Re: [PATCH] mm: fix page_mkclean_one

[Guillaume Chazarain <guichaz@yahoo.fr>]

Guillaume Chazarain a écrit :
> I get this kind of corruption: 
> http://guichaz.free.fr/linux-bug/corruption.png

Actually in qemu, I get three different behaviours:
- no corruption at all : with linux-2.4
- corruption only on the first chunks: before  [PATCH] mm: balance dirty 
pages as identified by Kenneth
- corruption of all chunks: after the balance dirty pages patch

Bisecting in linux-2.5 land I found 
http://kernel.org/pub/linux/kernel/people/akpm/patches/2.5/2.5.66/2.5.66-mm3/broken-out/fadvise-flush-data.patch 
to cause the corruption for me.

The attached patch fixes the corruption for me.

--
Guillaume

diff -r 3859b1144d3a mm/fadvise.c
--- a/mm/fadvise.c	Sun Dec 24 05:00:03 2006 +0000
+++ b/mm/fadvise.c	Thu Dec 28 19:53:40 2006 +0100
@@ -96,9 +96,6 @@ asmlinkage long sys_fadvise64_64(int fd,
 	case POSIX_FADV_NOREUSE:
 		break;
 	case POSIX_FADV_DONTNEED:
-		if (!bdi_write_congested(mapping->backing_dev_info))
-			filemap_flush(mapping);
-
 		/* First and last FULL page! */
 		start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
 		end_index = (endbyte >> PAGE_CACHE_SHIFT);