On Sun, Jan 22, 2017 at 06:19:24PM +0000, Matthew Wilcox wrote: > No, I mean a network filesystem like 9p or cifs or nfs. If the memcpy > is supposed to be performed by the backing device struct backing_dev has no relation to the DAX code. Even more so what's the point of doing a DAXish memcpy in that case? If we buffer in memory for network I/O we should just use the page cache. > (Also, the network filesystem might have a command, like RDMA has/will have, to ensure that the write has reached persistence) I know very well due to my work for a DAX-backed pNFS layout. But that is mostly transparent to the NFS frontend code and won't use DAX on the client at all. Just pagecache as a source for RDMA READ/WRITE. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html