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-rw-r--r--fs/xfs/scrub/bmap_repair.c867
1 files changed, 867 insertions, 0 deletions
diff --git a/fs/xfs/scrub/bmap_repair.c b/fs/xfs/scrub/bmap_repair.c
new file mode 100644
index 000000000000..a4bb89fdd510
--- /dev/null
+++ b/fs/xfs/scrub/bmap_repair.c
@@ -0,0 +1,867 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2018-2023 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_defer.h"
+#include "xfs_btree.h"
+#include "xfs_btree_staging.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_alloc.h"
+#include "xfs_rtalloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_refcount.h"
+#include "xfs_quota.h"
+#include "xfs_ialloc.h"
+#include "xfs_ag.h"
+#include "xfs_reflink.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+#include "scrub/repair.h"
+#include "scrub/bitmap.h"
+#include "scrub/fsb_bitmap.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/newbt.h"
+#include "scrub/reap.h"
+
+/*
+ * Inode Fork Block Mapping (BMBT) Repair
+ * ======================================
+ *
+ * Gather all the rmap records for the inode and fork we're fixing, reset the
+ * incore fork, then recreate the btree.
+ */
+
+enum reflink_scan_state {
+ RLS_IRRELEVANT = -1, /* not applicable to this file */
+ RLS_UNKNOWN, /* shared extent scans required */
+ RLS_SET_IFLAG, /* iflag must be set */
+};
+
+struct xrep_bmap {
+ /* Old bmbt blocks */
+ struct xfsb_bitmap old_bmbt_blocks;
+
+ /* New fork. */
+ struct xrep_newbt new_bmapbt;
+
+ /* List of new bmap records. */
+ struct xfarray *bmap_records;
+
+ struct xfs_scrub *sc;
+
+ /* How many blocks did we find allocated to this file? */
+ xfs_rfsblock_t nblocks;
+
+ /* How many bmbt blocks did we find for this fork? */
+ xfs_rfsblock_t old_bmbt_block_count;
+
+ /* get_records()'s position in the free space record array. */
+ xfarray_idx_t array_cur;
+
+ /* How many real (non-hole, non-delalloc) mappings do we have? */
+ uint64_t real_mappings;
+
+ /* Which fork are we fixing? */
+ int whichfork;
+
+ /* What d the REFLINK flag be set when the repair is over? */
+ enum reflink_scan_state reflink_scan;
+
+ /* Do we allow unwritten extents? */
+ bool allow_unwritten;
+};
+
+/* Is this space extent shared? Flag the inode if it is. */
+STATIC int
+xrep_bmap_discover_shared(
+ struct xrep_bmap *rb,
+ xfs_fsblock_t startblock,
+ xfs_filblks_t blockcount)
+{
+ struct xfs_scrub *sc = rb->sc;
+ xfs_agblock_t agbno;
+ xfs_agblock_t fbno;
+ xfs_extlen_t flen;
+ int error;
+
+ agbno = XFS_FSB_TO_AGBNO(sc->mp, startblock);
+ error = xfs_refcount_find_shared(sc->sa.refc_cur, agbno, blockcount,
+ &fbno, &flen, false);
+ if (error)
+ return error;
+
+ if (fbno != NULLAGBLOCK)
+ rb->reflink_scan = RLS_SET_IFLAG;
+
+ return 0;
+}
+
+/* Remember this reverse-mapping as a series of bmap records. */
+STATIC int
+xrep_bmap_from_rmap(
+ struct xrep_bmap *rb,
+ xfs_fileoff_t startoff,
+ xfs_fsblock_t startblock,
+ xfs_filblks_t blockcount,
+ bool unwritten)
+{
+ struct xfs_bmbt_irec irec = {
+ .br_startoff = startoff,
+ .br_startblock = startblock,
+ .br_state = unwritten ? XFS_EXT_UNWRITTEN : XFS_EXT_NORM,
+ };
+ struct xfs_bmbt_rec rbe;
+ struct xfs_scrub *sc = rb->sc;
+ int error = 0;
+
+ /*
+ * If we're repairing the data fork of a non-reflinked regular file on
+ * a reflink filesystem, we need to figure out if this space extent is
+ * shared.
