svn commit: r232648 - stable/9/sys/fs/nullfs

[Konstantin Belousov]

Author: kib
Date: Wed Mar  7 08:10:55 2012
New Revision: 232648
URL: http://svn.freebsd.org/changeset/base/232648

Log:
  MFC r232305:
  Allow shared locks for reads when lower filesystem accept shared locking.

Modified:
  stable/9/sys/fs/nullfs/null_vfsops.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/fs/nullfs/null_vfsops.c
==============================================================================
--- stable/9/sys/fs/nullfs/null_vfsops.c	Wed Mar  7 08:08:36 2012	(r232647)
+++ stable/9/sys/fs/nullfs/null_vfsops.c	Wed Mar  7 08:10:55 2012	(r232648)
@@ -180,7 +180,8 @@ nullfs_mount(struct mount *mp)
 		MNT_IUNLOCK(mp);
 	}
 	MNT_ILOCK(mp);
-	mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE;
+	mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag &
+	    (MNTK_MPSAFE | MNTK_SHARED_WRITES);
 	MNT_IUNLOCK(mp);
 	mp->mnt_data =  xmp;
 	vfs_getnewfsid(mp);