From 89b005fc27d306fad29f5e750c032358c760fd7d Mon Sep 17 00:00:00 2001
From: chs <chs@NetBSD.org>
Date: Wed, 27 Dec 2000 09:17:04 +0000
Subject: [PATCH] when we fail to allocate anons to represent new swap space,
 just return an error rather than panicing.

---
 sys/uvm/uvm_anon.c | 20 ++++++++++----------
 sys/uvm/uvm_anon.h |  4 ++--
 sys/uvm/uvm_swap.c | 27 ++++++++++++++++++---------
 3 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/sys/uvm/uvm_anon.c b/sys/uvm/uvm_anon.c
index d649cc684718..f69856031d05 100644
--- a/sys/uvm/uvm_anon.c
+++ b/sys/uvm/uvm_anon.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_anon.c,v 1.10 2000/11/25 06:27:59 chs Exp $	*/
+/*	$NetBSD: uvm_anon.c,v 1.11 2000/12/27 09:17:04 chs Exp $	*/
 
 /*
  *
@@ -88,7 +88,7 @@ uvm_anon_init()
  *
  * => swap_syscall_lock should be held (protects anonblock_list).
  */
-void
+int
 uvm_anon_add(count)
 	int	count;
 {
@@ -102,17 +102,16 @@ uvm_anon_add(count)
 	simple_unlock(&uvm.afreelock);
 
 	if (needed <= 0) {
-		return;
+		return 0;
 	}
- 
-	MALLOC(anonblock, void *, sizeof(*anonblock), M_UVMAMAP, M_WAITOK);
 	anon = (void *)uvm_km_alloc(kernel_map, sizeof(*anon) * needed);
-
-	/* XXX Should wait for VM to free up. */
-	if (anonblock == NULL || anon == NULL) {
-		printf("uvm_anon_add: can not allocate %d anons\n", needed);
-		panic("uvm_anon_add");
+	if (anon == NULL) {
+		simple_lock(&uvm.afreelock);
+		uvmexp.nanonneeded -= count;
+		simple_unlock(&uvm.afreelock);
+		return ENOMEM;
 	}
+	MALLOC(anonblock, void *, sizeof(*anonblock), M_UVMAMAP, M_WAITOK);
 
 	anonblock->count = needed;
 	anonblock->anons = anon;
@@ -129,6 +128,7 @@ uvm_anon_add(count)
 		simple_lock_init(&uvm.afree->an_lock);
 	}
 	simple_unlock(&uvm.afreelock);
+	return 0;
 }
 
 /*
diff --git a/sys/uvm/uvm_anon.h b/sys/uvm/uvm_anon.h
index 7ed395427a4b..fc5ba5f61030 100644
--- a/sys/uvm/uvm_anon.h
+++ b/sys/uvm/uvm_anon.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_anon.h,v 1.12 2000/01/11 06:57:49 chs Exp $	*/
+/*	$NetBSD: uvm_anon.h,v 1.13 2000/12/27 09:17:04 chs Exp $	*/
 
 /*
  *
@@ -101,7 +101,7 @@ struct vm_aref {
 struct vm_anon *uvm_analloc __P((void));
 void uvm_anfree __P((struct vm_anon *));
 void uvm_anon_init __P((void));
-void uvm_anon_add __P((int));
+int uvm_anon_add __P((int));
 void uvm_anon_remove __P((int));
 struct vm_page *uvm_anon_lockloanpg __P((struct vm_anon *));
 void uvm_anon_dropswap __P((struct vm_anon *));
diff --git a/sys/uvm/uvm_swap.c b/sys/uvm/uvm_swap.c
index a66ac45cd664..724dfddfacf0 100644
--- a/sys/uvm/uvm_swap.c
+++ b/sys/uvm/uvm_swap.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: uvm_swap.c,v 1.42 2000/12/23 12:13:05 enami Exp $	*/
+/*	$NetBSD: uvm_swap.c,v 1.43 2000/12/27 09:17:04 chs Exp $	*/
 
 /*
  * Copyright (c) 1995, 1996, 1997 Matthew R. Green
@@ -927,16 +927,20 @@ swap_on(p, sdp)
 		printf("leaving %d pages of swap\n", size);
 	}
 
+  	/*
+	 * try to add anons to reflect the new swap space.
+	 */
+
+	error = uvm_anon_add(size);
+	if (error) {
+		goto bad;
+	}
+
 	/*
 	 * add a ref to vp to reflect usage as a swap device.
 	 */
 	vref(vp);
 
-  	/*
-	 * add anons to reflect the new swap space
-	 */
-	uvm_anon_add(size);
-
 	/*
 	 * now add the new swapdev to the drum and enable.
 	 */
@@ -949,12 +953,17 @@ swap_on(p, sdp)
 	simple_unlock(&uvm.swap_data_lock);
 	return (0);
 
-bad:
 	/*
-	 * failure: close device if necessary and return error.
+	 * failure: clean up and return error.
 	 */
-	if (vp != rootvp)
+
+bad:
+	if (sdp->swd_ex) {
+		extent_destroy(sdp->swd_ex);
+	}
+	if (vp != rootvp) {
 		(void)VOP_CLOSE(vp, FREAD|FWRITE, p->p_ucred, p);
+	}
 	return (error);
 }