+ */
+ if (rb->reflink_scan == RLS_UNKNOWN && !unwritten) {
+ error = xrep_bmap_discover_shared(rb, startblock, blockcount);
+ if (error)
+ return error;
+ }
+
+ do {
+ xfs_failaddr_t fa;
+
+ irec.br_blockcount = min_t(xfs_filblks_t, blockcount,
+ XFS_MAX_BMBT_EXTLEN);
+
+ fa = xfs_bmap_validate_extent(sc->ip, rb->whichfork, &irec);
+ if (fa)
+ return -EFSCORRUPTED;
+
+ xfs_bmbt_disk_set_all(&rbe, &irec);
+
+ trace_xrep_bmap_found(sc->ip, rb->whichfork, &irec);
+
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ error = xfarray_append(rb->bmap_records, &rbe);
+ if (error)
+ return error;
+
+ rb->real_mappings++;
+
+ irec.br_startblock += irec.br_blockcount;
+ irec.br_startoff += irec.br_blockcount;
+ blockcount -= irec.br_blockcount;
+ } while (blockcount > 0);
+
+ return 0;
+}
+
+/* Check for any obvious errors or conflicts in the file mapping. */
+STATIC int
+xrep_bmap_check_fork_rmap(
+ struct xrep_bmap *rb,
+ struct xfs_btree_cur *cur,
+ const struct xfs_rmap_irec *rec)
+{
+ struct xfs_scrub *sc = rb->sc;
+ enum xbtree_recpacking outcome;
+ int error;
+
+ /*
+ * Data extents for rt files are never stored on the data device, but
+ * everything else (xattrs, bmbt blocks) can be.
+ */
+ if (XFS_IS_REALTIME_INODE(sc->ip) &&
+ !(rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK)))
+ return -EFSCORRUPTED;
+
+ /* Check that this is within the AG. */
+ if (!xfs_verify_agbext(cur->bc_ag.pag, rec->rm_startblock,
+ rec->rm_blockcount))
+ return -EFSCORRUPTED;
+
+ /* Check the file offset range. */
+ if (!(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) &&
+ !xfs_verify_fileext(sc->mp, rec->rm_offset, rec->rm_blockcount))
+ return -EFSCORRUPTED;
+
+ /* No contradictory flags. */
+ if ((rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK)) &&
+ (rec->rm_flags & XFS_RMAP_UNWRITTEN))
+ return -EFSCORRUPTED;
+
+ /* Make sure this isn't free space. */
+ error = xfs_alloc_has_records(sc->sa.bno_cur, rec->rm_startblock,
+ rec->rm_blockcount, &outcome);
+ if (error)
+ return error;
+ if (outcome != XBTREE_RECPACKING_EMPTY)
+ return -EFSCORRUPTED;
+
+ /* Must not be an inode chunk. */
+ error = xfs_ialloc_has_inodes_at_extent(sc->sa.ino_cur,
+ rec->rm_startblock, rec->rm_blockcount, &outcome);
+ if (error)
+ return error;
+ if (outcome != XBTREE_RECPACKING_EMPTY)
+ return -EFSCORRUPTED;
+
+ return 0;
+}
+
+/* Record extents that belong to this inode's fork. */
+STATIC int
+xrep_bmap_walk_rmap(
+ struct xfs_btree_cur *cur,
+ const struct xfs_rmap_irec *rec,
+ void *priv)
+{
+ struct xrep_bmap *rb = priv;
+ struct xfs_mount *mp = cur->bc_mp;
+ xfs_fsblock_t fsbno;
+ int error = 0;
+
+ if (xchk_should_terminate(rb->sc, &error))
+ return error;
+
+ if (rec->rm_owner != rb->sc->ip->i_ino)
+ return 0;
+
+ error = xrep_bmap_check_fork_rmap(rb, cur, rec);
+ if (error)
+ return error;
+
+ /*
+ * Record all blocks allocated to this file even if the extent isn't
+ * for the fork we're rebuilding so that we can reset di_nblocks later.
