diff options
Diffstat (limited to 'fs/xfs/scrub/bmap.c')
| -rw-r--r-- | fs/xfs/scrub/bmap.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c new file mode 100644 index 000000000..755889155 --- /dev/null +++ b/fs/xfs/scrub/bmap.c @@ -0,0 +1,959 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2017-2023 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_btree.h" +#include "xfs_bit.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_inode.h" +#include "xfs_alloc.h" +#include "xfs_bmap.h" +#include "xfs_bmap_btree.h" +#include "xfs_rmap.h" +#include "xfs_rmap_btree.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/btree.h" +#include "xfs_ag.h" + +/* Set us up with an inode's bmap. */ +int +xchk_setup_inode_bmap( + struct xfs_scrub *sc) +{ + int error; + + if (xchk_need_intent_drain(sc)) + xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN); + + error = xchk_iget_for_scrubbing(sc); + if (error) + goto out; + + xchk_ilock(sc, XFS_IOLOCK_EXCL); + + /* + * We don't want any ephemeral data/cow fork updates sitting around + * while we inspect block mappings, so wait for directio to finish + * and flush dirty data if we have delalloc reservations. + */ + if (S_ISREG(VFS_I(sc->ip)->i_mode) && + sc->sm->sm_type != XFS_SCRUB_TYPE_BMBTA) { + struct address_space *mapping = VFS_I(sc->ip)->i_mapping; + + xchk_ilock(sc, XFS_MMAPLOCK_EXCL); + + inode_dio_wait(VFS_I(sc->ip)); + + /* + * Try to flush all incore state to disk before we examine the + * space mappings for the data fork. Leave accumulated errors + * in the mapping for the writer threads to consume. + * + * On ENOSPC or EIO writeback errors, we continue into the + * extent mapping checks because write failures do not + * necessarily imply anything about the correctness of the file + * metadata. The metadata and the file data could be on + * completely separate devices; a media failure might only + * affect a subset of the disk, etc. We can handle delalloc + * extents in the scrubber, so leaving them in memory is fine. + */ + error = filemap_fdatawrite(mapping); + if (!error) + error = filemap_fdatawait_keep_errors(mapping); + if (error && (error != -ENOSPC && error != -EIO)) + goto out; + } + + /* Got the inode, lock it and we're ready to go. */ + error = xchk_trans_alloc(sc, 0); + if (error) + goto out; + + xchk_ilock(sc, XFS_ILOCK_EXCL); +out: + /* scrub teardown will unlock and release the inode */ + return error; +} + +/* + * Inode fork block mapping (BMBT) scrubber. + * More complex than the others because we have to scrub + * all the extents regardless of whether or not the fork + * is in btree format. + */ + +struct xchk_bmap_info { + struct xfs_scrub *sc; + + /* Incore extent tree cursor */ + struct xfs_iext_cursor icur; + + /* Previous fork mapping that we examined */ + struct xfs_bmbt_irec prev_rec; + + /* Is this a realtime fork? */ + bool is_rt; + + /* May mappings point to shared space? */ + bool is_shared; + + /* Was the incore extent tree loaded? */ + bool was_loaded; + + /* Which inode fork are we checking? */ + int whichfork; +}; + +/* Look for a corresponding rmap for this irec. */ +static inline bool +xchk_bmap_get_rmap( + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec, + xfs_agblock_t agbno, + uint64_t owner, + struct xfs_rmap_irec *rmap) +{ + xfs_fileoff_t offset; + unsigned int rflags = 0; + int has_rmap; + int error; + + if (info->whichfork == XFS_ATTR_FORK) + rflags |= XFS_RMAP_ATTR_FORK; + if (irec->br_state == XFS_EXT_UNWRITTEN) + rflags |= XFS_RMAP_UNWRITTEN; + + /* + * CoW staging extents are owned (on disk) by the refcountbt, so + * their rmaps do not have offsets. + */ + if (info->whichfork == XFS_COW_FORK) + offset = 0; + else + offset = irec->br_startoff; + + /* + * If the caller thinks this could be a shared bmbt extent (IOWs, + * any data fork extent of a reflink inode) then we have to use the + * range rmap lookup to make sure we get the correct owner/offset. + */ + if (info->is_shared) { + error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno, + owner, offset, rflags, rmap, &has_rmap); + } else { + error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno, + owner, offset, rflags, rmap, &has_rmap); + } + if (!xchk_should_check_xref(info->sc, &error, &info->sc->sa.rmap_cur)) + return false; + + if (!has_rmap) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + return has_rmap; +} + +/* Make sure that we have rmapbt records for this data/attr fork extent. */ +STATIC void +xchk_bmap_xref_rmap( + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec, + xfs_agblock_t agbno) +{ + struct xfs_rmap_irec rmap; + unsigned long long rmap_end; + uint64_t owner = info->sc->ip->i_ino; + + if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm)) + return; + + /* Find the rmap record for this irec. */ + if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap)) + return; + + /* + * The rmap must be an exact match for this incore file mapping record, + * which may have arisen from multiple ondisk records. + */ + if (rmap.rm_startblock != agbno) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount; + if (rmap_end != agbno + irec->br_blockcount) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* Check the logical offsets. */ + if (rmap.rm_offset != irec->br_startoff) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + rmap_end = (unsigned long long)rmap.rm_offset + rmap.rm_blockcount; + if (rmap_end != irec->br_startoff + irec->br_blockcount) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* Check the owner */ + if (rmap.rm_owner != owner) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* + * Check for discrepancies between the unwritten flag in the irec and + * the rmap. Note that the (in-memory) CoW fork distinguishes between + * unwritten and written extents, but we don't track that in the rmap + * records because the blocks are owned (on-disk) by the refcountbt, + * which doesn't track unwritten state. + */ + if (!!(irec->br_state == XFS_EXT_UNWRITTEN) != + !!(rmap.rm_flags & XFS_RMAP_UNWRITTEN)) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + if (!!(info->whichfork == XFS_ATTR_FORK) != + !!(rmap.rm_flags & XFS_RMAP_ATTR_FORK)) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); +} + +/* Make sure that we have rmapbt records for this COW fork extent. */ +STATIC void +xchk_bmap_xref_rmap_cow( + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec, + xfs_agblock_t agbno) +{ + struct xfs_rmap_irec rmap; + unsigned long long rmap_end; + uint64_t owner = XFS_RMAP_OWN_COW; + + if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm)) + return; + + /* Find the rmap record for this irec. */ + if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap)) + return; + + /* + * CoW staging extents are owned by the refcount btree, so the rmap + * can start before and end after the physical space allocated to this + * mapping. There are no offsets to check. + */ + if (rmap.rm_startblock > agbno) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount; + if (rmap_end < agbno + irec->br_blockcount) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* Check the owner */ + if (rmap.rm_owner != owner) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* + * No flags allowed. Note that the (in-memory) CoW fork distinguishes + * between unwritten and written extents, but we don't track that in + * the rmap records because the blocks are owned (on-disk) by the + * refcountbt, which doesn't track unwritten state. + */ + if (rmap.rm_flags & XFS_RMAP_ATTR_FORK) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + if (rmap.rm_flags & XFS_RMAP_UNWRITTEN) + xchk_fblock_xref_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); +} + +/* Cross-reference a single rtdev extent record. */ +STATIC void +xchk_bmap_rt_iextent_xref( + struct xfs_inode *ip, + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + xchk_xref_is_used_rt_space(info->sc, irec->br_startblock, + irec->br_blockcount); +} + +/* Cross-reference a single datadev extent record. */ +STATIC void +xchk_bmap_iextent_xref( + struct xfs_inode *ip, + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + struct xfs_owner_info oinfo; + struct xfs_mount *mp = info->sc->mp; + xfs_agnumber_t agno; + xfs_agblock_t agbno; + xfs_extlen_t len; + int error; + + agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock); + agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock); + len = irec->br_blockcount; + + error = xchk_ag_init_existing(info->sc, agno, &info->sc->sa); + if (!xchk_fblock_process_error(info->sc, info->whichfork, + irec->br_startoff, &error)) + goto out_free; + + xchk_xref_is_used_space(info->sc, agbno, len); + xchk_xref_is_not_inode_chunk(info->sc, agbno, len); + switch (info->whichfork) { + case XFS_DATA_FORK: + xchk_bmap_xref_rmap(info, irec, agbno); + if (!xfs_is_reflink_inode(info->sc->ip)) { + xfs_rmap_ino_owner(&oinfo, info->sc->ip->i_ino, + info->whichfork, irec->br_startoff); + xchk_xref_is_only_owned_by(info->sc, agbno, + irec->br_blockcount, &oinfo); + xchk_xref_is_not_shared(info->sc, agbno, + irec->br_blockcount); + } + xchk_xref_is_not_cow_staging(info->sc, agbno, + irec->br_blockcount); + break; + case XFS_ATTR_FORK: + xchk_bmap_xref_rmap(info, irec, agbno); + xfs_rmap_ino_owner(&oinfo, info->sc->ip->i_ino, + info->whichfork, irec->br_startoff); + xchk_xref_is_only_owned_by(info->sc, agbno, irec->br_blockcount, + &oinfo); + xchk_xref_is_not_shared(info->sc, agbno, + irec->br_blockcount); + xchk_xref_is_not_cow_staging(info->sc, agbno, + irec->br_blockcount); + break; + case XFS_COW_FORK: + xchk_bmap_xref_rmap_cow(info, irec, agbno); + xchk_xref_is_only_owned_by(info->sc, agbno, irec->br_blockcount, + &XFS_RMAP_OINFO_COW); + xchk_xref_is_cow_staging(info->sc, agbno, + irec->br_blockcount); + xchk_xref_is_not_shared(info->sc, agbno, + irec->br_blockcount); + break; + } + +out_free: + xchk_ag_free(info->sc, &info->sc->sa); +} + +/* + * Directories and attr forks should never have blocks that can't be addressed + * by a xfs_dablk_t. + */ +STATIC void +xchk_bmap_dirattr_extent( + struct xfs_inode *ip, + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t off; + + if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK) + return; + + if (!xfs_verify_dablk(mp, irec->br_startoff)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + off = irec->br_startoff + irec->br_blockcount - 1; + if (!xfs_verify_dablk(mp, off)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, off); +} + +/* Scrub a single extent record. */ +STATIC void +xchk_bmap_iextent( + struct xfs_inode *ip, + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + struct xfs_mount *mp = info->sc->mp; + + /* + * Check for out-of-order extents. This record could have come + * from the incore list, for which there is no ordering check. + */ + if (irec->br_startoff < info->prev_rec.br_startoff + + info->prev_rec.br_blockcount) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + xchk_bmap_dirattr_extent(ip, info, irec); + + /* Make sure the extent points to a valid place. */ + if (info->is_rt && + !xfs_verify_rtext(mp, irec->br_startblock, irec->br_blockcount)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + if (!info->is_rt && + !xfs_verify_fsbext(mp, irec->br_startblock, irec->br_blockcount)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* We don't allow unwritten extents on attr forks. */ + if (irec->br_state == XFS_EXT_UNWRITTEN && + info->whichfork == XFS_ATTR_FORK) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return; + + if (info->is_rt) + xchk_bmap_rt_iextent_xref(ip, info, irec); + else + xchk_bmap_iextent_xref(ip, info, irec); +} + +/* Scrub a bmbt record. */ +STATIC int +xchk_bmapbt_rec( + struct xchk_btree *bs, + const union xfs_btree_rec *rec) +{ + struct xfs_bmbt_irec irec; + struct xfs_bmbt_irec iext_irec; + struct xfs_iext_cursor icur; + struct xchk_bmap_info *info = bs->private; + struct xfs_inode *ip = bs->cur->bc_ino.ip; + struct xfs_buf *bp = NULL; + struct xfs_btree_block *block; + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, info->whichfork); + uint64_t owner; + int i; + + /* + * Check the owners of the btree blocks up to the level below + * the root since the verifiers don't do that. + */ + if (xfs_has_crc(bs->cur->bc_mp) && + bs->cur->bc_levels[0].ptr == 1) { + for (i = 0; i < bs->cur->bc_nlevels - 1; i++) { + block = xfs_btree_get_block(bs->cur, i, &bp); + owner = be64_to_cpu(block->bb_u.l.bb_owner); + if (owner != ip->i_ino) + xchk_fblock_set_corrupt(bs->sc, + info->whichfork, 0); + } + } + + /* + * Check that the incore extent tree contains an extent that matches + * this one exactly. We validate those cached bmaps later, so we don't + * need to check them here. If the incore extent tree was just loaded + * from disk by the scrubber, we assume that its contents match what's + * on disk (we still hold the ILOCK) and skip the equivalence check. + */ + if (!info->was_loaded) + return 0; + + xfs_bmbt_disk_get_all(&rec->bmbt, &irec); + if (xfs_bmap_validate_extent(ip, info->whichfork, &irec) != NULL) { + xchk_fblock_set_corrupt(bs->sc, info->whichfork, + irec.br_startoff); + return 0; + } + + if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur, + &iext_irec) || + irec.br_startoff != iext_irec.br_startoff || + irec.br_startblock != iext_irec.br_startblock || + irec.br_blockcount != iext_irec.br_blockcount || + irec.br_state != iext_irec.br_state) + xchk_fblock_set_corrupt(bs->sc, info->whichfork, + irec.br_startoff); + return 0; +} + +/* Scan the btree records. */ +STATIC int +xchk_bmap_btree( + struct xfs_scrub *sc, + int whichfork, + struct xchk_bmap_info *info) +{ + struct xfs_owner_info oinfo; + struct xfs_ifork *ifp = xfs_ifork_ptr(sc->ip, whichfork); + struct xfs_mount *mp = sc->mp; + struct xfs_inode *ip = sc->ip; + struct xfs_btree_cur *cur; + int error; + + /* Load the incore bmap cache if it's not loaded. */ + info->was_loaded = !xfs_need_iread_extents(ifp); + + error = xfs_iread_extents(sc->tp, ip, whichfork); + if (!xchk_fblock_process_error(sc, whichfork, 0, &error)) + goto out; + + /* Check the btree structure. */ + cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork); + xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork); + error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info); + xfs_btree_del_cursor(cur, error); +out: + return error; +} + +struct xchk_bmap_check_rmap_info { + struct xfs_scrub *sc; + int whichfork; + struct xfs_iext_cursor icur; +}; + +/* Can we find bmaps that fit this rmap? */ +STATIC int +xchk_bmap_check_rmap( + struct xfs_btree_cur *cur, + const struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_bmbt_irec irec; + struct xfs_rmap_irec check_rec; + struct xchk_bmap_check_rmap_info *sbcri = priv; + struct xfs_ifork *ifp; + struct xfs_scrub *sc = sbcri->sc; + bool have_map; + + /* Is this even the right fork? */ + if (rec->rm_owner != sc->ip->i_ino) + return 0; + if ((sbcri->whichfork == XFS_ATTR_FORK) ^ + !!(rec->rm_flags & XFS_RMAP_ATTR_FORK)) + return 0; + if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK) + return 0; + + /* Now look up the bmbt record. */ + ifp = xfs_ifork_ptr(sc->ip, sbcri->whichfork); + if (!ifp) { + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + rec->rm_offset); + goto out; + } + have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset, + &sbcri->icur, &irec); + if (!have_map) + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + rec->rm_offset); + /* + * bmap extent record lengths are constrained to 2^21 blocks in length + * because of space constraints in the on-disk metadata structure. + * However, rmap extent record lengths are constrained only by AG + * length, so we have to loop through the bmbt to make sure that the + * entire rmap is covered by bmbt records. + */ + check_rec = *rec; + while (have_map) { + if (irec.br_startoff != check_rec.rm_offset) + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + check_rec.rm_offset); + if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp, + cur->bc_ag.pag->pag_agno, + check_rec.rm_startblock)) + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + check_rec.rm_offset); + if (irec.br_blockcount > check_rec.rm_blockcount) + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + check_rec.rm_offset); + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + break; + check_rec.rm_startblock += irec.br_blockcount; + check_rec.rm_offset += irec.br_blockcount; + check_rec.rm_blockcount -= irec.br_blockcount; + if (check_rec.rm_blockcount == 0) + break; + have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec); + if (!have_map) + xchk_fblock_set_corrupt(sc, sbcri->whichfork, + check_rec.rm_offset); + } + +out: + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return -ECANCELED; + return 0; +} + +/* Make sure each rmap has a corresponding bmbt entry. */ +STATIC int +xchk_bmap_check_ag_rmaps( + struct xfs_scrub *sc, + int whichfork, + struct xfs_perag *pag) +{ + struct xchk_bmap_check_rmap_info sbcri; + struct xfs_btree_cur *cur; + struct xfs_buf *agf; + int error; + + error = xfs_alloc_read_agf(pag, sc->tp, 0, &agf); + if (error) + return error; + + cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, pag); + + sbcri.sc = sc; + sbcri.whichfork = whichfork; + error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri); + if (error == -ECANCELED) + error = 