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* Fix access-off-end-of-array in clog.c.Tom Lane2017-10-06
| | | | | | | | | | | | | Sloppy loop coding in set_status_by_pages() resulted in fetching one array element more than it should from the subxids[] array. The odds of this resulting in SIGSEGV are pretty small, but we've certainly seen that happen with similar mistakes elsewhere. While at it, we can get rid of an extra TransactionIdToPage() calculation per loop. Per report from David Binderman. Back-patch to all supported branches, since this code is quite old. Discussion: https://postgr.es/m/HE1PR0802MB2331CBA919CBFFF0C465EB429C710@HE1PR0802MB2331.eurprd08.prod.outlook.com
* Fix typo in README.Tom Lane2017-10-05
| | | | s/BeginInternalSubtransaction/BeginInternalSubTransaction/
* Add background worker typePeter Eisentraut2017-09-29
| | | | | | | | | | | | | | | | | Add bgw_type field to background worker structure. It is intended to be set to the same value for all workers of the same type, so they can be grouped in pg_stat_activity, for example. The backend_type column in pg_stat_activity now shows bgw_type for a background worker. The ps listing also no longer calls out that a process is a background worker but just show the bgw_type. That way, being a background worker is more of an implementation detail now that is not shown to the user. However, most log messages still refer to 'background worker "%s"'; otherwise constructing sensible and translatable log messages would become tricky. Reviewed-by: Michael Paquier <michael.paquier@gmail.com> Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
* Revert to 9.6 treatment of ALTER TYPE enumtype ADD VALUE.Tom Lane2017-09-27
| | | | | | | | | | | | | This reverts commit 15bc038f9, along with the followon commits 1635e80d3 and 984c92074 that tried to clean up the problems exposed by bug #14825. The result was incomplete because it failed to address parallel-query requirements. With 10.0 release so close upon us, now does not seem like the time to be adding more code to fix that. I hope we can un-revert this code and add the missing parallel query support during the v11 cycle. Back-patch to v10. Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
* Use a blacklist to distinguish original from add-on enum values.Tom Lane2017-09-26
| | | | | | | | | | | | | | | | | | | | | | | | Commit 15bc038f9 allowed ALTER TYPE ADD VALUE to be executed inside transaction blocks, by disallowing the use of the added value later in the same transaction, except under limited circumstances. However, the test for "limited circumstances" was heuristic and could reject references to enum values that were created during CREATE TYPE AS ENUM, not just later. This breaks the use-case of restoring pg_dump scripts in a single transaction, as reported in bug #14825 from Balazs Szilfai. We can improve this by keeping a "blacklist" table of enum value OIDs created by ALTER TYPE ADD VALUE during the current transaction. Any visible-but-uncommitted value whose OID is not in the blacklist must have been created by CREATE TYPE AS ENUM, and can be used safely because it could not have a lifespan shorter than its parent enum type. This change also removes the restriction that a renamed enum value can't be used before being committed (unless it was on the blacklist). Andrew Dunstan, with cosmetic improvements by me. Back-patch to v10. Discussion: https://postgr.es/m/20170922185904.1448.16585@wrigleys.postgresql.org
* Refactor new file permission handlingPeter Eisentraut2017-09-23
| | | | | | | | | | | | | | | | | | | The file handling functions from fd.c were called with a diverse mix of notations for the file permissions when they were opening new files. Almost all files created by the server should have the same permissions set. So change the API so that e.g. OpenTransientFile() automatically uses the standard permissions set, and OpenTransientFilePerm() is a new function that takes an explicit permissions set for the few cases where it is needed. This also saves an unnecessary argument for call sites that are just opening an existing file. While we're reviewing these APIs, get rid of the FileName typedef and use the standard const char * for the file name and mode_t for the file mode. This makes these functions match other file handling functions and removes an unnecessary layer of mysteriousness. We can also get rid of a few casts that way. Author: David Steele <david@pgmasters.net>
* For wal_consistency_checking, mask page checksum as well as page LSN.Robert Haas2017-09-22
