PostgreSQL's Windows port has never been able to handle files larger
than 2GB due to the use of off_t for file offsets, only 32-bit on
Windows. This causes signed integer overflow at exactly 2^31 bytes when
trying to handle files larger than 2GB, for the routines touched by this
commit.
Note that large files are forbidden by ./configure (3c6248a828) and
meson (recent change, see 79cd66f28c). This restriction also exists
in v16 and older versions for the now-dead MSVC scripts.
The code base already defines pgoff_t as __int64 (64-bit) on Windows for
this purpose, and some function declarations in headers use it, but many
internals still rely on off_t. This commit switches more routines to
use pgoff_t, offering more portability, for areas mainly related to file
extensions and storage.
These are not critical for WAL segments yet, which have currently a
maximum size allowed of 1GB (well, this opens the door at allowing a
larger size for them). This matters more for segment files if we want
to lift the large file restriction in ./configure and meson in the
future, which would make sense to remove once/if all traces of off_t are
gone from the tree. This can additionally matter for out-of-core code
that may want files larger than 2GB in places where off_t is four bytes
in size.
Note that off_t is still used in other parts of the tree like
buffile.c, WAL sender/receiver, base backup, pg_combinebackup, etc.
These other code paths can be addressed separately, and their update
will be required if we want to remove the large file restriction in the
future. This commit is a good first cut in itself towards more
portability, hopefully.
On Unix-like systems, pgoff_t is defined as off_t, so this change only
affects Windows behavior.
Author: Bryan Green <dbryan.green@gmail.com>
Reviewed-by: Thomas Munro <thomas.munro@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/0f238ff4-c442-42f5-adb8-01b762c94ca1@gmail.com
pg_logical_slot_get_changes_guts() previously assigned InvalidXLogRecPtr to
the local variable upto_nchanges, which is of type int32, not XLogRecPtr.
While this caused no functional issue since InvalidXLogRecPtr is defined as 0,
it was semantically incorrect.
This commit fixes the issue by updating pg_logical_slot_get_changes_guts()
to set upto_nchanges to 0 instead of InvalidXLogRecPtr.
No backpatch is needed, as the previous behavior was harmless.
Author: Fujii Masao <masao.fujii@gmail.com>
Reviewed-by: Steven Niu <niushiji@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwHKHuR5NGnGxU3+ebz7cbC1ZAR=AgG4Bueq==Lj6iX8Sw@mail.gmail.com
Since this is a test module, leaking a couple of LWLock tranches is
fine, but we want to discourage that pattern in third-party code.
This commit teaches the module to create only one tranche and to
store its ID in shared memory for use by other backends.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/dd36d384-55df-4fc2-825c-5bc56c950fa9%40gmail.com
If DSM entry initialization fails, backends could try to use an
uninitialized DSM segment, DSA, or dshash table (since the entry is
still added to the registry). To fix, keep track of whether
initialization completed, and ERROR if a backend tries to attach to
an uninitialized entry. We could instead retry initialization as
needed, but that seemed complicated, error prone, and unlikely to
help most cases. Furthermore, such problems probably indicate a
coding error.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/dd36d384-55df-4fc2-825c-5bc56c950fa9%40gmail.com
Backpatch-through: 17
Before we started to freeze async notify entries (commit 8eeb4a0f7c),
no one looked at the 'xid' on an entry with invalid 'dboid'. But now
we might actually need to freeze it later. Initialize them with
InvalidTransactionId to begin with, to avoid that work later.
Álvaro pointed this out in review of commit 8eeb4a0f7c, but I forgot
to include this change there.
Author: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://www.postgresql.org/message-id/202511071410.52ll56eyixx7@alvherre.pgsql
Backpatch-through: 14
Previous commit fixed a bug where VACUUM would truncate the CLOG
that's still needed to check the commit status of XIDs in the async
notify queue, but as mentioned in the commit message, it wasn't a full
fix. If a backend is executing asyncQueueReadAllNotifications() and
has just made a local copy of an async SLRU page which contains old
XIDs, vacuum can concurrently truncate the CLOG covering those XIDs,
and the backend still gets an error when it calls
TransactionIdDidCommit() on those XIDs in the local copy. This commit
fixes that race condition.
