--- /dev/null
+/*
+ * Copyright (C) 2017 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_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_icache.h"
+#include "xfs_rmap.h"
+#include "xfs_log.h"
+#include "xfs_trans_priv.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/*
+ * Set us up to scrub inode btrees.
+ * If we detect a discrepancy between the inobt and the inode,
+ * try again after forcing logged inode cores out to disk.
+ */
+int
+xfs_scrub_setup_ag_iallocbt(
+       struct xfs_scrub_context        *sc,
+       struct xfs_inode                *ip)
+{
+       return xfs_scrub_setup_ag_btree(sc, ip, sc->try_harder);
+}
+
+/* Inode btree scrubber. */
+
+/* Is this chunk worth checking? */
+STATIC bool
+xfs_scrub_iallocbt_chunk(
+       struct xfs_scrub_btree          *bs,
+       struct xfs_inobt_rec_incore     *irec,
+       xfs_agino_t                     agino,
+       xfs_extlen_t                    len)
+{
+       struct xfs_mount                *mp = bs->cur->bc_mp;
+       xfs_agnumber_t                  agno = bs->cur->bc_private.a.agno;
+       xfs_agblock_t                   bno;
+
+       bno = XFS_AGINO_TO_AGBNO(mp, agino);
+       if (bno + len <= bno ||
+           !xfs_verify_agbno(mp, agno, bno) ||
+           !xfs_verify_agbno(mp, agno, bno + len - 1))
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       return true;
+}
+
+/* Count the number of free inodes. */
+static unsigned int
+xfs_scrub_iallocbt_freecount(
+       xfs_inofree_t                   freemask)
+{
+       BUILD_BUG_ON(sizeof(freemask) != sizeof(__u64));
+       return hweight64(freemask);
+}
+
+/* Check a particular inode with ir_free. */
+STATIC int
+xfs_scrub_iallocbt_check_cluster_freemask(
+       struct xfs_scrub_btree          *bs,
+       xfs_ino_t                       fsino,
+       xfs_agino_t                     chunkino,
+       xfs_agino_t                     clusterino,
+       struct xfs_inobt_rec_incore     *irec,
+       struct xfs_buf                  *bp)
+{
+       struct xfs_dinode               *dip;
+       struct xfs_mount                *mp = bs->cur->bc_mp;
+       bool                            inode_is_free = false;
+       bool                            freemask_ok;
+       bool                            inuse;
+       int                             error = 0;
+
+       if (xfs_scrub_should_terminate(bs->sc, &error))
+               return error;
+
+       dip = xfs_buf_offset(bp, clusterino * mp->m_sb.sb_inodesize);
+       if (be16_to_cpu(dip->di_magic) != XFS_DINODE_MAGIC ||
+           (dip->di_version >= 3 &&
+            be64_to_cpu(dip->di_ino) != fsino + clusterino)) {
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+               goto out;
+       }
+
+       if (irec->ir_free & XFS_INOBT_MASK(chunkino + clusterino))
+               inode_is_free = true;
+       error = xfs_icache_inode_is_allocated(mp, bs->cur->bc_tp,
+                       fsino + clusterino, &inuse);
+       if (error == -ENODATA) {
+               /* Not cached, just read the disk buffer */
+               freemask_ok = inode_is_free ^ !!(dip->di_mode);
+               if (!bs->sc->try_harder && !freemask_ok)
+                       return -EDEADLOCK;
+       } else if (error < 0) {
+               /*
+                * Inode is only half assembled, or there was an IO error,
+                * or the verifier failed, so don't bother trying to check.
+                * The inode scrubber can deal with this.
+                */
+               goto out;
+       } else {
+               /* Inode is all there. */
+               freemask_ok = inode_is_free ^ inuse;
+       }
+       if (!freemask_ok)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+out:
+       return 0;
+}
+
+/* Make sure the free mask is consistent with what the inodes think. */
+STATIC int
+xfs_scrub_iallocbt_check_freemask(
+       struct xfs_scrub_btree          *bs,
+       struct xfs_inobt_rec_incore     *irec)
+{
+       struct xfs_owner_info           oinfo;
+       struct xfs_imap                 imap;
+       struct xfs_mount                *mp = bs->cur->bc_mp;
+       struct xfs_dinode               *dip;
+       struct xfs_buf                  *bp;
+       xfs_ino_t                       fsino;
+       xfs_agino_t                     nr_inodes;
+       xfs_agino_t                     agino;
+       xfs_agino_t                     chunkino;
+       xfs_agino_t                     clusterino;
+       xfs_agblock_t                   agbno;
+       int                             blks_per_cluster;
+       uint16_t                        holemask;
+       uint16_t                        ir_holemask;
+       int                             error = 0;
+
+       /* Make sure the freemask matches the inode records. */
+       blks_per_cluster = xfs_icluster_size_fsb(mp);
+       nr_inodes = XFS_OFFBNO_TO_AGINO(mp, blks_per_cluster, 0);
+       xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
+
+       for (agino = irec->ir_startino;
+            agino < irec->ir_startino + XFS_INODES_PER_CHUNK;
+            agino += blks_per_cluster * mp->m_sb.sb_inopblock) {
+               fsino = XFS_AGINO_TO_INO(mp, bs->cur->bc_private.a.agno, agino);
+               chunkino = agino - irec->ir_startino;
+               agbno = XFS_AGINO_TO_AGBNO(mp, agino);
+
+               /* Compute the holemask mask for this cluster. */
+               for (clusterino = 0, holemask = 0; clusterino < nr_inodes;
+                    clusterino += XFS_INODES_PER_HOLEMASK_BIT)
+                       holemask |= XFS_INOBT_MASK((chunkino + clusterino) /
+                                       XFS_INODES_PER_HOLEMASK_BIT);
+