+ */
+ rb->nblocks += rec->rm_blockcount;
+
+ /* If this rmap isn't for the fork we want, we're done. */
+ if (rb->whichfork == XFS_DATA_FORK &&
+ (rec->rm_flags & XFS_RMAP_ATTR_FORK))
+ return 0;
+ if (rb->whichfork == XFS_ATTR_FORK &&
+ !(rec->rm_flags & XFS_RMAP_ATTR_FORK))
+ return 0;
+
+ /* Reject unwritten extents if we don't allow those. */
+ if ((rec->rm_flags & XFS_RMAP_UNWRITTEN) && !rb->allow_unwritten)
+ return -EFSCORRUPTED;
+
+ fsbno = XFS_AGB_TO_FSB(mp, cur->bc_ag.pag->pag_agno,
+ rec->rm_startblock);
+
+ if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK) {
+ rb->old_bmbt_block_count += rec->rm_blockcount;
+ return xfsb_bitmap_set(&rb->old_bmbt_blocks, fsbno,
+ rec->rm_blockcount);
+ }
+
+ return xrep_bmap_from_rmap(rb, rec->rm_offset, fsbno,
+ rec->rm_blockcount,
+ rec->rm_flags & XFS_RMAP_UNWRITTEN);
+}
+
+/*
+ * Compare two block mapping records. We want to sort in order of increasing
+ * file offset.
+ */
+static int
+xrep_bmap_extent_cmp(
+ const void *a,
+ const void *b)
+{
+ const struct xfs_bmbt_rec *ba = a;
+ const struct xfs_bmbt_rec *bb = b;
+ xfs_fileoff_t ao = xfs_bmbt_disk_get_startoff(ba);
+ xfs_fileoff_t bo = xfs_bmbt_disk_get_startoff(bb);
+
+ if (ao > bo)
+ return 1;
+ else if (ao < bo)
+ return -1;
+ return 0;
+}
+
+/*
+ * Sort the bmap extents by fork offset or else the records will be in the
+ * wrong order. Ensure there are no overlaps in the file offset ranges.
+ */
+STATIC int
+xrep_bmap_sort_records(
+ struct xrep_bmap *rb)
+{
+ struct xfs_bmbt_irec irec;
+ xfs_fileoff_t next_off = 0;
+ xfarray_idx_t array_cur;
+ int error;
+
+ error = xfarray_sort(rb->bmap_records, xrep_bmap_extent_cmp,
+ XFARRAY_SORT_KILLABLE);
+ if (error)
+ return error;
+
+ foreach_xfarray_idx(rb->bmap_records, array_cur) {
+ struct xfs_bmbt_rec rec;
+
+ if (xchk_should_terminate(rb->sc, &error))
+ return error;
+
+ error = xfarray_load(rb->bmap_records, array_cur, &rec);
+ if (error)
+ return error;
+
+ xfs_bmbt_disk_get_all(&rec, &irec);
+
+ if (irec.br_startoff < next_off)
+ return -EFSCORRUPTED;
+
+ next_off = irec.br_startoff + irec.br_blockcount;
+ }
+
+ return 0;
+}
+
+/* Scan one AG for reverse mappings that we can turn into extent maps. */
+STATIC int
+xrep_bmap_scan_ag(
+ struct xrep_bmap *rb,
+ struct xfs_perag *pag)
+{
+ struct xfs_scrub *sc = rb->sc;
+ int error;
+
+ error = xrep_ag_init(sc, pag, &sc->sa);
+ if (error)
+ return error;
+
+ error = xfs_rmap_query_all(sc->sa.rmap_cur, xrep_bmap_walk_rmap, rb);
+ xchk_ag_free(sc, &sc->sa);
+ return error;
+}
+
+/* Find the delalloc extents from the old incore extent tree. */
+STATIC int
+xrep_bmap_find_delalloc(
+ struct xrep_bmap *rb)
+{
+ struct xfs_bmbt_irec irec;
+ struct xfs_iext_cursor icur;
+ struct xfs_bmbt_rec rbe;
+ struct xfs_inode *ip = rb->sc->ip;
+ struct xfs_ifork *ifp = xfs_ifork_ptr(ip, rb->whichfork);
+ int error = 0;
+
+ /*
+ * Skip this scan if we don't expect to find delayed allocation
+ * reservations in this fork.