To fix, hold the SLRU bank lock across the TransactionIdDidCommit()
calls in NOTIFY processing.
Per Tom Lane's idea. Backpatch to all supported versions.
Reviewed-by: Joel Jacobson <joel@compiler.org>
Reviewed-by: Arseniy Mukhin <arseniy.mukhin.dev@gmail.com>
Discussion: https://www.postgresql.org/message-id/2759499.1761756503@sss.pgh.pa.us
Backpatch-through: 14
The async notification queue contains the XID of the sender, and when
processing notifications we call TransactionIdDidCommit() on the
XID. But we had no safeguards to prevent the CLOG segments containing
those XIDs from being truncated away. As a result, if a backend didn't
for some reason process its notifications for a long time, or when a
new backend issued LISTEN, you could get an error like:
test=# listen c21;
ERROR: 58P01: could not access status of transaction 14279685
DETAIL: Could not open file "pg_xact/000D": No such file or directory.
LOCATION: SlruReportIOError, slru.c:1087
To fix, make VACUUM "freeze" the XIDs in the async notification queue
before truncating the CLOG. Old XIDs are replaced with
FrozenTransactionId or InvalidTransactionId.
Note: This commit is not a full fix. A race condition remains, where a
backend is executing asyncQueueReadAllNotifications() and has just
made a local copy of an async SLRU page which contains old XIDs, while
vacuum concurrently truncates the CLOG covering those XIDs. When the
backend then calls TransactionIdDidCommit() on those XIDs from the
local copy, you still get the error. The next commit will fix that
remaining race condition.
This was first reported by Sergey Zhuravlev in 2021, with many other
people hitting the same issue later. Thanks to:
- Alexandra Wang, Daniil Davydov, Andrei Varashen and Jacques Combrink
for investigating and providing reproducable test cases,
- Matheus Alcantara and Arseniy Mukhin for review and earlier proposed
patches to fix this,
- Álvaro Herrera and Masahiko Sawada for reviews,
- Yura Sokolov aka funny-falcon for the idea of marking transactions
as committed in the notification queue, and
- Joel Jacobson for the final patch version. I hope I didn't forget
anyone.
Backpatch to all supported versions. I believe the bug goes back all
the way to commit d1e027221d, which introduced the SLRU-based async
notification queue.
Discussion: https://www.postgresql.org/message-id/16961-25f29f95b3604a8a@postgresql.org
Discussion: https://www.postgresql.org/message-id/18804-bccbbde5e77a68c2@postgresql.org
Discussion: https://www.postgresql.org/message-id/CAK98qZ3wZLE-RZJN_Y%2BTFjiTRPPFPBwNBpBi5K5CU8hUHkzDpw@mail.gmail.com
Backpatch-through: 14
Previously, if async notify processing encountered an error, we would
report the error to the client and advance our read position past the
offending entry to prevent trying to process it over and over
again. Trying to continue after an error has a few problems however:
- We have no way of telling the client that a notification was
lost. They get an ERROR, but that doesn't tell you much. As such,
it's not clear if keeping the connection alive after losing a
notification is a good thing. Depending on the application logic,
missing a notification could cause the application to get stuck
waiting, for example.
- If the connection is idle, PqCommReadingMsg is set and any ERROR is
turned into FATAL anyway.
- We bailed out of the notification processing loop on first error
without processing any subsequent notifications. The subsequent
notifications would not be processed until another notify interrupt
arrives. For example, if there were two notifications pending, and
processing the first one caused an ERROR, the second notification
would not be processed until someone sent a new NOTIFY.
This commit changes the behavior so that any ERROR while processing
async notifications is turned into FATAL, causing the client
connection to be terminated. That makes the behavior more consistent
as that's what happened in idle state already, and terminating the
connection is a clear signal to the application that it might've
missed some notifications.
The reason to do this now is that the next commits will change the
notification processing code in a way that would make it harder to
skip over just the offending notification entry on error.
Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Arseniy Mukhin <arseniy.mukhin.dev@gmail.com>
Discussion: https://www.postgresql.org/message-id/fedbd908-4571-4bbe-b48e-63bfdcc38f64@iki.fi
Backpatch-through: 14
In order to make the errorhandling code in backend libpq be thread-
safe the global variable used by the certificate verification call-
back need to be replaced with passing private data.
