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2019-02-01Add more columns to pg_stat_sslPeter Eisentraut
Add columns client_serial and issuer_dn to pg_stat_ssl. These allow uniquely identifying the client certificate. Rename the existing column clientdn to client_dn, to make the naming more consistent and easier to read. Discussion: https://www.postgresql.org/message-id/flat/398754d8-6bb5-c5cf-e7b8-22e5f0983caf@2ndquadrant.com/
2019-01-30Log PostgreSQL version number on startupPeter Eisentraut
Logging the PostgreSQL version on startup is useful for two reasons: There is a clear marker in the log file that a new postmaster is beginning, and it's useful for tracking the server version across startup while upgrading. Author: Christoph Berg <christoph.berg@credativ.de> Discussion: https://www.postgresql.org/message-id/flat/20181121144611.GJ15795@msg.credativ.de/
2019-01-30postmaster: Start syslogger earlierPeter Eisentraut
When the syslogger was originally added (bdf8ef6925de6ea1a9330fa1ce32e1a315d07eb2), nothing was normally logged before the point where it was started. But since f9dfa5c9776649f769d537dd0923003b35f128de, the creation of sockets causes messages of level LOG to be written routinely, so those don't go to the syslogger now. To improve that, arrange the sequence in PostmasterMain() slightly so that the syslogger is started early enough to capture those messages. Discussion: https://www.postgresql.org/message-id/d5d50936-20b9-85f1-06bc-94a01c5040c1%402ndquadrant.com Reviewed-by: Christoph Berg <christoph.berg@credativ.de>
2019-01-26Change function call information to be variable length.Andres Freund
Before this change FunctionCallInfoData, the struct arguments etc for V1 function calls are stored in, always had space for FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two arrays. For nearly every function call 100 arguments is far more than needed, therefore wasting memory. Arg and argnull being two separate arrays also guarantees that to access a single argument, two cachelines have to be touched. Change the layout so there's a single variable-length array with pairs of value / isnull. That drastically reduces memory consumption for most function calls (on x86-64 a two argument function now uses 64bytes, previously 936 bytes), and makes it very likely that argument value and its nullness are on the same cacheline. Arguments are stored in a new NullableDatum struct, which, due to padding, needs more memory per argument than before. But as usually far fewer arguments are stored, and individual arguments are cheaper to access, that's still a clear win. It's likely that there's other places where conversion to NullableDatum arrays would make sense, e.g. TupleTableSlots, but that's for another commit. Because the function call information is now variable-length allocations have to take the number of arguments into account. For heap allocations that can be done with SizeForFunctionCallInfoData(), for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro that helps to allocate an appropriately sized and aligned variable. Some places with stack allocation function call information don't know the number of arguments at compile time, and currently variably sized stack allocations aren't allowed in postgres. Therefore allow for FUNC_MAX_ARGS space in these cases. They're not that common, so for now that seems acceptable. Because of the need to allocate FunctionCallInfo of the appropriate size, older extensions may need to update their code. To avoid subtle breakages, the FunctionCallInfoData struct has been renamed to FunctionCallInfoBaseData. Most code only references FunctionCallInfo, so that shouldn't cause much collateral damage. This change is also a prerequisite for more efficient expression JIT compilation (by allocating the function call information on the stack, allowing LLVM to optimize it away); previously the size of the call information caused problems inside LLVM's optimizer. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de
2019-01-21Remove superfluous tqual.h includes.Andres Freund
Most of these had been obsoleted by 568d4138c / the SnapshotNow removal. This is is preparation for moving most of tqual.[ch] into either snapmgr.h or heapam.h, which in turn is in preparation for pluggable table AMs. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
2019-01-21Replace uses of heap_open et al with the corresponding table_* function.Andres Freund
Author: Andres Freund Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
2019-01-19Replace @postgresql.org with @lists.postgresql.org for mailinglistsMagnus Hagander
Commit c0d0e54084 replaced the ones in the documentation, but missed out on the ones in the code. Replace those as well, but unlike c0d0e54084, don't backpatch the code changes to avoid breaking translations.
