openzfs
zvol snapshot rename doesn't rename -partN devices
System information
| Type | Version/Name |
|---|---|
| Distribution Name | Ubuntu |
| Distribution Version | 24.04 |
| Kernel Version | 6.8.0-60-generic |
| Architecture | amd64 |
| OpenZFS Version | 2.2.7 |
Describe the problem you're observing
This is related to issue #14223 / #16600. Although the top level snapshot is correctly renamed any -partN devices related to it remain in /dev/zvol/.../.../ referencing the old name.
Describe how to reproduce the problem
- create a zvol with a partition table, there should be /dev/zvol/ztank/name, /dev/zvol/ztank/name-part1 devices
- create a snapshot , e.g. zfs snapshot ztank/name@snap1 of that volume (snapdev=visible), there should be /dev/zvol/ztank/name@snap1, /dev/zvol/ztank/name@snap1-part1
- rename the snapshot, e.g. zfs rename ztank/name@snap1 ztank/name@snap2, /dev/zvol/tank/name@snap2 exists but /dev/zvol/ztank/name@snap1-part1 is not renamed to /dev/zvol/ztank/name@snap2-part1
Running with udevadm monitor -k -u we see no change event for the p1 device:
# zfs create ztank/name@snap1
KERNEL[82773.152904] add /devices/virtual/bdi/230:3888 (bdi)
KERNEL[82773.154845] add /devices/virtual/block/zd3888 (block)
KERNEL[82773.154991] add /devices/virtual/block/zd3888/zd3888p1 (block)
UDEV [82773.170977] add /devices/virtual/bdi/230:3888 (bdi)
UDEV [82773.280616] add /devices/virtual/block/zd3888 (block)
UDEV [82773.390334] add /devices/virtual/block/zd3888/zd3888p1 (block)
# zfs rename ztank/name@snap1 ztank/name@snap2
KERNEL[82973.460582] change /devices/virtual/block/zd3888 (block)
KERNEL[82973.460954] change /devices/virtual/block/zd3888 (block)
UDEV [82973.573731] change /devices/virtual/block/zd3888 (block)
UDEV [82973.671342] change /devices/virtual/block/zd3888 (block)
Include any warning/errors/backtraces from the system logs
On further investigation that it is a snapshot is irrelevant, the same behaviour is observed for the volume. I have a working solution which is based on the Linux kernel disk_uevent() function but that requires the use of GPL symbols. What is the usual way to approach the licence incompatibility? I've done a bit of a search but can't find any guidelines.
I have a wip branch for this: https://github.com/JKDingwall/zfs/tree/JKDingwall/17428-zvol-rename-partition-uevents