xfs: scrub rmap btrees

Check the reverse mapping records to make sure that the contents
make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 09232f6..61fb281 100644 (file)
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -148,6 +148,7 @@ xfs-y                               += $(addprefix scrub/, \
                                   btree.o \
                                   common.o \
                                   ialloc.o \
+                                  rmap.o \
                                   scrub.o \
                                   )
 endif

diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 74df6ec..fb1d997 100644 (file)
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -492,9 +492,10 @@ struct xfs_scrub_metadata {
 #define XFS_SCRUB_TYPE_CNTBT   6       /* freesp by length btree */
 #define XFS_SCRUB_TYPE_INOBT   7       /* inode btree */
 #define XFS_SCRUB_TYPE_FINOBT  8       /* free inode btree */
+#define XFS_SCRUB_TYPE_RMAPBT  9       /* reverse mapping btree */
 
 /* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR      9
+#define XFS_SCRUB_TYPE_NR      10
 
 /* i: Repair this metadata. */
 #define XFS_SCRUB_IFLAG_REPAIR         (1 << 0)

diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 17830b8..7922775 100644 (file)
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -83,6 +83,8 @@ int xfs_scrub_setup_ag_allocbt(struct xfs_scrub_context *sc,
                               struct xfs_inode *ip);
 int xfs_scrub_setup_ag_iallocbt(struct xfs_scrub_context *sc,
                                struct xfs_inode *ip);
+int xfs_scrub_setup_ag_rmapbt(struct xfs_scrub_context *sc,
+                             struct xfs_inode *ip);
 
 
 void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);

diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
new file mode 100644 (file)
index 0000000..97846c4
--- /dev/null
+++ b/fs/xfs/scrub/rmap.c
@@ -0,0 +1,138 @@
+/*
+ * 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_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_rmap.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
+xfs_scrub_setup_ag_rmapbt(
+       struct xfs_scrub_context        *sc,
+       struct xfs_inode                *ip)
+{
+       return xfs_scrub_setup_ag_btree(sc, ip, false);
+}
+
+/* Reverse-mapping scrubber. */
+
+/* Scrub an rmapbt record. */
+STATIC int
+xfs_scrub_rmapbt_rec(
+       struct xfs_scrub_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 (!xfs_scrub_btree_process_error(bs->sc, bs->cur, 0, &error))
+               goto out;
+
+       /* Check extent. */
+       if (irec.rm_startblock + irec.rm_blockcount <= irec.rm_startblock)
+               xfs_scrub_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)
+                       xfs_scrub_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))
+                       xfs_scrub_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)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       if (non_inode && irec.rm_offset != 0)
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       if (is_unwritten && (is_bmbt || non_inode || is_attr))
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       if (non_inode && (is_bmbt || is_unwritten || is_attr))
+               xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+       if (!non_inode) {
+               if (!xfs_verify_ino(mp, irec.rm_owner))
+                       xfs_scrub_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)
+                       xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+       }
+out:
+       return error;
+}
+
+/* Scrub the rmap btree for some AG. */
+int
+xfs_scrub_rmapbt(
+       struct xfs_scrub_context        *sc)
+{
+       struct xfs_owner_info           oinfo;
+
+       xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+       return xfs_scrub_btree(sc, sc->sa.rmap_cur, xfs_scrub_rmapbt_rec,
+                       &oinfo, NULL);
+}

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 1303194..fcaf586 100644 (file)
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -191,6 +191,11 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
                .scrub  = xfs_scrub_finobt,
                .has    = xfs_sb_version_hasfinobt,
        },
+       { /* rmapbt */
+               .setup  = xfs_scrub_setup_ag_rmapbt,
+               .scrub  = xfs_scrub_rmapbt,
+               .has    = xfs_sb_version_hasrmapbt,
+       },
 };
 
 /* This isn't a stable feature, warn once per day. */

diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index 5d97453..0d1e78b 100644 (file)
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -75,5 +75,6 @@ int xfs_scrub_bnobt(struct xfs_scrub_context *sc);
 int xfs_scrub_cntbt(struct xfs_scrub_context *sc);
 int xfs_scrub_inobt(struct xfs_scrub_context *sc);
 int xfs_scrub_finobt(struct xfs_scrub_context *sc);
+int xfs_scrub_rmapbt(struct xfs_scrub_context *sc);
 
 #endif /* __XFS_SCRUB_SCRUB_H__ */