* find snapshot parent?
@ 2019-07-06 15:53 Ulli Horlacher
2019-07-06 16:57 ` Nikolay Borisov
2019-07-06 23:24 ` Ulli Horlacher
0 siblings, 2 replies; 10+ messages in thread
From: Ulli Horlacher @ 2019-07-06 15:53 UTC (permalink / raw)
To: linux-btrfs
Is there a standard way to find the path of the subvolume parent of a
snapshot?
For example:
root@xerus:/test# btrfs sub list /test
ID 269 gen 9818 top level 5 path tux/test
ID 1026 gen 9804 top level 1011 path tmp/xx/ss1
ID 1027 gen 9804 top level 1011 path tmp/xx/ss2
root@xerus:/test# btrfs subvolume show /test/tmp
/test/tmp
Name: tmp
UUID: 5a873eca-9b6c-fc4e-aed5-eb287839d693
Parent UUID: -
Received UUID: -
Creation time: 2019-07-04 00:17:11 +0200
Subvolume ID: 1011
Generation: 9813
Gen at creation: 9749
Parent ID: 5
Top level ID: 5
Flags: -
Snapshot(s):
xx/ss1
xx/ss2
root@xerus:/test# btrfs subvolume show /test/tmp/xx/ss1
/test/tmp/xx/ss1
Name: ss1
UUID: 3641bb81-d1fd-4440-8f29-6f17ff9ec4e1
Parent UUID: 5a873eca-9b6c-fc4e-aed5-eb287839d693
Received UUID: -
Creation time: 2019-07-05 11:13:15 +0200
Subvolume ID: 1026
Generation: 9804
Gen at creation: 9793
Parent ID: 1011
Top level ID: 1011
Flags: readonly
Snapshot(s):
Must I call "btrfs subvolume show" for every subvolume to find the
matching Parent ID/UUID or parse the "Snapshot(s)" section?
And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
Do all snapshots have a "Parent UUID" and regular subvolumes not?
--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<20190706155353.GA13656@tik.uni-stuttgart.de>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: find snapshot parent?
2019-07-06 15:53 find snapshot parent? Ulli Horlacher
@ 2019-07-06 16:57 ` Nikolay Borisov
2019-07-06 20:43 ` Ulli Horlacher
2019-07-06 23:24 ` Ulli Horlacher
1 sibling, 1 reply; 10+ messages in thread
From: Nikolay Borisov @ 2019-07-06 16:57 UTC (permalink / raw)
To: linux-btrfs
On 6.07.19 г. 18:53 ч., Ulli Horlacher wrote:
> Is there a standard way to find the path of the subvolume parent of a
> snapshot?
>
> For example:
>
> root@xerus:/test# btrfs sub list /test
> ID 269 gen 9818 top level 5 path tux/test
> ID 1026 gen 9804 top level 1011 path tmp/xx/ss1
> ID 1027 gen 9804 top level 1011 path tmp/xx/ss2
>
> root@xerus:/test# btrfs subvolume show /test/tmp
> /test/tmp
> Name: tmp
> UUID: 5a873eca-9b6c-fc4e-aed5-eb287839d693
> Parent UUID: -
> Received UUID: -
> Creation time: 2019-07-04 00:17:11 +0200
> Subvolume ID: 1011
> Generation: 9813
> Gen at creation: 9749
> Parent ID: 5
> Top level ID: 5
> Flags: -
> Snapshot(s):
> xx/ss1
> xx/ss2
>
> root@xerus:/test# btrfs subvolume show /test/tmp/xx/ss1
> /test/tmp/xx/ss1
> Name: ss1
> UUID: 3641bb81-d1fd-4440-8f29-6f17ff9ec4e1
> Parent UUID: 5a873eca-9b6c-fc4e-aed5-eb287839d693
> Received UUID: -
> Creation time: 2019-07-05 11:13:15 +0200
> Subvolume ID: 1026
> Generation: 9804
> Gen at creation: 9793
> Parent ID: 1011
> Top level ID: 1011
> Flags: readonly
> Snapshot(s):
>
> Must I call "btrfs subvolume show" for every subvolume to find the
> matching Parent ID/UUID or parse the "Snapshot(s)" section?
That seems to be the way, looking at code for the Snapshot(s) section it
iterates every subvolume and checks if its Parent UUID matches the UUID
of the subvolume - if yes it adds that particular subvol (snapshots are
subvolumes with a parent) to the "SNapshot(s)" section.
