Bug #64063
closedrbd-nbd: incorrect device size immediately after mapping images using ioctl
0%
Description
Mapped rbd images/snapshots to nbd devices using ioctl method, which is currently the default method of mapping using rbd-nbd. Checked the device size and the MD5 checksum of the device immediately after the mapping. The device size and the MD5 checksum were zero bytes and d41d8cd98f00b204e9800998ecf8427e (MD5 checksum of a zero byte file) respectively. After sleeping for a few seconds, the correct device size and MD5 checksum were reported. It seems like the command to map a rbd image to a nbd device using ioctl method returns before waiting for the device to be ready for use.
However, no such issues were observed when mapping a rbd image to a nbd device using the netlink method.
Updated by Ilya Dryomov about 2 years ago
Unclear if it's worth working around this by waiting internally at this point. I think the action here is to use the netlink method by default, keeping the legacy ioctl method with all of its issues only as a fallback.
Updated by Ramana Raja about 2 years ago
- Status changed from New to In Progress
- Assignee set to Ramana Raja
Updated by Ilya Dryomov about 2 years ago
- Status changed from In Progress to Resolved
Updated by Ilya Dryomov about 1 year ago
- Related to QA Run #69414: wip-yuri4-testing-2025-01-07-1424-reef (wip-yuri4-testing-2025-01-02-1314-reef) added
Updated by Ilya Dryomov about 1 year ago
- Related to QA Run #70319: wip-yuri5-testing-2025-03-05-0756-reef added
Updated by Ilya Dryomov about 1 year ago
- Status changed from Resolved to Pending Backport
- Backport set to reef
We didn't backport this originally due to a general desire to change defaults only in major releases, but this has gotten out of hand completely on CentOS Stream 9. qa/workunits/rbd/luks-encryption.sh workunit which maps and unmaps an rbd-nbd device a couple dozen times fails 10 out of 10 times now, so a backport is in order IMO.
Updated by Upkeep Bot about 1 year ago
- Copied to Backport #70364: reef: rbd-nbd: incorrect device size immediately after mapping images using ioctl added
Updated by Upkeep Bot about 1 year ago
- Tags (freeform) set to backport_processed
Updated by Upkeep Bot about 1 year ago
- Status changed from Pending Backport to Resolved
While running with --resolve-parent, the script "backport-create-issue" noticed that all backports of this issue are in status "Resolved" or "Rejected".
Updated by Upkeep Bot 9 months ago
- Merge Commit set to 2b11aa38eaf6572a4d2f56e9ca63d41b1ed77d80
- Fixed In set to v19.0.0-896-g2b11aa38eaf
- Released In set to v19.2.0~850
- Upkeep Timestamp set to 2025-07-11T16:43:48+00:00