Fix rare checksum failure in EXEC_BACKEND LocalProcessControlFile()

git remote add commitfest https://github.com/postgresql-cfbot/postgresql.git
git fetch commitfest cf/5124
git checkout commitfest/cf/5124

race condition when writing pg_control ×

First at 2020-05-04 17:44:21 by "Bossart, Nathan" <bossartn at amazon.com>
Latest at 2024-07-30 23:54:55 by Noah Misch <noah at leadboat.com>
Latest attachment (v1-0001-Fix-pg_control-corruption-in-EXEC_BACKEND-startup.patch) at 2024-05-18 05:29:12 from Thomas Munro <thomas.munro at gmail.com>

    Attachment (v1-0001-Fix-pg_control-corruption-in-EXEC_BACKEND-startup.patch) at 2024-05-18 05:29:12 from Thomas Munro <thomas.munro at gmail.com> (Patch: Yes)
    Attachment (0003-Assert-that-ControlFileLock-is-held-within-UpdateCon.patch) at 2020-05-31 21:11:35 from "Bossart, Nathan" <bossartn at amazon.com> (Patch: Yes)
    Attachment (v1-0001-Assert-that-ControlFileLock-is-held-exclusively-i.patch) at 2020-05-26 19:30:54 from "Bossart, Nathan" <bossartn at amazon.com> (Patch: Yes)
    Attachment (0001-Fix-race-condition-that-could-corrupt-pg_control.patch) at 2020-05-22 04:51:47 from Thomas Munro <thomas.munro at gmail.com> (Patch: Yes)
    Attachment (v1-0001-Prevent-race-condition-when-writing-pg_control.patch) at 2020-05-04 17:44:21 from "Bossart, Nathan" <bossartn at amazon.com> (Patch: Yes)