On Thu, 26 Jun 2025, Amir Goldstein wrote: > On Wed, Jun 25, 2025 at 1:07 AM NeilBrown <neil@xxxxxxxxxx> wrote: > > > > This series of patches for overlayfs is primarily focussed on preparing > > for some proposed changes to directory locking. In the new scheme we > > wil lock individual dentries in a directory rather than the whole > > directory. > > > > ovl currently will sometimes lock a directory on the upper filesystem > > and do a few different things while holding the lock. This is > > incompatible with the new scheme. > > > > This series narrows the region of code protected by the directory lock, > > taking it multiple times when necessary. This theoretically open up the > > possibilty of other changes happening on the upper filesytem between the > > unlock and the lock. To some extent the patches guard against that by > > checking the dentries still have the expect parent after retaking the > > lock. In general, I think ovl would have trouble if upperfs were being > > changed independantly, and I don't think the changes here increase the > > problem in any important way. > > > > The first patch in this series doesn't exactly match the above, but it > > does relate to directory locking and I think it is a sensible > > simplificaiton. > > > > I have tested this with fstests, both generic and unionfs tests. I > > wouldn't be surprised if I missed something though, so please review > > carefully. > > Can you share a git branch for me to pull and test? My current work tree can be found at https://github.com/neilbrown/linux/tree/pdirops or branch "pdirops" of https://github.com/neilbrown/linux.git Thanks for the thorough review - I'll work through it and respond over coming days. Thanks, NeilBrown
