add uvm_swap_check_range to scan for contig free space at end of swap.

will be needed shortly for hibernate.

ok deraadt@

2 files changed, 47 insertions, 2 deletions

diff --git a/sys/uvm/uvm_swap.c b/sys/uvm/uvm_swap.c
index 6610be38497..6b7568b0a65 100644
--- a/sys/uvm/uvm_swap.c
+++ b/sys/uvm/uvm_swap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_swap.c,v 1.105 2012/06/14 15:53:38 jasper Exp $	*/
+/*	$OpenBSD: uvm_swap.c,v 1.106 2012/07/11 10:07:40 mlarkin Exp $	*/
 /*	$NetBSD: uvm_swap.c,v 1.40 2000/11/17 11:39:39 mrg Exp $	*/
 
 /*
@@ -2080,3 +2080,47 @@ swapmount(void)
 
 	VOP_UNLOCK(vp, 0, curproc);
 }
+
+/*
+ * Check if free swap available at end of swap dev swdev.
+ * Used by hibernate to check for usable swap area before writing the image
+ */
+int
+uvm_swap_check_range(dev_t swdev, size_t size)
+{
+	struct swapdev *sdp, *swd = NULL;
+	struct swappri *spp;
+	struct extent *ex;
+	struct extent_region *exr;
+	int r = 0, start,  npages = size / PAGE_SIZE;
+
+	/* no swap devices configured yet? then range is not in use */
+	if (uvmexp.nswapdev < 1)
+		return (0);
+
+	for (spp = LIST_FIRST(&swap_priority); spp != NULL;
+	     spp = LIST_NEXT(spp, spi_swappri))
+		for (sdp = CIRCLEQ_FIRST(&spp->spi_swapdev);
+		     sdp != (void *)&spp->spi_swapdev;
+		     sdp = CIRCLEQ_NEXT(sdp,swd_next)) {
+			if (sdp->swd_dev == swdev)
+				swd = sdp;
+		}
+
+	if (swd == NULL)
+		return (0);
+
+	if ((swd->swd_flags & SWF_ENABLE) == 0)
+		return (0);
+
+	ex = swd->swd_ex;
+	start = swd->swd_drumsize-npages;
+
+	LIST_FOREACH(exr, &ex->ex_regions, er_link)
+		{
+			if (exr->er_end >= start)
+				r = 1;
+		}
+
+	return (r);
+}
diff --git a/sys/uvm/uvm_swap.h b/sys/uvm/uvm_swap.h
index ba3629579a5..c0dc9e68e12 100644
--- a/sys/uvm/uvm_swap.h
+++ b/sys/uvm/uvm_swap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_swap.h,v 1.13 2010/07/01 19:48:05 oga Exp $	*/
+/*	$OpenBSD: uvm_swap.h,v 1.14 2012/07/11 10:07:40 mlarkin Exp $	*/
 /*	$NetBSD: uvm_swap.h,v 1.5 2000/01/11 06:57:51 chs Exp $	*/
 
 /*
@@ -44,6 +44,7 @@ int			uvm_swap_alloc(int *, boolean_t);
 void			uvm_swap_free(int, int);
 void			uvm_swap_markbad(int, int);
 void			uvm_swap_freepages(struct vm_page **, int);
+int			uvm_swap_check_range(dev_t, size_t);
 #ifdef UVM_SWAP_ENCRYPT
 void			uvm_swap_initcrypt_all(void);
 void			uvm_swap_finicrypt_all(void);