>
> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
> Do all snapshots have a "Parent UUID" and regular subvolumes not?
Indeed, only snapshots have a Parent UUID.
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: find snapshot parent?
2019-07-06 16:57 ` Nikolay Borisov
@ 2019-07-06 20:43 ` Ulli Horlacher
2019-07-07 5:27 ` Andrei Borzenkov
2019-07-07 6:43 ` Nikolay Borisov
0 siblings, 2 replies; 10+ messages in thread
From: Ulli Horlacher @ 2019-07-06 20:43 UTC (permalink / raw)
To: linux-btrfs
On Sat 2019-07-06 (19:57), Nikolay Borisov wrote:
> > And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
> > Do all snapshots have a "Parent UUID" and regular subvolumes not?
>
> Indeed, only snapshots have a Parent UUID.
Not all:
root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1
Create a readonly snapshot of '/test' in '/test/ss1'
root@xerus:/test# btrfs subvolume show /test/ss1
/test/ss1
Name: ss1
UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be
Parent UUID: -
Received UUID: -
Creation time: 2019-07-06 22:37:37 +0200
Subvolume ID: 1036
Generation: 9824
Gen at creation: 9824
Parent ID: 5
Top level ID: 5
Flags: readonly
Snapshot(s):
root@xerus:/test# btrfs subvolume show /test
/test is toplevel subvolume
--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<1e70c50e-54d7-0507-60ad-9c486e3517a9@suse.com>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: find snapshot parent?
2019-07-06 20:43 ` Ulli Horlacher
@ 2019-07-07 5:27 ` Andrei Borzenkov
2019-07-07 6:43 ` Nikolay Borisov
1 sibling, 0 replies; 10+ messages in thread
From: Andrei Borzenkov @ 2019-07-07 5:27 UTC (permalink / raw)
To: linux-btrfs
06.07.2019 23:43, Ulli Horlacher пишет:
> On Sat 2019-07-06 (19:57), Nikolay Borisov wrote:
>
>>> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
>>> Do all snapshots have a "Parent UUID" and regular subvolumes not?
>>
>> Indeed, only snapshots have a Parent UUID.
>
> Not all:
>
> root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1
> Create a readonly snapshot of '/test' in '/test/ss1'
>
> root@xerus:/test# btrfs subvolume show /test/ss1
> /test/ss1
> Name: ss1
> UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be
> Parent UUID: -
> Received UUID: -
> Creation time: 2019-07-06 22:37:37 +0200
> Subvolume ID: 1036
> Generation: 9824
> Gen at creation: 9824
> Parent ID: 5
> Top level ID: 5
> Flags: readonly
> Snapshot(s):
>
> root@xerus:/test# btrfs subvolume show /test
> /test is toplevel subvolume
>
Which is one more reason to not use btrfs top level directly.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: find snapshot parent?
2019-07-06 20:43 ` Ulli Horlacher
2019-07-07 5:27 ` Andrei Borzenkov
@ 2019-07-07 6:43 ` Nikolay Borisov
2019-07-07 7:37 ` Andrei Borzenkov
1 sibling, 1 reply; 10+ messages in thread
From: Nikolay Borisov @ 2019-07-07 6:43 UTC (permalink / raw)
To: linux-btrfs
On 6.07.19 г. 23:43 ч., Ulli Horlacher wrote:
> On Sat 2019-07-06 (19:57), Nikolay Borisov wrote:
>
>>> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
>>> Do all snapshots have a "Parent UUID" and regular subvolumes not?
>>
>> Indeed, only snapshots have a Parent UUID.
>
> Not all:
>
> root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1
> Create a readonly snapshot of '/test' in '/test/ss1'
>
> root@xerus:/test# btrfs subvolume show /test/ss1
> /test/ss1
> Name: ss1
> UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be
> Parent UUID: -
> Received UUID: -
> Creation time: 2019-07-06 22:37:37 +0200
> Subvolume ID: 1036
> Generation: 9824
> Gen at creation: 9824
> Parent ID: 5
> Top level ID: 5
> Flags: readonly
> Snapshot(s):
>
> root@xerus:/test# btrfs subvolume show /test
> /test is toplevel subvolume
This is really odd, looking at create_pending_snapshot the codes :
memcpy(new_root_item->parent_uuid, root->root_item.uuid,
BTRFS_UUID_SIZE);
And that's not conditional on whether the snapshot is read only or not.
