mm: do_sync_mapping_range integrity fix

Chris Mason notices do_sync_mapping_range didn't actually ask for data
integrity writeout.  Unfortunately, it is advertised as being usable for
data integrity operations.

This is a data integrity bug.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/sync.c

@@ -295,7 +295,7 @@ int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
 
 	if (flags & SYNC_FILE_RANGE_WRITE) {
 		ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
-						WB_SYNC_NONE);
+						WB_SYNC_ALL);
 		if (ret < 0)
 			goto out;
 	}