svn commit: r296388 - head/sys/fs/nullfs

[Konstantin Belousov]

Author: kib
Date: Fri Mar  4 17:24:28 2016
New Revision: 296388
URL: https://svnweb.freebsd.org/changeset/base/296388

Log:
  Pass MNTK_NO_IOPF and MNTK_UNMAPPED_BUFS flags from the lower
  filesystem to the nullfs mount.
  
  MNTK_NO_IOPF must be present on the nullfs struct mount so that struct
  file fo_read and fo_write fops operate in the mode requested by the
  lower mount.
  
  MNTK_UNMAPPED_BUFS allows VOP_GETPAGES() to use unmapped buffers.  It
  does not matter for VOP_GETPAGES() calls from vm_fault() since handle
  of the vm_object always points to the lower vnode.  But it may be
  useful for other situations where VOP_GETPAGES() is used.
  
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks

Modified:
  head/sys/fs/nullfs/null_vfsops.c

Modified: head/sys/fs/nullfs/null_vfsops.c
==============================================================================
--- head/sys/fs/nullfs/null_vfsops.c	Fri Mar  4 16:03:15 2016	(r296387)
+++ head/sys/fs/nullfs/null_vfsops.c	Fri Mar  4 17:24:28 2016	(r296388)
@@ -199,7 +199,7 @@ nullfs_mount(struct mount *mp)
 	}
 	mp->mnt_kern_flag |= MNTK_LOOKUP_EXCL_DOTDOT;
 	mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag &
-	    MNTK_USES_BCACHE;
+	    (MNTK_USES_BCACHE | MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS);
 	MNT_IUNLOCK(mp);
 	mp->mnt_data = xmp;
 	vfs_getnewfsid(mp);