1 files changed, 235 insertions, 0 deletions
diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
new file mode 100644
index 000000000..229826b2e
--- /dev/null
+++ b/fs/xfs/scrub/rmap.c
@@ -0,0 +1,235 @@
+// 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_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_refcount.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "xfs_ag.h"
+
+/*
+ * Set us up to scrub reverse mapping btrees.
+ */
+int
+xchk_setup_ag_rmapbt(
+	struct xfs_scrub	*sc)
+{
+	return xchk_setup_ag_btree(sc, 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,
+	const union xfs_btree_rec *rec)
+{
+	struct xfs_mount	*mp = bs->cur->bc_mp;
+	struct xfs_rmap_irec	irec;
+	struct xfs_perag	*pag = bs->cur->bc_ag.pag;
+	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(pag, irec.rm_startblock) ||
+		    !xfs_verify_agbno(pag, 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)
+{
+	return xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
+			&XFS_RMAP_OINFO_AG, 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,
+	const 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,
+	const 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,
+	const 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);
+}