2019-01-15Fix typos in documentation and for one wait eventMichael Paquier
These have been found while cross-checking for the use of unique words in the documentation, and a wait event was not getting generated in a way consistent to what the documentation provided. Author: Alexander Lakhin Discussion: https://postgr.es/m/9b5a3a85-899a-ae62-dbab-1e7943aa5ab1@gmail.com
2019-01-02Update copyright for 2019Bruce Momjian
Backpatch-through: certain files through 9.4
2019-01-01Remove configure switch --disable-strong-randomMichael Paquier
This removes a portion of infrastructure introduced by fe0a0b5 to allow compilation of Postgres in environments where no strong random source is available, meaning that there is no linking to OpenSSL and no /dev/urandom (Windows having its own CryptoAPI). No systems shipped this century lack /dev/urandom, and the buildfarm is actually not testing this switch at all, so just remove it. This simplifies particularly some backend code which included a fallback implementation using shared memory, and removes a set of alternate regression output files from pgcrypto. Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/20181230063219.GG608@paquier.xyz
2018-12-29Use pg_strong_random() to select each server process's random seed.Tom Lane
Previously we just set the seed based on process ID and start timestamp. Both those values are directly available within the session, and can be found out or guessed by other users too, making the session's series of random(3) values fairly predictable. Up to now, our backend-internal uses of random(3) haven't seemed security-critical, but commit 88bdbd3f7 added one that potentially is: when using log_statement_sample_rate, a user might be able to predict which of his SQL statements will get logged. To improve this situation, upgrade the per-process seed initialization method to use pg_strong_random() if available, greatly reducing the predictability of the initial seed value. This adds a few tens of microseconds to process start time, but since backend startup time is at least a couple of milliseconds, that seems an acceptable price. This means that pg_strong_random() needs to be able to run without reliance on any backend infrastructure, since it will be invoked before any of that is up. It was safe for that already, but adjust comments and #include commands to make it clearer. Discussion: https://postgr.es/m/3859.1545849900@sss.pgh.pa.us
2018-12-24Prioritize history files when archivingMichael Paquier
At the end of recovery for the post-promotion process, a new history file is created followed by the last partial segment of the previous timeline. Based on the timing, the archiver would first try to archive the last partial segment and then the history file. This can delay the detection of a new timeline taken, particularly depending on the time it takes to transfer the last partial segment as it delays the moment the history file of the new timeline gets archived. This can cause promoted standbys to use the same timeline as one already taken depending on the circumstances if multiple instances look at archives at the same location. This commit changes the order of archiving so as history files are archived in priority over other file types, which reduces the likelihood of the same timeline being taken (still not reducing the window to zero), and it makes the archiver behave more consistently with the startup process doing its post-promotion business. Author: David Steele Reviewed-by: Michael Paquier, Kyotaro Horiguchi Discussion: https://postgr.es/m/929068cf-69e1-bba2-9dc0-e05986aed471@pgmasters.net Backpatch-through: 9.5
2018-12-16Modernize our code for looking up descriptive strings for Unix signals.Tom Lane
At least as far back as the 2008 spec, POSIX has defined strsignal(3) for looking up descriptive strings for signal numbers. We hadn't gotten the word though, and were still using the crufty old sys_siglist array, which is in no standard even though most Unixen provide it. Aside from not being formally standards-compliant, this was just plain ugly because it involved #ifdef's at every place using the code. To eliminate the #ifdef's, create a portability function pg_strsignal, which wraps strsignal(3) if available and otherwise falls back to sys_siglist[] if available. The set of Unixen with neither API is probably empty these days, but on any platform with neither, you'll just get "unrecognized signal". All extant callers print the numeric signal number too, so no need to work harder than that. Along the way, upgrade pg_basebackup's child-error-exit reporting to match the rest of the system. Discussion: https://postgr.es/m/25758.1544983503@sss.pgh.pa.us
2018-12-16Improve detection of child-process SIGPIPE failures.Tom Lane
Commit ffa4cbd62 added logic to detect SIGPIPE failure of a COPY child process, but it only worked correctly if the SIGPIPE occurred in the immediate child process. Depending on the shell in use and the complexity of the shell command string, we might instead get back an exit code of 128 + SIGPIPE, representing a shell error exit reporting SIGPIPE in the child process. We could just hack up ClosePipeToProgram() to add the extra case, but it seems like this is a fairly general issue deserving a more general and better-documented solution. I chose to add a couple of functions in src/common/wait_error.c, which is a natural place to know about wait-result encodings, that will test for either a specific child-process signal type or any child-process signal failure. Then, adjust other places that were doing ad-hoc tests of this type to use the common functions. In RestoreArchivedFile, this fixes a race condition affecting whether the process will report an error or just silently proc_exit(1): before, that depended on whether the intermediate shell got SIGTERM'd itself or reported a child process failing on SIGTERM. Like the previous patch, back-patch to v10; we could go further but there seems no real need to. Per report from Erik Rijkers. Discussion: https://postgr.es/m/f3683f87ab1701bea5d86a7742b22432@xs4all.nl
