On 2/15/23 2:05 PM, Alan Somers wrote:
On Wed, Feb 15, 2023 at 2:33 PM John Baldwin <[email protected]> wrote:
The branch main has been updated by jhb:
URL:
https://cgit.FreeBSD.org/src/commit/?id=98844e99d40a90ae89d84762e07150af3a8f89bd
commit 98844e99d40a90ae89d84762e07150af3a8f89bd
Author: John Baldwin <[email protected]>
AuthorDate: 2023-02-15 21:32:52 +0000
Commit: John Baldwin <[email protected]>
CommitDate: 2023-02-15 21:32:52 +0000
aio: Fix more synchronization issues in aio_biowakeup.
- Use atomic_store to set job->error. atomic_set does an or
operation, not assignment.
- Use refcount_* to manage job->nbio.
This ensures proper memory barriers are present so that the last bio
won't see a possibly stale value of job->error.
- Don't re-read job->error after reading it via atomic_load.
Reported by: markj (1)
Reviewed by: mjg, markj
Differential Revision: https://reviews.freebsd.org/D38611
Thanks for fixing these subtle problems in aio_(read|write)v. Will you MFC too?
Yes. I only noticed these while reviewing the original fix from the folks at
TidalScale FWIW.
--
John Baldwin