0; + + xfs_btree_del_cursor(cur, error); + xfs_trans_brelse(sc->tp, agf); + return error; +} + +/* + * Decide if we want to walk every rmap btree in the fs to make sure that each + * rmap for this file fork has corresponding bmbt entries. + */ +static bool +xchk_bmap_want_check_rmaps( + struct xchk_bmap_info *info) +{ + struct xfs_scrub *sc = info->sc; + struct xfs_ifork *ifp; + + if (!xfs_has_rmapbt(sc->mp)) + return false; + if (info->whichfork == XFS_COW_FORK) + return false; + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return false; + + /* Don't support realtime rmap checks yet. */ + if (info->is_rt) + return false; + + /* + * The inode repair code zaps broken inode forks by resetting them back + * to EXTENTS format and zero extent records. If we encounter a fork + * in this state along with evidence that the fork isn't supposed to be + * empty, we need to scan the reverse mappings to decide if we're going + * to rebuild the fork. Data forks with nonzero file size are scanned. + * xattr forks are never empty of content, so they are always scanned. + */ + ifp = xfs_ifork_ptr(sc->ip, info->whichfork); + if (ifp->if_format == XFS_DINODE_FMT_EXTENTS && ifp->if_nextents == 0) { + if (info->whichfork == XFS_DATA_FORK && + i_size_read(VFS_I(sc->ip)) == 0) + return false; + + return true; + } + + return false; +} + +/* Make sure each rmap has a corresponding bmbt entry. */ +STATIC int +xchk_bmap_check_rmaps( + struct xfs_scrub *sc, + int whichfork) +{ + struct xfs_perag *pag; + xfs_agnumber_t agno; + int error; + + for_each_perag(sc->mp, agno, pag) { + error = xchk_bmap_check_ag_rmaps(sc, whichfork, pag); + if (error || + (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) { + xfs_perag_rele(pag); + return error; + } + } + + return 0; +} + +/* Scrub a delalloc reservation from the incore extent map tree. */ +STATIC void +xchk_bmap_iextent_delalloc( + struct xfs_inode *ip, + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + struct xfs_mount *mp = info->sc->mp; + + /* + * Check for out-of-order extents. This record could have come + * from the incore list, for which there is no ordering check. + */ + if (irec->br_startoff < info->prev_rec.br_startoff + + info->prev_rec.br_blockcount) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount)) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + + /* Make sure the extent points to a valid place. */ + if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN) + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); +} + +/* Decide if this individual fork mapping is ok. */ +static bool +xchk_bmap_iext_mapping( + struct xchk_bmap_info *info, + const struct xfs_bmbt_irec *irec) +{ + /* There should never be a "hole" extent in either extent list. */ + if (irec->br_startblock == HOLESTARTBLOCK) + return false; + if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN) + return false; + return true; +} + +/* Are these two mappings contiguous with each other? */ +static inline bool +xchk_are_bmaps_contiguous( + const struct xfs_bmbt_irec *b1, + const struct xfs_bmbt_irec *b2) +{ + /* Don't try to combine unallocated mappings. */ + if (!xfs_bmap_is_real_extent(b1)) + return false; + if (!xfs_bmap_is_real_extent(b2)) + return false; + + /* Does b2 come right after b1 in the logical and physical range? */ + if (b1->br_startoff + b1->br_blockcount != b2->br_startoff) + return false; + if (b1->br_startblock + b1->br_blockcount != b2->br_startblock) + return false; + if (b1->br_state != b2->br_state) + return false; + return true; +} + +/* + * Walk the incore extent records, accumulating consecutive contiguous records + * into a single incore mapping. Returns true if @irec has been set to a + * mapping or false if there are no more mappings. Caller must ensure that + * @info.icur is zeroed before the first call. + */ +static bool +xchk_bmap_iext_iter( + struct xchk_bmap_info *info, + struct xfs_bmbt_irec *irec) +{ + struct xfs_bmbt_irec got; + struct xfs_ifork *ifp; + unsigned int nr = 0; + + ifp = xfs_ifork_ptr(info->sc->ip, info->whichfork); + + /* Advance to the next iextent record and check the mapping. */ + xfs_iext_next(ifp, &info->icur); + if (!xfs_iext_get_extent(ifp, &info->icur, irec)) + return false; + + if (!xchk_bmap_iext_mapping(info, irec)) { + xchk_fblock_set_corrupt(info->sc, info->whichfork, + irec->br_startoff); + return