On Thu, May 20 2010, Miklos Szeredi wrote: > On Wed, 19 May 2010, Jens Axboe wrote: > > On Wed, May 19 2010, Jens Axboe wrote: > > > On Wed, May 19 2010, Linus Torvalds wrote: > > > > > > > > > > > > On Wed, 19 May 2010, Miklos Szeredi wrote: > > > > > > > > > > One issue I see is that it's possible to grow pipes indefinitely. > > > > > Should this be restricted to privileged users? > > > > > > > > Yes. But perhaps only if it grows past the default (or perhaps "default*2" > > > > or similar). That way a normal user could shrink the pipe buffers, and > > > > then grow them again if he wants to. > > > > > > That's still a bit arbitrary, I don't think allowing default*2 only for > > > non-root is going to be hugely interesting. But limiting makes sense, > > > but lets at least allow a larger max limit for the normal user. I'm > > > suspecting that the media application that wants to use this will not be > > > running as root, and we don't make the feature properly available to the > > > ones that want to use it, then we may as well not do it. > > > > > > Or we could expose a sysctl for instance that holds the max non-root > > > size. And make that default to default*16 or something. How does that > > > sound? > > > > > > > Oh, and I think you need to also require that there be at least two > > > > buffers. Otherwise we can't guarantee POSIX behavior, I think. > > > > > > Good point, and at least that part is easily doable :-) > > > > So I updated the patch, that branch was pretty ancient... The fcntl pipe > > numbers were also screwed up, so got that fixed. New patch is here: > > > > http://git.kernel.dk/?p=linux-2.6-block.git;a=commit;h=23dcb845246946aeda5a5e398c6911381ad28365 > > Not sure why you didn't take my updated patch. Yours misses > conversion of kernel/trace/trace.c as well as some hunks below (that > renaming the "pages" and "partial" arrays and a compile test would > have revealed). Sorry, I missed that you had done extra changes. I had to rebase the whole thing anyway, and as I said it was totally untested. I'll get it updated. The main reason I didn't push it before is that I wasn't completely sure that we wanted to use fcntl() for this. But Linus doesn't seem to object on that side at least. -- 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
