xfs: repair superblocks

If one of the backup superblocks is found to differ seriously from
superblock 0, write out a fresh copy from the in-core sb.

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

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index d734445..e8d67a4 100644 (file)
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -168,6 +168,7 @@ xfs-$(CONFIG_XFS_QUOTA)             += scrub/quota.o
 # online repair
 ifeq ($(CONFIG_XFS_ONLINE_REPAIR),y)
 xfs-y                          += $(addprefix scrub/, \
+                                  agheader_repair.o \
                                   repair.o \
                                   )
 endif

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index ea6c85a..d485e14 100644 (file)
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -1097,3 +1097,25 @@ xfs_sb_read_secondary(
        *bpp = bp;
        return 0;
 }
+
+/* Get an uninitialised secondary superblock buffer. */
+int
+xfs_sb_get_secondary(
+       struct xfs_mount        *mp,
+       struct xfs_trans        *tp,
+       xfs_agnumber_t          agno,
+       struct xfs_buf          **bpp)
+{
+       struct xfs_buf          *bp;
+
+       ASSERT(agno != 0 && agno != NULLAGNUMBER);
+       bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+                       XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
+                       XFS_FSS_TO_BB(mp, 1), 0);
+       if (!bp)
+               return -ENOMEM;
+       bp->b_ops = &xfs_sb_buf_ops;
+       xfs_buf_oneshot(bp);
+       *bpp = bp;
+       return 0;
+}

diff --git a/fs/xfs/libxfs/xfs_sb.h b/fs/xfs/libxfs/xfs_sb.h
index 03e0cc6..244e016 100644 (file)
--- a/fs/xfs/libxfs/xfs_sb.h
+++ b/fs/xfs/libxfs/xfs_sb.h
@@ -50,5 +50,8 @@ extern int    xfs_fs_geometry(struct xfs_sb *sbp, struct xfs_fsop_geom *geo,
 extern int     xfs_sb_read_secondary(struct xfs_mount *mp,
                                struct xfs_trans *tp, xfs_agnumber_t agno,
                                struct xfs_buf **bpp);
+extern int     xfs_sb_get_secondary(struct xfs_mount *mp,
+                               struct xfs_trans *tp, xfs_agnumber_t agno,
+                               struct xfs_buf **bpp);
 
 #endif /* __XFS_SB_H__ */

diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
new file mode 100644 (file)
index 0000000..8b91e9e
--- /dev/null
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2018 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_rmap.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Superblock */
+
+/* Repair the superblock. */
+int
+xfs_repair_superblock(
+       struct xfs_scrub_context        *sc)
+{
+       struct xfs_mount                *mp = sc->mp;
+       struct xfs_buf                  *bp;
+       xfs_agnumber_t                  agno;
+       int                             error;
+
+       /* Don't try to repair AG 0's sb; let xfs_repair deal with it. */
+       agno = sc->sm->sm_agno;
+       if (agno == 0)
+               return -EOPNOTSUPP;
+
+       error = xfs_sb_get_secondary(mp, sc->tp, agno, &bp);
+       if (error)
+               return error;
+
+       /* Copy AG 0's superblock to this one. */
+       xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
+       xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
+
+       /* Write this to disk. */
+       xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_SB_BUF);
+       xfs_trans_log_buf(sc->tp, bp, 0, BBTOB(bp->b_length) - 1);
+       return error;
+}

diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index e9213e7..f2b0895 100644 (file)
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -102,6 +102,7 @@ int xfs_repair_ino_dqattach(struct xfs_scrub_context *sc);
 /* Metadata repairers */
 
 int xfs_repair_probe(struct xfs_scrub_context *sc);
+int xfs_repair_superblock(struct xfs_scrub_context *sc);
 
 #else
 
@@ -124,6 +125,7 @@ xfs_repair_calc_ag_resblks(
 }
 
 #define xfs_repair_probe               xfs_repair_notsupported
+#define xfs_repair_superblock          xfs_repair_notsupported
 
 #endif /* CONFIG_XFS_ONLINE_REPAIR */
 

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index c5999c2..36db098 100644 (file)
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -216,7 +216,7 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
                .type   = ST_PERAG,
                .setup  = xfs_scrub_setup_fs,
                .scrub  = xfs_scrub_superblock,
-               .repair = xfs_repair_notsupported,
+               .repair = xfs_repair_superblock,
        },
        [XFS_SCRUB_TYPE_AGF] = {        /* agf */
                .type   = ST_PERAG,