2018-12-10Ensure cleanup of orphan archive status filesMichael Paquier
When a WAL segment is recycled, its ".ready" and ".done" status files get also automatically removed, however this is not done in a durable manner. Hence, in a subsequent crash, it could be possible that a ".ready" status file is still around with its corresponding segment already gone. If the backend reaches such a state, the archive command would most likely complain about a segment non-existing and would keep retrying, causing WAL segments to bloat pg_wal/, potentially making Postgres crash hard when running out of space. As status files are removed after each individual segment, using durable_unlink() does not completely close the window either, as a crash could happen between the moment the WAL segment is recycled and the moment its status files are removed. This has also some performance impact with the additional fsync() calls needed to make the removal in a durable manner. Doing the cleanup at recovery is not cost-free either as this makes crash recovery potentially take longer than necessary. So, instead, as per an idea of Stephen Frost, make the archiver aware of orphan status files and remove them on-the-fly if the corresponding segment goes missing. Removal failures follow a model close to what happens for WAL segments, where multiple attempts are done before giving up temporarily, and where a successful orphan removal makes the archiver move immediately to the next WAL segment thought as ready to be archived. Author: Michael Paquier Reviewed-by: Nathan Bossart, Andres Freund, Stephen Frost, Kyotaro Horiguchi Discussion: https://postgr.es/m/20180928032827.GF1500@paquier.xyz
2018-11-23Silence compiler warningsAlvaro Herrera
Commit cfdf4dc4fc96 left a few unnecessary assignments, one of which caused compiler warnings, as reported by Erik Rijkers. Remove them all. Discussion: https://postgr.es/m/df0dcca2025b3d90d946ecc508ca9678@xs4all.nl
2018-11-23Add WL_EXIT_ON_PM_DEATH pseudo-event.Thomas Munro
Users of the WaitEventSet and WaitLatch() APIs can now choose between asking for WL_POSTMASTER_DEATH and then handling it explicitly, or asking for WL_EXIT_ON_PM_DEATH to trigger immediate exit on postmaster death. This reduces code duplication, since almost all callers want the latter. Repair all code that was previously ignoring postmaster death completely, or requesting the event but ignoring it, or requesting the event but then doing an unconditional PostmasterIsAlive() call every time through its event loop (which is an expensive syscall on platforms for which we don't have USE_POSTMASTER_DEATH_SIGNAL support). Assert that callers of WaitLatchXXX() under the postmaster remember to ask for either WL_POSTMASTER_DEATH or WL_EXIT_ON_PM_DEATH, to prevent future bugs. The only process that doesn't handle postmaster death is syslogger. It waits until all backends holding the write end of the syslog pipe (including the postmaster) have closed it by exiting, to be sure to capture any parting messages. By using the WaitEventSet API directly it avoids the new assertion, and as a by-product it may be slightly more efficient on platforms that have epoll(). Author: Thomas Munro Reviewed-by: Kyotaro Horiguchi, Heikki Linnakangas, Tom Lane Discussion: https://postgr.es/m/CAEepm%3D1TCviRykkUb69ppWLr_V697rzd1j3eZsRMmbXvETfqbQ%40mail.gmail.com, https://postgr.es/m/CAEepm=2LqHzizbe7muD7-2yHUbTOoF7Q+qkSD5Q41kuhttRTwA@mail.gmail.com
2018-11-20Remove WITH OIDS support, change oid catalog column visibility.Andres Freund
Previously tables declared WITH OIDS, including a significant fraction of the catalog tables, stored the oid column not as a normal column, but as part of the tuple header. This special column was not shown by default, which was somewhat odd, as it's often (consider e.g. pg_class.oid) one of the more important parts of a row. Neither pg_dump nor COPY included the contents of the oid column by default. The fact that the oid column was not an ordinary column necessitated a significant amount of special case code to support oid columns. That already was painful for the existing, but upcoming work aiming to make table storage pluggable, would have required expanding and duplicating that "specialness" significantly. WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0). Remove it. Removing includes: - CREATE TABLE and ALTER TABLE syntax for declaring the table to be WITH OIDS has been removed (WITH (oids[ = true]) will error out) - pg_dump does not support dumping tables declared WITH OIDS and will issue a warning when dumping one (and ignore the oid column). - restoring an pg_dump archive with pg_restore will warn when restoring a table with oid contents (and ignore the oid column) - COPY will refuse to load binary dump that includes oids. - pg_upgrade will error out when encountering tables declared WITH OIDS, they have to be altered to remove the oid column first. - Functionality to access the oid of the last inserted row (like plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed. The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false) for CREATE TABLE) is still supported. While that requires a bit of support code, it seems unnecessary