On Sun, Nov 30, 2014 at 9:23 AM, Shriramana Sharma <samjnaa@xxxxxxxxx> wrote: > > > Why should noCoW affect cp --reflink anyhow? I just created a 500 MiB > file from /dev/urandom under a chattr +C-ed dir, and copied to another > subvol using cp --reflink, and fi df still shows 500 MiB, not 1 GiB. Looks like I might have spoken too soon (because I've read that some changes aren't visible until the next FS commit) so right now it actually says 1 GiB used, which I can't grok because why should a nocow file be physically copied (to new blocks) just because it's nocow? Is it because it is possible that the two copies are overwritten separately at the same time? But still, it seems to me that mv should make it so that the nocow attr is temporarily (atomically?) suspended/ignored just for the duration of the relocation, since there aren't going to be any two copies to be overwritten at the same time. Comments? -- Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
