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. > Thanks. > -- With best wishes, Vladimir -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/