This commit reverts the fix "Make inherited TRUNCATE perform access
permission checks on parent table only" only in the back branches.
It's not hard to imagine that there are some applications expecting
the old behavior and the fix breaks their security. To avoid this
compatibility problem, we decided to apply the fix only in HEAD and
revert it in all supported back branches.
Discussion: https://postgr.es/m/21015.1580400165@sss.pgh.pa.us
If we attempt to create a DSM segment when no slots are available,
we should return the memory to the operating system. Previously
we did that if the DSM_CREATE_NULL_IF_MAXSEGMENTS flag was
passed in, but we didn't do it if an error was raised. Repair.
Back-patch to 9.4, where DSM segments arrived.
Author: Thomas Munro
Reviewed-by: Robert Haas
Reported-by: Julian Backes
Discussion: https://postgr.es/m/CA%2BhUKGKAAoEw-R4om0d2YM4eqT1eGEi6%3DQot-3ceDR-SLiWVDw%40mail.gmail.com
Commit fc7695891 changed CheckAttributeType to recurse into ranges,
but made it pass down the wrong collation (always InvalidOid, since
ranges as such have no collation). This would result in guaranteed
failure when considering a range type whose subtype is collatable.
Embarrassingly, we lack any regression tests that would expose such
a problem (but fortunately, somebody noticed before we shipped this
bug in any release).
Fix it to pass down the range's subtype collation property instead,
and add some regression test cases to exercise collatable-subtype
ranges a bit more. Back-patch to all supported branches, as the
previous patch was.
Report and patch by Julien Rouhaud, test cases tweaked by me
Discussion: https://postgr.es/m/CAOBaU_aBWqNweiGUFX0guzBKkcfJ8mnnyyGC_KBQmO12Mj5f_A@mail.gmail.com
If we failed to fork a worker process, or create a communication pipe
for one, WaitForTerminatingWorkers would suffer an assertion failure
if assert-enabled, otherwise crash or go into an infinite loop. This
was a consequence of not accounting for the startup condition where
we've not yet forked all the workers.
The original bug was that ParallelBackupStart would set workerStatus to
WRKR_IDLE before it had successfully forked a worker. I made things
worse in commit b7b8cc0cf by not understanding the undocumented fact
that the WRKR_TERMINATED state was also meant to represent the case
where a worker hadn't been started yet: I changed enum T_WorkerStatus
so that *all* the worker slots were initially in WRKR_IDLE state. But
this wasn't any more broken in practice, since even one slot in the
wrong state would keep WaitForTerminatingWorkers from terminating.
In v10 and later, introduce an explicit T_WorkerStatus value for
worker-not-started, in hopes of preventing future oversights of the
same ilk. Before that, just document that WRKR_TERMINATED is supposed
to cover that case (partly because it wasn't actively broken, and
partly because the enum is exposed outside parallel.c in those branches,
so there's microscopically more risk involved in changing it).
In all branches, introduce a WORKER_IS_RUNNING status test macro
to hide which T_WorkerStatus values mean that, and be more careful
not to access ParallelSlot fields till we're sure they're valid.
Per report from Vignesh C, though this is my patch not his.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/CALDaNm1Luv-E3sarR+-unz-BjchquHHyfP+YC+2FS2pt_J+wxg@mail.gmail.com
Very recent gcc complains that PLyObject_ToJsonbValue could return
a pointer to a local variable. I think it's wrong; but the coding
is fragile enough, and the savings of one palloc() minimal enough,
that it seems better to just do a palloc() all the time. (My other
idea of tweaking the if-condition doesn't suppress the warning.)
Back-patch to v11 where this code was introduced.
Discussion: https://postgr.es/m/21547.1580170366@sss.pgh.pa.us
If no DSM slots are available, a ParallelContext can still be
created, but its seg pointer is NULL. Teach parallel btree build
to cope with that by falling back to a regular non-parallel build,
to avoid crashing with a segmentation fault.
Back-patch to 11, where parallel CREATE INDEX landed.
Reported-by: Nicola Contu
Reviewed-by: Peter Geoghegan
Discussion: https://postgr.es/m/CA%2BhUKGJgJEBnkuODBVomyK3MWFvDBbMVj%3Dgdt6DnRPU-5sQ6UQ%40mail.gmail.com
Previously, TRUNCATE command through a parent table checked the
permissions on not only the parent table but also the children tables
inherited from it. This was a bug and inherited queries should perform
access permission checks on the parent table only. This commit fixes
that bug.
