A future patch will add support for extending relations by multiple blocks at
once. To be concurrency safe, the buffers for those blocks need to be marked
as BM_IO_IN_PROGRESS. Until now we only had infrastructure for recovering from
an IO error for a single buffer. This commit extends that infrastructure to
multiple buffers by using the resource owner infrastructure.
This commit increases the size of the ResourceOwnerData struct, which appears
to have a just about measurable overhead in very extreme workloads. Medium
term we are planning to substantially shrink the size of
ResourceOwnerData. Short term the increase is small enough to not worry about
it for now.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/20221029025420.eplyow6k7tgu6he3@awork3.anarazel.de
Discussion: https://postgr.es/m/20221029200025.w7bvlgvamjfo6z44@awork3.anarazel.de
Similarly to the cryptohash implementations, this refactors the existing
HMAC code into a single set of APIs that can be plugged with any crypto
libraries PostgreSQL is built with (only OpenSSL currently). If there
is no such libraries, a fallback implementation is available. Those new
APIs are designed similarly to the existing cryptohash layer, so there
is no real new design here, with the same logic around buffer bound
checks and memory handling.
HMAC has a dependency on cryptohashes, so all the cryptohash types
supported by cryptohash{_openssl}.c can be used with HMAC. This
refactoring is an advantage mainly for SCRAM, that included its own
implementation of HMAC with SHA256 without relying on the existing
crypto libraries even if PostgreSQL was built with their support.
This code has been tested on Windows and Linux, with and without
OpenSSL, across all the versions supported on HEAD from 1.1.1 down to
1.0.1. I have also checked that the implementations are working fine
using some sample results, a custom extension of my own, and doing
cross-checks across different major versions with SCRAM with the client
and the backend.
Author: Michael Paquier
Reviewed-by: Bruce Momjian
Discussion: https://postgr.es/m/X9m0nkEJEzIPXjeZ@paquier.xyz
The use of low-level hash routines is not recommended by upstream
OpenSSL since 2000, and pgcrypto already switched to EVP as of 5ff4a67.
This takes advantage of the refactoring done in 87ae969 that has
introduced the allocation and free routines for cryptographic hashes.
Since 1.1.0, OpenSSL does not publish the contents of the cryptohash
contexts, forcing any consumers to rely on OpenSSL for all allocations.
Hence, the resource owner callback mechanism gains a new set of routines
to track and free cryptohash contexts when using OpenSSL, preventing any
risks of leaks in the backend. Nothing is needed in the frontend thanks
to the refactoring of 87ae969, and the resowner knowledge is isolated
into cryptohash_openssl.c.
Note that this also fixes a failure with SCRAM authentication when using
FIPS in OpenSSL, but as there have been few complaints about this
problem and as this causes an ABI breakage, no backpatch is done.
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson, Heikki Linnakangas
Discussion: https://postgr.es/m/20200924025314.GE7405@paquier.xyz
Discussion: https://postgr.es/m/20180911030250.GA27115@paquier.xyz
This commit introduces:
1) JIT provider abstraction, which allows JIT functionality to be
implemented in separate shared libraries. That's desirable because
it allows to install JIT support as a separate package, and because
it allows experimentation with different forms of JITing.
2) JITContexts which can be, using functions introduced in follow up
commits, used to emit JITed functions, and have them be cleaned up
on error.
3) The outline of a LLVM JIT provider, which will be fleshed out in
subsequent commits.
Documentation for GUCs added, and for JIT in general, will be added in
later commits.
Author: Andres Freund, with architectural input from Jeff Davis
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
Bruce Momjian
Andres Freund
Michael Paquier
Tom Lane
Robert Haas
Alvaro Herrera