When downgrading the read-write mount to read-only, do_unmount() sets

MNT_RDONLY flag before the VFS_MOUNT() is called. In ufs_inactive()
and ufs_itimes_locked(), UFS verifies whether the fs is read-only by
checking MNT_RDONLY, but this may cause loss of the IN_MODIFIED flag
for inode on the fs being remounted rw->ro.

Introduce UFS_RDONLY() struct ufsmount' method that reports the value
of the fs_ronly. The later is set to 1 only after the remount is
finished.

Reviewed by:	tegge
In collaboration with:	pho
MFC after:	 1 month

3 files changed, 11 insertions, 0 deletions

diff --git a/sys/ufs/ffs/ffs_extern.h b/sys/ufs/ffs/ffs_extern.h
index 22afbaa..d5dfa12 100644
--- a/sys/ufs/ffs/ffs_extern.h
+++ b/sys/ufs/ffs/ffs_extern.h
@@ -131,4 +131,6 @@ int     softdep_process_worklist(struct mount *, int);
 int     softdep_fsync(struct vnode *);
 int	softdep_waitidle(struct mount *);
 
+int	ffs_rdonly(struct inode *);
+
 #endif /* !_UFS_FFS_EXTERN_H */
diff --git a/sys/ufs/ffs/ffs_inode.c b/sys/ufs/ffs/ffs_inode.c
index 0a9bc9d..4c58e41 100644
--- a/sys/ufs/ffs/ffs_inode.c
+++ b/sys/ufs/ffs/ffs_inode.c
@@ -646,3 +646,11 @@ ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
 	*countp = blocksreleased;
 	return (allerror);
 }
+
+int
+ffs_rdonly(struct inode *ip)
+{
+
+	return (ip->i_ump->um_fs->fs_ronly != 0);
+}
+
diff --git a/sys/ufs/ffs/ffs_vfsops.c b/sys/ufs/ffs/ffs_vfsops.c
index 91cd7cf..67d4496 100644
--- a/sys/ufs/ffs/ffs_vfsops.c
+++ b/sys/ufs/ffs/ffs_vfsops.c
@@ -734,6 +734,7 @@ ffs_mountfs(devvp, mp, td)
 	ump->um_valloc = ffs_valloc;
 	ump->um_vfree = ffs_vfree;
 	ump->um_ifree = ffs_ifree;
+	ump->um_rdonly = ffs_rdonly;
 	mtx_init(UFS_MTX(ump), "FFS", "FFS Lock", MTX_DEF);
 	bcopy(bp->b_data, ump->um_fs, (u_int)fs->fs_sbsize);
 	if (fs->fs_sbsize < SBLOCKSIZE)