:: Re: [DNG] For all you automounter p…
Top Page
Delete this message
Reply to this message
Author: Jim Murphy
To: Didier Kryn, dng
Subject: Re: [DNG] For all you automounter programmers
On Tue, May 3, 2016 at 7:28 AM, Didier Kryn <kryn@???> wrote:
> Le 03/05/2016 14:06, Jim Murphy a écrit :
>> On Tue, May 3, 2016 at 4:04 AM, Didier Kryn<kryn@???> wrote:
>>> Le 02/05/2016 14:12, fsmithred a écrit :
>>>> No support for file system labels at this time. If someone can tell me a
>>>> reliable way for unprivileged user to get the labels, I'll add it. Feel
>>>> free to use these scripts as they are or as motivation to create
>>>> something
>>>> better.
>>>> -fsr
>>>> On 04/28/2016 01:52 PM, fsmithred wrote:
>>>>> On 04/27/2016 08:28 PM, fsmithred wrote:
>>>>>> You could get the label from lsblk, do 'pmount label' and it will be
>>>>>> mounted at /media/label. Every time you plug in a thumb drive labeled
>>>>>> backup, it'll go to the same place. If you unmount the drive,
>>>>>> /media/label
>>>>>> will no longer exist, so you could even have the backup script check
>>>>>> to
>>>>>> make sure it's there.
>>>>>> -fsr
>>>>> Correction - Only root can get the label from lsblk. User can get the
>>>>> label from '/sbin/blkid -s LABEL', but only after root has run blkid at
>>>>> least once. Other than that, I've now got a script that will handle the
>>>>> labels... sometimes.
>>>>> -fsr
>>> kryn@apcnb98:~$ /sbin/blkid /dev/sda5
>>> /dev/sda5: LABEL="/" UUID="d91acaa3-5fdc-49e9-9f2b-ba7f3efb33f9"
>>> UUID_SUB="6a0c80cd-5dc6-4135-8018-575686e7e11e" TYPE="btrfs"
>>> kryn@apcnb98:~$ /sbin/blkid /dev/sda6
>>> /dev/sda6: LABEL="/usr" UUID="05f9f811-b8b1-445f-ac8c-9537a202a9f9"
>>> UUID_SUB="52b8e1b8-7080-4696-94e1-8f7580005871" TYPE="btrfs"
>>>      Didier

>> Problem, blkid uses a cache that is only updated when root runs blkid.
>> Any changes are not automatically updated. A user only sees the cache.
>> The issues is, fsr is trying to do everything as a "user" so tools like
>> lsblk and blkid don't work for this case. For blkid, the cache will not
>> be up to date when say a flash-drive is add/or removed.
>> Jim
>     I cannot reproduce what you describe. I just tried it with a usb stick:
> kryn@apcnb98:~$ /sbin/blkid /dev/sdb2
> /dev/sdb2: LABEL="Didier-Kryn-2" UUID="64f73abe-34b9-4d4c-bac7-6dd85f0e4696"
> TYPE="reiserfs"

>     This was done on debian-wheezy, from the console, without any DE
> running, and even display manager stopped, and after a fresh reboot. If
> blkid, invoked by normal user, runs from cache, then it means it has been
> invoked by root after insertion - I suspect udev and consider it a good
> thing, and I can tell you that vdev does systematically invoke blkid for
> every block device.

>     Didier


Not sure where the change took place, wheezy is 2.20, I'm look at 2.25 right
now on grm(rebuild my other system right now)l and there has been changes.
Not sure why they changed it. Even the man page states you have to be root
to update the cache. fsr is reporting the same issue. You are correct on
wheezy it does appear to work.