diff -urNp --exclude CVS --exclude BitKeeper xx-ref/fs/inode.c xx/fs/inode.c
--- xx-ref/fs/inode.c	2003-05-27 04:54:24.000000000 +0200
+++ xx/fs/inode.c	2003-05-27 04:54:30.000000000 +0200
@@ -147,6 +147,7 @@ void inode_init_once(struct inode *inode
 	INIT_LIST_HEAD(&inode->i_data.clean_pages);
 	INIT_LIST_HEAD(&inode->i_data.dirty_pages);
 	INIT_LIST_HEAD(&inode->i_data.locked_pages);
+	frlock_init(&inode->i_data.truncate_lock);
 	INIT_LIST_HEAD(&inode->i_dentry);
 	INIT_LIST_HEAD(&inode->i_dirty_buffers);
 	INIT_LIST_HEAD(&inode->i_dirty_data_buffers);
diff -urNp --exclude CVS --exclude BitKeeper xx-ref/include/linux/fs.h xx/include/linux/fs.h
--- xx-ref/include/linux/fs.h	2003-05-27 04:54:28.000000000 +0200
+++ xx/include/linux/fs.h	2003-05-27 04:54:52.000000000 +0200
@@ -21,6 +21,7 @@
 #include <linux/cache.h>
 #include <linux/stddef.h>
 #include <linux/string.h>
+#include <linux/frlock.h>
 
 #include <asm/atomic.h>
 #include <asm/bitops.h>
@@ -422,6 +423,7 @@ struct address_space {
 	struct vm_area_struct	*i_mmap;	/* list of private mappings */
 	struct vm_area_struct	*i_mmap_shared; /* list of shared mappings */
 	spinlock_t		i_shared_lock;  /* and spinlock protecting it */
+	frlock_t		truncate_lock; /* serialize ->nopage against truncate */
 	int			gfp_mask;	/* how to allocate the pages */
 };
 
diff -urNp --exclude CVS --exclude BitKeeper xx-ref/mm/memory.c xx/mm/memory.c
--- xx-ref/mm/memory.c	2003-05-27 04:54:28.000000000 +0200
+++ xx/mm/memory.c	2003-05-27 04:54:30.000000000 +0200
@@ -1127,6 +1127,7 @@ int vmtruncate(struct inode * inode, lof
 	if (inode->i_size < offset)
 		goto do_expand;
 	i_size_write(inode, offset);
+	fr_write_lock(&mapping->truncate_lock);
 	spin_lock(&mapping->i_shared_lock);
 	if (!mapping->i_mmap && !mapping->i_mmap_shared)
 		goto out_unlock;
@@ -1140,6 +1141,7 @@ int vmtruncate(struct inode * inode, lof
 out_unlock:
 	spin_unlock(&mapping->i_shared_lock);
 	truncate_inode_pages(mapping, offset);
+	fr_write_unlock(&mapping->truncate_lock);
 	goto out_truncate;
 
 do_expand:
@@ -1335,12 +1337,19 @@ static int do_no_page(struct mm_struct *
 {
 	struct page * new_page;
 	pte_t entry;
+	unsigned truncate_sequence;
+	struct file *file;
+	struct address_space *mapping;
 
 	if (!vma->vm_ops || !vma->vm_ops->nopage)
 		return do_anonymous_page(mm, vma, page_table, pmd, write_access, address);
 	spin_unlock(&mm->page_table_lock);
 	pte_kunmap(page_table);
 
+	file = vma->vm_file;
+	mapping = file->f_dentry->d_inode->i_mapping;
+	truncate_sequence = fr_read_begin(&mapping->truncate_lock);
+
 	new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, 0);
 
 	if (new_page == NULL)	/* no page was available -- SIGBUS */
@@ -1366,6 +1375,21 @@ static int do_no_page(struct mm_struct *
 
 	page_table = pte_offset_atomic(pmd, address);
 	spin_lock(&mm->page_table_lock);
+	if (unlikely(truncate_sequence != fr_read_end(&mapping->truncate_lock))) {
+		struct inode *inode;
+
+		spin_unlock(&mm->page_table_lock);
+
+		/*
+		 * Don't worthless loop here forever overloading the cpu
+		 * until the truncate has completed.
+		 */
+		inode = mapping->host;
+		down(&inode->i_sem);
+		up(&inode->i_sem);
+
+		goto retry;
+	}
 
 	/*
 	 * This silly early PAGE_DIRTY setting removes a race
@@ -1388,6 +1412,7 @@ static int do_no_page(struct mm_struct *
 		set_pte(page_table, entry);
 	} else {
 		spin_unlock(&mm->page_table_lock);
+	retry:
 		pte_kunmap(page_table);
 		/* One of our sibling threads was faster, back out. */
 		page_cache_release(new_page);
diff -urNp --exclude CVS --exclude BitKeeper xx-ref/mm/vmscan.c xx/mm/vmscan.c
--- xx-ref/mm/vmscan.c	2003-05-27 04:54:25.000000000 +0200
+++ xx/mm/vmscan.c	2003-05-27 04:54:30.000000000 +0200
@@ -165,11 +165,10 @@ drop_pte:
 		goto drop_pte;
 
 	/*
-	 * Anonymous buffercache pages can be left behind by
+	 * Anonymous buffercache pages can't be left behind by
 	 * concurrent truncate and pagefault.
 	 */
-	if (page->buffers)
-		goto preserve;
+	BUG_ON(page->buffers);
 
 	/*
 	 * This is a dirty, swappable page.  First of all,