[PATCH 13/13] NTFS: Critical bug fix (affects MIPS and possibly others)

[Chris Wright <chrisw@sous-sol.org>]

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-stable review patch.  If anyone has any objections, please let us know.
------------------

From: Anton Altaparmakov <aia21@cam.ac.uk>

It fixes a crash in NTFS on architectures where flush_dcache_page()
is a real function.  I never noticed this as all my testing is done on
i386 where flush_dcache_page() is NULL.

http://bugzilla.kernel.org/show_bug.cgi?id=6700

Many thanks to Pauline Ng for the detailed bug report and analysis!

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

 fs/ntfs/file.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- linux-2.6.16.21.orig/fs/ntfs/file.c
+++ linux-2.6.16.21/fs/ntfs/file.c
@@ -1489,14 +1489,15 @@ static inline void ntfs_flush_dcache_pag
 		unsigned nr_pages)
 {
 	BUG_ON(!nr_pages);
+	/*
+	 * Warning: Do not do the decrement at the same time as the call to
+	 * flush_dcache_page() because it is a NULL macro on i386 and hence the
+	 * decrement never happens so the loop never terminates.
+	 */
 	do {
-		/*
-		 * Warning: Do not do the decrement at the same time as the
-		 * call because flush_dcache_page() is a NULL macro on i386
-		 * and hence the decrement never happens.
-		 */
+		--nr_pages;
 		flush_dcache_page(pages[nr_pages]);
-	} while (--nr_pages > 0);
+	} while (nr_pages > 0);
 }
 
 /**

--