4 ms·

The bug was finally fixed with the following commit: https://github.com/openzfs/zfs/pull/15579/commits/679738cc408d575289af2e31cdb1db9e311f0adf https://github.c

by szpght 3y ago

The bug was finally fixed with the following commit: https://github.com/openzfs/zfs/pull/15579/commits/679738cc408d575289af2e31cdb1db9e311f0adf https://github.com/openzfs/zfs/pull/15579/commits/679738cc40... It looks like they managed to exactly pin down what was happening.

lvncelot 3y ago
Sidenote: What a great commit message. The expanded comment explains why both checks are necessary, but the commit message gives so much more context for anyone wondering and `git blame`ing that line.
- solarkraft 3y ago
  Totally. Also: I've never seen Sponsored-by: > Signed-off-by: Rob Norris <rob.norris@klarasystems.com> > Sponsored-by: Klara, Inc. > Sponsored-by: Wasabi Technology, Inc.
  - emaste 3y ago
    This is a longstanding tradition from FreeBSD. A list of our commit message trailers: https://docs.freebsd.org/en/articles/committers-guide/#_include_appropriate_metadata_in_a_footer https://docs.freebsd.org/en/articles/committers-guide/#_incl.... "Sponsored by:" search in FreeBSD commit messages: https://freshbsd.org/?q=%22Sponsored+by%3A%22 https://freshbsd.org/?q=%22Sponsored+by%3A%22
    - solarkraft 3y ago
      I like it! Seems like a great way to incentivise companies to contribute.
      - throw0101b 3y ago
        > I like it! Seems like a great way to incentivise companies to contribute. It also helps with lawsuits, which was a major thing right at the beginning of history of BSD. * https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc._v._Berkeley_Software_Design,_Inc https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc..... Linux later had the lawsuit issue with SCO and IBM and tracking where certain things came from (which was not helped by the fact that Linus Torvalds refused to use source code tracking for the longest time (later taking up Bitkeeper, and later developing git)). * https://en.wikipedia.org/wiki/SCO–Linux_disputes https://en.wikipedia.org/wiki/SCO–Linux_disputes
        chasil 3y ago
        The beginning of BSD was the 1978 shipment of 1BSD by Bill Joy. You likely mean the end of the effort to replace all AT&T code, which was more than a decade later.
frankjr 3y ago
A more "correct" fix has been posted https://github.com/openzfs/zfs/pull/15615 https://github.com/openzfs/zfs/pull/15615
- jeffbee 3y ago
  Neither of these fixes are great because neither of them include tests. This is a dataloss bug in a filesystem, no existing test covered it, and no new tests were added to demonstrate the efficacy of the supposed fix or prevent regressions.
  - frankjr 3y ago
    There's an ongoing work on a stress test for this. https://github.com/openzfs/zfs/pull/15608 https://github.com/openzfs/zfs/pull/15608
  - rincebrain 3y ago
    There was, actually, a test, but it turns out to be rather hard to make a deterministic test to reproduce a rare race condition without sticking your fingers in at runtime and forcing the "wrong" ordering.
  - mnd999 3y ago
    The same was true of the fix for the completely deterministic cp from unencrypted to encrypted with block cloning. There doesn’t seem to me much incentive to write tests.

by szpght 3y ago

lvncelot 3y ago

Sidenote: What a great commit message. The expanded comment explains why both checks are necessary, but the commit message gives so much more context for anyone wondering and `git blame`ing that line.

solarkraft 3y ago
Totally. Also: I've never seen Sponsored-by: > Signed-off-by: Rob Norris <rob.norris@klarasystems.com> > Sponsored-by: Klara, Inc. > Sponsored-by: Wasabi Technology, Inc.
- emaste 3y ago
  This is a longstanding tradition from FreeBSD. A list of our commit message trailers: https://docs.freebsd.org/en/articles/committers-guide/#_include_appropriate_metadata_in_a_footer https://docs.freebsd.org/en/articles/committers-guide/#_incl.... "Sponsored by:" search in FreeBSD commit messages: https://freshbsd.org/?q=%22Sponsored+by%3A%22 https://freshbsd.org/?q=%22Sponsored+by%3A%22
  - solarkraft 3y ago
    I like it! Seems like a great way to incentivise companies to contribute.
    - throw0101b 3y ago
      > I like it! Seems like a great way to incentivise companies to contribute. It also helps with lawsuits, which was a major thing right at the beginning of history of BSD. * https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc._v._Berkeley_Software_Design,_Inc https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc..... Linux later had the lawsuit issue with SCO and IBM and tracking where certain things came from (which was not helped by the fact that Linus Torvalds refused to use source code tracking for the longest time (later taking up Bitkeeper, and later developing git)). * https://en.wikipedia.org/wiki/SCO–Linux_disputes https://en.wikipedia.org/wiki/SCO–Linux_disputes
      - chasil 3y ago
        The beginning of BSD was the 1978 shipment of 1BSD by Bill Joy. You likely mean the end of the effort to replace all AT&T code, which was more than a decade later.

frankjr 3y ago

A more "correct" fix has been posted https://github.com/openzfs/zfs/pull/15615 https://github.com/openzfs/zfs/pull/15615

jeffbee 3y ago
Neither of these fixes are great because neither of them include tests. This is a dataloss bug in a filesystem, no existing test covered it, and no new tests were added to demonstrate the efficacy of the supposed fix or prevent regressions.
- frankjr 3y ago
  There's an ongoing work on a stress test for this. https://github.com/openzfs/zfs/pull/15608 https://github.com/openzfs/zfs/pull/15608
- rincebrain 3y ago
  There was, actually, a test, but it turns out to be rather hard to make a deterministic test to reproduce a rare race condition without sticking your fingers in at runtime and forcing the "wrong" ordering.
- mnd999 3y ago
  The same was true of the fix for the completely deterministic cp from unencrypted to encrypted with block cloning. There doesn’t seem to me much incentive to write tests.