This moves the threadsafety needle a little but forwards, the call
to strerror_r also needs to be replaced with the error buffer made
thread local. This is left as future work for when add the thread
primitives required for this to the tree.
Author: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/353226C7-97A1-4507-A380-36AA92983AE6@yesql.se
Instead of having to write a semicolon inside the macro argument, we can
insert a semicolon with another macro layer. This no longer gives
pg_bsd_indent indigestion, so we can remove the digestive aids that had
to be installed in the pgindent Perl script.
Author: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/202511111134.njrwf5w5nbjm@alvherre.pgsql
Backpatch-through: 18
Add documentation describing sequence synchronization support in logical
replication. It explains how sequence changes are synchronized from the
publisher to the subscriber, the configuration requirements, and provide
examples illustrating setup and usage.
Additionally, document the pg_get_sequence_data() function, which allows
users to query sequence details on the publisher to determine when to
refresh corresponding sequences on the subscriber.
Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
This new file is named pg_dependencies.c and includes all the code
directly related to the data type pg_dependencies, extracted from the
extended statistics code.
Some patches are under discussion to change its input and output
functions, and this separation makes the follow-up changes cleaner by
separating the logic related to the data type and the functional
dependencies statistics core logic in dependencies.c.
Author: Corey Huinker <corey.huinker@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aQ2k8--a0FfwSwX9@paquier.xyz
This new file is named pg_ndistinct.c and includes all the code directly
related to the data type pg_ndistinct, extracted from the extended
statistics code.
Some patches are under discussion to change its input and output
functions, and this separation makes the follow-up changes cleaner by
separating the logic related to the data type and the multivariate
ndistinct coefficient core logic in mvdistinct.c.
Author: Corey Huinker <corey.huinker@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aQ2k8--a0FfwSwX9@paquier.xyz
The synopsis for the ALTER PUBLICATION ... DROP ... command incorrectly
implied that a column list and WHERE clause could be specified as part of
the publication object. However, these options are not allowed for
DROP operations, making the documentation misleading.
This commit corrects the synopsis to clearly show only the valid forms
of publication objects.
Backpatched to v15, where the incorrect synopsis was introduced.
Author: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHut+PsPu+47Q7b0o6h1r-qSt90U3zgbAHMHUag5o5E1Lo+=uw@mail.gmail.com
Backpatch-through: 15
The maximum limits for point name, library name, function name and
private area size were not kept track of in the tests. The new function
introduced in 16a2f70695 gives a way to trigger them. This is not
critical but cheap to cover.
While on it, this commit cleans up some of the tests introduced by
16a2f70695 for NULL inputs by using more consistent argument values.
The coverage does not change, but it makes the whole less confusing with
argument values that are correct based their position in the SQL
function called.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/aRE7zhu6wOA29gFf@paquier.xyz
Previously, error messages for oversized injection point names, libraries,
and functions showed buffer sizes (64, 128, 128) instead of the usable
character limits (63, 127, 127) as it did not count for the
zero-terminated byte, which was confusing. These messages are adjusted
to show better the reality.
The limit enforced for the private area was also too strict by one byte,
as specifying a zone worth exactly INJ_PRIVATE_MAXLEN should be able to
work because three is no zero-terminated byte in this case.
This is a stylistic change (well, mostly, a private_area size of exactly
1024 bytes can be defined with this change, something that nobody seem
to care about based on the lack of complaints). However, this is a
testing facility let's keep the logic consistent across all the branches
where this code exists, as there is an argument in favor of out-of-core
extensions that use injection points.
Author: Xuneng Zhou <xunengzhou@gmail.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CABPTF7VxYp4Hny1h+7ejURY-P4O5-K8WZg79Q3GUx13cQ6B2kg@mail.gmail.com
Backpatch-through: 17
A similar check existed in the MSVC scripts that have been removed in
v17 by 1301c80b21, but nothing of the kind was checked in meson when
building with a 4-byte off_t.
This commit adds a check to fail the builds when trying to use a
relation file size higher than 1GB when off_t is 4 bytes, like
./configure, rather than detecting these failures at runtime because the
code is not able to handle large files in this case.