| | | | | | | | If the LSN is different, the checksum will be different, too. Ashwin Agrawal, reviewed by Michael Paquier and Kuntal Ghosh Discussion: http://postgr.es/m/CALfoeis5iqrAU-+JAN+ZzXkpPr7+-0OAGv7QUHwFn=-wDy4o4Q@mail.gmail.com
* Make WAL segment size configurable at initdb time.Andres Freund2017-09-19
| | | | | | | | | | | | | | | | | | | | | | | For performance reasons a larger segment size than the default 16MB can be useful. A larger segment size has two main benefits: Firstly, in setups using archiving, it makes it easier to write scripts that can keep up with higher amounts of WAL, secondly, the WAL has to be written and synced to disk less frequently. But at the same time large segment size are disadvantageous for smaller databases. So far the segment size had to be configured at compile time, often making it unrealistic to choose one fitting to a particularly load. Therefore change it to a initdb time setting. This includes a breaking changes to the xlogreader.h API, which now requires the current segment size to be configured. For that and similar reasons a number of binaries had to be taught how to recognize the current segment size. Author: Beena Emerson, editorialized by Andres Freund Reviewed-By: Andres Freund, David Steele, Kuntal Ghosh, Michael Paquier, Peter Eisentraut, Robert Hass, Tushar Ahuja Discussion: https://postgr.es/m/CAOG9ApEAcQ--1ieKbhFzXSQPw_YLmepaa4hNdnY5+ZULpt81Mw@mail.gmail.com
* Fix crash restart bug introduced in 8356753c212.Andres Freund2017-09-18
| | | | | | | | | | | | | | | | | | The bug was caused by not re-reading the control file during crash recovery restarts, which lead to an attempt to pfree() shared memory contents. The fix is to re-read the control file, which seems good anyway. It's unclear as of this moment, whether we want to keep the refactoring introduced in the commit referenced above, or come up with an alternative approach. But fixing the bug in the mean time seems like a good idea regardless. A followup commit will introduce regression test coverage for crash restarts. Reported-By: Tom Lane Discussion: https://postgr.es/m/14134.1505572349@sss.pgh.pa.us
* Add support for coordinating record typmods among parallel workers.Andres Freund2017-09-14
| | | | | | | | | | | | | | | | | | | | | | Tuples can have type RECORDOID and a typmod number that identifies a blessed TupleDesc in a backend-private cache. To support the sharing of such tuples through shared memory and temporary files, provide a typmod registry in shared memory. To achieve that, introduce per-session DSM segments, created on demand when a backend first runs a parallel query. The per-session DSM segment has a table-of-contents just like the per-query DSM segment, and initially the contents are a shared record typmod registry and a DSA area to provide the space it needs to grow. State relating to the current session is accessed via a Session object reached through global variable CurrentSession that may require significant redesign further down the road as we figure out what else needs to be shared or remodelled. Author: Thomas Munro Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
* Perform only one ReadControlFile() during startup.Andres Freund2017-09-14
| | | | | | | | | | | | | Previously we read the control file in multiple places. But soon the segment size will be configurable and stored in the control file, and that needs to be available earlier than it currently is needed. Instead of adding yet another place where it's read, refactor things so there's a single processing of the control file during startup (in EXEC_BACKEND that's every individual backend's startup). Author: Andres Freund Discussion: http://postgr.es/m/20170913092828.aozd3gvvmw67gmyc@alap3.anarazel.de
* Message style fixesPeter Eisentraut2017-09-11
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* Reduce excessive dereferencing of function pointersPeter Eisentraut2017-09-07
| | | | | | | | | | | | It is equivalent in ANSI C to write (*funcptr) () and funcptr(). These two styles have been applied inconsistently. After discussion, we'll use the more verbose style for plain function pointer variables, to make it clear that it's a variable, and the shorter style when the function pointer is in a struct (s.func() or s->func()), because then it's clear that it's not a plain function name, and otherwise the excessive punctuation makes some of those invocations hard to read. Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
* Fix handling of savepoint commands within multi-statement Query strings.Tom Lane2017-09-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Issuing a savepoint-related command in a Query message that contains multiple SQL statements led to a FATAL exit with a complaint about "unexpected state STARTED". This is a shortcoming of commit 4f896dac1, which attempted to prevent such misbehaviors in multi-statement strings; its quick hack of marking the individual statements as "not top-level" does the wrong thing in this case, and isn't a very accurate description of the situation anyway. To fix, let's introduce into xact.c an explicit model of what happens for multi-statement Query strings. This is an "implicit transaction block in progress" state, which for many purposes works like the normal TBLOCK_INPROGRESS state --- in particular, IsTransactionBlock returns true, causing the desired result that PreventTransactionChain will throw error. But in case of error abort it works like TBLOCK_STARTED, allowing the transaction to be cancelled without need for an explicit ROLLBACK command. Commit 4f896dac1 is reverted in toto, so that we go back to treating the individual statements as "top level". We could have left it as-is, but this allows sharpening the error message for PreventTransactionChain calls inside functions. Except for getting a normal error instead of a FATAL exit for savepoint commands, this patch should result in no user-visible behavioral change (other than that one error message rewording). There are some things we might want to do in the line of changing the appearance or wording of error and warning messages around this behavior, which would be much simpler to do now that it's an explicitly modeled state. But I haven't done them here. Although this fixes a long-standing bug, no backpatch. The consequences of the bug don't seem severe enough to justify the risk that this commit itself creates some new issue. Patch by me, but it owes something to previous investigation by Takayuki Tsunakawa, who also reported the bug in the first place. Also thanks to Michael Paquier for reviewing. Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F6BE40D@G01JPEXMBYT05
* Exclude special values in recovery_target_timeSimon Riggs2017-09-07
| | | | | | | | | | recovery_target_time accepts timestamp input, though does not allow use of special values, e.g. “today”. Report a useful error message for these cases. Reported-by: Piotr Stefaniak Author: Simon Riggs Discussion: https://postgr.es/m/CANP8+jJdKA+BkkYLWz9zAm16Y0s2ExBv0WfpAwXdTpPfWnA9Bg@mail.gmail.com
* Use group updates when setting transaction status in clog.Robert Haas2017-09-01
| | | | | | | | | | | | | | | Commit 0e141c0fbb211bdd23783afa731e3eef95c9ad7a introduced a mechanism to reduce contention on ProcArrayLock by having a single process clear XIDs in the procArray on behalf of multiple processes, reducing the need to hand the lock around. A previous attempt to introduce a similar mechanism for CLogControlLock in ccce90b398673d55b0387b3de66639b1b30d451b crashed and burned, but the design problem which resulted in those failures is believed to have been corrected in this version. Amit Kapila, with some cosmetic changes by me. See the previous commit message for additional credits. Discussion: http://postgr.es/m/CAA4eK1KudxzgWhuywY_X=yeSAhJMT4DwCjroV5Ay60xaeB2Eew@mail.gmail.com
* Clean up shm_mq cleanup.Tom Lane2017-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | The logic around shm_mq_detach was a few bricks shy of a load, because (contrary to the comments for shm_mq_attach) all it did was update the shared shm_mq state. That left us leaking a bit of process-local memory, but much worse, the on_dsm_detach callback for shm_mq_detach was still armed. That means that whenever we ultimately detach from the DSM segment, we'd run shm_mq_detach again for already-detached, possibly long-dead queues. This accidentally fails to fail today, because we only ever re-use a shm_mq's memory for another shm_mq, and multiple detach attempts on the last such shm_mq are fairly harmless. But it's gonna bite us someday, so let's clean it up. To do that, change shm_mq_detach's API so it takes a shm_mq_handle not the underlying shm_mq. This makes the callers simpler in most cases anyway. Also fix a few places in parallel.c that were just pfree'ing the handle structs rather than doing proper cleanup. Back-patch to v10 because of the risk that the revenant shm_mq_detach callbacks would cause a live bug sometime. Since this is an API change, it's too late to do it in 9.6. (We could make a variant patch that preserves API, but I'm not excited enough to do that.) Discussion: https://postgr.es/m/8670.1504192177@sss.pgh.pa.us
