From 34e2051fafc54d812e98bae8748b106e8f68213e Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Mon, 17 Feb 2020 15:11:07 +0000
Subject: [PATCH] Remove swblk_t.

It was used only to store the bounds of each swap device.  However,
since swblk_t is a signed 32-bit int and daddr_t is a signed 64-bit
int, swp_pager_isondev() may return an invalid result if swap devices
are repeatedly added and removed and sw_end for a device ends up
becoming a negative number.

Note that the removed comment about maximum swap size still applies.

Reviewed by:	jeff, kib
Tested by:	pho
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D23666
---
 lib/libkvm/kvm_getswapinfo.c |  6 ++----
 sys/vm/swap_pager.c          |  2 +-
 sys/vm/swap_pager.h          | 13 ++++---------
 3 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/lib/libkvm/kvm_getswapinfo.c b/lib/libkvm/kvm_getswapinfo.c
index 747ab5076ecd..7fd58f977614 100644
--- a/lib/libkvm/kvm_getswapinfo.c
+++ b/lib/libkvm/kvm_getswapinfo.c
@@ -115,8 +115,7 @@ int
 kvm_getswapinfo_kvm(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max,
     int flags)
 {
-	int i;
-	swblk_t ttl;
+	int i, ttl;
 	TAILQ_HEAD(, swdevt) swtailq;
 	struct swdevt *sp, swinfo;
 	struct kvm_swap tot;
@@ -167,8 +166,7 @@ int
 kvm_getswapinfo_sysctl(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max,
     int flags)
 {
-	int ti;
-	swblk_t ttl;
+	int ti, ttl;
 	size_t mibi, len;
 	int soid[SWI_MAXMIB];
 	struct xswdev xsd;
diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c
index 597af7b783d2..d62db64d1888 100644
--- a/sys/vm/swap_pager.c
+++ b/sys/vm/swap_pager.c
@@ -2334,7 +2334,7 @@ swaponsomething(struct vnode *vp, void *id, u_long nblks,
     sw_strategy_t *strategy, sw_close_t *close, dev_t dev, int flags)
 {
 	struct swdevt *sp, *tsp;
-	swblk_t dvbase;
+	daddr_t dvbase;
 	u_long mblocks;
 
 	/*
diff --git a/sys/vm/swap_pager.h b/sys/vm/swap_pager.h
index 76456a40e018..80dca93fbf85 100644
--- a/sys/vm/swap_pager.h
+++ b/sys/vm/swap_pager.h
@@ -38,14 +38,9 @@
  */
 
 #ifndef	_VM_SWAP_PAGER_H_
-#define	_VM_SWAP_PAGER_H_ 1
+#define	_VM_SWAP_PAGER_H_
 
-typedef	int32_t	swblk_t;	/*
-				 * swap offset.  This is the type used to
-				 * address the "virtual swap device" and
-				 * therefore the maximum swap space is
-				 * 2^32 pages.
-				 */
+#include <sys/_types.h>
 
 struct buf;
 struct swdevt;
@@ -62,8 +57,8 @@ struct swdevt {
 	dev_t	sw_dev;
 	struct vnode *sw_vp;
 	void	*sw_id;
-	swblk_t	sw_first;
-	swblk_t	sw_end;
+	__daddr_t sw_first;
+	__daddr_t sw_end;
 	struct blist *sw_blist;
 	TAILQ_ENTRY(swdevt)	sw_list;
 	sw_strategy_t		*sw_strategy;