From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephane Chazelas Subject: Re: strange btrfs sub list output Date: Fri, 27 May 2011 09:01:57 +0100 Message-ID: References: <20110526212203.GA4611@yahoo.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <20110526212203.GA4611@yahoo.fr> List-ID: 2011-05-26 22:22:03 +0100, Stephane Chazelas: [...] > I get a btrfs sub list output that I don't understand: > > # btrfs sub list /backup/ > ID 257 top level 5 path u1/linux/lvm+btrfs/storage/data/data > ID 260 top level 5 path u2/linux/lvm/linux/var/data > ID 262 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-10-11 > ID 263 top level 5 path u2/linux/lvm/linux/home/snapshots/2011-04-07 > ID 264 top level 5 path u2/linux/lvm/linux/root/snapshots/2011-04-07 > ID 265 top level 5 path u2/linux/lvm/linux/var/snapshots/2011-04-07 > ID 266 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-10-26 > ID 267 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-11-08 > ID 268 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-11-22 > ID 269 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-12-15 > ID 270 top level 5 path u2/linux/lvm/linux/home/snapshots/2011-04-14 > ID 271 top level 5 path u2/linux/lvm/linux/root/snapshots/2011-04-14 > ID 272 top level 5 path u2/linux/lvm/linux/var/snapshots/2011-04-14 > ID 273 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2010-12-29 > ID 274 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2011-01-26 > ID 275 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2011-03-07 > ID 276 top level 5 path u1/linux/lvm+btrfs/storage/data/snapshots/2011-04-01 > ID 277 top level 5 path u2/linux/lvm/linux/home/data > ID 278 top level 5 path u2/linux/lvm/linux/home/snapshots/2011-04-27 > ID 279 top level 5 path u2/linux/lvm/linux/root/snapshots/2011-04-27 > ID 280 top level 5 path u2/linux/lvm/linux/var/snapshots/2011-04-27 > ID 281 top level 5 path u3:10022/vm+xfs@u9/xvda1/g1/v4/data > ID 282 top level 5 path u3:10022/vm+xfs@u9/xvda1/g1/v4/snapshots/2011-05-19 > ID 283 top level 5 path u5/vm+xfs@u9/xvda1/g1/v5/data > ID 284 top level 5 path u6:10022/vm+xfs@u8/xvda1/g8/v3/data > ID 286 top level 5 path u5/vm+xfs@u9/xvda1/g1/v5/snapshots/2011-05-24 > ID 287 top level 285 path data > ID 288 top level 5 path u4/vm+xfs@u9/xvda1/g1/v1/data > ID 289 top level 5 path u4/vm+xfs@u9/xvda1/g1/v1/snapshots/2011-03-11 > ID 290 top level 5 path u4/vm+xfs@u9/xvda1/g1/v2/data > ID 291 top level 5 path u4/vm+xfs@u9/xvda1/g1/v2/snapshots/2011-05-11 > ID 292 top level 5 path u4/vm+xfs@u9/xvda1/g1/v1/snapshots/2011-05-11 [...] > There is no "/backup/data" directory. There is however a > /backup/u6:10022/vm+xfs@u8/xvda1/g8/v3/snapshots/2011-03-30 that > contains the same thing as what I get if I mount the fs with > subvolid=287. And I did do a btrfs sub snap data > snapshots/2011-03/30 there. > > What could be the cause of that? How to fix it? > > In case that matters, there used to be more components in the > path of u6:10022/vm+xfs@u8/xvda1/g8/v3/data. [...] I tried deleting the /backup/u6:10022/vm+xfs@u8/xvda1/g8/v3/snapshots/2011-03-30 subvolume (what seems to be id 287) and I get: # btrfs sub delete snapshots/2011-03-30 Delete subvolume '/backup/u6:10022/vm+xfs@u8/xvda1/g8/v3/snapshots/2011-03-30' ERROR: cannot delete '/backup/u6:10022/vm+xfs@u8/xvda1/g8/v3/snapshots/2011-03-30' With a strace, it tells me: ioctl(3, 0x5000940f, 0x7fffc7841a80) = -1 ENOTEMPTY (Directory not empty) Then I realised that there was a "data" directory in there and that snapshots/2011-03-30 was actually id 285 (which doesn't appear in the btrfs sub list) and "snapshots/2011-03-30/data" is id 287. What do those top-level IDs mean by the way? Then I was able to delete snapshots/2011-03-30/data, but snapshots/2011-03-30 still didn't appear in the list. Then I was able to delete snapshots/2011-03-30 and recreate it, and this time it was fine. Still don't know what happened there. -- Stephane