+ */
+ if (rb->whichfork == XFS_ATTR_FORK || ip->i_delayed_blks == 0)
+ return 0;
+
+ for_each_xfs_iext(ifp, &icur, &irec) {
+ if (!isnullstartblock(irec.br_startblock))
+ continue;
+
+ xfs_bmbt_disk_set_all(&rbe, &irec);
+
+ trace_xrep_bmap_found(ip, rb->whichfork, &irec);
+
+ if (xchk_should_terminate(rb->sc, &error))
+ return error;
+
+ error = xfarray_append(rb->bmap_records, &rbe);
+ if (error)
+ return error;
+ }
+
+ return 0;
+}
+
+/*
+ * Collect block mappings for this fork of this inode and decide if we have
+ * enough space to rebuild. Caller is responsible for cleaning up the list if
+ * anything goes wrong.
+ */
+STATIC int
+xrep_bmap_find_mappings(
+ struct xrep_bmap *rb)
+{
+ struct xfs_scrub *sc = rb->sc;
+ struct xfs_perag *pag;
+ xfs_agnumber_t agno;
+ int error = 0;
+
+ /* Iterate the rmaps for extents. */
+ for_each_perag(sc->mp, agno, pag) {
+ error = xrep_bmap_scan_ag(rb, pag);
+ if (error) {
+ xfs_perag_rele(pag);
+ return error;
+ }
+ }
+
+ return xrep_bmap_find_delalloc(rb);
+}
+
+/* Retrieve real extent mappings for bulk loading the bmap btree. */
+STATIC int
+xrep_bmap_get_records(
+ struct xfs_btree_cur *cur,
+ unsigned int idx,
+ struct xfs_btree_block *block,
+ unsigned int nr_wanted,
+ void *priv)
+{
+ struct xfs_bmbt_rec rec;
+ struct xfs_bmbt_irec *irec = &cur->bc_rec.b;
+ struct xrep_bmap *rb = priv;
+ union xfs_btree_rec *block_rec;
+ unsigned int loaded;
+ int error;
+
+ for (loaded = 0; loaded < nr_wanted; loaded++, idx++) {
+ do {
+ error = xfarray_load(rb->bmap_records, rb->array_cur++,
+ &rec);
+ if (error)
+ return error;
+
+ xfs_bmbt_disk_get_all(&rec, irec);
+ } while (isnullstartblock(irec->br_startblock));
+
+ block_rec = xfs_btree_rec_addr(cur, idx, block);
+ cur->bc_ops->init_rec_from_cur(cur, block_rec);
+ }
+
+ return loaded;
+}
+
+/* Feed one of the new btree blocks to the bulk loader. */
+STATIC int
+xrep_bmap_claim_block(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr,
+ void *priv)
+{
+ struct xrep_bmap *rb = priv;
+
+ return xrep_newbt_claim_block(cur, &rb->new_bmapbt, ptr);
+}
+
+/* Figure out how much space we need to create the incore btree root block. */
+STATIC size_t
+xrep_bmap_iroot_size(
+ struct xfs_btree_cur *cur,
+ unsigned int level,
+ unsigned int nr_this_level,
+ void *priv)
+{
+ ASSERT(level > 0);
+
+ return XFS_BMAP_BROOT_SPACE_CALC(cur->bc_mp, nr_this_level);
+}
+
+/* Update the inode counters. */
+STATIC int
+xrep_bmap_reset_counters(
+ struct xrep_bmap *rb)
+{
+ struct xfs_scrub *sc = rb->sc;
+ struct xbtree_ifakeroot *ifake = &rb->new_bmapbt.ifake;
+ int64_t delta;
+
+ if (rb->reflink_scan == RLS_SET_IFLAG)
+ sc->ip->i_diflags2 |= XFS_DIFLAG2_REFLINK;
+
+ /*
+ * Update the inode block counts to reflect the extents we found in the
+ * rmapbt.
+ */
+ delta = ifake->if_blocks - rb->old_bmbt_block_count;
+ sc->ip->i_nblocks = rb->nblocks + delta;
+ xfs_trans_log_inode(sc->tp, sc->ip, XFS_ILOG_CORE);
+
+ /*
+ * Adjust the quota counts by the difference in size between the old
+ * and new bmbt.
+ */
+ xfs_trans_mod_dquot_byino(sc->tp, sc->ip, XFS_TRANS_DQ_BCOUNT, delta);
+ return 0;
+}
+
+/*
+ * Create a new iext tree and load it with block mappings. If the inode is
+ * in extents format, that's all we need to do to commit the new mappings.