false; + } + nr++; + + /* + * Iterate subsequent iextent records and merge them with the one + * that we just read, if possible. + */ + while (xfs_iext_peek_next_extent(ifp, &info->icur, &got)) { + if (!xchk_are_bmaps_contiguous(irec, &got)) + break; + + if (!xchk_bmap_iext_mapping(info, &got)) { + xchk_fblock_set_corrupt(info->sc, info->whichfork, + got.br_startoff); + return false; + } + nr++; + + irec->br_blockcount += got.br_blockcount; + xfs_iext_next(ifp, &info->icur); + } + + /* + * If the merged mapping could be expressed with fewer bmbt records + * than we actually found, notify the user that this fork could be + * optimized. CoW forks only exist in memory so we ignore them. + */ + if (nr > 1 && info->whichfork != XFS_COW_FORK && + howmany_64(irec->br_blockcount, XFS_MAX_BMBT_EXTLEN) < nr) + xchk_ino_set_preen(info->sc, info->sc->ip->i_ino); + + return true; +} + +/* + * Scrub an inode fork's block mappings. + * + * First we scan every record in every btree block, if applicable. + * Then we unconditionally scan the incore extent cache. + */ +STATIC int +xchk_bmap( + struct xfs_scrub *sc, + int whichfork) +{ + struct xfs_bmbt_irec irec; + struct xchk_bmap_info info = { NULL }; + struct xfs_mount *mp = sc->mp; + struct xfs_inode *ip = sc->ip; + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); + xfs_fileoff_t endoff; + int error = 0; + + /* Non-existent forks can be ignored. */ + if (!ifp) + return -ENOENT; + + info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip); + info.whichfork = whichfork; + info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip); + info.sc = sc; + + switch (whichfork) { + case XFS_COW_FORK: + /* No CoW forks on non-reflink filesystems. */ + if (!xfs_has_reflink(mp)) { + xchk_ino_set_corrupt(sc, sc->ip->i_ino); + return 0; + } + break; + case XFS_ATTR_FORK: + if (!xfs_has_attr(mp) && !xfs_has_attr2(mp)) + xchk_ino_set_corrupt(sc, sc->ip->i_ino); + break; + default: + ASSERT(whichfork == XFS_DATA_FORK); + break; + } + + /* Check the fork values */ + switch (ifp->if_format) { + case XFS_DINODE_FMT_UUID: + case XFS_DINODE_FMT_DEV: + case XFS_DINODE_FMT_LOCAL: + /* No mappings to check. */ + if (whichfork == XFS_COW_FORK) + xchk_fblock_set_corrupt(sc, whichfork, 0); + return 0; + case XFS_DINODE_FMT_EXTENTS: + break; + case XFS_DINODE_FMT_BTREE: + if (whichfork == XFS_COW_FORK) { + xchk_fblock_set_corrupt(sc, whichfork, 0); + return 0; + } + + error = xchk_bmap_btree(sc, whichfork, &info); + if (error) + return error; + break; + default: + xchk_fblock_set_corrupt(sc, whichfork, 0); + return 0; + } + + if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return 0; + + /* Find the offset of the last extent in the mapping. */ + error = xfs_bmap_last_offset(ip, &endoff, whichfork); + if (!xchk_fblock_process_error(sc, whichfork, 0, &error)) + return error; + + /* + * Scrub extent records. We use a special iterator function here that + * combines adjacent mappings if they are logically and physically + * contiguous. For large allocations that require multiple bmbt + * records, this reduces the number of cross-referencing calls, which + * reduces runtime. Cross referencing with the rmap is simpler because + * the rmap must match the combined mapping exactly. + */ + while (xchk_bmap_iext_iter(&info, &irec)) { + if (xchk_should_terminate(sc, &error) || + (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) + return 0; + + if (irec.br_startoff >= endoff) { + xchk_fblock_set_corrupt(sc, whichfork, + irec.br_startoff); + return 0; + } + + if (isnullstartblock(irec.br_startblock)) + xchk_bmap_iextent_delalloc(ip, &info, &irec); + else + xchk_bmap_iextent(ip, &info, &irec); + memcpy(&info.prev_rec, &irec, sizeof(struct xfs_bmbt_irec)); + } + + if (xchk_bmap_want_check_rmaps(&info)) { + error = xchk_bmap_check_rmaps(sc, whichfork); + if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error)) + return error; + } + + return 0; +} + +/* Scrub an inode's data fork. */ +int +xchk_bmap_data( + struct xfs_scrub *sc) +{ + return xchk_bmap(sc, XFS_DATA_FORK); +} + +/* Scrub an inode's attr fork. */ +int +xchk_bmap_attr( + struct xfs_scrub *sc) +{ + return xchk_bmap(sc, XFS_ATTR_FORK); +} + +/* Scrub an inode's CoW fork. */ +int +xchk_bmap_cow( + struct xfs_scrub *sc) +{ + return xchk_bmap(sc, XFS_COW_FORK); +} |