Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes: > On Sat, Feb 15, 2014 at 3:23 PM, Eric W. Biederman > <ebiederm@xxxxxxxxxxxx> wrote: >> >> Except that today d_invalidate drops the dcache lock and >> calls shrink_dcache_parent. Which gets you into exactly the same >> complex "walk parents and check all siblings" code. > > Hmm. It only does that for directories that have sub-entries, though. > > I think you may care just about directories (because that's what your > series is about), but d_invalidate() is used for other cases too, > notably d_revalidate() (ie things like stale NFS lookups of normal > files). > > That said, I'll have to think about this more. If d_subdir is empty, I > guess d_walk() will be fairly cheap. It's very different, but maybe > not as disastrous as I thought. Thank you for taking the time to look. It is also very true that I have been mostly focusing on the semantics and correctness rather than on the performance of these changes. I did keep a weather eye on the performance impact of these changes though and as long as we can stand a slow down in the rare case where mount points are present my changes should be fine. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
