On Tue, Oct 04, 2016 at 10:02:31AM -0400, Theodore Ts'o wrote: > On Tue, Oct 04, 2016 at 11:00:41AM +0200, Jan Kara wrote: > > Never seen this but I suspect it is a fallout from Al's directory locking > > changes. In particular ext4_htree_fill_tree() builds rb-tree of found > > directory entries in file->private_data (and generally modifies the > > structure stored there) but after Al's changes we don't have exclusive > > access to struct file if I'm right so if two processes end up calling > > getdents() for the same 'struct file' we are doomed. > > I haven't seen it either, and I've been doing a lot of testing on the > ext4 test branch. So I'm guessing Tony has the only reliable repro > for the problem at the moment. That being said, it shouldn't be that > hard to create a test case for this and add it to xfstests. > > I'm pretty sure Jan is right about this, though, but it would be great > to a get a quick confirmation from Tony if at all possible. Jan is wrong - we do have per-struct-file serialization for getdents() et.al. It might be a race between getdents() on *different* struct file for the same directory, but ->private_data is not a problem. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
