Messages in this thread | | | Date | Thu, 16 Oct 2014 18:33:31 -0400 | From | Matthew Wilcox <> | Subject | Re: [PATCH v11 07/21] dax,ext2: Replace XIP read and write with DAX I/O |
| |
On Thu, Oct 16, 2014 at 03:51:12PM -0400, Matthew Wilcox wrote: > On Thu, Oct 16, 2014 at 11:50:27AM +0200, Mathieu Desnoyers wrote: > > > + if (rw == WRITE) { > > > + if (!buffer_mapped(bh)) { > > > + retval = -EIO; > > > + /* FIXME: fall back to buffered I/O */ > > > > Fallback on buffered I/O would void guarantee about having data stored > > into persistent memory after write returns. Not sure we actually want > > that. > > Yeah, I think that comment is just stale. I can't see a way in which > buffered I/O would succeed after DAX I/O falis.
On further consideration, I think the whole thing is just foolish. I don't see how get_block(create == 1) can return success *and* a buffer that is !mapped.
So I did this nice simplification:
- if (rw == WRITE) { - if (!buffer_mapped(bh)) { - retval = -EIO; - /* FIXME: fall back to buffered I/O */ - break; - } - hole = false; - } else { - hole = !buffer_written(bh); - } + hole = (rw != WRITE) && !buffer_written(bh);
(compile-tested only; I'm going to run all the changes through xfstests next week when I'm back home before sending out a v12).
| |