On Wed, Mar 28, 2018 at 10:43 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > On Wed, Mar 07, 2018 at 03:37:10PM +0200, Amir Goldstein wrote: >> On Wed, Mar 7, 2018 at 3:21 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: >> > On Wed, Mar 07, 2018 at 09:07:22AM +0200, Amir Goldstein wrote: >> >> On Tue, Mar 6, 2018 at 10:54 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: >> >> > With the addition of an origin chain for regular files, it is possible >> >> > that we don't have an upperdentry and oe->numlower > 1 for non-dir. So >> >> > mark a path __OVL_TYPE_MERGE only if it is a directory. >> >> > >> >> >> >> Okay, but what's wrong with marking a non-dir as TYPE MERGE? >> >> It is, after all, a sort of merged entry. >> > >> > Conceptually, I can't think of anything wrong. Just that currently we use >> > MERGE in the context of directory and we don't need it in the context of >> > non-dir. So this is just trying to be safe to make sure not to break any >> > existing code. >> > >> > I guess we could mark metacopy regular files as MERGE as well, if need be. >> > But that could be part of a separate patch series where we could run >> > various tests and make sure nothing is broken. >> > >> >> I did a quick scan on all uses of OVL_TYPE_MERGE() they >> all have is_dir check in front of them or checked on a parent object. >> >> In fact, in the case of ovl_rename(), for directory, the test is >> if (ovl_type_merge_or_lower(old)) >> err = ovl_set_redirect(old, samedir); >> >> >> You could have removed the is_dir condition before this code instead >> of adding a different case for is_metacopy, although you did use a different >> argument for samedir in the metacopy case... > > Hi Amir, > > I am looking into merging code path for dir and non-dir. What I can't > understand is that why do we check for "ovl_type_merge_or_lower()" and > not just "ovl_type_merge()"? > > By now, "old" dentry has been copied up anyway. So no point is checking > if this is lower or not? It will always be "upper"? > > What am I missing? > I don;t think you are not missing anything. Maybe its a relic from the past. Only the use of ovl_type_merge_or_lower() in ovl_can_move() is really needed. 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
