Add necessary spl protection for swapper. The problem was located by

    Alfred while testing his SPLASSERT stuff.   This is not a complete fix,
    more protections are probably needed.

3 files changed, 19 insertions, 3 deletions

diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
index ca7a3fe..683eb9d 100644
--- a/sys/vm/swap_pager.c
+++ b/sys/vm/swap_pager.c
@@ -702,8 +702,6 @@ swap_pager_copy(srcobject, dstobject, offset, destroysource)
  *	distance.  We do not try to restrict it to the swap device stripe
  *	(that is handled in getpages/putpages).  It probably isn't worth
  *	doing here.
- *
- *	This routine must be called at splvm().
  */
 
 boolean_t
@@ -714,14 +712,17 @@ swap_pager_haspage(object, pindex, before, after)
 	int *after;
 {
 	daddr_t blk0;
+	int s;
 
 	/*
 	 * do we have good backing store at the requested index ?
 	 */
 
+	s = splvm();
 	blk0 = swp_pager_meta_ctl(object, pindex, 0);
 
 	if (blk0 == SWAPBLK_NONE) {
+		splx(s);
 		if (before)
 			*before = 0;
 		if (after)
@@ -764,7 +765,7 @@ swap_pager_haspage(object, pindex, before, after)
 		}
 		*after = (i - 1);
 	}
-
+	splx(s);
 	return (TRUE);
 }
 
diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c
index 91bf4ee..592f6cd 100644
--- a/sys/vm/vm_pageout.c
+++ b/sys/vm/vm_pageout.c
@@ -1151,6 +1151,7 @@ vm_pageout_page_stats()
 	int pcount,tpcount;		/* Number of pages to check */
 	static int fullintervalcount = 0;
 	int page_shortage;
+	int s0;
 
 	page_shortage = 
 	    (cnt.v_inactive_target + cnt.v_cache_max + cnt.v_free_min) -
@@ -1159,6 +1160,8 @@ vm_pageout_page_stats()
 	if (page_shortage <= 0)
 		return;
 
+	s0 = splvm();
+
 	pcount = cnt.v_active_count;
 	fullintervalcount += vm_pageout_stats_interval;
 	if (fullintervalcount < vm_pageout_full_stats_interval) {
@@ -1227,6 +1230,7 @@ vm_pageout_page_stats()
 
 		m = next;
 	}
+	splx(s0);
 }
 
 static int
diff --git a/sys/vm/vm_pager.h b/sys/vm/vm_pager.h
index c548231..3824c63 100644
--- a/sys/vm/vm_pager.h
+++ b/sys/vm/vm_pager.h
@@ -146,6 +146,17 @@ vm_pager_put_pages(
 	    (object, m, count, flags, rtvals);
 }
 
+/*
+ *	vm_pager_haspage
+ *
+ *	Check to see if an object's pager has the requested page.  The
+ *	object's pager will also set before and after to give the caller
+ *	some idea of the number of pages before and after the requested
+ *	page can be I/O'd efficiently.
+ *
+ *	This routine does not have to be called at any particular spl.
+ */
+
 static __inline boolean_t
 vm_pager_has_page(
 	vm_object_t object,