+ * If it is in btree format, this takes care of preloading the incore tree.
+ */
+STATIC int
+xrep_bmap_extents_load(
+ struct xrep_bmap *rb)
+{
+ struct xfs_iext_cursor icur;
+ struct xfs_bmbt_irec irec;
+ struct xfs_ifork *ifp = rb->new_bmapbt.ifake.if_fork;
+ xfarray_idx_t array_cur;
+ int error;
+
+ ASSERT(ifp->if_bytes == 0);
+
+ /* Add all the mappings (incl. delalloc) to the incore extent tree. */
+ xfs_iext_first(ifp, &icur);
+ foreach_xfarray_idx(rb->bmap_records, array_cur) {
+ struct xfs_bmbt_rec rec;
+
+ error = xfarray_load(rb->bmap_records, array_cur, &rec);
+ if (error)
+ return error;
+
+ xfs_bmbt_disk_get_all(&rec, &irec);
+
+ xfs_iext_insert_raw(ifp, &icur, &irec);
+ if (!isnullstartblock(irec.br_startblock))
+ ifp->if_nextents++;
+
+ xfs_iext_next(ifp, &icur);
+ }
+
+ return xrep_ino_ensure_extent_count(rb->sc, rb->whichfork,
+ ifp->if_nextents);
+}
+
+/*
+ * Reserve new btree blocks, bulk load the bmap records into the ondisk btree,
+ * and load the incore extent tree.
+ */
+STATIC int
+xrep_bmap_btree_load(
+ struct xrep_bmap *rb,
+ struct xfs_btree_cur *bmap_cur)
+{
+ struct xfs_scrub *sc = rb->sc;
+ int error;
+
+ /* Compute how many blocks we'll need. */
+ error = xfs_btree_bload_compute_geometry(bmap_cur,
+ &rb->new_bmapbt.bload, rb->real_mappings);
+ if (error)
+ return error;
+
+ /* Last chance to abort before we start committing fixes. */
+ if (xchk_should_terminate(sc, &error))
+ return error;
+
+ /*
+ * Guess how many blocks we're going to need to rebuild an entire bmap
+ * from the number of extents we found, and pump up our transaction to
+ * have sufficient block reservation. We're allowed to exceed file
+ * quota to repair inconsistent metadata.
+ */
+ error = xfs_trans_reserve_more_inode(sc->tp, sc->ip,
+ rb->new_bmapbt.bload.nr_blocks, 0, true);
+ if (error)
+ return error;
+
+ /* Reserve the space we'll need for the new btree. */
+ error = xrep_newbt_alloc_blocks(&rb->new_bmapbt,
+ rb->new_bmapbt.bload.nr_blocks);
+ if (error)
+ return error;
+
+ /* Add all observed bmap records. */
+ rb->array_cur = XFARRAY_CURSOR_INIT;
+ error = xfs_btree_bload(bmap_cur, &rb->new_bmapbt.bload, rb);
+ if (error)
+ return error;
+
+ /*
+ * Load the new bmap records into the new incore extent tree to
+ * preserve delalloc reservations for regular files. The directory
+ * code loads the extent tree during xfs_dir_open and assumes
+ * thereafter that it remains loaded, so we must not violate that
+ * assumption.
+ */
+ return xrep_bmap_extents_load(rb);
+}
+
+/*
+ * Use the collected bmap information to stage a new bmap fork. If this is
+ * successful we'll return with the new fork information logged to the repair
+ * transaction but not yet committed. The caller must ensure that the inode
+ * is joined to the transaction; the inode will be joined to a clean
+ * transaction when the function returns.
+ */
+STATIC int
+xrep_bmap_build_new_fork(
+ struct xrep_bmap *rb)
+{
+ struct xfs_owner_info oinfo;
+ struct xfs_scrub *sc = rb->sc;
+ struct xfs_btree_cur *bmap_cur;
+ struct xbtree_ifakeroot *ifake = &rb->new_bmapbt.ifake;
+ int error;
+
+ error = xrep_bmap_sort_records(rb);
+ if (error)
+ return error;
+
+ /*
+ * Prepare to construct the new fork by initializing the new btree
+ * structure and creating a fake ifork in the ifakeroot structure.
