[10/24] xfs: repair superblocks

Commit Message

Darrick J. Wong April 18, 2018, 2:42 a.m. UTC

From: Darrick J. Wong <[e-mail]>

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 <[e-mail]>
---
 fs/xfs/Makefile                |    1 +
 fs/xfs/scrub/agheader_repair.c |   76 ++++++++++++++++++++++++++++++++++++++++
 fs/xfs/scrub/repair.h          |    2 +
 fs/xfs/scrub/scrub.c           |    2 +
 4 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 fs/xfs/scrub/agheader_repair.c



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Patch

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 9175d51..cf64415 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -173,6 +173,7 @@  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/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
new file mode 100644
index 0000000..959b8c6
--- /dev/null
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -0,0 +1,76 @@ 
+/*
+ * Copyright (C) 2018 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * 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;
+	struct xfs_dsb			*sbp;
+	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;
+
+	bp = xfs_buf_get_uncached(mp->m_ddev_targp, XFS_FSS_TO_BB(mp, 1), 0);
+	if (!bp)
+		return -ENOMEM;
+
+	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
+	bp->b_bn = XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp));
+	bp->b_maps[0].bm_bn = XFS_AG_DADDR(mp, agno, XFS_SB_BLOCK(mp));
+	bp->b_ops = &xfs_sb_buf_ops;
+
+	/* Copy AG 0's superblock to this one. */
+	sbp = XFS_BUF_TO_SBP(bp);
+	xfs_sb_to_disk(sbp, &mp->m_sb);
+
+	/* Write this to disk. */
+	error = xfs_bwrite(bp);
+	xfs_buf_relse(bp);
+	return error;
+}
diff --git a/fs/xfs/scrub/repair.h b/fs/xfs/scrub/repair.h
index 0cb91dc..0090087 100644
--- a/fs/xfs/scrub/repair.h
+++ b/fs/xfs/scrub/repair.h
@@ -103,6 +103,7 @@  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
 
@@ -131,6 +132,7 @@  static inline int xfs_repair_reset_counters(struct xfs_mount *mp)
 }
 
 #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 9cdc3f0..d7bcf31 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -218,7 +218,7 @@  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,