Backpatch down to v16, where meson has been introduced.
Discussion: https://postgr.es/m/aQ0hG36IrkaSGfN8@paquier.xyz
Backpatch-through: 16
If you run pg_controldata on a cluster that has been initialized with
different PG_CONTROL_VERSION than what the pg_controldata program has
been compiled with, pg_controldata will still try to interpret the
control file, but the result is likely to be somewhat nonsensical. How
nonsensical it is depends on the differences between the versions. If
sizeof(ControlFileData) differs between the versions, the CRC will not
match and you get a warning of that, but otherwise you get no
warning.
Looking back at recent PG_CONTROL_VERSION updates, all changes that
would mess up the printed values have also changed
sizeof(ControlFileData), but there's no guarantee of that in future
versions.
Add an explicit check and warning for version number mismatch before
the CRC check. That way, you get a more clear warning if you use the
pg_controldata binary from wrong version, and if we change the control
file in the future in a way that doesn't change
sizeof(ControlFileData), this ensures that you get a warning in that
case too.
Discussion: https://www.postgresql.org/message-id/2afded89-f9f0-4191-84d8-8b8668e029a1@iki.fi
guc_var_compare() is invoked from qsort() on an array of struct
config_generic, but the function accesses these directly as
strings (char *). This relies on the name being the first field, so
this works. But we can write this more clearly by using the struct
and then accessing the field through the struct. Before the
reorganization of the GUC structs (commit a13833c35f), the old code
was probably more convenient, but now we can write this more clearly
and correctly.
After this change, it is no longer required that the name is the first
field in struct config_generic, so remove that comment.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/2c961fa1-14f6-44a2-985c-e30b95654e8d%40eisentraut.org
Commit 3e0ae46d90 added a field to ControlFileData and bumped
CATALOG_VERSION_NO, but CATALOG_VERSION_NO is not the right version
number for ControlFileData changes. Bumping either one will force an
initdb, but PG_CONTROL_VERSION is more accurate. Bump
PG_CONTROL_VERSION now.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/1874404.1762787779@sss.pgh.pa.us
This omission allowed table owners to create statistics in any
schema, potentially leading to unexpected naming conflicts. For
ALTER TABLE commands that require re-creating statistics objects,
skip this check in case the user has since lost CREATE on the
schema. The addition of a second parameter to CreateStatistics()
breaks ABI compatibility, but we are unaware of any impacted
third-party code.
Reported-by: Jelte Fennema-Nio <postgres@jeltef.nl>
Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Co-authored-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Security: CVE-2025-12817
Backpatch-through: 13
Several functions could overflow their size calculations, when presented
with very large inputs from remote and/or untrusted locations, and then
allocate buffers that were too small to hold the intended contents.
Switch from int to size_t where appropriate, and check for overflow
conditions when the inputs could have plausibly originated outside of
the libpq trust boundary. (Overflows from within the trust boundary are
still possible, but these will be fixed separately.) A version of
add_size() is ported from the backend to assist with code that performs
more complicated concatenation.
Reported-by: Aleksey Solovev (Positive Technologies)
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Security: CVE-2025-12818
Backpatch-through: 13
It seems plausible that someone might want to experiment with
different values. The pressing reason though is that I'm reviewing a
patch that requires pg_upgrade to manipulate SLRU files. That patch
needs to access SLRU_PAGES_PER_SEGMENT from pg_upgrade code, and
slru.h, where SLRU_PAGES_PER_SEGMENT is currently defined, cannot be
included from frontend code. Moving it to pg_config_manual.h makes it
accessible.
Now that it's a little more likely that someone might change
SLRU_PAGES_PER_SEGMENT, add a cluster compatibility check for it.
Bump catalog version because of the new field in the control file.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://www.postgresql.org/message-id/c7a4ea90-9f7b-4953-81be-b3fcb47db057@iki.fi
While there are many tests related to relation rewrites, nothing existed
to check how the cumulative statistics behave in such cases for
relations.
A different patch is under discussion to move the relation statistics to
be tracked on a per-relfilenode basis, so as these could be rebuilt
during crash recovery. This commit gives us a way to check (and perhaps
change) the existing behaviors for several rewrite scenarios, mixing
transactions, sub-transactions, two-phase commit and VACUUM.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aQ3X20hbqoThQXgp@ip-10-97-1-34.eu-west-3.compute.internal
This new function is able to take in input more data than the existing
injection_point_attach():
- A library name.