+ */
+ xfs_rmap_ino_bmbt_owner(&oinfo, sc->ip->i_ino, rb->whichfork);
+ error = xrep_newbt_init_inode(&rb->new_bmapbt, sc, rb->whichfork,
+ &oinfo);
+ if (error)
+ return error;
+
+ rb->new_bmapbt.bload.get_records = xrep_bmap_get_records;
+ rb->new_bmapbt.bload.claim_block = xrep_bmap_claim_block;
+ rb->new_bmapbt.bload.iroot_size = xrep_bmap_iroot_size;
+ bmap_cur = xfs_bmbt_stage_cursor(sc->mp, sc->ip, ifake);
+
+ /*
+ * Figure out the size and format of the new fork, then fill it with
+ * all the bmap records we've found. Join the inode to the transaction
+ * so that we can roll the transaction while holding the inode locked.
+ */
+ if (rb->real_mappings <= XFS_IFORK_MAXEXT(sc->ip, rb->whichfork)) {
+ ifake->if_fork->if_format = XFS_DINODE_FMT_EXTENTS;
+ error = xrep_bmap_extents_load(rb);
+ } else {
+ ifake->if_fork->if_format = XFS_DINODE_FMT_BTREE;
+ error = xrep_bmap_btree_load(rb, bmap_cur);
+ }
+ if (error)
+ goto err_cur;
+
+ /*
+ * Install the new fork in the inode. After this point the old mapping
+ * data are no longer accessible and the new tree is live. We delete
+ * the cursor immediately after committing the staged root because the
+ * staged fork might be in extents format.
+ */
+ xfs_bmbt_commit_staged_btree(bmap_cur, sc->tp, rb->whichfork);
+ xfs_btree_del_cursor(bmap_cur, 0);
+
+ /* Reset the inode counters now that we've changed the fork. */
+ error = xrep_bmap_reset_counters(rb);
+ if (error)
+ goto err_newbt;
+
+ /* Dispose of any unused blocks and the accounting information. */
+ error = xrep_newbt_commit(&rb->new_bmapbt);
+ if (error)
+ return error;
+
+ return xrep_roll_trans(sc);
+
+err_cur:
+ if (bmap_cur)
+ xfs_btree_del_cursor(bmap_cur, error);
+err_newbt:
+ xrep_newbt_cancel(&rb->new_bmapbt);
+ return error;
+}
+
+/*
+ * Now that we've logged the new inode btree, invalidate all of the old blocks
+ * and free them, if there were any.
+ */
+STATIC int
+xrep_bmap_remove_old_tree(
+ struct xrep_bmap *rb)
+{
+ struct xfs_scrub *sc = rb->sc;
+ struct xfs_owner_info oinfo;
+
+ /* Free the old bmbt blocks if they're not in use. */
+ xfs_rmap_ino_bmbt_owner(&oinfo, sc->ip->i_ino, rb->whichfork);
+ return xrep_reap_fsblocks(sc, &rb->old_bmbt_blocks, &oinfo);
+}
+
+/* Check for garbage inputs. Returns -ECANCELED if there's nothing to do. */
+STATIC int
+xrep_bmap_check_inputs(
+ struct xfs_scrub *sc,
+ int whichfork)
+{
+ struct xfs_ifork *ifp = xfs_ifork_ptr(sc->ip, whichfork);
+
+ ASSERT(whichfork == XFS_DATA_FORK || whichfork == XFS_ATTR_FORK);
+
+ if (!xfs_has_rmapbt(sc->mp))
+ return -EOPNOTSUPP;
+
+ /* No fork means nothing to rebuild. */
+ if (!ifp)
+ return -ECANCELED;
+
+ /*
+ * We only know how to repair extent mappings, which is to say that we
+ * only support extents and btree fork format. Repairs to a local
+ * format fork require a higher level repair function, so we do not
+ * have any work to do here.
