From d10c3c7af6cf0725dd0b8fac8930822ab66d056e Mon Sep 17 00:00:00 2001
From: kib <kib@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Tue, 4 Aug 2015 05:18:24 +0000
Subject: [PATCH] MFC r285878 (stable/10 r286145): Revert r173708's
 modifications to vm_object_page_remove(). This fixes inconsistencies
 encountered by vm_object_unwire() or by the buffer cache when the file is
 truncated.

Approved by:	re (gjb)


git-svn-id: https://svn.freebsd.org/base/releng/10.2@286276 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sys/vm/vm_object.c | 28 +++++-----------------------
 sys/vm/vm_object.h |  1 -
 2 files changed, 5 insertions(+), 24 deletions(-)

diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index ab1562eda..36a2ead2b 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1063,9 +1063,9 @@ vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
 			 */
 			flags = OBJPR_NOTMAPPED;
 		else if (old_msync)
-			flags = OBJPR_NOTWIRED;
+			flags = 0;
 		else
-			flags = OBJPR_CLEANONLY | OBJPR_NOTWIRED;
+			flags = OBJPR_CLEANONLY;
 		vm_object_page_remove(object, OFF_TO_IDX(offset),
 		    OFF_TO_IDX(offset + size + PAGE_MASK), flags);
 	}
@@ -1894,7 +1894,6 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
     int options)
 {
 	vm_page_t p, next;
-	int wirings;
 
 	VM_OBJECT_ASSERT_WLOCKED(object);
 	KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
@@ -1928,15 +1927,9 @@ again:
 			VM_OBJECT_WLOCK(object);
 			goto again;
 		}
-		if ((wirings = p->wire_count) != 0 &&
-		    (wirings = pmap_page_wired_mappings(p)) != p->wire_count) {
-			if ((options & (OBJPR_NOTWIRED | OBJPR_NOTMAPPED)) ==
-			    0) {
+		if (p->wire_count != 0) {
+			if ((options & OBJPR_NOTMAPPED) == 0)
 				pmap_remove_all(p);
-				/* Account for removal of wired mappings. */
-				if (wirings != 0)
-					p->wire_count -= wirings;
-			}
 			if ((options & OBJPR_CLEANONLY) == 0) {
 				p->valid = 0;
 				vm_page_undirty(p);
@@ -1957,19 +1950,8 @@ again:
 			if (p->dirty)
 				goto next;
 		}
-		if ((options & OBJPR_NOTMAPPED) == 0) {
-			if ((options & OBJPR_NOTWIRED) != 0 && wirings != 0)
-				goto next;
+		if ((options & OBJPR_NOTMAPPED) == 0)
 			pmap_remove_all(p);
-			/* Account for removal of wired mappings. */
-			if (wirings != 0) {
-				KASSERT(p->wire_count == wirings,
-				    ("inconsistent wire count %d %d %p",
-				    p->wire_count, wirings, p));
-				p->wire_count = 0;
-				atomic_subtract_int(&cnt.v_wire_count, 1);
-			}
-		}
 		vm_page_free(p);
 next:
 		vm_page_unlock(p);
diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index 8f65b4225..06111a124 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -207,7 +207,6 @@ struct vm_object {
  */
 #define	OBJPR_CLEANONLY	0x1		/* Don't remove dirty pages. */
 #define	OBJPR_NOTMAPPED	0x2		/* Don't unmap pages. */
-#define	OBJPR_NOTWIRED	0x4		/* Don't remove wired pages. */
 
 TAILQ_HEAD(object_q, vm_object);
 
-- 
2.45.0