3c84046 is the original commit that introduced index_set_state_flags(),
where the presence of SnapshotNow made necessary the use of an in-place
update. SnapshotNow has been removed in 813fb03, so there is no actual
reasons to not make this operation transactional.
As reported by Andrey, it is possible to trigger the assertion of this
routine expecting no transactional updates when switching the pg_index
state flags, using a predicate mark as immutable but calling stable or
volatile functions. 83158f7 has been around for a couple of months on
HEAD now with no issues found related to it, so it looks safe enough for
a backpatch.
Reported-by: Andrey Lepikhov
Author: Michael Paquier
Reviewed-by: Anastasia Lubennikova
Discussion: https://postgr.es/m/20200903080440.GA8559@paquier.xyz
Discussion: https://postgr.es/m/9b905019-5297-7372-0ad2-e1a4bb66a719@postgrespro.ru
Backpatch-through: 9.6
Attempting to use this function with event triggers failed, as, since
its introduction in a676201, this code has never associated an object
name with event triggers. This addresses the failure by adding the
event trigger name to the set defining its object address.
Note that regression tests are added within event_trigger and not
object_address to avoid issues with concurrent connections in parallel
schedules.
Author: Joel Jacobson
Discussion: https://postgr.es/m/3c905e77-a026-46ae-8835-c3f6cd1d24c8@www.fastmail.com
Backpatch-through: 9.6
Generally, members of inheritance trees must be plain tables (or,
in more recent versions, foreign tables). ALTER TABLE INHERIT
rejects creating an inheritance relationship that has a view at
either end. When DefineQueryRewrite attempts to convert a relation
to a view, it already had checks prohibiting doing so for partitioning
parents or children as well as traditional-inheritance parents ...
but it neglected to check that a traditional-inheritance child wasn't
being converted. Since the planner assumes that any inheritance
child is a table, this led to making plans that tried to do a physical
scan on a view, causing failures (or even crashes, in recent versions).
One could imagine trying to support such a case by expanding the view
normally, but since the rewriter runs before the planner does
inheritance expansion, it would take some very fundamental refactoring
to make that possible. There are probably a lot of other parts of the
system that don't cope well with such a situation, too. For now,
just forbid it.
Per bug #16856 from Yang Lin. Back-patch to all supported branches.
(In versions before v10, this includes back-patching the portion of
commit 501ed02cf that added has_superclass(). Perhaps the lack of
that infrastructure partially explains the missing check.)
Discussion: https://postgr.es/m/16856-0363e05c6e1612fd@postgresql.org
Specifying duplicated objects in this command would lead to unique
constraint violations in pg_default_acl or "tuple already updated by
self" errors. Similarly to GRANT/REVOKE, increment the command ID after
each subcommand processing to allow this case to work transparently.
A regression test is added by tweaking one of the existing queries of
privileges.sql to stress this case.
Reported-by: Andrus
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/ae2a7dc1-9d71-8cba-3bb9-e4cb7eb1f44e@hot.ee
Backpatch-through: 9.5
We reported the wrong types when complaining that an aggregate's
moving-aggregate implementation is inconsistent with its regular
implementation.
This was wrong since the feature was introduced, so back-patch
to all supported branches.
Jeff Janes
Discussion: https://postgr.es/m/CAMkU=1x808LH=LPhZp9mNSP0Xd1xDqEd+XeGcvEe48dfE6xV=A@mail.gmail.com
When a table is scanned by heapam_index_build_range_scan (née
IndexBuildHeapScan) and the table lock being held allows concurrent data
changes, it is possible for new HOT chains to sprout in a page that were
unknown when the scan of a page happened. This leads to an error such
as
ERROR: failed to find parent tuple for heap-only tuple at (X,Y) in table "tbl"
because the root tuple was not present when we first obtained the list
of the page's root tuples. This can be fixed by re-obtaining the list
of root tuples, if we see that a heap-only tuple appears to point to a
non-existing root.
This was reported by Anastasia as occurring for BRIN summarization
(which exists since 9.5), but I think it could theoretically also happen
with CREATE INDEX CONCURRENTLY (much older) or REINDEX CONCURRENTLY
(very recent). It seems a happy coincidence that BRIN forces us to
backpatch this all the way to 9.5.
