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2019-07-06In pg_log_generic(), be more paranoid about preserving errno.Tom Lane
This code failed to account for the possibility that malloc() would change errno, resulting in wrong output for %m, not to mention the possibility of message truncation. Such a change is obviously expected when malloc fails, but there's reason to fear that on some platforms even a successful malloc call can modify errno. Discussion: https://postgr.es/m/2576.1527382833@sss.pgh.pa.us
2019-06-24Make script output more pgindent compatiblePeter Eisentraut
2019-06-24Correct script name in README filePeter Eisentraut
2019-06-03Fix typos in various placesMichael Paquier
Author: Andrea Gelmini Reviewed-by: Michael Paquier, Justin Pryzby Discussion: https://postgr.es/m/20190528181718.GA39034@glet
2019-05-22Phase 2 pgindent run for v12.Tom Lane
Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22Initial pgindent run for v12.Tom Lane
This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
2019-05-14Move logging.h and logging.c from src/fe_utils/ to src/common/.Tom Lane
The original placement of this module in src/fe_utils/ is ill-considered, because several src/common/ modules have dependencies on it, meaning that libpgcommon and libpgfeutils now have mutual dependencies. That makes it pointless to have distinct libraries at all. The intended design is that libpgcommon is lower-level than libpgfeutils, so only dependencies from the latter to the former are acceptable. We already have the precedent that fe_memutils and a couple of other modules in src/common/ are frontend-only, so it's not stretching anything out of whack to treat logging.c as a frontend-only module in src/common/. To the extent that such modules help provide a common frontend/backend environment for the rest of common/ to use, it's a reasonable design. (logging.c does not yet provide an ereport() emulation, but one can dream.) Hence, move these files over, and revert basically all of the build-system changes made by commit cc8d41511. There are no places that need to grow new dependencies on libpgcommon, further reinforcing the idea that this is the right solution. Discussion: https://postgr.es/m/a912ffff-f6e4-778a-c86a-cf5c47a12933@2ndquadrant.com
2019-04-25Fix function names in comments.Fujii Masao
Commit 3eb77eba5a renamed some functions, but forgot to update some comments referencing to those functions. This commit fixes those function names in the comments. Kyotaro Horiguchi
2019-04-02Add support for partial TOAST decompressionStephen Frost
When asked for a slice of a TOAST entry, decompress enough to return the slice instead of decompressing the entire object. For use cases where the slice is at, or near, the beginning of the entry, this avoids a lot of unnecessary decompression work. This changes the signature of pglz_decompress() by adding a boolean to indicate if it's ok for the call to finish before consuming all of the source or destination buffers. Author: Paul Ramsey Reviewed-By: Rafia Sabih, Darafei Praliaskouski, Regina Obe Discussion: https://postgr.es/m/CACowWR07EDm7Y4m2kbhN_jnys%3DBBf9A6768RyQdKm_%3DNpkcaWg%40mail.gmail.com
2019-04-01Unified logging system for command-line programsPeter Eisentraut
This unifies the various ad hoc logging (message printing, error printing) systems used throughout the command-line programs. Features: - Program name is automatically prefixed. - Message string does not end with newline. This removes a common source of inconsistencies and omissions. - Additionally, a final newline is automatically stripped, simplifying use of PQerrorMessage() etc., another common source of mistakes. - I converted error message strings to use %m where possible. - As a result of the above several points, more translatable message strings can be shared between different components and between frontends and backend, without gratuitous punctuation or whitespace differences. - There is support for setting a "log level". This is not meant to be user-facing, but can be used internally to implement debug or verbose modes. - Lazy argument evaluation, so no significant overhead if logging at some level is disabled. - Some color in the messages, similar to gcc and clang. Set PG_COLOR=auto to try it out. Some colors are predefined, but can be customized by setting PG_COLORS. - Common files (common/, fe_utils/, etc.) can handle logging much more simply by just using one API without worrying too much about the context of the calling program, requiring callbacks, or having to pass "progname" around everywhere. - Some programs called setvbuf() to make sure that stderr is unbuffered, even on Windows. But not all programs did that. This is now done centrally. Soft goals: - Reduces vertical space use and visual complexity of error reporting in the source code. - Encourages more deliberate classification of messages. For example, in some cases it wasn't clear without analyzing the surrounding code whether a message was meant as an error or just an info. - Concepts and terms are vaguely aligned with popular logging frameworks such as log4j and Python logging. This is all just about printing stuff out. Nothing affects program flow (e.g., fatal exits). The uses are just too varied to do that. Some existing code had wrappers that do some kind of print-and-exit, and I adapted those. I tried to keep the output mostly the same, but there is a lot of historical baggage to unwind and special cases to consider, and I might not always have succeeded. One significant change is that pg_rewind used to write all error messages to stdout. That is now changed to stderr. Reviewed-by: Donald Dong <xdong@csumb.edu> Reviewed-by: Arthur Zakirov <a.zakirov@postgrespro.ru> Discussion: https://www.postgresql.org/message-id/flat/6a609b43-4f57-7348-6480-bd022f924310@2ndquadrant.com
2019-03-18Refactor more code logic to update the control fileMichael Paquier
ce6afc6 has begun the refactoring work by plugging pg_rewind into a central routine to update the control file, and left around two extra copies, with one in xlog.c for the backend and one in pg_resetwal.c. By adding an extra option to the central routine in controldata_utils.c to control if a flush of the control file needs to be done, it is proving to be straight-forward to make xlog.c and pg_resetwal.c use the central code path at the condition of moving the wait event tracking there. Hence, this allows to have only one central code path to update the control file, shaving the code from the duplicates. This refactoring actually fixes a problem in pg_resetwal. Previously, the control file was first removed before being recreated. So if a crash happened between the moment the file was removed and the moment the file was created, then it would have been possible to not have a control file anymore in the database folder. Author: Fabien Coelho Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/alpine.DEB.2.21.1903170935210.2506@lancre
2019-03-12Add routine able to update the control file to src/common/Michael Paquier
This adds a new routine to src/common/ which is compatible with both the frontend and backend code, able to update the control file's contents. This is now getting used only by pg_rewind, but some upcoming patches which add more control on checksums for offline instances will make use of it. This could also get used more by the backend as xlog.c has its own flavor of the same logic with some wait events and an additional flush phase before closing the opened file descriptor, but this is let as separate work. Author: Michael Banck, Michael Paquier Reviewed-by: Fabien Coelho, Sergei Kornilov Discussion: https://postgr.es/m/20181221201616.GD4974@nighthawk.caipicrew.dd-dns.de
2019-03-09Tighten use of OpenTransientFile and CloseTransientFileMichael Paquier
This fixes two sets of issues related to the use of transient files in the backend: 1) OpenTransientFile() has been used in some code paths with read-write flags while read-only is sufficient, so switch those calls to be read-only where necessary. These have been reported by Joe Conway. 2) When opening transient files, it is up to the caller to close the file descriptors opened. In error code paths, CloseTransientFile() gets called to clean up things before issuing an error. However in normal exit paths, a lot of callers of CloseTransientFile() never actually reported errors, which could leave a file descriptor open without knowing about it. This is an issue I complained about a couple of times, but never had the courage to write and submit a patch, so here we go. Note that one frontend code path is impacted by this commit so as an error is issued when fetching control file data, making backend and frontend to be treated consistently. Reported-by: Joe Conway, Michael Paquier Author: Michael Paquier Reviewed-by: Álvaro Herrera, Georgios Kokolatos, Joe Conway Discussion: https://postgr.es/m/20190301023338.GD1348@paquier.xyz Discussion: https://postgr.es/m/c49b69ec-e2f7-ff33-4f17-0eaa4f2cef27@joeconway.com
2019-02-28Make get_controlfile not leak file descriptorsJoe Conway
