On Wed, Dec 01, 2010 at 03:09:52PM -0500, Josef Bacik wrote: > On Wed, Dec 01, 2010 at 03:00:08PM -0500, J. Bruce Fields wrote: > > On Wed, Dec 01, 2010 at 02:54:33PM -0500, Josef Bacik wrote: > > > Oh well crud, I was hoping that I could leave the inode numbers as 256 for > > > everything, but I forgot about readdir. So the inode item in the parent would > > > have to have a unique inode number that would get spit out in readdir, but then > > > if we stat'ed the directory we'd get 256 for the inode number. Oh well, > > > incompat flag it is then. > > > > I think you're already fine: > > > > # mkdir TMP > > # dd if=/dev/zero of=TMP-image bs=1M count=512 > > # mkfs.btrfs TMP-image > > # mount -oloop TMP-image TMP/ > > # btrfs subvolume create sub-a > > # btrfs subvolume create sub-b > > ../readdir-inos . > > . 256 256 > > .. 256 4130609 > > sub-a 256 256 > > sub-b 257 256 > > > > Where readdir-inos is my silly test program below, and the first number is from > > readdir, the second from stat. > > > > Heh as soon as I typed my email I went and actually looked at the code, looks > like for readdir we fill in the root id, which will be unique, so hotdamn we are > good and I don't have to use a stupid incompat flag. Thanks for checking that > :), My only complaint was just about how you said this: "When you create a subvolume, the directory inode that is created in the parent subvolume has the inode number of 256" If you revise that you might want to clarify. (Maybe "Every subvolume has a root directory inode with inode number 256"?) The way you've stated it sounds like you're talking about the readdir-returned number, which would normally come from the inode that has been covered up by the mount, and which really is an inode in the parent filesystem.... --b. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
