From: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-Off-By: Dave Chinner <dchinner@xxxxxxxxxx>
---
mkfs/xfs_mkfs.c | 63 ++++++++++++++++++++++++++++++++-------------------------
1 file changed, 36 insertions(+), 27 deletions(-)
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 13af1ef1cd41..1fd5108be520 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -2468,6 +2468,39 @@ initialise_ag_freespace(
libxfs_trans_commit(tp);
}
+/*
+ * rewrite several secondary superblocks with the root inode number filled out.
+ * This can help repair recovery from a trashed primary superblock without
+ * losing the root inode.
+ */
+static void
+rewrite_secondary_superblocks(
+ struct xfs_mount *mp)
+{
+ struct xfs_buf *buf;
+
+ /* rewrite the last superblock */
+ buf = libxfs_readbuf(mp->m_dev,
+ XFS_AGB_TO_DADDR(mp, mp->m_sb.sb_agcount - 1,
+ XFS_SB_DADDR),
+ XFS_FSS_TO_BB(mp, 1),
+ LIBXFS_EXIT_ON_FAILURE, &xfs_sb_buf_ops);
+ XFS_BUF_TO_SBP(buf)->sb_rootino = cpu_to_be64(mp->m_sb.sb_rootino);
+ libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
+
+ /* and one in the middle for luck if there's enough AGs for that */
+ if (mp->m_sb.sb_agcount <= 2)
+ return;
+
+ buf = libxfs_readbuf(mp->m_dev,
+ XFS_AGB_TO_DADDR(mp, (mp->m_sb.sb_agcount - 1) / 2,
+ XFS_SB_DADDR),
+ XFS_FSS_TO_BB(mp, 1),
+ LIBXFS_EXIT_ON_FAILURE, &xfs_sb_buf_ops);
+ XFS_BUF_TO_SBP(buf)->sb_rootino = cpu_to_be64(mp->m_sb.sb_rootino);
+ libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
+}
+
int
main(
int argc,
@@ -3688,34 +3721,10 @@ _("size %s specified for log subvolume is too large, maximum is %lld blocks\n"),
}
/*
- * Write out multiple secondary superblocks with rootinode field set
+ * Re-write multiple secondary superblocks with rootinode field set
*/
- if (mp->m_sb.sb_agcount > 1) {
- /*
- * the last superblock
- */
- buf = libxfs_readbuf(mp->m_dev,
- XFS_AGB_TO_DADDR(mp, mp->m_sb.sb_agcount-1,
- XFS_SB_DADDR),
- XFS_FSS_TO_BB(mp, 1),
- LIBXFS_EXIT_ON_FAILURE, &xfs_sb_buf_ops);
- XFS_BUF_TO_SBP(buf)->sb_rootino = cpu_to_be64(
- mp->m_sb.sb_rootino);
- libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
- /*
- * and one in the middle for luck
- */
- if (mp->m_sb.sb_agcount > 2) {
- buf = libxfs_readbuf(mp->m_dev,
- XFS_AGB_TO_DADDR(mp, (mp->m_sb.sb_agcount-1)/2,
- XFS_SB_DADDR),
- XFS_FSS_TO_BB(mp, 1),
- LIBXFS_EXIT_ON_FAILURE, &xfs_sb_buf_ops);
- XFS_BUF_TO_SBP(buf)->sb_rootino = cpu_to_be64(
- mp->m_sb.sb_rootino);
- libxfs_writebuf(buf, LIBXFS_EXIT_ON_FAILURE);
- }
- }
+ if (mp->m_sb.sb_agcount > 1)
+ rewrite_secondary_superblocks(mp);
/*
* Dump all inodes and buffers before marking us all done.
--
2.13.3
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