+ */
+ switch (ifp->if_format) {
+ case XFS_DINODE_FMT_DEV:
+ case XFS_DINODE_FMT_LOCAL:
+ case XFS_DINODE_FMT_UUID:
+ return -ECANCELED;
+ case XFS_DINODE_FMT_EXTENTS:
+ case XFS_DINODE_FMT_BTREE:
+ break;
+ default:
+ return -EFSCORRUPTED;
+ }
+
+ if (whichfork == XFS_ATTR_FORK)
+ return 0;
+
+ /* Only files, symlinks, and directories get to have data forks. */
+ switch (VFS_I(sc->ip)->i_mode & S_IFMT) {
+ case S_IFREG:
+ case S_IFDIR:
+ case S_IFLNK:
+ /* ok */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Don't know how to rebuild realtime data forks. */
+ if (XFS_IS_REALTIME_INODE(sc->ip))
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+/* Set up the initial state of the reflink scan. */
+static inline enum reflink_scan_state
+xrep_bmap_init_reflink_scan(
+ struct xfs_scrub *sc,
+ int whichfork)
+{
+ /* cannot share on non-reflink filesystem */
+ if (!xfs_has_reflink(sc->mp))
+ return RLS_IRRELEVANT;
+
+ /* preserve flag if it's already set */
+ if (xfs_is_reflink_inode(sc->ip))
+ return RLS_SET_IFLAG;
+
+ /* can only share regular files */
+ if (!S_ISREG(VFS_I(sc->ip)->i_mode))
+ return RLS_IRRELEVANT;
+
+ /* cannot share attr fork extents */
+ if (whichfork != XFS_DATA_FORK)
+ return RLS_IRRELEVANT;
+
+ /* cannot share realtime extents */
+ if (XFS_IS_REALTIME_INODE(sc->ip))
+ return RLS_IRRELEVANT;
+
+ return RLS_UNKNOWN;
+}
+
+/* Repair an inode fork. */
+int
+xrep_bmap(
+ struct xfs_scrub *sc,
+ int whichfork,
+ bool allow_unwritten)
+{
+ struct xrep_bmap *rb;
+ char *descr;
+ unsigned int max_bmbt_recs;
+ bool large_extcount;
+ int error = 0;
+
+ error = xrep_bmap_check_inputs(sc, whichfork);
+ if (error == -ECANCELED)
+ return 0;
+ if (error)
+ return error;
+
+ rb = kzalloc(sizeof(struct xrep_bmap), XCHK_GFP_FLAGS);
+ if (!rb)
+ return -ENOMEM;
+ rb->sc = sc;
+ rb->whichfork = whichfork;
+ rb->reflink_scan = xrep_bmap_init_reflink_scan(sc, whichfork);
+ rb->allow_unwritten = allow_unwritten;
+
+ /* Set up enough storage to handle the max records for this fork. */
+ large_extcount = xfs_has_large_extent_counts(sc->mp);
+ max_bmbt_recs = xfs_iext_max_nextents(large_extcount, whichfork);
+ descr = xchk_xfile_ino_descr(sc, "%s fork mapping records",
+ whichfork == XFS_DATA_FORK ? "data" : "attr");
+ error = xfarray_create(descr, max_bmbt_recs,
+ sizeof(struct xfs_bmbt_rec), &rb->bmap_records);
+ kfree(descr);
+ if (error)
+ goto out_rb;
+
+ /* Collect all reverse mappings for this fork's extents. */
+ xfsb_bitmap_init(&rb->old_bmbt_blocks);
+ error = xrep_bmap_find_mappings(rb);
+ if (error)
+ goto out_bitmap;
+
+ xfs_trans_ijoin(sc->tp, sc->ip, 0);
+
+ /* Rebuild the bmap information. */
+ error = xrep_bmap_build_new_fork(rb);
+ if (error)
+ goto out_bitmap;
+
+ /* Kill the old tree. */
+ error = xrep_bmap_remove_old_tree(rb);
+ if (error)
+ goto out_bitmap;
+
+out_bitmap:
+ xfsb_bitmap_destroy(&rb->old_bmbt_blocks);
+ xfarray_destroy(rb->bmap_records);
+out_rb:
+ kfree(rb);
+ return error;
+}
+
+/* Repair an inode's data fork. */
+int
+xrep_bmap_data(
+ struct xfs_scrub *sc)
+{
+ return xrep_bmap(sc, XFS_DATA_FORK, true);
+}
+
+/* Repair an inode's attr fork. */
+int
+xrep_bmap_attr(
+ struct xfs_scrub *sc)
+{
+ return xrep_bmap(sc, XFS_ATTR_FORK, false);
+}