From: Phillip Susi <psusi@ubuntu.com>
To: kreijack@inwind.it, Austin S Hemmelgarn <ahferroin7@gmail.com>,
Anand Jain <Anand.Jain@oracle.com>,
MegaBrutal <megabrutal@gmail.com>,
linux-btrfs <linux-btrfs@vger.kernel.org>
Cc: Robert White <rwhite@pobox.com>, Chris Mason <clm@fb.com>
Subject: Re: PROBLEM: #89121 BTRFS mixes up mounted devices with their snapshots
Date: Wed, 03 Dec 2014 22:09:29 -0500 [thread overview]
Message-ID: <547FD069.5050407@ubuntu.com> (raw)
In-Reply-To: <547EC8B5.1060002@inwind.it>
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On 12/03/2014 03:24 AM, Goffredo Baroncelli wrote:
> I am thinking about that. Today the device discovery happens: a)
> when a device appears, two udev rules run "btrfs dev scan
> <device>"
>
> /lib/udev/rules.d/70-btrfs.rules
> /lib/udev/rules.d/80-btrfs-lvm.rules
>
> b) during the boot it is ran a "btrfs device scan", which scan all
> the device (this happens in debian for other distros may be
> different)
>
> c) after a btrfs.mkfs, which starts a device scan on each devices
> of the new filesystem
>
> d) by the user
Are you sure the kernel only gains awareness of btrfs volumes when
user space runs btrfs device scan? If that is so then that means you
can not boot from a multi device btrfs root without using an
initramfs. I thought the kernel auto scanned all devices if you tried
to mount a multi device volume, but if this is so, then yes, the udev
rules could be fixed to not call btrfs device scan on an lvm snapshot.
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next prev parent reply other threads:[~2014-12-04 3:10 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-01 12:56 PROBLEM: #89121 BTRFS mixes up mounted devices with their snapshots MegaBrutal
2014-12-01 17:27 ` Robert White
2014-12-01 22:10 ` MegaBrutal
2014-12-01 23:24 ` Robert White
2014-12-02 0:15 ` MegaBrutal
2014-12-02 7:50 ` Goffredo Baroncelli
2014-12-02 8:28 ` MegaBrutal
2014-12-02 11:14 ` Goffredo Baroncelli
2014-12-02 11:54 ` Anand Jain
2014-12-02 12:23 ` Austin S Hemmelgarn
2014-12-02 19:11 ` Phillip Susi
2014-12-03 8:24 ` Goffredo Baroncelli
2014-12-04 3:09 ` Phillip Susi [this message]
2014-12-04 5:15 ` Duncan
2014-12-04 8:20 ` MegaBrutal
2014-12-04 13:14 ` Duncan
2014-12-02 19:14 ` Phillip Susi
2014-12-08 0:05 ` Konstantin
2014-12-01 21:45 ` Konstantin
2014-12-02 5:47 ` MegaBrutal
2014-12-02 19:19 ` Phillip Susi
2014-12-03 3:01 ` Russell Coker
2014-12-08 0:32 ` Konstantin
2014-12-08 14:59 ` Phillip Susi
2014-12-08 22:25 ` Konstantin
2014-12-09 16:04 ` Phillip Susi
2014-12-10 3:10 ` Anand Jain
2014-12-10 15:57 ` Phillip Susi
2014-12-08 17:20 ` Robert White
2014-12-08 22:38 ` Konstantin
2014-12-08 23:17 ` Robert White
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