Reported-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Diagnosed-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Co-authored-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/602d8487-f0b2-5486-0088-0f372b2549fa@postgrespro.ru
Backpatch: 9.5 - master
We were acquiring object locks then deleting objects one by one, instead
of acquiring all object locks first, ignoring those that did not exist,
and then deleting all objects together. The latter is the correct
protocol to use, and what this commits changes to code to do. Failing
to follow that leads to "cache lookup failed for relation XYZ" error
reports when DROP OWNED runs concurrently with other DDL -- for example,
a session termination that removes some temp tables.
Author: Álvaro Herrera
Reported-by: Mithun Chicklore Yogendra (Mithun CY)
Reviewed-by: Ahsan Hadi, Tom Lane
Discussion: https://postgr.es/m/CADq3xVZTbzK4ZLKq+dn_vB4QafXXbmMgDP3trY-GuLnib2Ai1w@mail.gmail.com
index.c supposed that it could just use a PG_TRY block to clean up the
state associated with an active REINDEX operation. However, that code
doesn't run if we do a FATAL exit --- for example, due to a SIGTERM
shutdown signal --- while the REINDEX is happening. And that state does
get consulted during catalog accesses, which makes it problematic if we
do any catalog accesses during shutdown --- for example, to clean up any
temp tables created in the session.
If this combination of circumstances occurred, we could find ourselves
trying to access already-freed memory. In debug builds that'd fairly
reliably cause an assertion failure. In production we might often
get away with it, but with some bad luck it could cause a core dump.
Another possible bad outcome is an erroneous conclusion that an
index-to-be-accessed is being reindexed; but it looks like that would
be unlikely to have any consequences worse than failing to drop temp
tables right away. (They'd still get dropped by the next session that
uses that temp schema.)
To fix, get rid of the use of PG_TRY here, and instead hook into
the transaction abort mechanisms to clean up reindex state.
Per bug #16378 from Alexander Lakhin. This has been wrong for a
very long time, so back-patch to all supported branches.
Discussion: https://postgr.es/m/16378-7a70ca41b3ec2009@postgresql.org
Until now, only selected bulk operations (e.g. COPY) did this. If a
given relfilenode received both a WAL-skipping COPY and a WAL-logged
operation (e.g. INSERT), recovery could lose tuples from the COPY. See
src/backend/access/transam/README section "Skipping WAL for New
RelFileNode" for the new coding rules. Maintainers of table access
methods should examine that section.
To maintain data durability, just before commit, we choose between an
fsync of the relfilenode and copying its contents to WAL. A new GUC,
wal_skip_threshold, guides that choice. If this change slows a workload
that creates small, permanent relfilenodes under wal_level=minimal, try
adjusting wal_skip_threshold. Users setting a timeout on COMMIT may
need to adjust that timeout, and log_min_duration_statement analysis
will reflect time consumption moving to COMMIT from commands like COPY.
Internally, this requires a reliable determination of whether
RollbackAndReleaseCurrentSubTransaction() would unlink a relation's
current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the
specification of rd_createSubid such that the field is zero when a new
rel has an old rd_node. Make relcache.c retain entries for certain
dropped relations until end of transaction.
Back-patch to 9.5 (all supported versions). This introduces a new WAL
record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As
always, update standby systems before master systems. This changes
sizeof(RelationData) and sizeof(IndexStmt), breaking binary
compatibility for affected extensions. (The most recent commit to
affect the same class of extensions was
089e4d405d0f3b94c74a2c6a54357a84a681754b.)
Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert
Haas. Heikki Linnakangas and Michael Paquier implemented earlier
designs that materially clarified the problem. Reviewed, in earlier
designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane,
Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout.
Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
If the command is attempted for an extension that the object already
depends on, silently do nothing.
In particular, this means that if a database containing multiple such
entries is dumped, the restore will silently do the right thing and
record just the first one. (At least, in a world where pg_dump does
dump such entries -- which it doesn't currently, but it will.)
Backpatch to 9.6, where this kind of dependency was introduced.
Reviewed-by: Ibrar Ahmed, Tom Lane (offlist)
Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql
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
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
We probably should have thought of this case when ranges were added,
but we didn't. (It's not the fault of commit eb51af71f, because
ranges didn't exist then.)
It's an old bug, so back-patch to all supported branches.
Discussion: https://postgr.es/m/7782.1577051475@sss.pgh.pa.us
If CheckAttributeType() threw an error about the datatype of an
index expression column, it would report an empty column name,
which is pretty unhelpful and certainly not the intended behavior.
