--- 2.5.70-mm8/./drivers/mtd/devices/blkmtd.c	2003-05-26 20:00:21.000000000 -0500
+++ 2.5.70-mm8-trunc/./drivers/mtd/devices/blkmtd.c	2003-06-12 13:45:48.000000000 -0500
@@ -1189,6 +1189,7 @@ static int __init init_blkmtd(void)
   INIT_LIST_HEAD(&mtd_rawdevice->as.locked_pages);
   mtd_rawdevice->as.host = NULL;
   init_MUTEX(&(mtd_rawdevice->as.i_shared_sem));
+  seqlock_init(&(mtd_rawdevice->as.truncate_lock));
 
   mtd_rawdevice->as.a_ops = &blkmtd_aops;
   INIT_LIST_HEAD(&mtd_rawdevice->as.i_mmap);
--- 2.5.70-mm8/./include/linux/fs.h	2003-06-12 13:37:28.000000000 -0500
+++ 2.5.70-mm8-trunc/./include/linux/fs.h	2003-06-12 13:42:51.000000000 -0500
@@ -19,6 +19,7 @@
 #include <linux/cache.h>
 #include <linux/radix-tree.h>
 #include <linux/kobject.h>
+#include <linux/seqlock.h>
 #include <asm/atomic.h>
 
 struct iovec;
@@ -323,6 +324,7 @@ struct address_space {
 	struct list_head	i_mmap;		/* list of private mappings */
 	struct list_head	i_mmap_shared;	/* list of shared mappings */
 	struct semaphore	i_shared_sem;	/* protect both above lists */
+	seqlock_t		truncate_lock;	/* Cover race condition with truncate */
 	unsigned long		dirtied_when;	/* jiffies of first page dirtying */
 	int			gfp_mask;	/* how to allocate the pages */
 	struct backing_dev_info *backing_dev_info; /* device readahead, etc */
--- 2.5.70-mm8/./fs/inode.c	2003-06-12 13:37:22.000000000 -0500
+++ 2.5.70-mm8-trunc/./fs/inode.c	2003-06-12 13:43:29.000000000 -0500
@@ -185,6 +185,7 @@ void inode_init_once(struct inode *inode
 	INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
 	spin_lock_init(&inode->i_data.page_lock);
 	init_MUTEX(&inode->i_data.i_shared_sem);
+	seqlock_init(&inode->i_data.truncate_lock);
 	INIT_LIST_HEAD(&inode->i_data.private_list);
 	spin_lock_init(&inode->i_data.private_lock);
 	INIT_LIST_HEAD(&inode->i_data.i_mmap);
--- 2.5.70-mm8/./mm/swap_state.c	2003-05-26 20:00:39.000000000 -0500
+++ 2.5.70-mm8-trunc/./mm/swap_state.c	2003-06-12 13:40:54.000000000 -0500
@@ -44,6 +44,7 @@ struct address_space swapper_space = {
 	.i_mmap		= LIST_HEAD_INIT(swapper_space.i_mmap),
 	.i_mmap_shared	= LIST_HEAD_INIT(swapper_space.i_mmap_shared),
 	.i_shared_sem	= __MUTEX_INITIALIZER(swapper_space.i_shared_sem),
+	.truncate_lock  = SEQLOCK_UNLOCKED,
 	.private_lock	= SPIN_LOCK_UNLOCKED,
 	.private_list	= LIST_HEAD_INIT(swapper_space.private_list),
 };
--- 2.5.70-mm8/./mm/memory.c	2003-06-12 13:37:31.000000000 -0500
+++ 2.5.70-mm8-trunc/./mm/memory.c	2003-06-12 13:40:54.000000000 -0500
@@ -1138,6 +1138,9 @@ invalidate_mmap_range(struct address_spa
 			hlen = ULONG_MAX - hba + 1;
 	}
 	down(&mapping->i_shared_sem);
+	/* Protect against page fault */
+	write_seqlock(&mapping->truncate_lock);
+	write_sequnlock(&mapping->truncate_lock);
 	if (unlikely(!list_empty(&mapping->i_mmap)))
 		invalidate_mmap_range_list(&mapping->i_mmap, hba, hlen);
 	if (unlikely(!list_empty(&mapping->i_mmap_shared)))
@@ -1390,8 +1393,11 @@ do_no_page(struct mm_struct *mm, struct 
 	unsigned long address, int write_access, pte_t *page_table, pmd_t *pmd)
 {
 	struct page * new_page;
+	struct inode *inode;
+	struct address_space *mapping;
 	pte_t entry;
 	struct pte_chain *pte_chain;
+	unsigned sequence;
 	int ret;
 
 	if (!vma->vm_ops || !vma->vm_ops->nopage)
@@ -1400,6 +1406,10 @@ do_no_page(struct mm_struct *mm, struct 
 	pte_unmap(page_table);
 	spin_unlock(&mm->page_table_lock);
 
+	inode = vma->vm_file->f_dentry->d_inode;
+	mapping = inode->i_mapping;
+retry:
+	sequence = read_seqbegin(&mapping->truncate_lock);
 	new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, 0);
 
 	/* no page was available -- either SIGBUS or OOM */
@@ -1428,6 +1438,17 @@ do_no_page(struct mm_struct *mm, struct 
 	}
 
 	spin_lock(&mm->page_table_lock);
+	/*
+	 * If someone invalidated the page, serialize against the inode,
+	 * then go try again.
+	 */
+	if (unlikely(read_seqretry(&mapping->truncate_lock, sequence))) {
+		spin_unlock(&mm->page_table_lock);
+		down(&inode->i_sem);
+		up(&inode->i_sem);
+		goto retry;
+	}
+
 	page_table = pte_offset_map(pmd, address);
 
 	/*