* Final pgindent + perltidy run for v10.Tom Lane2017-08-14
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* Handle elog(FATAL) during ROLLBACK more robustly.Tom Lane2017-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Stress testing by Andreas Seltenreich disclosed longstanding problems that occur if a FATAL exit (e.g. due to receipt of SIGTERM) occurs while we are trying to execute a ROLLBACK of an already-failed transaction. In such a case, xact.c is in TBLOCK_ABORT state, so that AbortOutOfAnyTransaction would skip AbortTransaction and go straight to CleanupTransaction. This led to an assert failure in an assert-enabled build (due to the ROLLBACK's portal still having a cleanup hook) or without assertions, to a FATAL exit complaining about "cannot drop active portal". The latter's not disastrous, perhaps, but it's messy enough to want to improve it. We don't really want to run all of AbortTransaction in this code path. The minimum required to clean up the open portal safely is to do AtAbort_Memory and AtAbort_Portals. It seems like a good idea to do AtAbort_Memory unconditionally, to be entirely sure that we are starting with a safe CurrentMemoryContext. That means that if the main loop in AbortOutOfAnyTransaction does nothing, we need an extra step at the bottom to restore CurrentMemoryContext = TopMemoryContext, which I chose to do by invoking AtCleanup_Memory. This'll result in calling AtCleanup_Memory twice in many of the paths through this function, but that seems harmless and reasonably inexpensive. The original motivation for the assertion in AtCleanup_Portals was that we wanted to be sure that any user-defined code executed as a consequence of the cleanup hook runs during AbortTransaction not CleanupTransaction. That still seems like a valid concern, and now that we've seen one case of the assertion firing --- which means that exactly that would have happened in a production build --- let's replace the Assert with a runtime check. If we see the cleanup hook still set, we'll emit a WARNING and just drop the hook unexecuted. This has been like this a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/877ey7bmun.fsf@ansel.ydns.eu
* Remove AtEOXact_CatCache().Tom Lane2017-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sole useful effect of this function, to check that no catcache entries have positive refcounts at transaction end, has really been obsolete since we introduced ResourceOwners in PG 8.1. We reduced the checks to assertions years ago, so that the function was a complete no-op in production builds. There have been previous discussions about removing it entirely, but consensus up to now was that it had some small value as a cross-check for bugs in the ResourceOwner logic. However, it now emerges that it's possible to trigger these assertions if you hit an assert-enabled backend with SIGTERM during a call to SearchCatCacheList, because that function temporarily increases the refcounts of entries it's intending to add to a catcache list construct. In a normal ERROR scenario, the extra refcounts are cleaned up by SearchCatCacheList's PG_CATCH block; but in a FATAL exit we do a transaction abort and exit without ever executing PG_CATCH handlers. There's a case to be made that this is a generic hazard and we should consider restructuring elog(FATAL) handling so that pending PG_CATCH handlers do get run. That's pretty scary though: it could easily create more problems than it solves. Preliminary stress testing by Andreas Seltenreich suggests that there are not many live problems of this ilk, so we rejected that idea. There are more-localized ways to fix the problem; the most principled one would be to use PG_ENSURE_ERROR_CLEANUP instead of plain PG_TRY. But adding cycles to SearchCatCacheList isn't very appealing. We could also weaken the assertions in AtEOXact_CatCache in some more or less ad-hoc way, but that just makes its raison d'etre even less compelling. In the end, the most reasonable solution seems to be to just remove AtEOXact_CatCache altogether, on the grounds that it's not worth trying to fix it. It hasn't found any bugs for us in many years. Per report from Jeevan Chalke. Back-patch to all supported branches. Discussion: https://postgr.es/m/CAM2+6=VEE30YtRQCZX7_sCFsEpoUkFBV1gZazL70fqLn8rcvBA@mail.gmail.com
* Remove uses of "slave" in replication contextsPeter Eisentraut2017-08-10
| | | | | This affects mostly code comments, some documentation, and tests. Official APIs already used "standby".
