On Thu, Jan 18, 2018 at 4:24 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > On Wed, Nov 29, 2017 at 10:54:47AM -0500, Vivek Goyal wrote: >> If file is metacopy only, it is possible that lower is encrypted while >> other is not. In that case, report file as encrypted (despite the fact >> that only data is encrypted while metadata is not). >> >> Similarly if lower is compressed, report that in stat for a metacopy >> only file. >> > > Hi Amir, > > Thinking more about this patch. Taking union of lower and upper attributes > (encryption and compressed) does not feel right. > > Right now if lower is compressed and upper is not (metacopy), then we will > report file as compressed. But if lower is not compressed while upper is, > still we will report file as compressed. So there is an anomaly here. > > I think, compression and encryption primarily represent the data state. > So always report the state from inode which has file data (lower). And > don't take union with upper metacopy only inode. Because state in > upper inode does not matter till data is copied up. > > This will also simplify my implementation when supporting metacopy in > middle layer. That way I don't have to do getattr() on all intermediate > metacopy inodes in the chain and take a union. Instead I can go to lowest > most data inode and take encryption and compression attributes from there. > > I am not sure why did we decide to take union of lower and upper attrs. > Right now it does not seem to make sense to me. > Now I am not sure either. I suspect that userspace may need the ability to know if a file is encrypted, but I can't say for sure. If you want to know better ask the developers that work of fs/crypto. I don't mind if you leave this patch out. Cheers, 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
