Public bug reported:

We mount btrfs volumes, and we are seeing a change in behavior from the
5.15.0-126 kernel to 5.15.0.136

In the old behavior (existing for as long as we have had the product),
mounting a btrfs lvm results in:

$: grep /DataStore0 /proc/mounts
/dev/mapper/VG0-LV0 /DataStore0 btrfs 
rw,seclabel,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0

however same mount with the new kernel results in a different output:

$: grep /DataStore0 /proc/mounts
/dev/VG0/LV0 /DataStore0 btrfs 
rw,seclabel,relatime,space_cache=v2,subvolid=5,subvol=/ 0 0

(notice the /dev/VG0/LV0 vs. /dev/mapper/VG0-LV0) for the same mount.
Our application code uses /dev/mapper checking extensively and we would
like to avoid a rewrite if possible.

Online searches bring me to this bug: https://bugs.gentoo.org/947126
which seems very similar

We have this change as part of the new kernel:

$:git log --oneline --grep "btrfs: avoid unnecessary device path update for the 
same device" Ubuntu-5.15.0-126.136..Ubuntu-5.15.0-136.147
fc83c00ca63b btrfs: avoid unnecessary device path update for the same device

https://lore.kernel.org/linux-
btrfs/30aefd8b4e8c1f0c5051630b106a1ff3570d28ed.1735537399.git....@suse.com/T/#u
seems like a fix , I don't see this accepted yet though.

If we could either revert this change or provide guidance how we should
be reading this file that would be great. Thank you.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2107516

Title:
  Ubuntu 22.04 kernel 5.15.0.136 changes /proc/mounts for btfs volumes

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2107516/+subscriptions


-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to