I (tgl) evidently broke this in commit cfc5008a5, by not noticing
that the column's attname was used above where I'd placed the
assignment of it.
In HEAD and v12, this is trivially fixable by moving up the
assignment of attname. Before v12 the code is a bit more messy;
to avoid doing substantial refactoring, I took the lazy way out
and just put in two copies of the assignment code.
Report and patch by Amit Langote. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/CA+HiwqFA+BGyBFimjiYXXMa2Hc3fcL0+OJOyzUNjhU4NCa_XXw@mail.gmail.com
We implement ON COMMIT DELETE ROWS by truncating tables marked that
way, which requires also truncating/rebuilding their indexes. But
RelationTruncateIndexes asks the relcache for up-to-date copies of any
index expressions, which may cause execution of eval_const_expressions
on them, which can result in actual execution of subexpressions.
This is a bad thing to have happening during ON COMMIT. Manuel Rigger
reported that use of a SQL function resulted in crashes due to
expectations that ActiveSnapshot would be set, which it isn't.
The most obvious fix perhaps would be to push a snapshot during
PreCommit_on_commit_actions, but I think that would just open the door
to more problems: CommitTransaction explicitly expects that no
user-defined code can be running at this point.
Fortunately, since we know that no tuples exist to be indexed, there
seems no need to use the real index expressions or predicates during
RelationTruncateIndexes. We can set up dummy index expressions
instead (we do need something that will expose the right data type,
as there are places that build index tupdescs based on this), and
just ignore predicates and exclusion constraints.
In a green field it'd likely be better to reimplement ON COMMIT DELETE
ROWS using the same "init fork" infrastructure used for unlogged
relations. That seems impractical without catalog changes though,
and even without that it'd be too big a change to back-patch.
So for now do it like this.
Per private report from Manuel Rigger. This has been broken forever,
so back-patch to all supported branches.
query_tree_walker and query_tree_mutator were skipping the
windowClause of the query, without regard for the fact that the
startOffset and endOffset in a WindowClause node are expression trees
that need to be processed. This was an oversight in commit ec4be2ee6
from 2010 which added the expression fields; the main symptom is that
function parameters in window frame clauses don't work in inlined
functions.
Fix (as conservatively as possible since this needs to not break
existing out-of-tree callers) and add tests.
Backpatch all the way, since this has been broken since 9.0.
Per report from Alastair McKinley; fix by me with kibitzing and review
from Tom Lane.
Discussion: https://postgr.es/m/DB6PR0202MB2904E7FDDA9D81504D1E8C68E3800@DB6PR0202MB2904.eurprd02.prod.outlook.com
Commit aa27977fe2 introduced this
restriction for pg_temp.function_name(arg); do likewise for types
created in temporary schemas. Programs that this breaks should add
"pg_temp." schema qualification or switch to arg::type_name syntax.
Back-patch to 9.4 (all supported versions).
Reviewed by Tom Lane. Reported by Tom Lane.
Security: CVE-2019-10208
ATExecAlterColumnType failed to consider the possibility that an index
that needs to be rebuilt might be a child of a constraint that needs to be
rebuilt. We missed this so far because usually a constraint index doesn't
have a direct dependency on its table, just on the constraint object.
But if there's a WHERE clause, then dependency analysis of the WHERE
clause results in direct dependencies on the column(s) mentioned in WHERE.
This led to trying to drop and rebuild both the constraint and its
underlying index.
In v11/HEAD, we successfully drop both the index and the constraint,
and then try to rebuild both, and of course the second rebuild hits a
duplicate-index-name problem. Before v11, it fails with obscure messages
about a missing relation OID, due to trying to drop the index twice.
This is essentially the same kind of problem noted in commit
20bef2c31: the possible dependency linkages are broader than what
ATExecAlterColumnType was designed for. It was probably OK when
written, but it's certainly been broken since the introduction of
partial exclusion constraints. Fix by adding an explicit check
for whether any of the indexes-to-be-rebuilt belong to any of the
constraints-to-be-rebuilt, and ignoring any that do.
In passing, fix a latent bug introduced by commit 8b08f7d48: in
get_constraint_index() we must "continue" not "break" when rejecting
a relation of a wrong relkind. This is harmless today because we don't
expect that code path to be taken anyway; but if there ever were any
relations to be ignored, the existing coding would have an extremely
undesirable dependency on the order of pg_depend entries.