to break applications / dumps that do not use oids, and are explicit about not using them. The biggest user of WITH OID columns was postgres' catalog. This commit changes all 'magic' oid columns to be columns that are normally declared and stored. To reduce unnecessary query breakage all the newly added columns are still named 'oid', even if a table's column naming scheme would indicate 'reloid' or such. This obviously requires adapting a lot code, mostly replacing oid access via HeapTupleGetOid() with access to the underlying Form_pg_*->oid column. The bootstrap process now assigns oids for all oid columns in genbki.pl that do not have an explicit value (starting at the largest oid previously used), only oids assigned later by oids will be above FirstBootstrapObjectId. As the oid column now is a normal column the special bootstrap syntax for oids has been removed. Oids are not automatically assigned during insertion anymore, all backend code explicitly assigns oids with GetNewOidWithIndex(). For the rare case that insertions into the catalog via SQL are called for the new pg_nextoid() function can be used (which only works on catalog tables). The fact that oid columns on system tables are now normal columns means that they will be included in the set of columns expanded by * (i.e. SELECT * FROM pg_class will now include the table's oid, previously it did not). It'd not technically be hard to hide oid column by default, but that'd mean confusing behavior would either have to be carried forward forever, or it'd cause breakage down the line. While it's not unlikely that further adjustments are needed, the scope/invasiveness of the patch makes it worthwhile to get merge this now. It's painful to maintain externally, too complicated to commit after the code code freeze, and a dependency of a number of other patches. Catversion bump, for obvious reasons. Author: Andres Freund, with contributions by John Naylor Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
2018-11-17Avoid defining SIGTTIN/SIGTTOU on Windows.Tom Lane
Setting them to SIG_IGN seems unlikely to have any beneficial effect on that platform, and given the signal numbering collision with SIGABRT, it could easily have bad effects. Given the lack of field complaints that can be traced to this, I don't presently feel a need to back-patch. Discussion: https://postgr.es/m/5627.1542477392@sss.pgh.pa.us
2018-11-17Leave SIGTTIN/SIGTTOU signal handling alone in postmaster child processes.Tom Lane
For reasons lost in the mists of time, most postmaster child processes reset SIGTTIN/SIGTTOU signal handling to SIG_DFL, with the major exception that backend sessions do not. It seems like a pretty bad idea for any postmaster children to do that: if stderr is connected to the terminal, and the user has put the postmaster in background, any log output would result in the child process freezing up. Hence, switch them all to doing what backends do, ie, nothing. This allows them to inherit the postmaster's SIG_IGN setting. On the other hand, manually-launched processes such as standalone backends will have default processing, which seems fine. In passing, also remove useless resets of SIGCONT and SIGWINCH signal processing. Perhaps the postmaster once changed those to something besides SIG_DFL, but it doesn't now, so these are just wasted (and confusing) syscalls. Basically, this propagates the changes made in commit 8e2998d8a from backends to other postmaster children. Probably the only reason these calls now exist elsewhere is that I missed changing pgstat.c along with postgres.c at the time. Given the lack of field complaints that can be traced to this, I don't presently feel a need to back-patch. Discussion: https://postgr.es/m/5627.1542477392@sss.pgh.pa.us
2018-11-15Further adjustment to random() seed initialization.Thomas Munro
Per complaint from Tom Lane, don't chomp the timestamp at 32 bits, so we can shift in some of its higher bits. Discussion: https://postgr.es/m/14712.1542253115%40sss.pgh.pa.us
2018-11-15Increase the number of possible random seeds per time period.Thomas Munro
Commit 197e4af9 refactored the initialization of the libc random() seed, but reduced the number of possible seeds values that could be chosen in a given time period. This negation of the effects of commit 98c50656c was unintentional. Replace with code that shifts the fast moving timestamp bits left, similar to the original algorithm (though not the previous float-tolerating coding, which is no longer necessary). Author: Thomas Munro Reported-by: Noah Misch Reviewed-by: Tom Lane Discussion: https://postgr.es/m/20181112083358.GA1073796%40rfd.leadboat.com
2018-10-25Add pg_promote functionMichael Paquier
This function is able to promote a standby with this new SQL-callable function. Execution access can be granted to non-superusers so that failover tools can observe the principle of least privilege. Catalog version is bumped. Author: Laurenz Albe Reviewed-by: Michael Paquier, Masahiko Sawada Discussion: https://postgr.es/m/6e7c79b3ec916cf49742fb8849ed17cd87aed620.camel@cybertec.at
2018-10-24List wait events in alphabetical orderMichael Paquier
This changes the documentation, and the related structures so as everything is consistent. Some wait events were not listed alphabetically since their introduction, others have been added rather randomly. Keeping all those entries in order helps in maintenance, and helps the user looking at the documentation. Author: Michael Paquier, Kuntal Ghosh Discussion: https://postgr.es/m/20181024002539.GI1658@paquier.xyz Backpatch-through: 10, only for the documentation part to avoid an ABI breakage.