So everytime we creata a snapshot it ought to be receiving the parent's
subvolume UUID in its parent_uuid field. And indeed testing with latest misc-next kernel:
root@ubuntu-virtual:~# btrfs subvol create /media/scratch/subvol10
Create subvolume '/media/scratch/subvol10'
root@ubuntu-virtual:~# btrfs subvol snapshot /media/scratch/subvol10/ /media/scratch/snap-subvol10
Create a snapshot of '/media/scratch/subvol10/' in '/media/scratch/snap-subvol10'
root@ubuntu-virtual:~# btrfs subvol snapshot -r /media/scratch/subvol10/ /media/scratch/snap-subvol10-ro
Create a readonly snapshot of '/media/scratch/subvol10/' in '/media/scratch/snap-subvol10-ro'
root@ubuntu-virtual:~# btrfs subvol show /media/scratch/snap-subvol10
snap-subvol10
Name: snap-subvol10
UUID: 8000e96e-5d6e-3c49-a4d3-5e3868ac6972
Parent UUID: 6352b676-fce5-0945-88d9-745a6ae72783
Received UUID: -
Creation time: 2019-07-07 06:40:15 +0000
Subvolume ID: 262
Generation: 17
Gen at creation: 17
Parent ID: 5
Top level ID: 5
Flags: -
Snapshot(s):
root@ubuntu-virtual:~# btrfs subvol show /media/scratch/snap-subvol10-ro/
snap-subvol10-ro
Name: snap-subvol10-ro
UUID: 8964dab3-37b0-fc4e-b891-69323d3aaea0
Parent UUID: 6352b676-fce5-0945-88d9-745a6ae72783
Received UUID: -
Creation time: 2019-07-07 06:40:26 +0000
Subvolume ID: 263
Generation: 18
Gen at creation: 18
Parent ID: 5
Top level ID: 5
Flags: readonly
Snapshot(s):
Note that the related code hasn't change in a long time.
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: find snapshot parent?
2019-07-07 6:43 ` Nikolay Borisov
@ 2019-07-07 7:37 ` Andrei Borzenkov
2019-07-07 9:12 ` Nikolay Borisov
0 siblings, 1 reply; 10+ messages in thread
From: Andrei Borzenkov @ 2019-07-07 7:37 UTC (permalink / raw)
To: Nikolay Borisov, linux-btrfs
07.07.2019 9:43, Nikolay Borisov пишет:
>
>
> On 6.07.19 г. 23:43 ч., Ulli Horlacher wrote:
>> On Sat 2019-07-06 (19:57), Nikolay Borisov wrote:
>>
>>>> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
>>>> Do all snapshots have a "Parent UUID" and regular subvolumes not?
>>>
>>> Indeed, only snapshots have a Parent UUID.
>>
>> Not all:
>>
>> root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1
>> Create a readonly snapshot of '/test' in '/test/ss1'
>>
>> root@xerus:/test# btrfs subvolume show /test/ss1
>> /test/ss1
>> Name: ss1
>> UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be
>> Parent UUID: -
>> Received UUID: -
>> Creation time: 2019-07-06 22:37:37 +0200
>> Subvolume ID: 1036
>> Generation: 9824
>> Gen at creation: 9824
>> Parent ID: 5
>> Top level ID: 5
>> Flags: readonly
>> Snapshot(s):
>>
>> root@xerus:/test# btrfs subvolume show /test
>> /test is toplevel subvolume
>
> This is really odd, looking at create_pending_snapshot the codes :
>
> memcpy(new_root_item->parent_uuid, root->root_item.uuid,
> BTRFS_UUID_SIZE);
>
> And that's not conditional on whether the snapshot is read only or not.
> So everytime we creata a snapshot it ought to be receiving the parent's
> subvolume UUID in its parent_uuid field.
Does top level subvolume of btrfs have subvolume UUID at all? How can
one display it? None of "btrfs subvolume" commands show it.
> And indeed testing with latest misc-next kernel:
>
> root@ubuntu-virtual:~# btrfs subvol create /media/scratch/subvol10
> Create subvolume '/media/scratch/subvol10'
>
> root@ubuntu-virtual:~# btrfs subvol snapshot /media/scratch/subvol10/ /media/scratch/snap-subvol10
> Create a snapshot of '/media/scratch/subvol10/' in '/media/scratch/snap-subvol10'
>
/media/scratch/subvol10 is not top level subvolume.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: find snapshot parent?
