Messages in this thread |  | | Date | Sun, 20 May 2001 11:23:51 +0100 | From | Russell King <> | Subject | Re: [RFD w/info-PATCH] device arguments from lookup, partion code |
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On Sat, May 19, 2001 at 08:26:20PM -0700, Linus Torvalds wrote: > You're missing the point.
I don't think Richard is actually. I think Richard has hit a nail dead on its head.
> It's ok to do "read()/write()" on structures.
Ok, we can read()/write() structures. So someone invents the following structure:
struct foo { int cmd; void *data; } foo;
Now they use write(fd, &foo, sizeof(foo)); Haven't they just swapped the ioctl() interface for write() instead?
Ok, lets hope that humanity isn't that stupid, so lets take another example:
struct bar { int in_size; void *in_data; int out_size; void *out_data; };
struct foo { int cmd; struct bar1; } foo;
Same write call, but ok, we have a structure of known size. Its still the same problem.
What I'm trying to say is that I think that read+write is open to more or the same abuse that ioctl has been, not less.
However, it does have one good thing going for it - you can support poll on blocking "ioctls" like TIOCMIWAIT.
> None of which are "network-nice". Basically, ioctl() is historically used > as a "pass any crap into driver xxxx, and the driver - and ONLY the driver > - will know what to do with it".
I still see read()/write() being a "pass any crap" interface. The implementer of the target for read()/write() will probably still be a driver which will need to decode what its given, whether its in ASCII or binary.
And driver writers are already used to writing ioctl-like interfaces.
-- Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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