--- linux-2.4.2-ac26/mm/shmem.c.~1~	Tue Mar 27 18:41:50 2001
+++ linux-2.4.2-ac26/mm/shmem.c	Sun Apr  1 02:52:14 2001
@@ -226,7 +226,7 @@
  */
 static int shmem_writepage(struct page * page)
 {
-	int error;
+	int error = 0;
 	struct shmem_inode_info *info;
 	swp_entry_t *entry, swap;
 	struct inode *inode;
@@ -234,6 +234,11 @@
 	if (!PageLocked(page))
 		BUG();
 	
+	/* Only move to the swap cache if there are no other users of
+	 * the page. */
+	if (atomic_read(&page->count) > 2)
+		goto out;
+	
 	inode = page->mapping->host;
 	info = &inode->u.shmem_i;
 	swap = __get_swap_page(2);
@@ -243,16 +248,14 @@
 		return -ENOMEM;
 	}
 
+	spin_lock(&info->lock);
 	entry = shmem_swp_entry(info, page->index);
 	if (IS_ERR(entry))	/* this had been allocted on page allocation */
 		BUG();
-	spin_lock(&info->lock);
 	shmem_recalc_inode(page->mapping->host);
 	error = -EAGAIN;
-	if (entry->val) {
-		__swap_free(swap, 2);
-		goto out;
-	}
+	if (entry->val)
+		BUG();
 
 	*entry = swap;
 	error = 0;
@@ -265,8 +268,9 @@
 	page_cache_release(page);
 	set_page_dirty(page);
 	info->swapped++;
-out:
+
 	spin_unlock(&info->lock);
+out:
 	UnlockPage(page);
 	return error;
 }
@@ -307,8 +311,10 @@
 	 * cache and swap cache.  We need to recheck the page cache
 	 * under the protection of the info->lock spinlock. */
 
-	page = find_lock_page(mapping, idx);
+	page = __find_get_page(mapping, idx, page_hash(mapping, idx));
 	if (page) {
+		if (TryLockPage(page))
+			goto wait_retry;
 		spin_unlock (&info->lock);
 		return page;
 	}
@@ -317,7 +323,8 @@
 		unsigned long flags;
 
 		/* Look it up and read it in.. */
-		page = lookup_swap_cache(*entry);
+		page = __find_get_page(&swapper_space, entry->val,
+				       page_hash(&swapper_space, entry->val));
 		if (!page) {
 			spin_unlock (&info->lock);
 			lock_kernel();
@@ -326,6 +333,11 @@
 			unlock_kernel();
 			if (!page) 
 				return ERR_PTR(-ENOMEM);
+			if (!Page_Uptodate(page)) {
+				page_cache_release(page);
+				return ERR_PTR(-EIO);
+			}
+			
 			/* Too bad we can't trust this page, because we
 			 * dropped the info->lock spinlock */
 			page_cache_release(page);
@@ -333,13 +345,12 @@
 		}
 
 		/* We have to this with page locked to prevent races */
-		if (TryLockPage(page)) {
-			spin_unlock(&info->lock);
- 			wait_on_page(page);
-			page_cache_release(page);
-			goto repeat;
-		}
-			
+		if (TryLockPage(page)) 
+			goto wait_retry;
+
+		if (swap_count(page) > 2)
+			BUG();
+		
 		swap_free(*entry);
 		*entry = (swp_entry_t) {0};
 		delete_from_swap_cache_nolock(page);
@@ -371,7 +382,6 @@
 		add_to_page_cache (page, mapping, idx);
 	}
 
-	
 	/* We have the page */
 	SetPageUptodate(page);
 	if (info->locked)
@@ -380,6 +390,12 @@
 no_space:
 	spin_unlock (&inode->i_sb->u.shmem_sb.stat_lock);
 	return ERR_PTR(-ENOSPC);
+
+wait_retry:
+	spin_unlock (&info->lock);
+	wait_on_page(page);
+	page_cache_release(page);
+	goto repeat;
 }
 
 static int shmem_getpage(struct inode * inode, unsigned long idx, struct page **ptr)
@@ -640,8 +656,8 @@
 			buf += bytes;
 			if (pos > inode->i_size) 
 				inode->i_size = pos;
-			if (inode->u.shmem_i.max_index < index)
-				inode->u.shmem_i.max_index = index;
+			if (inode->u.shmem_i.max_index <= index)
+				inode->u.shmem_i.max_index = index+1;
 
 		}
 unlock: