On 2017/6/19 16:28, Amir Goldstein wrote: > On Mon, Jun 19, 2017 at 10:59 AM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: >> On Mon, Jun 19, 2017 at 6:00 AM, zhangyi (F) <yi.zhang@xxxxxxxxxx> wrote: >> >> I still don't like adding the impure flag because of a whiteout. >> Impure dir means it contains a copied up object. In fact a valid (but >> probably not worthwhile) optimizition would be to remove the impure >> flag on removal of the last copied up object. >> >> What's wrong with testing for (origin || merge) to see if we need to >> check for whiteouts? >> > > Fine by me. > > Yi, > > Please note that you cannot use the test OVL_TYPE_ORIGIN(type) > in ovl_dir_is_real(), because that flag is only set when the lower > dentry is found by lookup. Instead, you should explicitly check for > existence of OVL_XATTR_ORIGIN. > Note that even ovl_get_origin_fh() is too strict, because it discards > empty (unkown) origin, but for your use case, unknown origin is also > candidate to contain whiteouts. > I realize that impure flag is not quite suitable. If we use (origin || merge) to see whether we need to check whiteouts or not, I think we still have a problem. Thought: In my current test case, testdir was copyuped when we delete the test file, so it have OVL_XATTR_ORIGIN (it's OK), but if the testdir is a merged dir originally, it will not be copied up and the OVL_XATTR_ORIGIN will not be set. So, if we want to use (origin || merge), we have to set OVL_XATTR_ORIGIN for the merged parent dir when it create whiteout, any side effects? Thanks, ZhangYi. -- 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