+               /* The whole cluster must be a hole or not a hole. */
+               ir_holemask = (irec->ir_holemask & holemask);
+               if (ir_holemask != holemask && ir_holemask != 0) {
+                       xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+                       continue;
+               }
+
+               /* If any part of this is a hole, skip it. */
+               if (ir_holemask)
+                       continue;
+
+               /* Grab the inode cluster buffer. */
+               imap.im_blkno = XFS_AGB_TO_DADDR(mp, bs->cur->bc_private.a.agno,
+                               agbno);
+               imap.im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
+               imap.im_boffset = 0;
+
+               error = xfs_imap_to_bp(mp, bs->cur->bc_tp, &imap,
+                               &dip, &bp, 0, 0);
+               if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, 0, &error))
+                       continue;
+
+               /* Which inodes are free? */
+               for (clusterino = 0; clusterino < nr_inodes; clusterino++) {
+                       error = xfs_scrub_iallocbt_check_cluster_freemask(bs,
+                                       fsino, chunkino, clusterino, irec, bp);
+                       if (error) {
+                               xfs_trans_brelse(bs->cur->bc_tp, bp);
+                               return error;
+                       }
+               }
+
+               xfs_trans_brelse(bs->cur->bc_tp, bp);
+       }
+
+       return error;
+}
+
+/* Scrub an inobt/finobt record. */
+STATIC int
+xfs_scrub_iallocbt_rec(
+       struct xfs_scrub_btree          *bs,
+       union xfs_btree_rec             *rec)
+{
+       struct xfs_mount                *mp = bs->cur->bc_mp;
+       struct xfs_inobt_rec_incore     irec;
+       uint64_t                        holes;
+       xfs_agnumber_t                  agno = bs->cur->bc_private.a.agno;
+       xfs_agino_t                     agino;
+       xfs_agblock_t                   agbno;
+       xfs_extlen_t                    len;
+       int                             holecount;
+       int                             i;
+       int                             error = 0;
+       unsigned int                    real_freecount;
+       uint16_t                        holemask;
+
+       xfs_inobt_btrec_to_irec(mp, rec, &irec);
+
+       if (irec.ir_count > XFS_INODES_PER_CHUNK ||
+           irec.ir_freecount > XFS_INODES_PER_CHUNK)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       real_freecount = irec.ir_freecount +
+                       (XFS_INODES_PER_CHUNK - irec.ir_count);
+       if (real_freecount != xfs_scrub_iallocbt_freecount(irec.ir_free))
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       agino = irec.ir_startino;
+       /* Record has to be properly aligned within the AG. */
+       if (!xfs_verify_agino(mp, agno, agino) ||
+           !xfs_verify_agino(mp, agno, agino + XFS_INODES_PER_CHUNK - 1)) {
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+               goto out;
+       }
+
+       /* Make sure this record is aligned to cluster and inoalignmnt size. */
+       agbno = XFS_AGINO_TO_AGBNO(mp, irec.ir_startino);
+       if ((agbno & (xfs_ialloc_cluster_alignment(mp) - 1)) ||
+           (agbno & (xfs_icluster_size_fsb(mp) - 1)))
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       /* Handle non-sparse inodes */
+       if (!xfs_inobt_issparse(irec.ir_holemask)) {
+               len = XFS_B_TO_FSB(mp,
+                               XFS_INODES_PER_CHUNK * mp->m_sb.sb_inodesize);
+               if (irec.ir_count != XFS_INODES_PER_CHUNK)
+                       xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+               if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
+                       goto out;
+               goto check_freemask;
+       }
+
+       /* Check each chunk of a sparse inode cluster. */
+       holemask = irec.ir_holemask;
+       holecount = 0;
+       len = XFS_B_TO_FSB(mp,
+                       XFS_INODES_PER_HOLEMASK_BIT * mp->m_sb.sb_inodesize);
+       holes = ~xfs_inobt_irec_to_allocmask(&irec);
+       if ((holes & irec.ir_free) != holes ||
+           irec.ir_freecount > irec.ir_count)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       for (i = 0; i < XFS_INOBT_HOLEMASK_BITS; i++) {
+               if (holemask & 1)
+                       holecount += XFS_INODES_PER_HOLEMASK_BIT;
+               else if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
+                       break;
+               holemask >>= 1;
+               agino += XFS_INODES_PER_HOLEMASK_BIT;
+       }
+
+       if (holecount > XFS_INODES_PER_CHUNK ||
+           holecount + irec.ir_count != XFS_INODES_PER_CHUNK)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+check_freemask:
+       error = xfs_scrub_iallocbt_check_freemask(bs, &irec);
+       if (error)
+               goto out;
+
+out:
+       return error;
+}
+
+/* Scrub the inode btrees for some AG. */
+STATIC int
+xfs_scrub_iallocbt(
+       struct xfs_scrub_context        *sc,
+       xfs_btnum_t                     which)
+{
+       struct xfs_btree_cur            *cur;
+       struct xfs_owner_info           oinfo;
+
+       xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
+       cur = which == XFS_BTNUM_INO ? sc->sa.ino_cur : sc->sa.fino_cur;
+       return xfs_scrub_btree(sc, cur, xfs_scrub_iallocbt_rec, &oinfo, NULL);
+}
+
+int
+xfs_scrub_inobt(
+       struct xfs_scrub_context        *sc)
+{
+       return xfs_scrub_iallocbt(sc, XFS_BTNUM_INO);
+}
+
+int
+xfs_scrub_finobt(
+       struct xfs_scrub_context        *sc)
+{
+       return xfs_scrub_iallocbt(sc, XFS_BTNUM_FINO);
+}