[PATCH] md: make sure bitmap updates are visible through filesystem

When we update a page_cache page in the kernel, we need to flush_dache_page or
userspace might not see the change.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index ee4a342..76a189c 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -315,6 +315,8 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait)
        if (bitmap->file == NULL)
                return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
 
+       flush_dcache_page(page); /* make sure visible to anyone reading the file */
+
        if (wait)
                lock_page(page);
        else {