On Fri, Jan 24, 2020 at 10:12:54AM -0800, Eric Biggers wrote: > > Thanks for your web reference, I will look into it. I think there > > is no worry about dentry->d_parent here because of this only one > > dereference on dentry->d_parent. > > > > You could ignore my words anyway, just my little thought though. > > Other part of the patch is ok. > > > > While that does make it really unlikely to cause a real-world problem, it's > still undefined behavior to not properly annotate a data race, it would make the > code harder to understand as there would be no indication that there's a data > race, and it would confuse tools that try to automatically detect data races. > So let's keep the READ_ONCE() on d_parent. *nod* Note that on everything except alpha it'll generate the same code, unless the compiler screws up an generates multiple loads. On alpha it adds a barrier and I really don't want to sit down and check if its absense could lead to anything unpleasant.
