fuse: implement missing functionality on "direct_io" files

Fuse allows filesystems to bypass the page cache using the "direct_io"
flag.  This is not the same as O_DIRECT, it's dictated by the
filesystem not the application.

Some functionality didn't work in this mode, however.  This short
patchset improves that:

 1. fuse: allow kernel to access "direct_io" files
 2. fuse: allow private mappings of "direct_io" files
 3. splice: implement default splice_read method

The third patch is not fuse specific, it implements ->splice_read()
for any filesystem which doesn't provide one.

Comments are welcome.

Thanks,
Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html