Re: [patch] remove artificial software max_loop limit

[Bill Davidsen <davidsen@tmr.com>]

Jan Engelhardt wrote:
> On Apr 1 2007 11:10, Ken Chen wrote:
>> On 4/1/07, Tomas M <tomas@slax.org> wrote:
>>
>>> I believe that IF you _really_ need to preserve the max_loop module 
>>> parameter, then the parameter should _not_ be ignored, rather it 
>>> should have the same function like before - to limit the loop driver 
>>> so if you use max_loop=10 for example, it should not allow loop.c to 
>>> create more than 10 loops.
>> Blame on the dual meaning of max_loop that it uses currently: to 
>> initialize a set of loop devices and as a side effect, it also sets 
>> the upper limit.  People are complaining about the former constrain, 
>> isn't it?  Does anyone uses the 2nd meaning of upper limit?
> 
> Who cares if the user specifies max_loop=8 but still is able to open up 
> /dev/loop8, loop9, etc.? max_loop=X basically meant (at least to me) 
> "have at least X" loops ready.
> 
You have just come up with a really good reason not to do unlimited 
loops. With the current limit people can count on a script mounting 
files, or similar, to neither loop for a VERY long time or to eat their 
memory. Whatever you think of programs without limit checking, this 
falls in the range of expecting an unsigned char to have a certain upper 
bound, and argues that the default limit should be the current limit and 
that setting a lower bound should work as a real and enforced limit.

If a new capability is being added, and I think it's a great one, then 
people using the capability should be the ones explicitly doing 
something different. Plauger's law of least astonishment.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot