Messages in this thread | | | Date | Sun, 24 May 2015 20:07:09 -0400 | From | Tejun Heo <> | Subject | Re: [PATCH] fs: sysfs: don't pass count == 0 to bin file readers |
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On Fri, May 22, 2015 at 03:46:51AM +0300, Vladimir Zapolskiy wrote: > Hello Tejun, > > On 22.05.2015 02:26, Tejun Heo wrote: > > Hello, Vladimir. > > > > On Fri, May 22, 2015 at 02:04:31AM +0300, Vladimir Zapolskiy wrote: > >> But "!size" is a special case, > >> > >> if (!count || pos >= size) > >> return 0; > >> > >> seems to be incorrect in case of !size ===> (pos >= size) == true. > > > > Hmmm... Why is that wrong tho? If size is zero and pos is zero, > > there's nothing to do, no? > > positive size value in the context means the fixed exact length of the > file and if size == 0, then it represents some undefined size, often > dynamic in runtime. So, if size is zero and pos is zero it stands for > reading from the beginning of the file as many bytes as allowed by > battr->read() realization. This special case is utilized by quite many > bin_attribute users, probably more than half of them set .size to 0.
Ah, right, I completely forgot about that. Please feel free to add
Acked-by: Tejun Heo <tj@kernel.org>
to the original patch.
Thanks for the patience.
-- tejun
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