Also adjust a couple of obsolete comments.
Per bug #15835 from Yaroslav Schekin. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/15835-32d9b7a76c06a7a9@postgresql.org
For a non-superuser, changing a comment on a domain constraint was
leading to a cache lookup failure as the code tried to perform the
ownership lookup on the constraint OID itself, thinking that it was a
type, but this check needs to happen on the type the domain constraint
relies on. As the type a domain constraint relies on can be guessed
directly based on the constraint OID, first fetch its type OID and
perform the ownership on it.
This is broken since 7eca575, which has split the handling of comments
for table constraints and domain constraints, so back-patch down to
9.5.
Reported-by: Clemens Ladisch
Author: Daniel Gustafsson, Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/15833-808e11904835d26f@postgresql.org
Backpatch-through: 9.5
Commits 3dbb317d3 et al failed under CLOBBER_CACHE_ALWAYS testing.
Investigation showed that to reindex pg_class_oid_index, we must
suppress accesses to the index (via SetReindexProcessing) before we call
RelationSetNewRelfilenode, or at least before we do CommandCounterIncrement
therein; otherwise, relcache reloads happening within the CCI may try to
fetch pg_class rows using the index's new relfilenode value, which is as
yet an empty file.
Of course, the point of 3dbb317d3 was that that ordering didn't work
either, because then RelationSetNewRelfilenode's own update of the index's
pg_class row cannot access the index, should it need to.
There are various ways we might have got around that, but Andres Freund
came up with a brilliant solution: for a mapped index, we can really just
skip the pg_class update altogether. The only fields it was actually
changing were relpages etc, but it was just setting them to zeroes which
is useless make-work. (Correct new values will be installed at the end
of index build.) All pg_class indexes are mapped and probably always will
be, so this eliminates the problem by removing work rather than adding it,
always a pleasant outcome. Having taught RelationSetNewRelfilenode to do
it that way, we can revert the code reordering in reindex_index. (But
I left the moved setup code where it was; there seems no reason why it
has to run without use of the old index. If you're trying to fix a
busted pg_class index, you'll have had to disable system index use
altogether to get this far.)
Moreover, this means we don't need RelationSetIndexList at all, because
reindex_relation's hacking to make "REINDEX TABLE pg_class" work is
likewise now unnecessary. We'll leave that code in place in the back
branches, but a follow-on patch will remove it in HEAD.
In passing, do some minor cleanup for commit 5c1560606 (in HEAD only),
notably removing a duplicate newrnode assignment.
Patch by me, using a core idea due to Andres Freund. Back-patch to all
supported branches, as 3dbb317d3 was.
Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
When reindexing individual indexes on pg_class it was possible to
either trigger an assertion failure:
TRAP: FailedAssertion("!(!ReindexIsProcessingIndex(((index)->rd_id)))
That's because reindex_index() called SetReindexProcessing() - which
enables an asserts ensuring no index insertions happen into the index
- before calling RelationSetNewRelfilenode(). That not correct for
indexes on pg_class, because RelationSetNewRelfilenode() updates the
relevant pg_class row, which needs to update the indexes.
The are two reasons this wasn't noticed earlier. Firstly the bug
doesn't trigger when reindexing all of pg_class, as reindex_relation
has code "hiding" all yet-to-be-reindexed indexes. Secondly, the bug
only triggers when the the update to pg_class doesn't turn out to be a
HOT update - otherwise there's no index insertion to trigger the
bug. Most of the time there's enough space, making this bug hard to
trigger.
To fix, move RelationSetNewRelfilenode() to before the
SetReindexProcessing() (and, together with some other code, to outside
of the PG_TRY()).
To make sure the error checking intended by SetReindexProcessing() is
more robust, modify CatalogIndexInsert() to check
ReindexIsProcessingIndex() even when the update is a HOT update.
Also add a few regression tests for REINDEXing of system catalogs.
The last two improvements would have prevented some of the issues
fixed in 5c1560606d from being introduced in the first place.
Reported-By: Michael Paquier
Diagnosed-By: Tom Lane and Andres Freund
Author: Andres Freund
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/20190418011430.GA19133@paquier.xyz
Backpatch: 9.4-, the bug is present in all branches
pg_identify_object_as_address crashes when passed certain tuples from
inconsistent system catalogs. Make it more defensive.
