xfs: fix bad_features2 fixups for the root filesystem

Currently the bad_features2 fixup and the alignment updates in the superblock
are skipped if we mount a filesystem read-only.  But for the root filesystem
the typical case is to mount read-only first and only later remount writeable
so we'll never perform this update at all.  It's not a big problem but means
the logs of people needing the fixup get spammed at every boot because they
never happen on disk.

Reported-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index c1e028467327..e37eff6761eb 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -327,6 +327,8 @@ typedef struct xfs_mount {
         spinlock_t              m_sync_lock;    /* work item list lock */
         int                     m_sync_seq;     /* sync thread generation no. */
         wait_queue_head_t       m_wait_single_sync_task;
+        __int64_t               m_update_flags; /* sb flags we need to update
+                                                   on the next remount,rw */
 } xfs_mount_t;
 
 /*
@@ -514,6 +516,7 @@ extern int	xfs_mod_incore_sb_unlocked(xfs_mount_t *, xfs_sb_field_t,
                         int64_t, int);
 extern int      xfs_mod_incore_sb_batch(xfs_mount_t *, xfs_mod_sb_t *,
                         uint, int);
+extern int      xfs_mount_log_sb(xfs_mount_t *, __int64_t);
 extern struct xfs_buf *xfs_getsb(xfs_mount_t *, int);
 extern int      xfs_readsb(xfs_mount_t *, int);
 extern void     xfs_freesb(xfs_mount_t *);