Back-patch to all supported branches.
Author: Amit Langote
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/CAHGQGwFHdSvifhJE+-GSNqUHSfbiKxaeQQ7HGcYz6SC2n_oDcg@mail.gmail.com
Advancing a physical replication slot with pg_replication_slot_advance()
did not mark the slot as dirty if any advancing was done, preventing the
follow-up checkpoint to flush the slot data to disk. This caused the
advancing to be lost even on clean restarts. This does not happen for
logical slots as any advancing marked the slot as dirty. Per
discussion, the original feature has been implemented so as in the event
of a crash the slot may move backwards to a past LSN. This property is
kept and more documentation is added about that.
This commit adds some new TAP tests to check the persistency of physical
and logical slots after advancing across clean restarts.
Author: Alexey Kondratov, Michael Paquier
Reviewed-by: Andres Freund, Kyotaro Horiguchi, Craig Ringer
Discussion: https://postgr.es/m/059cc53a-8b14-653a-a24d-5f867503b0ee@postgrespro.ru
Backpatch-through: 11
channel_binding's longest allowed value is not "7", it is actually "8".
gssencmode also got that wrong.
A similar mistake has been fixed as of f4051e3.
Backpatch down to v12, where gssencmode has been introduced.
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20200128053633.GD1552@paquier.xyz
Backpatch-through: 12
EvalPlanQualStart() supposed that it could re-use the relsubs_rowmark
and relsubs_done arrays from a prior instantiation. But since they are
allocated in the es_query_cxt of the recheckestate, that's just wrong;
EvalPlanQualEnd() will blow away that storage. Therefore we were using
storage that could have been reallocated to something else, causing all
sorts of havoc.
I think this was modeled on the old code's handling of es_epqTupleSlot,
but since the code was anyway clearing the arrays at re-use, there's
clearly no expectation of importing any outside state. So it's just
a dubious savings of a couple of pallocs, which is negligible compared
to setting up a new planstate tree. Therefore, just allocate the
arrays always. (I moved the allocations slightly for readability.)
In principle this bug could cause a problem whenever EPQ rechecks are
needed in more than one target table of a ModifyTable plan node.
In practice it seems not quite so easy to trigger as that; I couldn't
readily duplicate a crash with a partitioned target table, for instance.
That's probably down to incidental choices about when to free or
reallocate stuff. The added isolation test case does seem to reliably
show an assertion failure, though.
Per report from Oleksii Kliukin. Back-patch to v12 where the bug was
introduced (evidently by commit 3fb307bc4).
Discussion: https://postgr.es/m/EEF05F66-2871-4786-992B-5F45C92FEE2E@hintbits.com
Currently, Parallel Hash Join cannot be used for full/right joins,
so there is no point in setting the match flag. It turns out that
the cache coherence traffic generated by those writes slows down
large systems running many-core joins, so let's stop doing that.
In future, if we need to use match bits in parallel joins, we might
want to consider setting them only if not already set.
Back-patch to 11, where Parallel Hash Join arrived.
Reported-by: Deng, Gang
Discussion: https://postgr.es/m/0F44E799048C4849BAE4B91012DB910462E9897A%40SHSMSX103.ccr.corp.intel.com
In non-TEXT output formats, the "Settings" field should appear when
requested, even if it would be empty.
Also, get rid of the premature optimization of counting all the
GUC_EXPLAIN variables at startup. Since there was no provision for
adjusting that count later, all it'd take would be some extension marking
a parameter as GUC_EXPLAIN to risk an assertion failure or memory stomp.
We could make get_explain_guc_options() count those variables on-the-fly,
or dynamically resize its array ... but TBH I do not think that making a
transient array of pointers a bit smaller is worth any extra complication,
especially when you consider all the other transient space EXPLAIN eats.
So just allocate that array at the max possible size.
In HEAD, also add some regression test coverage for this feature.
Because of the memory-stomp hazard, back-patch to v12 where this
feature was added.
Discussion: https://postgr.es/m/19416.1580069629@sss.pgh.pa.us
In a statement like "UPDATE remote_tab SET (x,y) = (SELECT ...)",
we'd conclude that the statement could be directly executed remotely,
because the sub-SELECT is in a resjunk tlist item that's not examined
for shippability. Currently that ends up crashing if the sub-SELECT
contains any remote Vars. Prevent the crash by deeming MULTIEXEC
Params to be unshippable.
