On Fri, May 01, 2015 at 12:24:13PM -0700, Andy Grover wrote: > Hey, at least it's just a bug and not another API issue. I think it is, see below. > So, TCMU just wants its tcmu_execute_rw called just once, even for BIDI > commands (e.g. COMPARE_AND_WRITE and XDWRITEREAD*) COMPARE_AND_WRITE isn't a bidi command, it's a command that in pratice uses two DATA OUT buffers but partitioning the one available to it. Can you explain why you want this? Right now backends in lio have a very simple abstraction for I/O, why do read and writes and most other things are built ontop of that, with a few exception for "magic" commands like the various discard operations. COMPARE_AND_WRITE is build on top of those basic operations by doing the reads and writes underneath, and providing synchronization in the core. If a backend (that is a non-passthrough) one wants to take control of these we need a specific hook for it instead of trying ot hack it up. I'm not entirely happy with adding this without a new in-kernel user given that we need to get the semantics right. -- To unsubscribe from this list: send the line "unsubscribe target-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
