On Fri, Jun 2, 2017 at 3:27 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Fri, Jun 2, 2017 at 8:32 AM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >> On Thu, Jun 1, 2017 at 10:55 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: >>> On Thu, Jun 1, 2017 at 11:02 AM, Amir Goldstein <amir73il@xxxxxxxxx> wrote: >>>> For the case of all layers not on the same fs, use the copy up >>>> origin st_ino/st_dev for non-dir, if we know it. >>>> >>>> This guarantied constant and persistent st_ino/st_dev for non-dir, >>>> but not system-wide uniqueness, like in the same fs case. >>> >>> I'd rather leave this until the st_dev uniqueness is sorted out. Non >>> unique st_ino/st_dev is just asking for trouble. >>> >> >> I don't mind leaving this out, but you do realize that this commit >> doesn't change st_dev/st_ino uniqueness one way or the other, right? > > Depends on how you look at it. > > Before the patch it was (just the non-samefs, non-directory case): > > - if lower: st_ino/st_dev comes from lower > - if upper: st_ino/st_dev comes from upper > > This only violates the uniqueness rule if check+use of st_ino/st_dev > races with the copy up > > After the patch it's: > > - if copied up: st_ino/st_dev comes from origin > - otherwise same as above > > Now the uniqueness is violated for all copied up files (origin and > overlay file will have the same st_ino/st_dev pair even though they > possibly have different contents). > > So that transforms a race into a permanent error, which is not good. > Right. of course. So do you want me to re-post the consistent d_ino for samefs case only? I would like to start posting the index/hardlink patches, so though I would flush out the constino buffer first. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
