[PATCH 2/5] xfs_repair: allow upgrades to v5 filesystems

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Add some helper functions so that we can allow users to upgrade V5
filesystems in a sane manner.  This just lands the boilerplate; the
actual feature validation and whatnot will land in the next patches.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
 repair/phase2.c |   40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)


diff --git a/repair/phase2.c b/repair/phase2.c
index 952ac4a5..f654edcc 100644
--- a/repair/phase2.c
+++ b/repair/phase2.c
@@ -131,6 +131,40 @@ zero_log(
 		libxfs_max_lsn = log->l_last_sync_lsn;
 }
 
+/* Perform the user's requested upgrades on filesystem. */
+static void
+upgrade_filesystem(
+	struct xfs_mount	*mp)
+{
+	struct xfs_buf		*bp;
+	bool			dirty = false;
+	int			error;
+
+        if (no_modify || !dirty)
+                return;
+
+        bp = libxfs_getsb(mp);
+        if (!bp || bp->b_error) {
+                do_error(
+	_("couldn't get superblock for feature upgrade, err=%d\n"),
+                                bp ? bp->b_error : ENOMEM);
+        } else {
+                libxfs_sb_to_disk(bp->b_addr, &mp->m_sb);
+
+                /*
+		 * Write the primary super to disk immediately so that
+		 * needsrepair will be set if repair doesn't complete.
+		 */
+                error = -libxfs_bwrite(bp);
+                if (error)
+                        do_error(
+	_("filesystem feature upgrade failed, err=%d\n"),
+                                        error);
+        }
+        if (bp)
+                libxfs_buf_relse(bp);
+}
+
 /*
  * ok, at this point, the fs is mounted but the root inode may be
  * trashed and the ag headers haven't been checked.  So we have
@@ -235,4 +269,10 @@ phase2(
 				do_warn(_("would correct\n"));
 		}
 	}
+
+	/*
+	 * Upgrade the filesystem now that we've done a preliminary check of
+	 * the superblocks, the AGs, the log, and the metadata inodes.
+	 */
+	upgrade_filesystem(mp);
 }