From mboxrd@z Thu Jan 1 00:00:00 1970 From: Calvin Walton Subject: Re: Problems with set-default, home subvolume and snapshot Date: Tue, 06 Sep 2011 08:16:18 -0400 Message-ID: <1315311380.2530.6.camel@ayu> References: <20110905130742.GA4756@zambezi.lan> <4E64E026.4020009@cyberphoria.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-btrfs@vger.kernel.org To: =?ISO-8859-1?Q?Bj=F6rn?= Kalkbrenner Return-path: In-Reply-To: <4E64E026.4020009@cyberphoria.org> List-ID: On Mon, 2011-09-05 at 16:43 +0200, Bj=C3=B6rn Kalkbrenner wrote: > Hi Ilya, >=20 > Am 05.09.2011 15:07, schrieb Ilya Dryomov: > > Well, it's *sort of* expected if you think about it. When you mount= ed > > after set-default, your /home is no longer a valid subvolume access > > point (it was in the default subvolume, until you rebooted). Inside > > your snapshot /home is just an empty directory (there's more to it, > > that's why you can't delete it, but that's irrelevant here). Howeve= r > > if you mount with subvolid=3D, you point to a subvolume > > directly, skipping the lookup (which leads to an empty dir if you a= re > > inside your snapshot). That's why it works when you use the subvoli= d. > > We should probably tune the lookup to make subvol=3D work in this c= ase.=20 >=20 > Ah, thank you very much, that sounds logical with the lookup table an= d > the - not valid access point - BUT: >=20 > Why could i still manually "mount -o subvol=3Dhome /dev/mapper/root /= home" > and home was just empty but mounted (i looked at the mount table outp= ut)? > Shouldn't that give me an error that home can't be found in the looku= p > table? This is actually because of how the subvolume mounting works internally= =2E It turns out that currently, the command mount -o subvol=3Dhome /dev/mapper/root /home effectively does the same thing as mount /dev/mapper/root /home # Mount the "default" subvolume mount --bind /home/home /home # Switch to the "home" subvolume which of course succeeds if /home in your default subvolume is an empty directory. Hopefully this can be improved at some point :) --=20 Calvin Walton -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html