When backend functions were added to expose controldata via SQL, reading of pg_control was consolidated under src/common so that both frontend and backend could share the same code. That move from frontend-only to shared frontend-backend failed to recognize the risk (and coding standards violation) of using a bare open(). In particular, it risked leaking file descriptors if transient errors occurred while reading the file. Fix that by using OpenTransientFile() instead in the backend case, which is purpose-built for this type of usage. Since there have been no complaints from the field, and an intermittent failure low risk, no backpatch. Hard failure would of course be bad, but in that case these functions are probably the least of your worries. Author: Joe Conway Reviewed-By: Michael Paquier Reported by: Michael Paquier Discussion: https://postgr.es/m/20190227074728.GA15710@paquier.xyz
2019-02-24Tolerate EINVAL when calling fsync() on a directory.Thomas Munro
Previously, we tolerated EBADF as a way for the operating system to indicate that it doesn't support fsync() on a directory. Tolerate EINVAL too, for older versions of Linux CIFS. Bug #15636. Back-patch all the way. Reported-by: John Klann Discussion: https://postgr.es/m/15636-d380890dafd78fc6@postgresql.org
2019-02-13More float test and portability fixes.Andrew Gierth
Avoid assuming exact results in tstypes test; some platforms vary. (per buildfarm members eulachon, danio, lapwing) Avoid dubious usage (inherited from upstream) of bool parameters to copy_special_str, to see if this fixes the mac/ppc failures (per buildfarm members prariedog and locust). (Isolated test programs on a ppc mac don't seem to show any other cause that would explain them.)
2019-02-13Fix an overlooked UINT32_MAX.Andrew Gierth
Replace with PG_UINT32_MAX. Per buildfarm members dory and woodlouse.
2019-02-13Change floating-point output format for improved performance.Andrew Gierth
Previously, floating-point output was done by rounding to a specific decimal precision; by default, to 6 or 15 decimal digits (losing information) or as requested using extra_float_digits. Drivers that wanted exact float values, and applications like pg_dump that must preserve values exactly, set extra_float_digits=3 (or sometimes 2 for historical reasons, though this isn't enough for float4). Unfortunately, decimal rounded output is slow enough to become a noticable bottleneck when dealing with large result sets or COPY of large tables when many floating-point values are involved. Floating-point output can be done much faster when the output is not rounded to a specific decimal length, but rather is chosen as the shortest decimal representation that is closer to the original float value than to any other value representable in the same precision. The recently published Ryu algorithm by Ulf Adams is both relatively simple and remarkably fast. Accordingly, change float4out/float8out to output shortest decimal representations if extra_float_digits is greater than 0, and make that the new default. Applications that need rounded output can set extra_float_digits back to 0 or below, and take the resulting performance hit. We make one concession to portability for systems with buggy floating-point input: we do not output decimal values that fall exactly halfway between adjacent representable binary values (which would rely on the reader doing round-to-nearest-even correctly). This is known to be a problem at least for VS2013 on Windows. Our version of the Ryu code originates from https://github.com/ulfjack/ryu/ at commit c9c3fb1979, but with the following (significant) modifications: - Output format is changed to use fixed-point notation for small exponents, as printf would, and also to use lowercase 'e', a minimum of 2 exponent digits, and a mandatory sign on the exponent, to keep the formatting as close as possible to previous output. - The output of exact midpoint values is disabled as noted above. - The integer fast-path code is changed somewhat (since we have fixed-point output and the upstream did not). - Our project style has been largely applied to the code with the exception of C99 declaration-after-statement, which has been retained as an exception to our present policy. - Most of upstream's debugging and conditionals are removed, and we use our own configure tests to determine things like uint128 availability. Changing the float output format obviously affects a number of regression tests. This patch uses an explicit setting of extra_float_digits=0 for test output that is not expected to be exactly reproducible (e.g. due to numerical instability or differing algorithms for transcendental functions). Conversions from floats to numeric are unchanged by this patch. These may appear in index expressions and it is not yet clear whether any change should be made, so that can be left for another day. This patch assumes that the only supported floating point format is now IEEE format, and the documentation is updated to reflect that. Code by me, adapting the work of Ulf Adams and other contributors. References: https://dl.acm.org/citation.cfm?id=3192369 Reviewed-by: Tom Lane, Andres Freund, Donald Dong Discussion: https://postgr.es/m/87r2el1bx6.fsf@news-spur.riddles.org.uk