Author: Álvaro Herrera
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/20190218202743.GA12392@alvherre.pgsql
This was fixed for MSVC tools by commit 1df92eeafe, but per
buildfarm member bowerbird genbki.pl needs the same treatment.
Backpatch to all live branches.
Previously, it would only remove temp tables created in the same
session; but if the session uses the BackendId of a previously crashed
backend that left temp tables around, those would not get removed.
Since autovacuum would not drop them either (because it sees that the
BackendId is in use by the current session) these can cause annoying
xid-wraparound warnings.
Apply to branches 9.4 to 10. This is not a problem since version 11,
because commit 943576bddc added state tracking that makes autovacuum
realize that those temp tables are not ours, so it removes them.
This is useful to handle in DISCARD, because even though it does not
handle all situations, it does handle the common one where a connection
pooler keeps the same session open for an indefinitely long time.
Discussion: https://postgr.es/m/20181226190834.wsk2wzott5yzrjiq@alvherre.pgsql
Reviewed-by: Takayuki Tsunakawa, Michaël Paquier
This patch fixes several related cases in which pg_shdepend entries were
never made, or were lost, for references to roles appearing in the ACLs of
schemas and/or types. While that did no immediate harm, if a referenced
role were later dropped, the drop would be allowed and would leave a
dangling reference in the object's ACL. That still wasn't a big problem
for normal database usage, but it would cause obscure failures in
subsequent dump/reload or pg_upgrade attempts, taking the form of
attempts to grant privileges to all-numeric role names. (I think I've
seen field reports matching that symptom, but can't find any right now.)
Several cases are fixed here:
1. ALTER DOMAIN SET/DROP DEFAULT would lose the dependencies for any
existing ACL entries for the domain. This case is ancient, dating
back as far as we've had pg_shdepend tracking at all.
2. If a default type privilege applies, CREATE TYPE recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for types in 9.2.
3. If a default schema privilege applies, CREATE SCHEMA recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for schemas in v10
(commit ab89e465c).
Another somewhat-related problem is that when creating a relation
rowtype or implicit array type, TypeCreate would apply any available
default type privileges to that type, which we don't really want
since such an object isn't supposed to have privileges of its own.
(You can't, for example, drop such privileges once they've been added
to an array type.)
ab89e465c is also to blame for a race condition in the regression tests:
privileges.sql transiently installed globally-applicable default
privileges on schemas, which sometimes got absorbed into the ACLs of
schemas created by concurrent test scripts. This should have resulted
in failures when privileges.sql tried to drop the role holding such
privileges; but thanks to the bug fixed here, it instead led to dangling
ACLs in the final state of the regression database. We'd managed not to
notice that, but it became obvious in the wake of commit da906766c, which
allowed the race condition to occur in pg_upgrade tests.
To fix, add a function recordDependencyOnNewAcl to encapsulate what
callers of get_user_default_acl need to do; while the original call
sites got that right via ad-hoc code, none of the later-added ones
have. Also change GenerateTypeDependencies to generate these
dependencies, which requires adding the typacl to its parameter list.
(That might be annoying if there are any extensions calling that
function directly; but if there are, they're most likely buggy in the
same way as the core callers were, so they need work anyway.) While
I was at it, I changed GenerateTypeDependencies to accept most of its
parameters in the form of a Form_pg_type pointer, making its parameter
list a bit less unwieldy and mistake-prone.
The test race condition is fixed just by wrapping the addition and
removal of default privileges into a single transaction, so that that
state is never visible externally. We might eventually prefer to
separate out tests of default privileges into a script that runs by
itself, but that would be a bigger change and would make the tests
run slower overall.
Back-patch relevant parts to all supported branches.
Discussion: https://postgr.es/m/15719.1541725287@sss.pgh.pa.us
Index DDL cascading on partitioned tables introduced a way for ALTER
TABLE to be called reentrantly. This caused an an important deficiency
in event trigger support to be exposed: on exiting the reentrant call,
the alter table state object was clobbered, causing a crash when the
outer alter table tries to finalize its processing. Fix the crash by
creating a stack of event trigger state objects. There are still ways
to cause things to misbehave (and probably other crashers) with more
elaborate tricks, but at least it now doesn't crash in the obvious
scenario.
Backpatch to 9.5, where DDL deparsing of event triggers was introduced.