This is a bit of a brute-force solution, since if the sub-SELECT
*doesn't* contain any remote Vars, the current execution technology
would work; but that's not a terribly common use-case for this syntax,
I think. In any case, we generally don't try to ship sub-SELECTs, so
it won't surprise anybody that this doesn't end up as a remote direct
update. I'd be inclined to see if that general limitation can be fixed
before worrying about this case further.
Per report from Lukáš Sobotka.
Back-patch to 9.6. 9.5 had MULTIEXPR, but we didn't try to perform
remote direct updates then, so the case didn't arise anyway.
Discussion: https://postgr.es/m/CAJif3k+iA_ekBB5Zw2hDBaE1wtiQa4LH4_JUXrrMGwTrH0J01Q@mail.gmail.com
I had supposed that the from_char_seq_search() call sites were
all passing the constant arrays you'd expect them to pass ...
but on looking closer, the one for DY format was passing the
days[] array not days_short[]. This accidentally worked because
the day abbreviations in English are all the same as the first
three letters of the full day names. However, once we took out
the "maximum comparison length" logic, it stopped working.
As penance for that oversight, add regression test cases covering
this, as well as every other switch case in DCH_from_char() that
was not reached according to the code coverage report.
Also, fold the DCH_RM and DCH_rm cases into one --- now that
seq_search is case independent, there's no need to pass different
comparison arrays for those cases.
Back-patch, as the previous commit was.
seq_search(), which is used to match input substrings to constants
such as month and day names, had a lot of bizarre and unnecessary
behaviors. It was mostly possible to avert our eyes from that before,
but we don't want to duplicate those behaviors in the upcoming patch
to allow recognition of non-English month and day names. So it's time
to clean this up. In particular:
* seq_search scribbled on the input string, which is a pretty dangerous
thing to do, especially in the badly underdocumented way it was done here.
Fortunately the input string is a temporary copy, but that was being made
three subroutine levels away, making it something easy to break
accidentally. The behavior is externally visible nonetheless, in the form
of odd case-folding in error reports about unrecognized month/day names.
The scribbling is evidently being done to save a few calls to pg_tolower,
but that's such a cheap function (at least for ASCII data) that it's
pretty pointless to worry about. In HEAD I switched it to be
pg_ascii_tolower to ensure it is cheap in all cases; but there are corner
cases in Turkish where this'd change behavior, so leave it as pg_tolower
in the back branches.
* seq_search insisted on knowing the case form (all-upper, all-lower,
or initcap) of the constant strings, so that it didn't have to case-fold
them to perform case-insensitive comparisons. This likewise seems like
excessive micro-optimization, given that pg_tolower is certainly very
cheap for ASCII data. It seems unsafe to assume that we know the case
form that will come out of pg_locale.c for localized month/day names, so
it's better just to define the comparison rule as "downcase all strings
before comparing". (The choice between downcasing and upcasing is
arbitrary so far as English is concerned, but it might not be in other
locales, so follow citext's lead here.)
* seq_search also had a parameter that'd cause it to report a match
after a maximum number of characters, even if the constant string were
longer than that. This was not actually used because no caller passed
a value small enough to cut off a comparison. Replicating that behavior
for localized month/day names seems expensive as well as useless, so
let's get rid of that too.
* from_char_seq_search used the maximum-length parameter to truncate
the input string in error reports about not finding a matching name.
This leads to rather confusing reports in many cases. Worse, it is
outright dangerous if the input string isn't all-ASCII, because we
risk truncating the string in the middle of a multibyte character.
That'd lead either to delivering an illegible error message to the
client, or to encoding-conversion failures that obscure the actual
data problem. Get rid of that in favor of truncating at whitespace
if any (a suggestion due to Alvaro Herrera).
In addition to fixing these things, I const-ified the input string
pointers of DCH_from_char and its subroutines, to make sure there
aren't any other scribbling-on-input problems.
The risk of generating a badly-encoded error message seems like
enough of a bug to justify back-patching, so patch all supported
branches.