2019-07-07 7:37 ` Andrei Borzenkov
@ 2019-07-07 9:12 ` Nikolay Borisov
2019-07-07 22:18 ` Ulli Horlacher
0 siblings, 1 reply; 10+ messages in thread
From: Nikolay Borisov @ 2019-07-07 9:12 UTC (permalink / raw)
To: Andrei Borzenkov, linux-btrfs
On 7.07.19 г. 10:37 ч., Andrei Borzenkov wrote:
> 07.07.2019 9:43, Nikolay Borisov пишет:
>>
>>
>> On 6.07.19 г. 23:43 ч., Ulli Horlacher wrote:
>>> On Sat 2019-07-06 (19:57), Nikolay Borisov wrote:
>>>
>>>>> And how can I see whether /test/tmp/xx/ss1 is a snapshot at all?
>>>>> Do all snapshots have a "Parent UUID" and regular subvolumes not?
>>>>
>>>> Indeed, only snapshots have a Parent UUID.
>>>
>>> Not all:
>>>
>>> root@xerus:/test# btrfs subvolume snapshot -r /test /test/ss1
>>> Create a readonly snapshot of '/test' in '/test/ss1'
>>>
>>> root@xerus:/test# btrfs subvolume show /test/ss1
>>> /test/ss1
>>> Name: ss1
>>> UUID: 02bd07bc-0bab-3442-96be-40790e1ba9be
>>> Parent UUID: -
>>> Received UUID: -
>>> Creation time: 2019-07-06 22:37:37 +0200
>>> Subvolume ID: 1036
>>> Generation: 9824
>>> Gen at creation: 9824
>>> Parent ID: 5
>>> Top level ID: 5
>>> Flags: readonly
>>> Snapshot(s):
>>>
>>> root@xerus:/test# btrfs subvolume show /test
>>> /test is toplevel subvolume
>>
>> This is really odd, looking at create_pending_snapshot the codes :
>>
>> memcpy(new_root_item->parent_uuid, root->root_item.uuid,
>> BTRFS_UUID_SIZE);
>>
>> And that's not conditional on whether the snapshot is read only or not.
>> So everytime we creata a snapshot it ought to be receiving the parent's
>> subvolume UUID in its parent_uuid field.
>
> Does top level subvolume of btrfs have subvolume UUID at all? How can
> one display it? None of "btrfs subvolume" commands show it.
>
>> And indeed testing with latest misc-next kernel:
>>
>> root@ubuntu-virtual:~# btrfs subvol create /media/scratch/subvol10
>> Create subvolume '/media/scratch/subvol10'
>>
>> root@ubuntu-virtual:~# btrfs subvol snapshot /media/scratch/subvol10/ /media/scratch/snap-subvol10
>> Create a snapshot of '/media/scratch/subvol10/' in '/media/scratch/snap-subvol10'
>>
>
> /media/scratch/subvol10 is not top level subvolume.
root@ubuntu-virtual:~# mkfs.btrfs /dev/vdc
root@ubuntu-virtual:~# mount /dev/vdc /media/scratch/
root@ubuntu-virtual:~# btrfs subvolume snapshot /media/scratch/ /media/scratch/snap1
Create a snapshot of '/media/scratch/' in '/media/scratch/snap1'
root@ubuntu-virtual:~# btrfs subvolume snapshot -r /media/scratch/ /media/scratch/snap-ro
Create a readonly snapshot of '/media/scratch/' in '/media/scratch/snap-ro'
root@ubuntu-virtual:~# btrfs subvol show /media/scratch/
/
Name: <FS_TREE>
UUID: 80633e8d-fa8a-4922-ac0c-b46d7b2e2d81
Parent UUID: -
Received UUID: -
Creation time: 2019-07-07 09:09:15 +0000
Subvolume ID: 5
Generation: 8
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
Snapshot(s):
snap1
snap-ro
root@ubuntu-virtual:~# btrfs subvol show /media/scratch/snap1/
snap1
Name: snap1
UUID: df861e02-5f54-a74c-a560-dfa66a80b528
Parent UUID: 80633e8d-fa8a-4922-ac0c-b46d7b2e2d81
Received UUID: -
Creation time: 2019-07-07 09:09:38 +0000
Subvolume ID: 257
Generation: 6
Gen at creation: 6
Parent ID: 5
Top level ID: 5
Flags: -
Snapshot(s):
root@ubuntu-virtual:~# btrfs subvol show /media/scratch/snap-ro/
snap-ro
Name: snap-ro
UUID: f9c1a467-2d8a-2343-9011-a4ad07e701b7
Parent UUID: 80633e8d-fa8a-4922-ac0c-b46d7b2e2d81
Received UUID: -
Creation time: 2019-07-07 09:11:34 +0000
Subvolume ID: 258
Generation: 8
Gen at creation: 8
Parent ID: 5
Top level ID: 5
Flags: readonly
Snapshot(s):
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: find snapshot parent?