Reported-by: Marco Slot
Authors: Michaël Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CANNhMLCpi+HQ7M36uPfGbJZEQLyTy7XvX=5EFkpR-b1bo0uJew@mail.gmail.com
It's necessary to make sure that owning tables have a relcache
invalidation prior to advancing the command counter to make
newly-entered catalog tuples for the index visible. inval.c must be
able to maintain the consistency of the local caches in the event of
transaction abort. There is usually only a problem when CREATE INDEX
transactions abort, since there is a generic invalidation once we reach
index_update_stats().
This bug is of long standing. Problems were made much more likely by
the addition of parallel CREATE INDEX (commit 9da0cc3528), but it is
strongly suspected that similar problems can be triggered without
involving plan_create_index_workers(). (plan_create_index_workers()
triggers a relcache build or rebuild, which previously only happened in
rare edge cases.)
Author: Peter Geoghegan
Reported-By: Luca Ferrari
Diagnosed-By: Andres Freund
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAKoxK+5fVodiCtMsXKV_1YAKXbzwSfp7DgDqUmcUAzeAhf=HEQ@mail.gmail.com
Backpatch: 9.3-
Collations, conversions, extended statistics objects (in >= v10),
and all four types of text search objects have schema-qualified names.
getObjectDescription() ignored that and would emit just the base name of
the object, potentially producing wrong or at least highly misleading
output. Fix it to add the schema name whenever the object is not "visible"
in the current search path, as is the rule for other schema-qualifiable
object types.
Although in common situations the output won't change, this seems to me
(tgl) to be a bug worthy of back-patching, hence do so.
Kyotaro Horiguchi, per a complaint from me
Discussion: https://postgr.es/m/20180522.182020.114074746.horiguchi.kyotaro@lab.ntt.co.jp
The impact of VARIADIC on the combine/serialize/deserialize support
functions of an aggregate wasn't thought through carefully. There is
actually no impact, because variadicity isn't passed through to these
functions (and it doesn't seem like it would need to be). However,
lookup_agg_function was mistakenly told to check things as though it were
passed through. The net result was that it was impossible to declare an
aggregate that had both VARIADIC input and parallelism support functions.
In passing, fix a runtime check in nodeAgg.c for the combine function's
strictness to make its error message agree with the creation-time check.
The previous message was actually backwards, and it doesn't seem like
there's a good reason to have two versions of this message text anyway.
Back-patch to 9.6 where parallel aggregation was introduced.
Alexey Bashtanov; message fix by me
Discussion: https://postgr.es/m/f86dde87-fef4-71eb-0480-62754aaca01b@imap.cc
When selecting a new OID, we take care to avoid picking one that's already
in use in the target table, so as not to create duplicates after the OID
counter has wrapped around. However, up to now we used SnapshotDirty when
scanning for pre-existing entries. That ignores committed-dead rows, so
that we could select an OID matching a deleted-but-not-yet-vacuumed row.
While that mostly worked, it has two problems:
* If recently deleted, the dead row might still be visible to MVCC
snapshots, creating a risk for duplicate OIDs when examining the catalogs
within our own transaction. Such duplication couldn't be visible outside
the object-creating transaction, though, and we've heard few if any field
reports corresponding to such a symptom.
* When selecting a TOAST OID, deleted toast rows definitely *are* visible
to SnapshotToast, and will remain so until vacuumed away. This leads to
a conflict that will manifest in errors like "unexpected chunk number 0
(expected 1) for toast value nnnnn". We've been seeing reports of such
errors from the field for years, but the cause was unclear before.
The fix is simple: just use SnapshotAny to search for conflicting rows.
This results in a slightly longer window before object OIDs can be
recycled, but that seems unlikely to create any large problems.
Pavan Deolasee
Discussion: https://postgr.es/m/CABOikdOgWT2hHkYG3Wwo2cyZJq2zfs1FH0FgX-=h4OLosXHf9w@mail.gmail.com
For years, our makefiles have correctly observed that "there is no correct
way to write a rule that generates two files". However, what we did is to
provide empty rules that "generate" the secondary output files from the
primary one, and that's not right either. Depending on the details of
the creating process, the primary file might end up timestamped later than
one or more secondary files, causing subsequent make runs to consider the
secondary file(s) out of date. That's harmless in a plain build, since
make will just re-execute the empty rule and nothing happens. But it's
fatal in a VPATH build, since make will expect the secondary file to be
rebuilt in the build directory. This would manifest as "file not found"
failures during VPATH builds from tarballs, if we were ever unlucky enough
to ship a tarball with apparently out-of-date secondary files. (It's not
clear whether that has ever actually happened, but it definitely could.)
