---
- branch: MAIN
  date: Mon Mar 28 12:37:09 UTC 2022
  files:
  - new: '1.204'
    old: '1.203'
    path: src/sys/miscfs/specfs/spec_vnops.c
    pathrev: src/sys/miscfs/specfs/spec_vnops.c@1.204
    type: modified
  - new: '1.50'
    old: '1.49'
    path: src/sys/miscfs/specfs/specdev.h
    pathrev: src/sys/miscfs/specfs/specdev.h@1.50
    type: modified
  id: 20220328T123709Z.a13238693578faedf73d838b0c3b64186ba9f6f6
  log: |
    specfs: Prevent new opens while close is waiting to drain.

    Otherwise, bdev/cdev_close could have cancelled all _existing_ opens,
    and waited for them to complete (and freed resources used by them) --
    but a new one could start, and hang (e.g., a tty), at the same time
    spec_close tries to drain all pending I/O operations, one of which
    (the new open) is now hanging indefinitely.

    Preventing the new open from even starting until bdev/cdev_close is
    finished and all I/O operations have drained avoids this deadlock.
  module: src
  subject: 'CVS commit: src/sys/miscfs/specfs'
  unixtime: '1648471029'
  user: riastradh