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Diffstat (limited to 'fs/xfs/scrub/repair.c')
| -rw-r--r-- | fs/xfs/scrub/repair.c | 1089 |
1 files changed, 1089 insertions, 0 deletions
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c new file mode 100644 index 000000000000..e3e8fba1c99c --- /dev/null +++ b/fs/xfs/scrub/repair.c @@ -0,0 +1,1089 @@ +/* + * Copyright (C) 2018 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong <darrick.wong@oracle.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_btree.h" +#include "xfs_bit.h" +#include "xfs_log_format.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_inode.h" +#include "xfs_icache.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.h" +#include "xfs_refcount_btree.h" +#include "xfs_extent_busy.h" +#include "xfs_ag_resv.h" +#include "xfs_trans_space.h" +#include "xfs_quota.h" +#include "scrub/xfs_scrub.h" +#include "scrub/scrub.h" +#include "scrub/common.h" +#include "scrub/trace.h" +#include "scrub/repair.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 +xfs_repair_attempt( + struct xfs_inode *ip, + struct xfs_scrub_context *sc, + bool *fixed) +{ + int error = 0; + + trace_xfs_repair_attempt(ip, sc->sm, error); + + xfs_scrub_ag_btcur_free(&sc->sa); + + /* Repair whatever's broken. */ + ASSERT(sc->ops->repair); + error = sc->ops->repair(sc); + trace_xfs_repair_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; + *fixed = true; + return -EAGAIN; + case -EDEADLOCK: + case -EAGAIN: + /* Tell the caller to try again having grabbed all the locks. */ + if (!sc->try_harder) { + sc->try_harder = true; + 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 +xfs_repair_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 +xfs_repair_probe( + struct xfs_scrub_context *sc) +{ + int error = 0; + + if (xfs_scrub_should_terminate(sc, &error)) + return error; + + return 0; +} + +/* + * Roll a transaction, keeping the AG headers locked and reinitializing + * the btree cursors. + */ +int +xfs_repair_roll_ag_trans( + struct xfs_scrub_context *sc) +{ + int error; + + /* Keep the AG header buffers locked so we can keep going. */ + xfs_trans_bhold(sc->tp, sc->sa.agi_bp); + xfs_trans_bhold(sc->tp, sc->sa.agf_bp); + xfs_trans_bhold(sc->tp, sc->sa.agfl_bp); + + /* Roll the transaction. */ + error = xfs_trans_roll(&sc->tp); + if (error) + goto out_release; + + /* Join AG headers to the new transaction. */ + xfs_trans_bjoin(sc->tp, sc->sa.agi_bp); + xfs_trans_bjoin(sc->tp, sc->sa.agf_bp); + xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp); + + return 0; + +out_release: + /* + * Rolling failed, so release the hold on the buffers. The + * buffers will be released during teardown on our way out + * of the kernel. + */ + xfs_trans_bhold_release(sc->tp, sc->sa.agi_bp); + xfs_trans_bhold_release(sc->tp, sc->sa.agf_bp); + xfs_trans_bhold_release(sc->tp, sc->sa.agfl_bp); + + return error; +} + +/* + * 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 +xfs_repair_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 +xfs_repair_calc_ag_resblks( + struct xfs_scrub_context *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 = 0; + xfs_extlen_t aglen = 0; + 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; + + /* Use in-core counters if possible. */ + pag = xfs_perag_get(mp, sm->sm_agno); + if (pag->pagi_init) + icount = pag->pagi_count; + + /* + * Otherwise try to get the actual counters from disk; if not, make + * some worst case assumptions. + */ + if (icount == 0) { + error = xfs_ialloc_read_agi(mp, NULL, sm->sm_agno, &bp); + if (error) { + icount = mp->m_sb.sb_agblocks / mp->m_sb.sb_inopblock; + } else { + 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) { + aglen = mp->m_sb.sb_agblocks; + freelen = aglen; + usedlen = aglen; + } else { + aglen = be32_to_cpu(XFS_BUF_TO_AGF(bp)->agf_length); + freelen = pag->pagf_freeblks; + usedlen = aglen - freelen; + xfs_buf_relse(bp); + } + xfs_perag_put(pag); + + trace_xfs_repair_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_xfs_repair_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 +xfs_repair_alloc_ag_block( + struct xfs_scrub_context *sc, + 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 +xfs_repair_init_btblock( + struct xfs_scrub_context *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; + + trace_xfs_repair_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); + bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, fsb), + XFS_FSB_TO_BB(mp, 1), 0); + xfs_buf_zero(bp, 0, BBTOB(bp->b_length)); + xfs_btree_init_block(mp, bp, btnum, 0, 0, sc->sa.agno, 0); + xfs_trans_buf_set_type(tp, bp, XFS_BLFT_BTREE_BUF); + xfs_trans_log_buf(tp, bp, 0, bp->b_length); + 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 (exlist); 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 exlist 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 exlist. The bnobt records are collected as + * sublist. As with the other btrees we subtract sublist from exlist, and the + * result (since the rmapbt lives in the free space) are the blocks from the + * old rmapbt. + */ + +/* Collect a dead btree extent for later disposal. */ +int +xfs_repair_collect_btree_extent( + struct xfs_scrub_context *sc, + struct xfs_repair_extent_list *exlist, + xfs_fsblock_t fsbno, + xfs_extlen_t len) +{ + struct xfs_repair_extent *rex; + + trace_xfs_repair_collect_btree_extent(sc->mp, + XFS_FSB_TO_AGNO(sc->mp, fsbno), + XFS_FSB_TO_AGBNO(sc->mp, fsbno), len); + + rex = kmem_alloc(sizeof(struct xfs_repair_extent), KM_MAYFAIL); + if (!rex) + return -ENOMEM; + + INIT_LIST_HEAD(&rex->list); + rex->fsbno = fsbno; + rex->len = len; + list_add_tail(&rex->list, &exlist->list); + + return 0; +} + +/* + * An error happened during the rebuild so the transaction will be cancelled. + * The fs will shut down, and the administrator has to unmount and run repair. + * Therefore, free all the memory associated with the list so we can die. + */ +void +xfs_repair_cancel_btree_extents( + struct xfs_scrub_context *sc, + struct xfs_repair_extent_list *exlist) +{ + struct xfs_repair_extent *rex; + struct xfs_repair_extent *n; + + for_each_xfs_repair_extent_safe(rex, n, exlist) { + list_del(&rex->list); + kmem_free(rex); + } +} + +/* Compare two btree extents. */ +static int +xfs_repair_btree_extent_cmp( + void *priv, + struct list_head *a, + struct list_head *b) +{ + struct xfs_repair_extent *ap; + struct xfs_repair_extent *bp; + + ap = container_of(a, struct xfs_repair_extent, list); + bp = container_of(b, struct xfs_repair_extent, list); + + if (ap->fsbno > bp->fsbno) + return 1; + if (ap->fsbno < bp->fsbno) + return -1; + return 0; +} + +/* + * Remove all the blocks mentioned in @sublist from the extents in @exlist. + * + * The intent is that callers will iterate the rmapbt for all of its records + * for a given owner to generate @exlist; and iterate all the blocks of the + * metadata structures that are not being rebuilt and have the same rmapbt + * owner to generate @sublist. This routine subtracts all the extents + * mentioned in sublist from all the extents linked in @exlist, which leaves + * @exlist as the list of blocks that are not accounted for, which we assume + * are the dead blocks of the old metadata structure. The blocks mentioned in + * @exlist can be reaped. + */ +#define LEFT_ALIGNED (1 << 0) +#define RIGHT_ALIGNED (1 << 1) +int +xfs_repair_subtract_extents( + struct xfs_scrub_context *sc, + struct xfs_repair_extent_list *exlist, + struct xfs_repair_extent_list *sublist) +{ + struct list_head *lp; + struct xfs_repair_extent *ex; + struct xfs_repair_extent *newex; + struct xfs_repair_extent *subex; + xfs_fsblock_t sub_fsb; + xfs_extlen_t sub_len; + int state; + int error = 0; + + if (list_empty(&exlist->list) || list_empty(&sublist->list)) + return 0; + ASSERT(!list_empty(&sublist->list)); + + list_sort(NULL, &exlist->list, xfs_repair_btree_extent_cmp); + list_sort(NULL, &sublist->list, xfs_repair_btree_extent_cmp); + + /* + * Now that we've sorted both lists, we iterate exlist once, rolling + * forward through sublist and/or exlist as necessary until we find an + * overlap or reach the end of either list. We do not reset lp to the + * head of exlist nor do we reset subex to the head of sublist. The + * list traversal is similar to merge sort, but we're deleting + * instead. In this manner we avoid O(n^2) operations. + */ + subex = list_first_entry(&sublist->list, struct xfs_repair_extent, + list); + lp = exlist->list.next; + while (lp != &exlist->list) { + ex = list_entry(lp, struct xfs_repair_extent, list); + + /* + * Advance subex and/or ex until we find a pair that + * intersect or we run out of extents. + */ + while (subex->fsbno + subex->len <= ex->fsbno) { + if (list_is_last(&subex->list, &sublist->list)) + goto out; + subex = list_next_entry(subex, list); + } + if (subex->fsbno >= ex->fsbno + ex->len) { + lp = lp->next; + continue; + } + + /* trim subex to fit the extent we have */ + sub_fsb = subex->fsbno; + sub_len = subex->len; + if (subex->fsbno < ex->fsbno) { + sub_len -= ex->fsbno - subex->fsbno; + sub_fsb = ex->fsbno; + } + if (sub_len > ex->len) + sub_len = ex->len; + + state = 0; + if (sub_fsb == ex->fsbno) + state |= LEFT_ALIGNED; + if (sub_fsb + sub_len == ex->fsbno + ex->len) + state |= RIGHT_ALIGNED; + switch (state) { + case LEFT_ALIGNED: + /* Coincides with only the left. */ + ex->fsbno += sub_len; + ex->len -= sub_len; + break; + case RIGHT_ALIGNED: + /* Coincides with only the right. */ + ex->len -= sub_len; + lp = lp->next; + break; + case LEFT_ALIGNED | RIGHT_ALIGNED: + /* Total overlap, just delete ex. */ + lp = lp->next; + list_del(&ex->list); + kmem_free(ex); + break; + case 0: + /* + * Deleting from the middle: add the new right extent + * and then shrink the left extent. + */ + newex = kmem_alloc(sizeof(struct xfs_repair_extent), + KM_MAYFAIL); + if (!newex) { + error = -ENOMEM; + goto out; + } + INIT_LIST_HEAD(&newex->list); + newex->fsbno = sub_fsb + sub_len; + newex->len = ex->fsbno + ex->len - newex->fsbno; + list_add(&newex->list, &ex->list); + ex->len = sub_fsb - ex->fsbno; + lp = lp->next; + break; + default: + ASSERT(0); + break; + } + } + +out: + return error; +} +#undef LEFT_ALIGNED +#undef RIGHT_ALIGNED + +/* + * 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 (exlist) 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 exlist. In theory the extents + * remaining in exlist 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 @exlist, + * 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 @exlist. + */ + +/* + * 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 +xfs_repair_invalidate_blocks( + struct xfs_scrub_context *sc, + struct xfs_repair_extent_list *exlist) +{ + struct xfs_repair_extent *rex; + struct xfs_repair_extent *n; + struct xfs_buf *bp; + xfs_fsblock_t fsbno; + xfs_agblock_t i; + + /* + * 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_xfs_repair_extent_safe(rex, n, exlist) { + for (fsbno = rex->fsbno, i = rex->len; i > 0; fsbno++, i--) { + /* 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 +xfs_repair_fix_freelist( + struct xfs_scrub_context *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 +xfs_repair_put_freelist( + struct xfs_scrub_context *sc, + xfs_agblock_t agbno) +{ + struct xfs_owner_info oinfo; + int error; + + /* Make sure there's space on the freelist. */ + error = xfs_repair_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. + */ + xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG); + error = xfs_rmap_alloc(sc->tp, sc->sa.agf_bp, sc->sa.agno, agbno, 1, + &oinfo); + 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 metadata block. */ +STATIC int +xfs_repair_dispose_btree_block( + struct xfs_scrub_context *sc, + xfs_fsblock_t fsbno, + 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; + if (!agf_bp) + return -ENOMEM; + } 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); + if (error) + goto out_cur; + xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); + + /* + * 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 = xfs_repair_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 xfs_repair_roll_ag_trans(sc); + +out_cur: + xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); + if (agf_bp != sc->sa.agf_bp) + xfs_trans_brelse(sc->tp, agf_bp); + return error; +} + +/* Dispose of btree blocks from an old per-AG btree. */ +int +xfs_repair_reap_btree_extents( + struct xfs_scrub_context *sc, + struct xfs_repair_extent_list *exlist, + struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type type) +{ + struct xfs_repair_extent *rex; + struct xfs_repair_extent *n; + int error = 0; + + ASSERT(xfs_sb_version_hasrmapbt(&sc->mp->m_sb)); + + /* Dispose of every block from the old btree. */ + for_each_xfs_repair_extent_safe(rex, n, exlist) { + ASSERT(sc->ip != NULL || + XFS_FSB_TO_AGNO(sc->mp, rex->fsbno) == sc->sa.agno); + + trace_xfs_repair_dispose_btree_extent(sc->mp, + XFS_FSB_TO_AGNO(sc->mp, rex->fsbno), + XFS_FSB_TO_AGBNO(sc->mp, rex->fsbno), rex->len); + + for (; rex->len > 0; rex->len--, rex->fsbno++) { + error = xfs_repair_dispose_btree_block(sc, rex->fsbno, + oinfo, type); + if (error) + goto out; + } + list_del(&rex->list); + kmem_free(rex); + } + +out: + xfs_repair_cancel_btree_extents(sc, exlist); + 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 xfs_repair_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 + * xfs_repair_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 xfs_repair_findroot { + struct xfs_scrub_context *sc; + struct xfs_buf *agfl_bp; + struct xfs_agf *agf; + struct xfs_repair_find_ag_btree *btree_info; +}; + +/* See if our block is in the AGFL. */ +STATIC int +xfs_repair_findroot_agfl_walk( + struct xfs_mount *mp, + xfs_agblock_t bno, + void *priv) +{ + xfs_agblock_t *agbno = priv; + + return (*agbno == bno) ? XFS_BTREE_QUERY_RANGE_ABORT : 0; +} + +/* Does this block match the btree information passed in? */ +STATIC int +xfs_repair_findroot_block( + struct xfs_repair_findroot *ri, + struct xfs_repair_find_ag_btree *fab, + uint64_t owner, + xfs_agblock_t agbno, + bool *found_it) +{ + struct xfs_mount *mp = ri->sc->mp; + struct xfs_buf *bp; + struct xfs_btree_block *btblock; + xfs_daddr_t daddr; + int error; + + 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, + xfs_repair_findroot_agfl_walk, &agbno); + if (error == XFS_BTREE_QUERY_RANGE_ABORT) + return 0; + if (error) + return error; + } + + error = xfs_trans_read_buf(mp, ri->sc->tp, mp->m_ddev_targp, daddr, + mp->m_bsize, 0, &bp, NULL); + if (error) + return error; + + /* + * Does this look like a block matching our fs and higher than any + * other block we've found so far? If so, reattach buffer verifiers + * so the AIL won't complain if the buffer is also dirty. + */ + btblock = XFS_BUF_TO_BLOCK(bp); + if (be32_to_cpu(btblock->bb_magic) != fab->magic) + goto out; + if (xfs_sb_version_hascrc(&mp->m_sb) && + !uuid_equal(&btblock->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) + goto out; + bp->b_ops = fab->buf_ops; + + /* Ignore this block if it's lower in the tree than we've seen. */ + if (fab->root != NULLAGBLOCK && + xfs_btree_get_level(btblock) < fab->height) + goto out; + + /* Make sure we pass the verifiers. */ + bp->b_ops->verify_read(bp); + if (bp->b_error) + goto out; + fab->root = agbno; + fab->height = xfs_btree_get_level(btblock) + 1; + *found_it = true; + + trace_xfs_repair_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 +xfs_repair_findroot_rmap( + struct xfs_btree_cur *cur, + struct xfs_rmap_irec *rec, + void *priv) +{ + struct xfs_repair_findroot *ri = priv; + struct xfs_repair_find_ag_btree *fab; + xfs_agblock_t b; + bool found_it; + 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++) { + found_it = false; + for (fab = ri->btree_info; fab->buf_ops; fab++) { + if (rec->rm_owner != fab->rmap_owner) + continue; + error = xfs_repair_findroot_block(ri, fab, + rec->rm_owner, rec->rm_startblock + b, + &found_it); + if (error) + return error; + if (found_it) + break; + } + } + + return 0; +} + +/* Find the roots of the per-AG btrees described in btree_info. */ +int +xfs_repair_find_ag_btree_roots( + struct xfs_scrub_context *sc, + struct xfs_buf *agf_bp, + struct xfs_repair_find_ag_btree *btree_info, + struct xfs_buf *agfl_bp) +{ + struct xfs_mount *mp = sc->mp; + struct xfs_repair_findroot ri; + struct xfs_repair_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 = XFS_BUF_TO_AGF(agf_bp); + 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, xfs_repair_findroot_rmap, &ri); + xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); + + return error; +} + +/* Force a quotacheck the next time we mount. */ +void +xfs_repair_force_quotacheck( + struct xfs_scrub_context *sc, + uint dqtype) +{ + uint flag; + + flag = xfs_quota_chkd_flag(dqtype); + 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 +xfs_repair_ino_dqattach( + struct xfs_scrub_context *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) + xfs_repair_force_quotacheck(sc, XFS_DQ_USER); + if (XFS_IS_GQUOTA_ON(sc->mp) && !sc->ip->i_gdquot) + xfs_repair_force_quotacheck(sc, XFS_DQ_GROUP); + if (XFS_IS_PQUOTA_ON(sc->mp) && !sc->ip->i_pdquot) + xfs_repair_force_quotacheck(sc, XFS_DQ_PROJ); + /* fall through */ + case -ESRCH: + error = 0; + break; + default: + break; + } + + return error; +} |