flag(type); + if (!(flag & sc->mp->m_qflags)) + return; + + sc->mp->m_qflags &= ~flag; + spin_lock(&sc->mp->m_sb_lock); + sc->mp->m_sb.sb_qflags &= ~flag; + spin_unlock(&sc->mp->m_sb_lock); + xfs_log_sb(sc->tp); +} + +/* + * Attach dquots to this inode, or schedule quotacheck to fix them. + * + * This function ensures that the appropriate dquots are attached to an inode. + * We cannot allow the dquot code to allocate an on-disk dquot block here + * because we're already in transaction context with the inode locked. The + * on-disk dquot should already exist anyway. If the quota code signals + * corruption or missing quota information, schedule quotacheck, which will + * repair corruptions in the quota metadata. + */ +int +xrep_ino_dqattach( + struct xfs_scrub *sc) +{ + int error; + + error = xfs_qm_dqattach_locked(sc->ip, false); + switch (error) { + case -EFSBADCRC: + case -EFSCORRUPTED: + case -ENOENT: + xfs_err_ratelimited(sc->mp, +"inode %llu repair encountered quota error %d, quotacheck forced.", + (unsigned long long)sc->ip->i_ino, error); + if (XFS_IS_UQUOTA_ON(sc->mp) && !sc->ip->i_udquot) + xrep_force_quotacheck(sc, XFS_DQTYPE_USER); + if (XFS_IS_GQUOTA_ON(sc->mp) && !sc->ip->i_gdquot) + xrep_force_quotacheck(sc, XFS_DQTYPE_GROUP); + if (XFS_IS_PQUOTA_ON(sc->mp) && !sc->ip->i_pdquot) + xrep_force_quotacheck(sc, XFS_DQTYPE_PROJ); + /* fall through */ + case -ESRCH: + error = 0; + break; + default: + break; + } + + return error; +} |