Ceph » rbd

Ilya Dryomov wrote:

At the very least:

- m_first_valid_entry and m_first_free_entry aren't read from media (correct values are there but aren't used)

They are read from media when there's an existing cache with data [0]

- write_data_pos isn't written to media (incorrect value is there and is used)
- m_free_log_entries logic is bogus

https://github.com/ceph/ceph/pull/41101/ PR fixes the above two issues

[0] https://github.com/ceph/ceph/blob/master/src/librbd/cache/pwl/ssd/WriteLog.cc#L238-L239

Mahati Chamarthy wrote:

Ilya Dryomov wrote:

At the very least:

- m_first_valid_entry and m_first_free_entry aren't read from media (correct values are there but aren't used)

They are read from media when there's an existing cache with data [0]
[0] https://github.com/ceph/ceph/blob/master/src/librbd/cache/pwl/ssd/WriteLog.cc#L238-L239

If you trace that code carefully you will see that they are read but not used. I already have the fix, just haven't pushed yet because I'm running into other issues.

- write_data_pos isn't written to media (incorrect value is there and is used)
- m_free_log_entries logic is bogus

https://github.com/ceph/ceph/pull/41101/ PR fixes the above two issues

It does solve some of m_free_log_entries questions, but it doesn't fix write_data_pos problem. Again, I already have the fix -- if I don't track down the other failures I'm seeing by tomorrow, I'll open a draft PR just to get us on the same page.