Discussion: https://postgr.es/m/29432.1579731087@sss.pgh.pa.us
Attempting to use CREATE INDEX, DROP INDEX or REINDEX with CONCURRENTLY
on a temporary relation with ON COMMIT actions triggered unexpected
errors because those operations use multiple transactions internally to
complete their work. Here is for example one confusing error when using
ON COMMIT DELETE ROWS:
ERROR: index "foo" already contains data
Issues related to temporary relations and concurrent indexing are fixed
in this commit by enforcing the non-concurrent path to be taken for
temporary relations even if using CONCURRENTLY, transparently to the
user. Using a non-concurrent path does not matter in practice as locks
cannot be taken on a temporary relation by a session different than the
one owning the relation, and the non-concurrent operation is more
effective.
The problem exists with REINDEX since v12 with the introduction of
CONCURRENTLY, and with CREATE/DROP INDEX since CONCURRENTLY exists for
those commands. In all supported versions, this caused only confusing
error messages to be generated. Note that with REINDEX, it was also
possible to issue a REINDEX CONCURRENTLY for a temporary relation owned
by a different session, leading to a server crash.
The idea to enforce transparently the non-concurrent code path for
temporary relations comes originally from Andres Freund.
Reported-by: Manuel Rigger
Author: Michael Paquier, Heikki Linnakangas
Reviewed-by: Andres Freund, Álvaro Herrera, Heikki Linnakangas
Discussion: https://postgr.es/m/CA+u7OA6gP7YAeCguyseusYcc=uR8+ypjCcgDDCTzjQ+k6S9ksQ@mail.gmail.com
Backpatch-through: 9.4
The code checking whether an aggregate transition value needs to be
reparented into the current context has always only compared the
transition return value with the previous transition value by datum,
i.e. without regard for NULLness. This normally works, because when
the transition function returns NULL (via fcinfo->isnull), it'll
return a value that won't be the same as its input value.
But there's no hard requirement that that's the case. And it turns
out, it's possible to hit this case (see discussion or reproducers),
leading to a non-null transition value not being reparented, followed
by a crash caused by that.
Instead of adding another comparison of NULLness, instead have
ExecAggTransReparent() ensure that pergroup->transValue ends up as 0
when the new transition value is NULL. That avoids having to add an
additional branch to the much more common cases of the transition
function returning the old transition value (which is a pointer in
this case), and when the new value is different, but not NULL.
In branches since 69c3936a14, also deduplicate the reparenting code
between the expression evaluation based transitions, and the path for
ordered aggregates.
Reported-By: Teodor Sigaev, Nikita Glukhov
Author: Andres Freund
Discussion: https://postgr.es/m/bd34e930-cfec-ea9b-3827-a8bc50891393@sigaev.ru
Backpatch: 9.4-, this issue has existed since at least 7.4
This helps integration of extensions with Windows. The following
parameters are changed:
- idle_in_transaction_session_timeout (9.6 and newer versions)
- lock_timeout
- statement_timeout
- track_activities
- track_counts
- track_functions
Author: Pascal Legrand
Reviewed-by: Amit Kamila, Julien Rouhaud, Michael Paquier
Discussion: https://postgr.es/m/1579298868581-0.post@n3.nabble.com
Backpatch-through: 9.4
sigTermHandler() tried to be careful to invoke only operations that
are safe to do in a signal handler. But for some reason we forgot
that exit(3) is not among those, because it calls atexit handlers
that might do various random things. (pg_dump itself installs no
atexit handlers, but e.g. OpenSSL does.) That led to crashes or
lockups when attempting to terminate a parallel dump or restore
via a signal.
Fix by calling _exit() instead.
Per bug #16199 from Raúl Marín. Back-patch to all supported branches.
Discussion: https://postgr.es/m/16199-cb2f121146a96f9b@postgresql.org
The BRIN add_value() and union() functions need to make a longer-lived
copy of the argument, if they want to store it in the BrinValues struct
also passed as argument. The functions for the "inclusion operator
classes" used with box, range and inet types didn't take into account
that the union helper function might return its argument as is, without
making a copy. Check for that case, and make a copy if necessary. That
case arises at least with the range_union() function, when one of the
arguments is an 'empty' range:
CREATE TABLE brintest (n numrange);
CREATE INDEX brinidx ON brintest USING brin (n);
INSERT INTO brintest VALUES ('empty');
INSERT INTO brintest VALUES (numrange(0, 2^1000::numeric));
INSERT INTO brintest VALUES ('(-1, 0)');
SELECT brin_desummarize_range('brinidx', 0);
SELECT brin_summarize_range('brinidx', 0);
Backpatch down to 9.5, where BRIN was introduced.
