mirror of
https://github.com/postgres/postgres.git
synced 2025-05-05 09:19:17 +03:00
d493bed28f
Restoring a base backup taken in the middle of CreateDirAndVersionFile() or write_relmap_file() would lose the function's effects. The symptom was absence of the database directory, PG_VERSION file, or pg_filenode.map. If missing the directory, recovery would fail. Either missing file would not fail recovery but would render the new database unusable. Fix CreateDirAndVersionFile() with the transam/README "action first and then write a WAL entry" strategy. That has a side benefit of moving filesystem mutations out of a critical section, reducing the ways to PANIC. Fix the write_relmap_file() call with a lock acquisition, so it interacts with checkpoints like non-CREATE DATABASE calls do. Back-patch to v15, where commit 9c08aea6a3090a396be334cc58c511edab05776a introduced STRATEGY=WAL_LOG and made it the default. Discussion: https://postgr.es/m/20240130195003.0a.nmisch@google.com
# Generating dummy probes If Postgres isn't configured with dtrace enabled, we need to generate dummy probes for the entries in probes.d, that do nothing. This is accomplished in Unix via the sed script `Gen_dummy_probes.sed`. We used to use this in MSVC builds using the perl utility `psed`, which mimicked sed. However, that utility disappeared from Windows perl distributions and so we converted the sed script to a perl script to be used in MSVC builds. We still keep the sed script as the authoritative source for generating these dummy probes because except on Windows perl is not a hard requirement when building from a tarball. So, if you need to change the way dummy probes are generated, first change the sed script, and when it's working generate the perl script. This can be accomplished by using the perl utility s2p. s2p is no longer part of the perl core, so it might not be on your system, but it is available on CPAN and also in many package systems. e.g. on Fedora it can be installed using `cpan App::s2p` or `dnf install perl-App-s2p`. The Makefile contains a recipe for regenerating Gen_dummy_probes.pl, so all you need to do is once you have s2p installed is `make Gen_dummy_probes.pl` Note that in a VPATH build this will generate the file in the vpath tree, not the source tree.