2019-07-07 9:12 ` Nikolay Borisov
@ 2019-07-07 22:18 ` Ulli Horlacher
2019-07-08 4:05 ` Andrei Borzenkov
0 siblings, 1 reply; 10+ messages in thread
From: Ulli Horlacher @ 2019-07-07 22:18 UTC (permalink / raw)
To: linux-btrfs
On Sun 2019-07-07 (12:12), Nikolay Borisov wrote:
> root@ubuntu-virtual:~# mount /dev/vdc /media/scratch/
>
> root@ubuntu-virtual:~# btrfs subvol show /media/scratch/
> /
> Name: <FS_TREE>
> UUID: 80633e8d-fa8a-4922-ac0c-b46d7b2e2d81
> Parent UUID: -
> Received UUID: -
> Creation time: 2019-07-07 09:09:15 +0000
> Subvolume ID: 5
> Generation: 8
> Gen at creation: 0
> Parent ID: 0
> Top level ID: 0
> Flags: -
> Snapshot(s):
> snap1
> snap-ro
root@fex:~# lsb_release -d
Description: Ubuntu 18.04.2 LTS
root@fex:~# btrfs version
btrfs-progs v4.15.1
root@fex:~# mount|grep /local
/dev/sdd1 on /local type btrfs (rw,relatime,space_cache,user_subvol_rm_allowed,subvolid=5,subvol=/)
root@fex:~# btrfs subvolume show /local
/
Name: <FS_TREE>
UUID: -
Parent UUID: -
Received UUID: -
Creation time: -
Subvolume ID: 5
Generation: 1633457
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
No UUID!
--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<8bc57b91-fc13-979b-a25a-b7a16094d09a@suse.com>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: find snapshot parent?
2019-07-07 22:18 ` Ulli Horlacher
@ 2019-07-08 4:05 ` Andrei Borzenkov
0 siblings, 0 replies; 10+ messages in thread
From: Andrei Borzenkov @ 2019-07-08 4:05 UTC (permalink / raw)
To: linux-btrfs
08.07.2019 1:18, Ulli Horlacher пишет:
> On Sun 2019-07-07 (12:12), Nikolay Borisov wrote:
>
>
>> root@ubuntu-virtual:~# mount /dev/vdc /media/scratch/
>>
>> root@ubuntu-virtual:~# btrfs subvol show /media/scratch/
>> /
>> Name: <FS_TREE>
>> UUID: 80633e8d-fa8a-4922-ac0c-b46d7b2e2d81
>> Parent UUID: -
>> Received UUID: -
>> Creation time: 2019-07-07 09:09:15 +0000
>> Subvolume ID: 5
>> Generation: 8
>> Gen at creation: 0
>> Parent ID: 0
>> Top level ID: 0
>> Flags: -
>> Snapshot(s):
>> snap1
>> snap-ro
>
>
> root@fex:~# lsb_release -d
> Description: Ubuntu 18.04.2 LTS
>
> root@fex:~# btrfs version
> btrfs-progs v4.15.1
>
> root@fex:~# mount|grep /local
> /dev/sdd1 on /local type btrfs (rw,relatime,space_cache,user_subvol_rm_allowed,subvolid=5,subvol=/)
>
> root@fex:~# btrfs subvolume show /local
> /
> Name: <FS_TREE>
> UUID: -
> Parent UUID: -
> Received UUID: -
> Creation time: -
> Subvolume ID: 5
> Generation: 1633457
> Gen at creation: 0
> Parent ID: 0
> Top level ID: 0
> Flags: -
>
> No UUID!
