> The "at least" idea makes sense. So, I'd change my recommendation to: > > Pass the buffer size in and out in bytes (for consistency with other > APIs). Round the input (F_SETPIPE_SZ) value up as required by the > implementation. For the output (F_GETPIPE_SZ) value do one of the > following: > a) Return the value given on input. > b) Return the rounded up value actually used by the kernel. > > I suspect (b) might be more useful: if an application cares enough > about pipe size to want to change it, then at least some such > applications might care to know exactly the size that the kernel used. > (And: I can't see any downside to (b).) b definitely, since it's the real size (plus then we don't have to track the passed in size). > One other comment about the interface. We have > > if (!capable(CAP_SYS_ADMIN) && arg > pipe_max_pages) > return -EINVAL; > > The usual error on a capability denied is EPERM. Please change. Right, that looks like a thinko. I'll submit a patch changing it to bytes and the agreed API and fix this -Eerror. Thanks for your comments and suggestions! -- 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