To ensure that secondary output files have timestamps >= their primary's,
change our makefile convention to be that we provide a "touch $@" action
not an empty rule. Also, make sure that this rule actually gets invoked
during a distprep run, else the hazard remains.
It's been like this a long time, so back-patch to all supported branches.
In HEAD, I skipped the changes in src/backend/catalog/Makefile, because
those rules are due to get replaced soon in the bootstrap data format
patch, and there seems no need to create a merge issue for that patch.
If for some reason we fail to land that patch in v11, we'll need to
back-fill the changes in that one makefile from v10.
Discussion: https://postgr.es/m/18556.1521668179@sss.pgh.pa.us
These errors have been seen in the field in corrupted-data situations.
It seems worthwhile to report them with ERRCODE_DATA_CORRUPTED, rather
than the generic ERRCODE_INTERNAL_ERROR, for the benefit of log monitoring
and tools like amcheck. However, use errmsg_internal so that the text
strings still aren't translated; it seems unlikely to be worth
translators' time to do so.
Back-patch to 9.3, like the predecessor commit d70cf811f that introduced
these elog calls originally (replacing Asserts).
Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzmn4-Pg-UGFwyuyK-wiTih9j32pwg_7T9iwqXpAUZr=Mg@mail.gmail.com
The update path of an INSERT ... ON CONFLICT DO UPDATE requires SELECT
permission on the columns of the arbiter index, but it failed to check
for that in the case of an arbiter specified by constraint name.
In addition, for a table with row level security enabled, it failed to
check updated rows against the table's SELECT policies when the update
path was taken (regardless of how the arbiter index was specified).
Backpatch to 9.5 where ON CONFLICT DO UPDATE and RLS were introduced.
Security: CVE-2017-15099
On closer investigation, commits f3ea3e3e8 et al were a few bricks
shy of a load. What we need is not so much to lock down the result
type of a FieldSelect, as to lock down the existence of the column
it's trying to extract. Otherwise, we can break it by dropping that
column. The dependency on the result type is then held indirectly
through the column, and doesn't need to be recorded explicitly.
Out of paranoia, I left in the code to record a dependency on the
result type, but it's used only if we can't identify the pg_class OID
for the column. That shouldn't ever happen right now, AFAICS, but
it seems possible that in future the input node could be marked as
being of type RECORD rather than some specific composite type.
Likewise for FieldStore.
Like the previous patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/22571.1509064146@sss.pgh.pa.us
find_expr_references() neglected to record a dependency on the result type
of a FieldSelect node, allowing a DROP TYPE to break a view or rule that
contains such an expression. I think we'd omitted this case intentionally,
reasoning that there would always be a related dependency ensuring that the
DROP would cascade to the view. But at least with nested field selection
expressions, that's not true, as shown in bug #14867 from Mansur Galiev.
Add the dependency, and for good measure a dependency on the node's exposed
collation.
Likewise add a dependency on the result type of a FieldStore. I think here
the reasoning was that it'd only appear within an assignment to a field,
and the dependency on the field's column would be enough ... but having
seen this example, I think that's wrong for nested-composites cases.
Looking at nearby code, I notice we're not recording a dependency on the
exposed collation of CoerceViaIO, which seems inconsistent with our choices
for related node types. Maybe that's OK but I'm feeling suspicious of this
code today, so let's add that; it certainly can't hurt.
This patch does not do anything to protect already-existing views, only
views created after it's installed. But seeing that the issue has been
there a very long time and nobody noticed till now, that's probably good
enough.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/20171023150118.1477.19174@wrigleys.postgresql.org
This appears to have been an omission in the original commit
0d692a0dc9. All related information_schema views already include
foreign tables.
Reported-by: Nicolas Thauvin <nicolas.thauvin@dalibo.com>
Commit 3eefc51053 claimed to make
pg_user_mappings enforce the qualifications user_mapping_options had
been enforcing, but its removal of a longstanding restriction left them
distinct when the current user is the subject of a mapping yet has no
server privileges. user_mapping_options emits no rows for such a
mapping, but pg_user_mappings includes full umoptions. Change
pg_user_mappings to show null for umoptions. Back-patch to 9.2, like
the above commit.