2018-10-19Refactor pid, random seed and start time initialization.Thomas Munro
Background workers, including parallel workers, were generating the same sequence of numbers in random(). This showed up as DSM handle collisions when Parallel Hash created multiple segments, but any code that calls random() in background workers could be affected if it cares about different backends generating different numbers. Repair by making sure that all new processes initialize the seed at the same time as they set MyProcPid and MyStartTime in a new function InitProcessGlobals(), called by the postmaster, its children and also standalone processes. Also add a new high resolution MyStartTimestamp as a potentially useful by-product, and remove SessionStartTime from struct Port as it is now redundant. No back-patch for now, as the known consequences so far are just a bunch of harmless shm_open(O_EXCL) collisions. Author: Thomas Munro Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CAEepm%3D2eJj_6%3DB%2B2tEpGu2nf1BjthCf9nXXUouYvJJ4C5WSwhg%40mail.gmail.com
2018-09-28Add application_name to connection authorized msgStephen Frost
The connection authorized message has quite a bit of useful information in it, but didn't include the application_name (when provided), so let's add that as it can be very useful. Note that at the point where we're emitting the connection authorized message, we haven't processed GUCs, so it's not possible to get this by using log_line_prefix (which pulls from the GUC). There's also something to be said for having this included in the connection authorized message and then not needing to repeat it for every line, as having it in log_line_prefix would do. The GUC cleans the application name to pure-ascii, so do that here too, but pull out the logic for cleaning up a string into its own function in common and re-use it from those places, and check_cluster_name which was doing the same thing. Author: Don Seiler <don@seiler.us> Discussion: https://postgr.es/m/CAHJZqBB_Pxv8HRfoh%2BAB4KxSQQuPVvtYCzMg7woNR3r7dfmopw%40mail.gmail.com
2018-09-06Refactor dlopen() supportPeter Eisentraut
Nowadays, all platforms except Windows and older HP-UX have standard dlopen() support. So having a separate implementation per platform under src/backend/port/dynloader/ is a bit excessive. Instead, treat dlopen() like other library functions that happen to be missing sometimes and put a replacement implementation under src/port/. Discussion: https://www.postgresql.org/message-id/flat/e11a49cb-570a-60b7-707d-7084c8de0e61%402ndquadrant.com#54e735ae37476a121abb4e33c2549b03
2018-09-01Implement "pg_ctl logrotate" commandAlexander Korotkov
Currently there are two ways to trigger log rotation in logging collector process: call pg_rotate_logfile() SQL-function or send SIGUSR1 signal directly to logging collector process. However, it's nice to have more suitable way for external tools to do that, which wouldn't require SQL connection or knowledge of logging collector pid. This commit implements triggering log rotation by "pg_ctl logrotate" command. Discussion: https://postgr.es/m/20180416.115435.28153375.horiguchi.kyotaro%40lab.ntt.co.jp Author: Kyotaro Horiguchi, Alexander Kuzmenkov, Alexander Korotkov
2018-08-29Stop bgworkers during fast shutdown with postmaster in startup phaseMichael Paquier
When a postmaster gets into its phase PM_STARTUP, it would start background workers using BgWorkerStart_PostmasterStart mode immediately, which would cause problems for a fast shutdown as the postmaster forgets to send SIGTERM to already-started background workers. With smart and immediate shutdowns, this correctly happened, and fast shutdown is the only mode missing the shot. Author: Alexander Kukushkin Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/CAFh8B=mvnD8+DZUfzpi50DoaDfZRDfd7S=gwj5vU9GYn8UvHkA@mail.gmail.com Backpatch-through: 9.5
2018-08-26Make syslogger more robust against failures in opening CSV log files.Tom Lane
The previous coding figured it'd be good enough to postpone opening the first CSV log file until we got a message we needed to write there. This is unsafe, though, because if the open fails we end up in infinite recursion trying to report the failure. Instead make the CSV log file management code look as nearly as possible like the longstanding logic for the stderr log file. In particular, open it immediately at postmaster startup (if enabled), or when we get a SIGHUP in which we find that log_destination has been changed to enable CSV logging. It seems OK to fail if a postmaster-start-time open attempt fails, as we've long done for the stderr log file. But we can't die if we fail to open a CSV log file during SIGHUP, so we're still left with a problem. In that case, write any output meant for the CSV log file to the stderr log file. (This will also cover race-condition cases in which backends send CSV log data before or after we have the CSV log file open.) This patch also fixes an ancient oversight that, if CSV logging was turned off during a SIGHUP, we never actually closed the last CSV log file. In passing, remember to reset whereToSendOutput = DestNone during syslogger start, since (unlike all other postmaster children) it's forked before the postmaster has done that. This made for a platform-dependent difference in error reporting behavior between the syslogger and other children: except on Windows, it'd report problems to the original postmaster stderr as well as the normal error log file(s). It's barely possible that that was intentional at some point; but it doesn't seem likely to be desirable in production, and the platform dependency definitely isn't desirable. Per report from Alexander Kukushkin. It's been like this for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/CAFh8B==iLUD_gqC-dAENS0V+kVrCeGiKujtKqSQ7++S-caaChw@mail.gmail.com