* Remove incorrect assertion in clog.cRobert Haas2017-08-10
| | | | | | | | | | | We must advance the oldest XID that can be safely looked up in clog *before* truncating CLOG, and the oldest XID that can't be reused *after* truncating CLOG. This assertion, and the accompanying comment, are confused; remove them. Reported by Neha Sharma. Discussion: http://postgr.es/m/CANiYTQumC3T=UMBMd1Hor=5XWZYuCEQBioL3ug0YtNQCMMT5wQ@mail.gmail.com
* Make pg_stop_backup's wait_for_archive flag work on standbys.Robert Haas2017-08-05
| | | | | | | | | | | | Previously, it had no effect. Now, if archive_mode=always, it will work, and if not, you'll get a warning. Masahiko Sawada, Michael Paquier, and Robert Haas. The patch as submitted also changed the behavior so that we would write and remove history files on standbys, but that seems like material for a separate patch to me. Discussion: http://postgr.es/m/CAD21AoC2Xw6M=ZJyejq_9d_iDkReC_=rpvQRw5QsyzKQdfYpkw@mail.gmail.com
* Only kill sync workers at commit time in subscription DDLPeter Eisentraut2017-08-04
| | | | | | This allows a transaction abort to avoid killing those workers. Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
* Fix double shared memory allocation.Teodor Sigaev2017-07-21
| | | | | | | | | | | SLRU buffer lwlocks are allocated twice by oversight in commit fe702a7b3f9f2bc5bf6d173166d7d55226af82c8 where that locks were moved to separate tranche. The bug doesn't have user-visible effects except small overspending of shared memory. Backpatch to 9.6 where it was introduced. Alexander Korotkov with small editorization by me.
* Add static assertions about pg_control fitting into one disk sector.Tom Lane2017-07-19
| | | | | | | | | | | | | | | | | When pg_control was first designed, sizeof(ControlFileData) was small enough that a comment seemed like plenty to document the assumption that it'd fit into one disk sector. Now it's nearly 300 bytes, raising the possibility that somebody would carelessly add enough stuff to create a problem. Let's add a StaticAssertStmt() to ensure that the situation doesn't pass unnoticed if it ever occurs. While at it, rename PG_CONTROL_SIZE to PG_CONTROL_FILE_SIZE to make it clearer what that symbol means, and convert the existing runtime comparisons of sizeof(ControlFileData) vs. PG_CONTROL_FILE_SIZE to be static asserts --- we didn't have that technology when this code was first written. Discussion: https://postgr.es/m/9192.1500490591@sss.pgh.pa.us
* Fix typo in commentPeter Eisentraut2017-06-30
| | | | Author: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
* Fix typo in commentAlvaro Herrera2017-06-22
| | | | | | | | Once upon a time, WAL pointers could be NULL, but no longer. We talk about "valid" now. Reported-by: Amit Langote Discussion: https://postgr.es/m/33e9617d-27f1-eee8-3311-e27af98eaf2b@lab.ntt.co.jp
* Fix possibility of creating a "phantom" segment after promotion.Andres Freund2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When promoting a standby just after a XLOG_SWITCH record was replayed, and next segment(s) are already are locally available (via walsender, restore_command + trigger/recovery target), that segment could accidentally be recycled onto the past of the new timeline. Later checkpointer would create a .ready file for it, assuming there was an error during creation, and it would get archived. That causes trouble if another standby is later brought up from a basebackup from before the timeline creation, because it would try to read the segment, because XLogFileReadAnyTLI just tries all possible timelines, which doesn't have valid contents. Thus replay would fail. The problem, if already occurred, can be fixed by removing the segment and/or having restore_command filter it out. The reason for the creation of such "phantom" segments was, that after an XLOG_SWITCH record the EndOfLog variable points to the beginning of the next segment, and RemoveXlogFile() used XLByteToPrevSeg(). Normally RemoveXlogFile() doing so is harmless, because the last segment will still exist preventing InstallXLogFileSegment() from causing harm, but just after promotion there's no previous segment on the new timeline. Fix that by using XLByteToSeg() instead of XLByteToPrevSeg(). Author: Andres Freund Reported-By: Greg Burek Discussion: https://postgr.es/m/20170619073026.zcwpe6mydsaz5ygd@alap3.anarazel.de Backpatch: 9.2-, bug older than all supported versions
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Fix typos in commentsMagnus Hagander2017-06-17
| | | | Author: Daniel Gustafsson <daniel@yesql.se>
* Avoid bogus TwoPhaseState locking sequencesAlvaro Herrera2017-06-14
