v4.19.13 snapshot.
diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
new file mode 100644
index 0000000..5e293c1
--- /dev/null
+++ b/fs/xfs/scrub/rmap.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_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_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_rmap.h"
+#include "xfs_refcount.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 reverse mapping btrees.
+ */
+int
+xchk_setup_ag_rmapbt(
+ struct xfs_scrub *sc,
+ struct xfs_inode *ip)
+{
+ return xchk_setup_ag_btree(sc, ip, false);
+}
+
+/* Reverse-mapping scrubber. */
+
+/* Cross-reference a rmap against the refcount btree. */
+STATIC void
+xchk_rmapbt_xref_refc(
+ struct xfs_scrub *sc,
+ struct xfs_rmap_irec *irec)
+{
+ xfs_agblock_t fbno;
+ xfs_extlen_t flen;
+ bool non_inode;
+ bool is_bmbt;
+ bool is_attr;
+ bool is_unwritten;
+ int error;
+
+ if (!sc->sa.refc_cur || xchk_skip_xref(sc->sm))
+ return;
+
+ non_inode = XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
+ is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
+ is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
+ is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
+
+ /* If this is shared, must be a data fork extent. */
+ error = xfs_refcount_find_shared(sc->sa.refc_cur, irec->rm_startblock,
+ irec->rm_blockcount, &fbno, &flen, false);
+ if (!xchk_should_check_xref(sc, &error, &sc->sa.refc_cur))
+ return;
+ if (flen != 0 && (non_inode || is_attr || is_bmbt || is_unwritten))
+ xchk_btree_xref_set_corrupt(sc, sc->sa.refc_cur, 0);
+}
+
+/* Cross-reference with the other btrees. */
+STATIC void
+xchk_rmapbt_xref(
+ struct xfs_scrub *sc,
+ struct xfs_rmap_irec *irec)
+{
+ xfs_agblock_t agbno = irec->rm_startblock;
+ xfs_extlen_t len = irec->rm_blockcount;
+
+ if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return;
+
+ xchk_xref_is_used_space(sc, agbno, len);
+ if (irec->rm_owner == XFS_RMAP_OWN_INODES)
+ xchk_xref_is_inode_chunk(sc, agbno, len);
+ else
+ xchk_xref_is_not_inode_chunk(sc, agbno, len);
+ if (irec->rm_owner == XFS_RMAP_OWN_COW)
+ xchk_xref_is_cow_staging(sc, irec->rm_startblock,
+ irec->rm_blockcount);
+ else
+ xchk_rmapbt_xref_refc(sc, irec);
+}
+
+/* Scrub an rmapbt record. */
+STATIC int
+xchk_rmapbt_rec(
+ struct xchk_btree *bs,
+ union xfs_btree_rec *rec)
+{
+ struct xfs_mount *mp = bs->cur->bc_mp;
+ struct xfs_rmap_irec irec;
+ xfs_agnumber_t agno = bs->cur->bc_private.a.agno;
+ bool non_inode;
+ bool is_unwritten;
+ bool is_bmbt;
+ bool is_attr;
+ int error;
+
+ error = xfs_rmap_btrec_to_irec(rec, &irec);
+ if (!xchk_btree_process_error(bs->sc, bs->cur, 0, &error))
+ goto out;
+
+ /* Check extent. */
+ if (irec.rm_startblock + irec.rm_blockcount <= irec.rm_startblock)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ if (irec.rm_owner == XFS_RMAP_OWN_FS) {
+ /*
+ * xfs_verify_agbno returns false for static fs metadata.
+ * Since that only exists at the start of the AG, validate
+ * that by hand.
+ */
+ if (irec.rm_startblock != 0 ||
+ irec.rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ } else {
+ /*
+ * Otherwise we must point somewhere past the static metadata
+ * but before the end of the FS. Run the regular check.
+ */
+ if (!xfs_verify_agbno(mp, agno, irec.rm_startblock) ||
+ !xfs_verify_agbno(mp, agno, irec.rm_startblock +
+ irec.rm_blockcount - 1))
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ }
+
+ /* Check flags. */
+ non_inode = XFS_RMAP_NON_INODE_OWNER(irec.rm_owner);
+ is_bmbt = irec.rm_flags & XFS_RMAP_BMBT_BLOCK;
+ is_attr = irec.rm_flags & XFS_RMAP_ATTR_FORK;
+ is_unwritten = irec.rm_flags & XFS_RMAP_UNWRITTEN;
+
+ if (is_bmbt && irec.rm_offset != 0)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ if (non_inode && irec.rm_offset != 0)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ if (is_unwritten && (is_bmbt || non_inode || is_attr))
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ if (non_inode && (is_bmbt || is_unwritten || is_attr))
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ if (!non_inode) {
+ if (!xfs_verify_ino(mp, irec.rm_owner))
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ } else {
+ /* Non-inode owner within the magic values? */
+ if (irec.rm_owner <= XFS_RMAP_OWN_MIN ||
+ irec.rm_owner > XFS_RMAP_OWN_FS)
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+ }
+
+ xchk_rmapbt_xref(bs->sc, &irec);
+out:
+ return error;
+}
+
+/* Scrub the rmap btree for some AG. */
+int
+xchk_rmapbt(
+ struct xfs_scrub *sc)
+{
+ struct xfs_owner_info oinfo;
+
+ xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+ return xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
+ &oinfo, NULL);
+}
+
+/* xref check that the extent is owned by a given owner */
+static inline void
+xchk_xref_check_owner(
+ struct xfs_scrub *sc,
+ xfs_agblock_t bno,
+ xfs_extlen_t len,
+ struct xfs_owner_info *oinfo,
+ bool should_have_rmap)
+{
+ bool has_rmap;
+ int error;
+
+ if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
+ return;
+
+ error = xfs_rmap_record_exists(sc->sa.rmap_cur, bno, len, oinfo,
+ &has_rmap);
+ if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
+ return;
+ if (has_rmap != should_have_rmap)
+ xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+}
+
+/* xref check that the extent is owned by a given owner */
+void
+xchk_xref_is_owned_by(
+ struct xfs_scrub *sc,
+ xfs_agblock_t bno,
+ xfs_extlen_t len,
+ struct xfs_owner_info *oinfo)
+{
+ xchk_xref_check_owner(sc, bno, len, oinfo, true);
+}
+
+/* xref check that the extent is not owned by a given owner */
+void
+xchk_xref_is_not_owned_by(
+ struct xfs_scrub *sc,
+ xfs_agblock_t bno,
+ xfs_extlen_t len,
+ struct xfs_owner_info *oinfo)
+{
+ xchk_xref_check_owner(sc, bno, len, oinfo, false);
+}
+
+/* xref check that the extent has no reverse mapping at all */
+void
+xchk_xref_has_no_owner(
+ struct xfs_scrub *sc,
+ xfs_agblock_t bno,
+ xfs_extlen_t len)
+{
+ bool has_rmap;
+ int error;
+
+ if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
+ return;
+
+ error = xfs_rmap_has_record(sc->sa.rmap_cur, bno, len, &has_rmap);
+ if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
+ return;
+ if (has_rmap)
+ xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+}