Reviewed by Tom Lane. Reported by Jeff Janes.
Security: CVE-2017-7547
During pg_upgrade's restore run, all relfilenode choices should be
overridden by commands in the dump script. If we ever find ourselves
choosing a relfilenode in the ordinary way, someone blew it. Likewise for
pg_type OIDs. Since pg_upgrade might well succeed anyway, if there happens
not to be a conflict during the regression test run, we need assertions
here to keep us on the straight and narrow.
We might someday be able to remove the assertion in GetNewRelFileNode,
if pg_upgrade is rewritten to remove its assumption that old and new
relfilenodes always match. But it's hard to see how to get rid of the
pg_type OID constraint, since those OIDs are embedded in user tables
in some cases.
Back-patch as far as 9.5, because of the risk of back-patches breaking
something here even if it works in HEAD. I'd prefer to go back further,
but 9.4 fails both assertions due to get_rel_infos()'s use of a temporary
table. We can't use the later-branch solution of a CTE for compatibility
reasons (cf commit 5d16332e9), and it doesn't seem worth inventing some
other way to do the query. (I did check, by dint of changing the Asserts
to elog(WARNING), that there are no other cases of unwanted OID assignments
during 9.4's regression test run.)
Discussion: https://postgr.es/m/19785.1497215827@sss.pgh.pa.us
Commit 9aa3c782c added code to allow CREATE TABLE/CREATE TYPE to not fail
when the desired type name conflicts with an autogenerated array type, by
dint of renaming the array type out of the way. But I (tgl) overlooked
that the same case arises in ALTER TABLE/TYPE RENAME. Fix that too.
Back-patch to all supported branches.
Report and patch by Vik Fearing, modified a bit by me
Discussion: https://postgr.es/m/0f4ade49-4f0b-a9a3-c120-7589f01d1eb8@2ndquadrant.com
Both views replace the umoptions field with NULL when the user does not
meet qualifications to see it. They used different qualifications, and
pg_user_mappings documented qualifications did not match its implemented
qualifications. Make its documentation and implementation match those
of user_mapping_options. One might argue for stronger qualifications,
but these have long, documented tenure. pg_user_mappings has always
exhibited this problem, so back-patch to 9.2 (all supported versions).
Michael Paquier and Feike Steenbergen. Reviewed by Jeff Janes.
Reported by Andrew Wheelwright.
Security: CVE-2017-7486
The original coding was trying to use a TypeName as a string Value,
which doesn't work; an oversight in my commit a61fd533. Repair.
Also, make sure we cover the broken case in the relevant test script.
Backpatch to 9.5.
Discussion: https://postgr.es/m/20170315151829.bhxsvrp75xdxhm3n@alvherre.pgsql
In commit 6c268df, pg_init_privs was added to track the initial
privileges of catalog objects and extensions. Unfortunately, that
commit didn't include understanding of ALTER EXTENSION ADD/DROP, which
allows the objects associated with an extension to be changed after the
initial CREATE EXTENSION script has been run.
The result of this meant that ACLs for objects added through
ALTER EXTENSION ADD were not recorded into pg_init_privs and we would
end up including those ACLs in pg_dump when we shouldn't have.
This commit corrects that by making sure to have pg_init_privs updated
when ALTER EXTENSION ADD/DROP is run, recording the permissions as they
are at ALTER EXTENSION ADD time, and removing any if/when ALTER
EXTENSION DROP is called.
This issue was pointed out by Moshe Jacobson as commentary on bug #14456
(which was actually a bug about versions prior to 9.6 not handling
custom ACLs on extensions correctly, an issue now addressed with
pg_init_privs in 9.6).
Back-patch to 9.6 where pg_init_privs was introduced.
Previously, it was thought that this only needed to be done for the
benefit of possible standbys, so wal_level = minimal skipped it.
But that's not safe, because during crash recovery we might replay
XLOG_DBASE_CREATE or XLOG_TBLSPC_CREATE record which recursively
removes the directory that contains the new init fork. So log it
always.
The user-visible effect of this bug is that if you create a database
or tablespace, then create an unlogged table, then crash without
checkpointing, then restart, accessing the table will fail, because
the it won't have been properly reset. This commit fixes that.
Michael Paquier, per a report from Konstantin Knizhnik. Wording of
the comments per a suggestion from me.
