In order to allow for interruptible and asynchronous versions of
lock_page in conjunction with the wait_on_bit changes, we need to
define low-level lock page routines which take an additional
argument, i.e a wait queue entry and may return non-zero status,
e.g -EINTR, -EIOCBRETRY, -EWOULDBLOCK etc. This patch renames 
__lock_page to lock_page_slow, so that __lock_page and 
__lock_page_slow can denote the versions which take a wait queue 
parameter.

Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com>
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
diff -purN --exclude=description 71_wait_on_bit/include/linux/pagemap.h 72_lock_page_slow/include/linux/pagemap.h
--- 71_wait_on_bit/include/linux/pagemap.h	2005-08-04 15:56:06.000000000 -0400
+++ 72_lock_page_slow/include/linux/pagemap.h	2005-08-08 17:15:54.000000000 -0400
@@ -159,14 +159,14 @@ static inline pgoff_t linear_page_index(
 	return pgoff >> (PAGE_CACHE_SHIFT - PAGE_SHIFT);
 }
 
-extern void FASTCALL(__lock_page(struct page *page));
+extern void FASTCALL(lock_page_slow(struct page *page));
 extern void FASTCALL(unlock_page(struct page *page));
 
 static inline void lock_page(struct page *page)
 {
 	might_sleep();
 	if (TestSetPageLocked(page))
-		__lock_page(page);
+		lock_page_slow(page);
 }
 	
 /*
diff -purN --exclude=description 71_wait_on_bit/mm/filemap.c 72_lock_page_slow/mm/filemap.c
--- 71_wait_on_bit/mm/filemap.c	2005-08-08 17:15:51.000000000 -0400
+++ 72_lock_page_slow/mm/filemap.c	2005-08-08 17:15:54.000000000 -0400
@@ -485,14 +485,14 @@ EXPORT_SYMBOL(end_page_writeback);
  * chances are that on the second loop, the block layer's plug list is empty,
  * so sync_page() will then return in state TASK_UNINTERRUPTIBLE.
  */
-void fastcall __lock_page(struct page *page)
+void fastcall lock_page_slow(struct page *page)
 {
 	DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
 
 	__wait_on_bit_lock(page_waitqueue(page), &wait, sync_page,
 							TASK_UNINTERRUPTIBLE);
 }
-EXPORT_SYMBOL(__lock_page);
+EXPORT_SYMBOL(lock_page_slow);
 
 /*
  * a rather lightweight function, finding and getting a reference to a