Discussion: https://www.postgresql.org/message-id/e6e1d6eb-0a67-36aa-e779-bcca59167c14%40iki.fi
Reviewed-by: Emre Hasegeli, Tom Lane, Alvaro Herrera
ecpg_build_params() would crash on a null pointer dereference if
realloc() failed, due to updating the persistent "stmt" struct
too aggressively. (Even without the crash, this would've leaked
the old storage that we were trying to realloc.)
Per Coverity. This seems to have been broken in commit 0cc050794,
so back-patch into v12.
Mixing incorrect bounds set in the SSL context leads to confusing error
messages generated by OpenSSL which are hard to act on. New checks are
added within the GUC machinery to improve the user experience as they
apply to any SSL implementation, not only OpenSSL, and doing the checks
beforehand avoids the creation of a SSL during a reload (or startup)
which we know will never be used anyway.
Backpatch down to 12, as those parameters have been introduced by
e73e67c.
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20200114035420.GE1515@paquier.xyz
Backpatch-through: 12
Commit 9b63c13f0 turns out to have been fundamentally misguided:
the parent node's subPlan list is by no means the only way in which
a child SubPlan node can be hooked into the outer execution state.
As shown in bug #16213 from Matt Jibson, we can also get short-lived
tuple table slots added to the outer es_tupleTable list. At this point
I have little faith that there aren't other possible connections as
well; the long time it took to notice this problem shows that this
isn't a heavily-exercised situation.
Therefore, revert that fix, returning to the coding that passed a
NULL parent plan pointer down to the transiently-built subexpressions.
That gives us a pretty good guarantee that they won't hook into the
outer executor state in any way. But then we need some other solution
to make SubPlans work. Adopt the solution speculated about in the
previous commit's log message: do expression initialization at plan
startup for just those VALUES rows containing SubPlans, abandoning the
goal of reclaiming memory intra-query for those rows. In practice it
seems unlikely that queries containing a vast number of VALUES rows
would be using SubPlans in them, so this should not give up much.
(BTW, this test case also refutes my claim in connection with the prior
commit that the issue only arises with use of LATERAL. That was just
wrong: some variants of SubLink always produce SubPlans.)
As with previous patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/16213-871ac3bc208ecf23@postgresql.org
... specifically, set it incrementally as each individual change is
spilled down to disk. This way, it is set correctly when the
transaction disappears without trace, ie. without leaving an XACT_ABORT
wal record. (This happens when the server crashes midway through a
transaction.)
Failing to have final_lsn prevents ReorderBufferRestoreCleanup() from
working, since it needs the final_lsn in order to know the endpoint of
its iteration through spilled files.
Commit df9f682c7b already tried to fix the problem, but it didn't set
the final_lsn in all cases. Revert that, since it's no longer needed.
Author: Vignesh C
Reviewed-by: Amit Kapila, Dilip Kumar
Discussion: https://postgr.es/m/CALDaNm2CLk+K9JDwjYST0sPbGg5AQdvhUt0jbKyX_HdAE0jk3A@mail.gmail.com
The bitmap used by SlabCheck to cross-check free chunks in a block used
to be allocated for each SlabCheck call, and was never freed. The memory
leak could be fixed by simply adding a pfree call, but it's actually a
bad idea to do any allocations in SlabCheck at all as it assumes the
state of the memory management as a whole is sane.
So instead we allocate the bitmap as part of SlabContext, which means
we don't need to do any allocations in SlabCheck and the bitmap goes
away together with the SlabContext.
Backpatch to 10, where the Slab context was introduced.
Author: Tomas Vondra
Reported-by: Andres Freund
Reviewed-by: Tom Lane
Backpatch-through: 10
Discussion: https://www.postgresql.org/message-id/20200116044119.g45f7pmgz4jmodxj%40alap3.anarazel.de
The logic introduced in this routine as of 246a6c8 would report an
incorrect result when a session calls it to check if the temporary
namespace owned by the session is in use or not. It is possible to
optimize more the routine in this case to avoid a PGPROC lookup, but
let's keep the logic simple. As this routine is used only by autovacuum
for now, there were no live bugs, still let's be correct for any future
code involving it.
Author: Michael Paquier
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/20200113093703.GA41902@paquier.xyz
Backpatch-through: 11
A view with conditional INSTEAD rules and no unconditional INSTEAD
rules or INSTEAD OF triggers is not auto-updatable. Previously we
relied on a check in the executor to catch this, but that's
problematic since the planner may fail to properly handle such a query
and thus return a particularly unhelpful error to the user, before
reaching the executor check.