2018-08-15Clean up assorted misuses of snprintf()'s result value.Tom Lane
Fix a small number of places that were testing the result of snprintf() but doing so incorrectly. The right test for buffer overrun, per C99, is "result >= bufsize" not "result > bufsize". Some places were also checking for failure with "result == -1", but the standard only says that a negative value is delivered on failure. (Note that this only makes these places correct if snprintf() delivers C99-compliant results. But at least now these places are consistent with all the other places where we assume that.) Also, make psql_start_test() and isolation_start_test() check for buffer overrun while constructing their shell commands. There seems like a higher risk of overrun, with more severe consequences, here than there is for the individual file paths that are made elsewhere in the same functions, so this seemed like a worthwhile change. Also fix guc.c's do_serialize() to initialize errno = 0 before calling vsnprintf. In principle, this should be unnecessary because vsnprintf should have set errno if it returns a failure indication ... but the other two places this coding pattern is cribbed from don't assume that, so let's be consistent. These errors are all very old, so back-patch as appropriate. I think that only the shell command overrun cases are even theoretically reachable in practice, but there's not much point in erroneous error checks. Discussion: https://postgr.es/m/17245.1534289329@sss.pgh.pa.us
2018-08-13Make autovacuum more aggressive to remove orphaned temp tablesMichael Paquier
Commit dafa084, added in 10, made the removal of temporary orphaned tables more aggressive. This commit makes an extra step into the aggressiveness by adding a flag in each backend's MyProc which tracks down any temporary namespace currently in use. The flag is set when the namespace gets created and can be reset if the temporary namespace has been created in a transaction or sub-transaction which is aborted. The flag value assignment is assumed to be atomic, so this can be done in a lock-less fashion like other flags already present in PGPROC like databaseId or backendId, still the fact that the temporary namespace and table created are still locked until the transaction creating those commits acts as a barrier for other backends. This new flag gets used by autovacuum to discard more aggressively orphaned tables by additionally checking for the database a backend is connected to as well as its temporary namespace in-use, removing orphaned temporary relations even if a backend reuses the same slot as one which created temporary relations in a past session. The base idea of this patch comes from Robert Haas, has been written in its first version by Tsunakawa Takayuki, then heavily reviewed by me. Author: Tsunakawa Takayuki Reviewed-by: Michael Paquier, Kyotaro Horiguchi, Andres Freund Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8A4DC6@G01JPEXMBYT05 Backpatch: 11-, as PGPROC gains a new flag and we don't want silent ABI breakages on already released versions.
2018-08-08Don't run atexit callbacks in quickdie signal handlers.Heikki Linnakangas
exit() is not async-signal safe. Even if the libc implementation is, 3rd party libraries might have installed unsafe atexit() callbacks. After receiving SIGQUIT, we really just want to exit as quickly as possible, so we don't really want to run the atexit() callbacks anyway. The original report by Jimmy Yih was a self-deadlock in startup_die(). However, this patch doesn't address that scenario; the signal handling while waiting for the startup packet is more complicated. But at least this alleviates similar problems in the SIGQUIT handlers, like that reported by Asim R P later in the same thread. Backpatch to 9.3 (all supported versions). Discussion: https://www.postgresql.org/message-id/CAOMx_OAuRUHiAuCg2YgicZLzPVv5d9_H4KrL_OFsFP%3DVPekigA%40mail.gmail.com
2018-08-07Fix incorrect initialization of BackendActivityBuffer.Tom Lane
Since commit c8e8b5a6e, this has been zeroed out using the wrong length. In practice the length would always be too small, leading to not zeroing the whole buffer rather than clobbering additional memory; and that's pretty harmless, both because shmem would likely start out as zeroes and because we'd reinitialize any given entry before use. Still, it's bogus, so fix it. Reported by Petru-Florin Mihancea (bug #15312) Discussion: https://postgr.es/m/153363913073.1303.6518849192351268091@wrigleys.postgresql.org
2018-07-18Use a ResourceOwner to track buffer pins in all cases.Tom Lane
Historically, we've allowed auxiliary processes to take buffer pins without tracking them in a ResourceOwner. However, that creates problems for error recovery. In particular, we've seen multiple reports of assertion crashes in the startup process when it gets an error while holding a buffer pin, as for example if it gets ENOSPC during a write. In a non-assert build, the process would simply exit without releasing the pin at all. We've gotten away with that so far just because a failure exit of the startup process translates to a database crash anyhow; but any similar behavior in other aux processes could result in stuck pins and subsequent problems in vacuum. To improve this, institute a policy that we must *always* have a resowner backing any attempt to pin a buffer, which we can enforce just by removing the previous special-case code in resowner.c. Add infrastructure to make it easy to create a process-lifespan AuxProcessResourceOwner and clear out its contents at appropriate times. Replace existing ad-hoc resowner management in bgwriter.c and other aux processes with that. (Thus, while the startup process gains a resowner where it had none at all before, some other aux process types are replacing an ad-hoc resowner with this code.) Also use the AuxProcessResourceOwner to manage buffer pins taken during StartupXLOG and ShutdownXLOG, even when those are being run in a bootstrap process or a standalone backend rather than a true auxiliary process. In passing, remove some other ad-hoc resource owner creations that had gotten cargo-culted into various other places. As far as I can tell that was all unnecessary, and if it had been necessary it was incomplete, due to lacking any provision for clearing those resowners later. (Also worth noting in this connection is that a process that hasn't called InitBufferPoolBackend has no business accessing buffers; so there's more to do than just add the resowner if we want to touch buffers in processes not covered by this patch.) Although this fixes a very old bug, no back-patch, because there's no evidence of any significant problem in non-assert builds. Patch by me, pursuant to a report from Justin Pryzby. Thanks to Robert Haas and Kyotaro Horiguchi for reviews. Discussion: https://postgr.es/m/20180627233939.GA10276@telsasoft.com
2018-07-12Rename VACOPT_NOWAIT to VACOPT_SKIP_LOCKEDMichael Paquier
When it comes to SELECT ... FOR or LOCK, NOWAIT means to not wait for something to happen, and issue an error. SKIP LOCKED means to not wait for something to happen but to move on without issuing an error. The internal option of autovacuum and autoanalyze mentioned above, used only when wraparound is not involved was named NOWAIT, but behaves like SKIP LOCKED which is confusing. Author: Nathan Bossart Discussion: https://postgr.es/m/20180307050345.GA3095@paquier.xyz
2018-07-02Add wait event for fsync of WAL segmentsMichael Paquier
This has been visibly a forgotten spot in the first implementation of wait events for I/O added by 249cf07, and what has been missing is a fsync call for WAL segments which is a wrapper reacting on the value of GUC wal_sync_method. Reported-by: Konstantin Knizhnik Author: Konstantin Knizhnik Reviewed-by: Craig Ringer, Michael Paquier Discussion: https://postgr.es/m/4a243897-0ad8-f471-aa40-242591f2476e@postgrespro.ru
2018-05-03Further improve code for probing the availability of ARM CRC instructions.Tom Lane
Andrew Gierth pointed out that commit 1c72ec6f4 would yield the wrong answer on big-endian ARM systems, because the data being CRC'd would be different. To fix that, and avoid the rather unsightly hard-wired constant, simply compare the hardware and software implementations' results. While we're at it, also log the resulting decision at DEBUG1, and error out if the hw and sw results unexpectedly differ. Also, since this file must compile for both frontend and backend, avoid incorrect dependencies on backend-only headers. In passing, add a comment to postmaster.c about when the CRC function pointer will get initialized. Thomas Munro, based on complaints from Andrew Gierth and Tom Lane Discussion: https://postgr.es/m/HE1PR0801MB1323D171938EABC04FFE7FA9E3110@HE1PR0801MB1323.eurprd08.prod.outlook.com
2018-04-28In AtEOXact_Files, complain if any files remain unclosed at commit.Tom Lane
This change makes this module act more like most of our other low-level resource management modules. It's a caller error if something is not explicitly closed by the end of a successful transaction, so issue a WARNING about it. This would not actually have caught the file leak bug fixed in commit 231bcd080, because that was in a transaction-abort path; but it still seems like a good, and pretty cheap, cross-check. Discussion: https://postgr.es/m/152056616579.4966.583293218357089052@wrigleys.postgresql.org
2018-04-11Allocate enough shared string memory for stats of auxiliary processes.Heikki Linnakangas
This fixes a bug whereby the st_appname, st_clienthostname, and st_activity_raw fields for auxiliary processes point beyond the end of their respective shared memory segments. As a result, the application_name of a backend might show up as the client hostname of an auxiliary process. Backpatch to v10, where this bug was introduced, when the auxiliary processes were added to the array. Author: Edmund Horner Reviewed-by: Michael Paquier Discussion: https://www.postgresql.org/message-id/CAMyN-kA7aOJzBmrYFdXcc7Z0NmW%2B5jBaf_m%3D_-77uRNyKC9r%3DA%40mail.gmail.com
2018-04-11Make local copy of client hostnames in backend status array.Heikki Linnakangas
The other strings, application_name and query string, were snapshotted to local memory in pgstat_read_current_status(), but we forgot to do that for client hostnames. As a result, the client hostname would appear to change in the local copy, if the client disconnected. Backpatch to all supported versions. Author: Edmund Horner Reviewed-by: Michael Paquier Discussion: https://www.postgresql.org/message-id/CAMyN-kA7aOJzBmrYFdXcc7Z0NmW%2B5jBaf_m%3D_-77uRNyKC9r%3DA%40mail.gmail.com
2018-04-09Revert "Allow on-line enabling and disabling of data checksums"Magnus Hagander
This reverts the backend sides of commit 1fde38beaa0c3e66c340efc7cc0dc272d6254bb0. I have, at least for now, left the pg_verify_checksums tool in place, as this tool can be very valuable without the rest of the patch as well, and since it's a read-only tool that only runs when the cluster is down it should be a lot safer.
2018-04-07Fix EXEC BACKEND + Windows builds for group privsStephen Frost
Under EXEC BACKEND we also need to be going through the group privileges setup since we do support that on Unixy systems, so add that to SubPostmasterMain(). Under Windows, we need to simply return true from GetDataDirectoryCreatePerm(), but that wasn't happening due to a missing #else clause. Per buildfarm.
