On Tue, Aug 12 2008, David Woodhouse wrote: > On Tue, 2008-08-12 at 12:16 +0100, David Woodhouse wrote: > > There's a check in __make_request() which will return -EOPNOTSUPP for > > bios with BIO_RW_BARRIER set, in some circumstances. Is that OK too? > > A: No, it breaks submission of DISCARD|BARRIER requests. And I have to > change blk_empty_barrier() to explicitly omit discards too, to avoid the > check at line 1419 (in __generic_make_request()) returning -EOPNOTSUPP > before we even get there. > > Using BIO_RW_BARRIER seems conceptually cleaner, but in practice it's > messier. I think this version will work, but I'm inclined to prefer the > previous one I posted, using the R/W bit. Or just match the check before -EOPNOTSUPP with bio_has_data(), since it only applies to a barrier that carries data. -- Jens Axboe -- 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
