In message <84144f020710150447o94b1babo8b6e6a647828465f@xxxxxxxxxxxxxx>, "Pekka Enberg" writes: > Hi, > > On 10/15/07, Erez Zadok <ezk@xxxxxxxxxxxxx> wrote: > > Pekka, with a small change to your patch (to handle time-based cache > > coherency), your patch worked well and passed all my tests. Thanks. > > > > So now I wonder if we still need the patch to prevent AOP_WRITEPAGE_ACTIVATE > > from being returned to userland. I guess we still need it, b/c even with > > your patch, generic_writepages() can return AOP_WRITEPAGE_ACTIVATE back to > > the VFS and we need to ensure that doesn't "leak" outside the kernel. > > I wonder whether _not setting_ BDI_CAP_NO_WRITEBACK implies that > ->writepage() will never return AOP_WRITEPAGE_ACTIVATE for > !wbc->for_reclaim case which would explain why we haven't hit this bug > before. Hugh, Andrew? > > And btw, I think we need to fix ecryptfs too. Yes, ecryptfs needs this fix too (and probably a couple of other mmap fixes I've made to unionfs recently -- Mike Halcrow already knows :-) Of course, running ecryptfs on top of tmpfs is somewhat odd and uncommon; but with unionfs, users use tmpfs as the copyup branch very often. > Pekka Erez. - 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
