From: Benjamin LaHaise <bcrl@kvack.org>
To: Matthew Wilcox <willy@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>,
viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
linux-aio@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] aio: Fix type of iterator variable in do_io_submit()
Date: Wed, 23 Apr 2014 10:42:37 -0400 [thread overview]
Message-ID: <20140423144237.GY22552@kvack.org> (raw)
In-Reply-To: <20140423141617.GE13050@linux.intel.com>
On Wed, Apr 23, 2014 at 10:16:17AM -0400, Matthew Wilcox wrote:
> On Tue, Apr 22, 2014 at 05:57:03PM -0500, Eric Biggers wrote:
> > do_io_submit() iterated over the userspace iocb structure pointers using
> > a variable i of type 'int'. This was wrong since 'nr', the number of
> > iocb structure pointers, could potentially be up to LONG_MAX /
> > sizeof(struct iocb *). Fix it (and also remove the unnecessary
> > initialization to 0).
>
> You're not wrong, but do we *really* want users to be able to submit
> 144115188075855872 I/Os with a single system call? How about limiting
> them to a single billion? Given that they have to allocate 64GB of
> *control* data structures to submit this many I/Os, I think this will
> be sufficient for many years to come.
Practically speaking, this change has no effect. The io_submit() syscall
will exit far before we even hit INT_MAX because of the limits on the
number of iocbs.
-ben
--
"Thought is the essence of where you are now."
next prev parent reply other threads:[~2014-04-23 14:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-22 22:57 [PATCH] aio: Fix type of iterator variable in do_io_submit() Eric Biggers
2014-04-23 14:16 ` Matthew Wilcox
2014-04-23 14:42 ` Benjamin LaHaise [this message]
2014-04-23 15:24 ` Eric Biggers
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