Instead, trap this in the rewriter and report the correct error there.
Doing so also allows us to include more useful error detail than the
executor check can provide. This doesn't change the existing behaviour
of updatable views; it merely ensures that useful error messages are
reported when a view isn't updatable.
Per report from Pengzhou Tang, though not adopting that suggested fix.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAG4reAQn+4xB6xHJqWdtE0ve_WqJkdyCV4P=trYr4Kn8_3_PEA@mail.gmail.com
This test was trying to test the mechanism to release kernel FDs as needed
to get us under the max_safe_fds limit in case of spill files. To do that,
it needs to set max_files_per_process to a very low value which doesn't
even permit starting of the server in the case when there are a few already
opened files. This test also won't work on platforms where we use one FD
per semaphore.
Backpatch-through: 10, till where this test was added
Discussion:
https://postgr.es/m/CAA4eK1LHhERi06Q+MmP9qBXBBboi+7WV3910J0aUgz71LcnKAw@mail.gmail.comhttps://postgr.es/m/6485.1578583522@sss.pgh.pa.us
The use of pg_atoi() for parsing a string into an Oid fails for values
larger than INT32_MAX, since OIDs are unsigned. Instead, use
atooid(). While this has less error checking, the contents of the
data directory are expected to be trustworthy, so we don't need to go
out of our way to do full error checking.
Discussion: https://www.postgresql.org/message-id/flat/dea47fc8-6c89-a2b1-07e3-754ff1ab094b%402ndquadrant.com
When estimating the selectivity of "range_var <@ range_constant" or
"range_var @> range_constant", if the upper (or respectively lower)
bound of the range_constant was above the last bin of the range_var's
histogram, the code would access uninitialized memory and potentially
crash (though it seems the probability of a crash is quite low).
Handle the endpoint cases explicitly to fix that.
While at it, be more paranoid about the possibility of getting NaN
or other silly results from the range type's subdiff function.
And improve some comments.
Ordinarily we'd probably add a regression test case demonstrating
the bug in unpatched code. But it's too hard to get it to crash
reliably because of the uninitialized-memory dependence, so skip that.
Per bug #16122 from Adam Scott. It's been broken from the beginning,
apparently, so backpatch to all supported branches.
Diagnosis by Michael Paquier, patch by Andrey Borodin and Tom Lane.
Discussion: https://postgr.es/m/16122-eb35bc248c806c15@postgresql.org
On the publisher, it was assumed that an INSERT change cannot happen for
a relation with no replica identity. However this is true only for a
change that needs references to old rows, aka UPDATE or DELETE, so
trying to use logical replication with a relation that has no replica
identity led to an assertion failure in the publisher when issuing an
INSERT. This commit removes the incorrect assertion, and adds more
regression tests to provide coverage for relations without replica
identity.
Reported-by: Neha Sharma
Author: Dilip Kumar, Michael Paquier
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/CANiYTQsL1Hb8_Km08qd32svrqNumXLJeoGo014O7VZymgOhZEA@mail.gmail.com
Backpatch-through: 10
Fix assorted bugs in handling of non-blocking I/O when using GSSAPI
encryption. The encryption layer could return the wrong status
information to its caller, resulting in effectively dropping some data
(or possibly in aborting a not-broken connection), or in a "livelock"
situation where data remains to be sent but the upper layers think
transmission is done and just go to sleep. There were multiple small
thinkos contributing to that, as well as one big one (failure to think
through what to do when a send fails after having already transmitted
data). Note that these errors could cause failures whether the client
application asked for non-blocking I/O or not, since both libpq and
the backend always run things in non-block mode at this level.
Also get rid of use of static variables for GSSAPI inside libpq;
that's entirely not okay given that multiple connections could be
open at once inside a single client process.
Also adjust a bunch of random small discrepancies between the frontend
and backend versions of the send/receive functions -- except for error
handling, they should be identical, and now they are.
Also extend the Kerberos TAP tests to exercise cases where nontrivial
amounts of data need to be pushed through encryption. Before, those
tests didn't provide any useful coverage at all for the cases of
interest here. (They still might not, depending on timing, but at
least there's a chance.)
Per complaint from pmc@citylink and subsequent investigation.
Back-patch to v12 where this code was introduced.
Discussion: https://postgr.es/m/20200109181822.GA74698@gate.oper.dinoex.org
FileClose() failure ordinarily causes a PANIC. Suppose the user
disables that PANIC via data_sync_retry=on. After mdclose() issued a
FileClose() that failed, calls into md.c raised SIGSEGV. This fix adds
repalloc() calls during mdclose(); update a comment about ignoring
repalloc() cost. The rate of relation segment count change is a minor
factor; more relevant to overall performance is the rate of mdclose()
and subsequent re-opening of segments. Back-patch to v10, where commit
45e191e3aa introduced the bug.
Reviewed by Kyotaro Horiguchi.
Discussion: https://postgr.es/m/20191222091930.GA1280238@rfd.leadboat.com
Make the value null only at pg_stat_activity-output time, as suggested
by Tom Lane, instead of messing with the internal state. This should
appease buildfarm members with force_parallel_mode=regress, which are
running parallel queries on logical replication walsenders.
The fact that walsenders can run parallel queries should perhaps be
studied more carefully, but for the moment let's get rid of the red
blots in buildfarm.
Backpatch to pg10, like the previous commit.
Discussion: https://postgr.es/m/30804.1578438763@sss.pgh.pa.us
ALTER TABLE failed if a column referenced in a GENERATED expression
had been added or changed in type earlier in the ALTER command.
That's because the GENERATED expression needs to be evaluated
against the table's updated tuples, but it was being evaluated
against the original tuples. (Fortunately the executor has adequate
cross-checks to notice the mismatch, so we just got an obscure error
message and not anything more dangerous.)
Per report from Andreas Joseph Krogh. Back-patch to v12 where
GENERATED was added.
Discussion: https://postgr.es/m/VisenaEmail.200.231b0a41523275d0.16ea7f800c7@tc7-visena
Returning a non-NULL time is pointless, sinc a walsender is not a
process that would be running normal transactions anyway, but the code
was unintentionally exposing the process start time intermittently,
which was not only bogus but it also confused monitoring systems looking
for idle transactions. Fix by avoiding all updates in walsenders.
Backpatch to 11, where walsenders started appearing in pg_stat_activity.
Reported-by: Tomas Vondra
Discussion: https://postgr.es/m/20191209234409.exe7osmyalwkt5j4@development
Since the WAL flush position only moves forward, it's safe to cache
its previous value within each walsender process, and update from
shared memory only once we've caught up to the previously-seen value.
When there are many active walsenders, this makes for a very significant
reduction in the amount of contention on the XLogCtl->info_lck spinlock.
This patch also adjusts the logic so that we update our idea of the
flush position after processing a WAL record, rather than beforehand.
This may cause us to realize we're not caught up when the preceding
coding would've thought that we were, but that seems all to the good;
it may avoid a useless sleep-and-wakeup cycle.
Back-patch to v12. The contention problem exists in prior branches,
but it's much less severe (due to inefficiencies elsewhere) so there
seems no need to take any risk of back-patching further.
Pierre Ducroquet, reviewed by Julien Rouhaud
Discussion: https://postgr.es/m/2931018.Vxl9zapr77@pierred-pdoc
When row triggers exist in partitioned partitions that are not either
part of FKs or deferred unique constraints, they are not correctly
cloned to their partitions. That's because they are marked "internal",
and those are purposefully skipped when doing the clone triggers dance.
Fix by relaxing the condition on which internal triggers are skipped.
Amit Langote initially diagnosed the problem and proposed a fix, but I
used a different approach.
Reported-by: Petr Fedorov
Discussion: https://postgr.es/m/6b3f0646-ba8c-b3a9-c62d-1c6651a1920f@phystech.edu
Currently while decoding changes, if the number of changes exceeds a
certain threshold, we spill those to disk. And this happens for each
(sub)transaction. Now, while reading all these files, we don't close them
until we read all the files. While reading these files, if the number of
such files exceeds the maximum number of file descriptors, the operation
errors out.
Use PathNameOpenFile interface to open these files as that internally has
the mechanism to release kernel FDs as needed to get us under the
max_safe_fds limit.
Reported-by: Amit Khandekar
Author: Amit Khandekar
Reviewed-by: Amit Kapila
Backpatch-through: 9.4
Discussion: https://postgr.es/m/CAJ3gD9c-sECEn79zXw4yBnBdOttacoE-6gAyP0oy60nfs_sabQ@mail.gmail.com
