The mount_mfs process that stays in a supervisor context handling MFS

    I/O requests must be marked P_SYSTEM because if it isn't and the system
    decides to swap it or (god forbid) kill it, the system stands a good
    chance of locking up.

1 files changed, 11 insertions, 1 deletions

diff --git a/sys/ufs/mfs/mfs_vfsops.c b/sys/ufs/mfs/mfs_vfsops.c
index fa4ffc3..1ea0804 100644
--- a/sys/ufs/mfs/mfs_vfsops.c
+++ b/sys/ufs/mfs/mfs_vfsops.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)mfs_vfsops.c	8.11 (Berkeley) 6/19/95
- * $Id: mfs_vfsops.c,v 1.51 1998/10/12 09:02:19 peter Exp $
+ * $Id: mfs_vfsops.c,v 1.52 1998/12/07 21:58:49 archie Exp $
  */
 
 
@@ -391,6 +391,16 @@ mfs_start(mp, flags, p)
 	register int gotsig = 0;
 
 	base = mfsp->mfs_baseoff;
+
+	/*
+	 * Must set P_SYSTEM to prevent system from trying to kill
+	 * this process.  What happens is that the process is unkillable,
+	 * and the swapper loops trying to continuously kill it.  Nor
+	 * can we swap out this process - not unless you want a deadlock,
+	 * anyway.
+	 */
+	curproc->p_flag |= P_SYSTEM;
+
 	while (mfsp->mfs_active) {
 		while (bp = bufq_first(&mfsp->buf_queue)) {
 			bufq_remove(&mfsp->buf_queue, bp);