| | | | | | | | | | | | | The optimized code in 728bd991c3c4 contains a few invalid locking sequences. To wit, the original code would try to acquire an lwlock that it already holds. Avoid this by moving lock acquisitions to higher-level code, and install appropriate assertions in low-level that the correct mode is held. Authors: Michael Paquier, Álvaro Herrera Reported-By: chuanting wang Bug: #14680 Discussion: https://postgr.es/m/20170531033228.1487.10124@wrigleys.postgresql.org
* Formatting improvements in config file samplesPeter Eisentraut2017-06-09
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* Update code commentsPeter Eisentraut2017-06-09
| | | | Author: Neha Khatri <nehakhatri5@gmail.com>
* Clean up latch related code.Andres Freund2017-06-06
| | | | | | | | | | | | | | | | | | | | | | The larger part of this patch replaces usages of MyProc->procLatch with MyLatch. The latter works even early during backend startup, where MyProc->procLatch doesn't yet. While the affected code shouldn't run in cases where it's not initialized, it might get copied into places where it might. Using MyLatch is simpler and a bit faster to boot, so there's little point to stick with the previous coding. While doing so I noticed some weaknesses around newly introduced uses of latches that could lead to missed events, and an omitted CHECK_FOR_INTERRUPTS() call in worker_spi. As all the actual bugs are in v10 code, there doesn't seem to be sufficient reason to backpatch this. Author: Andres Freund Discussion: https://postgr.es/m/20170606195321.sjmenrfgl2nu6j63@alap3.anarazel.de https://postgr.es/m/20170606210405.sim3yl6vpudhmufo@alap3.anarazel.de Backpatch: -
* Prevent possibility of panics during shutdown checkpoint.Andres Freund2017-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the checkpointer writes the shutdown checkpoint, it checks afterwards whether any WAL has been written since it started and throws a PANIC if so. At that point, only walsenders are still active, so one might think this could not happen, but walsenders can also generate WAL, for instance in BASE_BACKUP and logical decoding related commands (e.g. via hint bits). So they can trigger this panic if such a command is run while the shutdown checkpoint is being written. To fix this, divide the walsender shutdown into two phases. First, checkpointer, itself triggered by postmaster, sends a PROCSIG_WALSND_INIT_STOPPING signal to all walsenders. If the backend is idle or runs an SQL query this causes the backend to shutdown, if logical replication is in progress all existing WAL records are processed followed by a shutdown. Otherwise this causes the walsender to switch to the "stopping" state. In this state, the walsender will reject any further replication commands. The checkpointer begins the shutdown checkpoint once all walsenders are confirmed as stopping. When the shutdown checkpoint finishes, the postmaster sends us SIGUSR2. This instructs walsender to send any outstanding WAL, including the shutdown checkpoint record, wait for it to be replicated to the standby, and then exit. Author: Andres Freund, based on an earlier patch by Michael Paquier Reported-By: Fujii Masao, Andres Freund Reviewed-By: Michael Paquier Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de Backpatch: 9.4, where logical decoding was introduced
* Revert "Prevent panic during shutdown checkpoint"Andres Freund2017-06-05
| | | | | | | | | | | This reverts commit 086221cf6b1727c2baed4703c582f657b7c5350e, which was made to master only. The approach implemented in the above commit has some issues. While those could easily be fixed incrementally, doing so would make backpatching considerably harder, so instead first revert this patch. Discussion: https://postgr.es/m/20170602002912.tqlwn4gymzlxpvs2@alap3.anarazel.de
* Don't be so trusting that shm_toc_lookup() will always succeed.Tom Lane2017-06-05
| | | | | | | | | | | | | | | | | | Given the possibility of race conditions and so on, it seems entirely unsafe to just assume that shm_toc_lookup() always finds the key it's looking for --- but that was exactly what all but one call site were doing. To fix, add a "bool noError" argument, similarly to what we have in many other functions, and throw an error on an unexpected lookup failure. Remove now-redundant Asserts that a rather random subset of call sites had. I doubt this will throw any light on buildfarm member lorikeet's recent failures, because if an unnoticed lookup failure were involved, you'd kind of expect a null-pointer-dereference crash rather than the observed symptom. But you never know ... and this is better coding practice even if it never catches anything. Discussion: https://postgr.es/m/9697.1496675981@sss.pgh.pa.us
* Restore accidentally-removed line.Robert Haas2017-05-31
| | | | | | | | Commit 88e66d193fbaf756b3cc9bf94cad116aacbb355b is to blame. Masahiko Sawada Discussion: http://postgr.es/m/CAD21AoAXeb7O4hgg+efs8JT_SxpR4doAH5c5s-Z5WoRLstBZJA@mail.gmail.com
* Post-PG 10 beta1 pgindent runBruce Momjian2017-05-17
| | | | perltidy run not included.
