From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Thu, 28 Jun 2018 20:11:57 +0000 (-0500)
Subject: xfs: repair superblocks
X-Git-Tag: v4.18.0-rc0~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b153fb40c81b5f1a56d160666b8123264e6ba129;p=thirdparty%2Fxfsprogs-dev.git

xfs: repair superblocks

Source kernel commit: d25522f10cfa342a20867086a516c45c87b0877c

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>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_sb.c b/libxfs/xfs_sb.c
index acb34f88f..63a79ea4a 100644
--- a/libxfs/xfs_sb.c
+++ b/libxfs/xfs_sb.c
@@ -1081,3 +1081,25 @@ 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/libxfs/xfs_sb.h b/libxfs/xfs_sb.h
index 03e0cc6bf..244e0162c 100644
--- a/libxfs/xfs_sb.h
+++ b/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__ */