Details:
- Write size should be exactly csum_block_size (4k by default)
- Write should be made into a new object (unallocated space)
- In this case, the checksum of the block was calculated as if the block was
padded with extra (2^32 - size) zero bytes due to a simple integer overflow
- As a cherry on the cake, such calculation was 'slightly' slow because it
was processing almost 4 GB of zeroes for a small write
Important fixes:
- Disable RWF_ATOMIC by default because Linux incorrectly requires all atomic
writes to be power-of-2-sized and length-aligned. Details: [use_atomic_flag](https://vitastor.io/en/docs/config/osd.html#use_atomic_flag)
- Fix cross-pool snapshots not working at all - always reading old data after taking the snapshot
- Fix level_placement (broken in 2.2.0)
- Fix CAS write return values in the client library (broken in 2.4.4), also breaking unaligned writes in VitastorFS
- Fix VitastorFS possibly losing some of intersecting parallel unaligned writes
- Prevent possible reads of the old data during unfinished intent writes in the new store
- Tests added for all of above problems to prevent future regressions
Other fixes:
- Allow to specify OSD tags and weights during prepare
- Only clear the first block instead of whole OSD metadata and journal areas during vitastor-disk
prepare - OSD anyway clears them on the first run
- Fix vitastor-cli dd non-seekable detection and error status
- Do not stop OSD on zero-copy tcp short send errors - these aren't a bug, but just caused
by TCP client disconnections
- Fix modify-osd not working after deleting the OSD configuration key from etcd
- Fix regular antietcd websocket disconnections in OSD due to lack of WS_PONG responses to WS_PING
- Reduce the number of allocated RDMA memory regions
- Allow routed RoCE
A single new feature: the new log-structured metadata store implementation, described
in the presentation from Moscow Highload'2025 (check it out [here](https://vitastor.io/en/docs/#talks-and-presentations)).
It's now the default store for new OSDs. The support for the old store is also left in place,
you can still choose it for new OSDs with `vitastor-disk prepare --meta_format 2`.
OSDs from previous versions with the old store format will also continue to operate just like before.
Vitaliy Filippov
Vitaliy Filippov