RE: [PATCH RFC] introduce ioctl to completely invalidate page cache

quoted

-		fsync_bdev(bdev);
-		invalidate_bdev(bdev);
+		flush_buffer_cache(bdev);
+		if (BLKFLSBUF2 == cmd)
+			return invalidate_inode_pages2(
+					bdev->bd_inode->i_mapping);
 		return 0;

We're currently ignoring the buffer cache sync and invalidation (which is odd),
but at least being consistent would be good.

Might also need a filemap_write_and_wait() to sync before invalidation.

(I've got zero knowledge in this area, so excuse my ignorance!)

Does filemap_write_and_wait() writes back modified, memory-mapped pages? If so, isn't there a race condition? Or have I got it completely wrong?