* Standardize "WAL location" terminologyPeter Eisentraut2017-05-12
| | | | Other previously used terms were "WAL position" or "log position".
* Replace "transaction log" with "write-ahead log"Peter Eisentraut2017-05-12
| | | | | This makes documentation and error messages match the renaming of "xlog" to "wal" in APIs and file naming.
* Rename WAL-related functions and views to use "lsn" not "location".Tom Lane2017-05-11
| | | | | | | | | | | | | | | Per discussion, "location" is a rather vague term that could refer to multiple concepts. "LSN" is an unambiguous term for WAL locations and should be preferred. Some function names, view column names, and function output argument names used "lsn" already, but others used "location", as well as yet other terms such as "wal_position". Since we've already renamed a lot of things in this area from "xlog" to "wal" for v10, we may as well incur a bit more compatibility pain and make these names all consistent. David Rowley, minor additional docs hacking by me Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
* Prevent panic during shutdown checkpointPeter Eisentraut2017-05-05
| | | | | | | | | | | | | | | | | | | | | | | | | When the checkpointer writes the shutdown checkpoint, it checks afterwards whether any WAL has been written since it started and throws a PANIC if so. At that point, only walsenders are still active, so one might think this could not happen, but walsenders can also generate WAL, for instance in BASE_BACKUP and certain variants of CREATE_REPLICATION_SLOT. So they can trigger this panic if such a command is run while the shutdown checkpoint is being written. To fix this, divide the walsender shutdown into two phases. First, the postmaster sends a SIGUSR2 signal to all walsenders. The walsenders then put themselves into the "stopping" state. In this state, they reject any new commands. (For simplicity, we reject all new commands, so that in the future we do not have to track meticulously which commands might generate WAL.) The checkpointer waits for all walsenders to reach this state before proceeding with the shutdown checkpoint. After the shutdown checkpoint is done, the postmaster sends SIGINT (previously unused) to the walsenders. This triggers the existing shutdown behavior of sending out the shutdown checkpoint record and then terminating. Author: Michael Paquier <michael.paquier@gmail.com> Reported-by: Fujii Masao <masao.fujii@gmail.com>
* Fix logical replication launcher wake up and resetPeter Eisentraut2017-05-01
| | | | | | | | | | | | | After the logical replication launcher was told to wake up at commit (for example, by a CREATE SUBSCRIPTION command), the flag to wake up was not reset, so it would be woken up at every following commit as well. So fix that by resetting the flag. Also, we don't need to wake up anything if the transaction was rolled back. Just reset the flag in that case. Author: Masahiko Sawada <sawada.mshk@gmail.com> Reported-by: Fujii Masao <masao.fujii@gmail.com>
* Rework handling of subtransactions in 2PC recoverySimon Riggs2017-04-27
| | | | | | | | | | | | | | The bug fixed by 0874d4f3e183757ba15a4b3f3bf563e0393dd9c2 caused us to question and rework the handling of subtransactions in 2PC during and at end of recovery. Patch adds checks and tests to ensure no further bugs. This effectively removes the temporary measure put in place by 546c13e11b29a5408b9d6a6e3cca301380b47f7f. Author: Simon Riggs Reviewed-by: Tom Lane, Michael Paquier Discussion: http://postgr.es/m/CANP8+j+vvXmruL_i2buvdhMeVv5TQu0Hm2+C5N+kdVwHJuor8w@mail.gmail.com
* Workaround for RecoverPreparedTransactions()Simon Riggs2017-04-23
| | | | | | Force overwriteOK = true while we investigate deeper fix Proposed by Tom Lane as temporary measure, accepted by me
* Fix order of arguments to SubTransSetParent().Tom Lane2017-04-23
| | | | | | | | | | | | | | ProcessTwoPhaseBuffer (formerly StandbyRecoverPreparedTransactions) mixed up the parent and child XIDs when calling SubTransSetParent to record the transactions' relationship in pg_subtrans. Remarkably, analysis by Simon Riggs suggests that this doesn't lead to visible problems (at least, not in non-Assert builds). That might explain why we'd not noticed it before. Nonetheless, it's surely wrong. This code was born broken, so back-patch to all supported branches. Discussion: https://postgr.es/m/20110.1492905318@sss.pgh.pa.us