- A function name.
- Some private data.
This gives more flexibility for tests so as these would not need to
reinvent a wrapper for InjectionPointAttach() when attaching a callback
from a library other than "injection_points". injection_point_detach()
can be used with both versions of injection_point_attach().
Author: Rahila Syed <rahilasyed.90@gmail.com>
Reviewed-by: Mihail Nikalayeu <mihailnikalayeu@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAH2L28sOG2b_TKkZU51dy+pWJtny1mqDmeFiFoUASGa0X0iiKQ@mail.gmail.com
generic-gcc.h maps our read and write barriers to C11 acquire and
release fences using compiler builtins, for platforms where we don't
have our own hand-rolled assembler. This is apparently enough for GCC,
but the C11 memory model is only defined in terms of atomic accesses,
and our barriers for non-atomic, non-volatile accesses were not always
respected under Clang's stricter interpretation of the standard.
This explains the occasional breakage observed on new RISC-V + Clang
animal greenfly in lock-free PgAioHandle manipulation code containing a
repeating pattern of loads and read barriers. The problem can also be
observed in code generated for MIPS and LoongAarch, though we aren't
currently testing those with Clang, and on x86, though we use our own
assembler there. The scariest aspect is that we use the generic version
on very common ARM systems, but it doesn't seem to reorder the relevant
code there (or we'd have debugged this long ago).
Fix by inserting an explicit compiler barrier. It expands to an empty
assembler block declared to have memory side-effects, so registers are
flushed and reordering is prevented. In those respects this is like the
architecture-specific assembler versions, but the compiler is still in
charge of generating the appropriate fence instruction. Done for write
barriers on principle, though concrete problems have only been observed
with read barriers.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Tested-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/d79691be-22bd-457d-9d90-18033b78c40a%40gmail.com
Backpatch-through: 13
This warning was disabled in meson.build (warning 4273). If you
enable it, it looks like this:
../src/backend/utils/misc/ps_status.c(27): warning C4273: '__p__environ': inconsistent dll linkage
C:\Program Files (x86)\Windows Kits\10\include\10.0.22621.0\ucrt\stdlib.h(1158): note: see previous definition of '__p__environ'
The declaration in ps_status.c was:
#if !defined(WIN32) || defined(_MSC_VER)
extern char **environ;
#endif
The declaration in the OS header file is:
_DCRTIMP char*** __cdecl __p__environ (void);
#define _environ (*__p__environ())
So it is evident that this could be problematic.
The old declaration was required by the old MSVCRT library, but we
don't support that anymore with MSVC.
To fix, disable the re-declaration in ps_status.c, and also in some
other places that use the same code pattern but didn't trigger the
warning.
Then we can also re-enable the warning (delete the disablement in
meson.build).
Reviewed-by: Bryan Green <dbryan.green@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/bf060644-47ff-441b-97cf-c685d0827757@eisentraut.org
This commit adds a new column, seq_sync_error_count, to the
pg_stat_subscription_stats view. This counter tracks the number of errors
encountered by the sequence synchronization worker during operation.
Since a single worker handles the synchronization of all sequences, this
value may reflect errors from multiple sequences. This addition improves
observability of sequence synchronization behavior and helps monitor
potential issues during replication.
Author: Vignesh C <vignesh21@gmail.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com
The following parameters can only be set at server start because
their context is PGC_POSTMASTER, but this information was missing
or incorrectly documented. This commit adds or corrects
that information for the following parameters:
* debug_io_direct
* dynamic_shared_memory_type
* event_source
* huge_pages
* io_max_combine_limit
* max_notify_queue_pages
* shared_memory_type
* track_commit_timestamp
* wal_decode_buffer_size
Backpatched to all supported branches.
Author: Karina Litskevich <litskevichkarina@gmail.com>
Reviewed-by: Chao Li <lic@highgo.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHGQGwGfPzcin-_6XwPgVbWTOUFVZgHF5g9ROrwLUdCTfjy=0A@mail.gmail.com
Backpatch-through: 13