>
Neither here on different versions of openSUSE. Note that it also
mistakenly displays subvolumes as snapshots (I assume, it simply
compares NULL subvolume UUID with NULL parent UUID in this case).
bor@leap423:~> sudo btrfs version
btrfs-progs v4.5.3+20160729
bor@leap423:~> uname -a
Linux leap423 4.4.180-102-default #1 SMP Mon Jun 17 13:11:23 UTC 2019
(7cfa20a) x86_64 x86_64 x86_64 GNU/Linux
bor@leap423:~> sudo btrfs su sh /mnt
/mnt is toplevel subvolume
bor@leap423:~>
bor@localhost:~> sudo btrfs version
btrfs-progs v4.19.1
bor@localhost:~> uname -a
Linux localhost 4.12.14-lp151.28.7-default #1 SMP Mon Jun 17 16:36:38
UTC 2019 (f8a1872) x86_64 x86_64 x86_64 GNU/Linux
bor@localhost:~> sudo btrfs su sh /mnt
/
Name: <FS_TREE>
UUID: -
Parent UUID: -
Received UUID: -
Creation time: -
Subvolume ID: 5
Generation: 338
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
Snapshot(s):
@
@/var
@/usr/local
@/tmp
@/srv
@/root
@/opt
@/home
@/boot/grub2/x86_64-efi
@/boot/grub2/i386-pc
@/.snapshots
@/.snapshots/1/snapshot
bor@localhost:~>
bor@10:~> sudo btrfs version
btrfs-progs v5.1
bor@10:~> uname -a
Linux 10.0.2.15 5.1.7-1-default #1 SMP Tue Jun 4 07:56:54 UTC 2019
(55f2451) x86_64 x86_64 x86_64 GNU/Linux
bor@10:~> sudo btrfs su sh /mnt
/
Name: <FS_TREE>
UUID: -
Parent UUID: -
Received UUID: -
Creation time: -
Subvolume ID: 5
Generation: 26638
Gen at creation: 0
Parent ID: 0
Top level ID: 0
Flags: -
Snapshot(s):
@
@/.snapshots
@/boot/grub2/i386-pc
@/boot/grub2/x86_64-efi
@/home
@/opt
@/srv
@/tmp
@/usr/local
@/var/cache
@/var/crash
@/var/lib/libvirt/images
@/var/lib/machines
@/var/lib/mailman
@/var/lib/mariadb
@/var/lib/mysql
@/var/lib/named
@/var/lib/pgsql
@/var/log
@/var/opt
@/var/spool
@/var/tmp
bor@10:~>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: find snapshot parent?
2019-07-06 15:53 find snapshot parent? Ulli Horlacher
2019-07-06 16:57 ` Nikolay Borisov
@ 2019-07-06 23:24 ` Ulli Horlacher
1 sibling, 0 replies; 10+ messages in thread
From: Ulli Horlacher @ 2019-07-06 23:24 UTC (permalink / raw)
To: linux-btrfs
I have now implemented "btrfs_subvolume_list", example:
root@xerus:~# df3 -T
Filesystem Type Mbytes Used Available Use% Mounted on
/dev/sda1 ext4 20,029 4,482 14,507 24% /
/dev/sdd4 btrfs 53,247 101 51,052 1% /test
root@xerus:~# btrfs_subvolume_list
rw /test
ro /test/.snapshot/2019-07-06_2236.test <- /test
ro /test/snapshot_1 <- /test
ro /test/ss1 <- /test
ro /test/ss3 <- -
rw /test/tmp
ro /test/tmp/xx/ss1 <- /test/tmp
ro /test/tmp/xx/ss2 <- /test/tmp
ro /test/tmp/xx/ss3 <- /test/ss3
rw /test/tmp/zz2 <- /test/tux/zz
rw /test/tux/test
ro /test/tux/test/.snapshot/2017-12-02_1341.test <- /test/tux/test
rw /test/tux/test2 <- /test/tux/test
rw /test/tux/test2/test <- /test/tux/test
rw /test/tux/zz
<- means: is snapshot of ...
Note: I have deleted the subvolume parent of /test/ss3
Sourcecode is available under:
https://fex.rus.uni-stuttgart.de/fas/framstag@rus.uni-stuttgart.de/linuxtools/anonymous@fex.rus.uni-stuttgart.de/k5JuaCkGRqGOYeFUHuB47S35rhs3vBZo
--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<20190706155353.GA13656@tik.uni-stuttgart.de>
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2019-07-08 4:11 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-06 15:53 find snapshot parent? Ulli Horlacher
2019-07-06 16:57 ` Nikolay Borisov
2019-07-06 20:43 ` Ulli Horlacher
2019-07-07 5:27 ` Andrei Borzenkov
2019-07-07 6:43 ` Nikolay Borisov
2019-07-07 7:37 ` Andrei Borzenkov
2019-07-07 9:12 ` Nikolay Borisov
2019-07-07 22:18 ` Ulli Horlacher
2019-07-08 4:05 ` Andrei Borzenkov
2019-07-06 23:24 ` Ulli Horlacher
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