2018-04-07Allow group access on PGDATAStephen Frost
Allow the cluster to be optionally init'd with read access for the group. This means a relatively non-privileged user can perform a backup of the cluster without requiring write privileges, which enhances security. The mode of PGDATA is used to determine whether group permissions are enabled for directory and file creates. This method was chosen as it's simple and works well for the various utilities that write into PGDATA. Changing the mode of PGDATA manually will not automatically change the mode of all the files contained therein. If the user would like to enable group access on an existing cluster then changing the mode of all the existing files will be required. Note that pg_upgrade will automatically change the mode of all migrated files if the new cluster is init'd with the -g option. Tests are included for the backend and all the utilities which operate on the PG data directory to ensure that the correct mode is set based on the data directory permissions. Author: David Steele <david@pgmasters.net> Reviewed-By: Michael Paquier, with discussion amongst many others. Discussion: https://postgr.es/m/ad346fe6-b23e-59f1-ecb7-0e08390ad629%40pgmasters.net
2018-04-07Refactor dir/file permissionsStephen Frost
Consolidate directory and file create permissions for tools which work with the PG data directory by adding a new module (common/file_perm.c) that contains variables (pg_file_create_mode, pg_dir_create_mode) and constants to initialize them (0600 for files and 0700 for directories). Convert mkdir() calls in the backend to MakePGDirectory() if the original call used default permissions (always the case for regular PG directories). Add tests to make sure permissions in PGDATA are set correctly by the tools which modify the PG data directory. Authors: David Steele <david@pgmasters.net>, Adam Brightwell <adam.brightwell@crunchydata.com> Reviewed-By: Michael Paquier, with discussion amongst many others. Discussion: https://postgr.es/m/ad346fe6-b23e-59f1-ecb7-0e08390ad629%40pgmasters.net
2018-04-05Allow on-line enabling and disabling of data checksumsMagnus Hagander
This makes it possible to turn checksums on in a live cluster, without the previous need for dump/reload or logical replication (and to turn it off). Enabling checkusm starts a background process in the form of a launcher/worker combination that goes through the entire database and recalculates checksums on each and every page. Only when all pages have been checksummed are they fully enabled in the cluster. Any failure of the process will revert to checksums off and the process has to be started. This adds a new WAL record that indicates the state of checksums, so the process works across replicated clusters. Authors: Magnus Hagander and Daniel Gustafsson Review: Tomas Vondra, Michael Banck, Heikki Linnakangas, Andrey Borodin
2018-04-05Allow background workers to bypass datallowconnMagnus Hagander
THis adds a "flags" field to the BackgroundWorkerInitializeConnection() and BackgroundWorkerInitializeConnectionByOid(). For now only one flag, BGWORKER_BYPASS_ALLOWCONN, is defined, which allows the worker to ignore datallowconn.
2018-03-14Log when a BRIN autosummarization request failsAlvaro Herrera
Autovacuum's 'workitem' request queue is of limited size, so requests can fail if they arrive more quickly than autovacuum can process them. Emit a log message when this happens, to provide better visibility of this. Backpatch to 10. While this represents an API change for AutoVacuumRequestWork, that function is not yet prepared to deal with external modules calling it, so there doesn't seem to be any risk (other than log spam, that is.) Author: Masahiko Sawada Reviewed-by: Fabrízio Mello, Ildar Musin, Álvaro Herrera Discussion: https://postgr.es/m/CAD21AoB1HrQhp6_4rTyHN5kWEJCEsG8YzsjZNt-ctoXSn5Uisw@mail.gmail.com
2018-03-13Avoid holding AutovacuumScheduleLock while rechecking table statistics.Tom Lane
In databases with many tables, re-fetching the statistics takes some time, so that this behavior seriously decreases the available concurrency for multiple autovac workers. There's discussion afoot about more complete fixes, but a simple and back-patchable amelioration is to claim the table and release the lock before rechecking stats. If we find out there's no longer a reason to process the table, re-taking the lock to un-claim the table is cheap enough. (This patch is quite old, but got lost amongst a discussion of more aggressive fixes. It's not clear when or if such a fix will be accepted, but in any case it'd be unlikely to get back-patched. Let's do this now so we have some improvement for the back branches.) In passing, make the normal un-claim step take AutovacuumScheduleLock not AutovacuumLock, since that is what is documented to protect the wi_tableoid field. This wasn't an actual bug in view of the fact that readers of that field hold both locks, but it creates some concurrency penalty against operations that need only AutovacuumLock. Back-patch to all supported versions. Jeff Janes Discussion: https://postgr.es/m/26118.1520865816@sss.pgh.pa.us
2018-03-08Fix cross-checking of ReservedBackends/max_wal_senders/MaxConnections.Tom Lane
We were independently checking ReservedBackends < MaxConnections and max_wal_senders < MaxConnections, but because walsenders aren't allowed to use superuser-reserved connections, that's really the wrong thing. Correct behavior is to insist on ReservedBackends + max_wal_senders being less than MaxConnections. Fix the code and associated documentation. This has been wrong for a long time, but since the situation probably hardly ever arises in the field (especially pre-v10, when the default for max_wal_senders was zero), no back-patch. Discussion: https://postgr.es/m/28271.1520195491@sss.pgh.pa.us