2019-02-13Remove useless castsPeter Eisentraut
Some of these were uselessly casting away "const", some were just nearby, but they where all unnecessary anyway. Discussion: https://www.postgresql.org/message-id/flat/53a28052-f9f3-1808-fed9-460fd43035ab%402ndquadrant.com
2019-01-09Use perfect hashing, instead of binary search, for keyword lookup.Tom Lane
We've been speculating for a long time that hash-based keyword lookup ought to be faster than binary search, but up to now we hadn't found a suitable tool for generating the hash function. Joerg Sonnenberger provided the inspiration, and sample code, to show us that rolling our own generator wasn't a ridiculous idea. Hence, do that. The method used here requires a lookup table of approximately 4 bytes per keyword, but that's less than what we saved in the predecessor commit afb0d0712, so it's not a big problem. The time savings is indeed significant: preliminary testing suggests that the total time for raw parsing (flex + bison phases) drops by ~20%. Patch by me, but it owes its existence to Joerg Sonnenberger; thanks also to John Naylor for review. Discussion: https://postgr.es/m/20190103163340.GA15803@britannica.bec.de
2019-01-06Replace the data structure used for keyword lookup.Tom Lane
Previously, ScanKeywordLookup was passed an array of string pointers. This had some performance deficiencies: the strings themselves might be scattered all over the place depending on the compiler (and some quick checking shows that at least with gcc-on-Linux, they indeed weren't reliably close together). That led to very cache-unfriendly behavior as the binary search touched strings in many different pages. Also, depending on the platform, the string pointers might need to be adjusted at program start, so that they couldn't be simple constant data. And the ScanKeyword struct had been designed with an eye to 32-bit machines originally; on 64-bit it requires 16 bytes per keyword, making it even more cache-unfriendly. Redesign so that the keyword strings themselves are allocated consecutively (as part of one big char-string constant), thereby eliminating the touch-lots-of-unrelated-pages syndrome. And get rid of the ScanKeyword array in favor of three separate arrays: uint16 offsets into the keyword array, uint16 token codes, and uint8 keyword categories. That reduces the overhead per keyword to 5 bytes instead of 16 (even less in programs that only need one of the token codes and categories); moreover, the binary search only touches the offsets array, further reducing its cache footprint. This also lets us put the token codes somewhere else than the keyword strings are, which avoids some unpleasant build dependencies. While we're at it, wrap the data used by ScanKeywordLookup into a struct that can be treated as an opaque type by most callers. That doesn't change things much right now, but it will make it less painful to switch to a hash-based lookup method, as is being discussed in the mailing list thread. Most of the change here is associated with adding a generator script that can build the new data structure from the same list-of-PG_KEYWORD header representation we used before. The PG_KEYWORD lists that plpgsql and ecpg used to embed in their scanner .c files have to be moved into headers, and the Makefiles have to be taught to invoke the generator script. This work is also necessary if we're to consider hash-based lookup, since the generator script is what would be responsible for constructing a hash table. Aside from saving a few kilobytes in each program that includes the keyword table, this seems to speed up raw parsing (flex+bison) by a few percent. So it's worth doing even as it stands, though we think we can gain even more with a follow-on patch to switch to hash-based lookup. John Naylor, with further hacking by me Discussion: https://postgr.es/m/CAJVSVGXdFVU2sgym89XPL=Lv1zOS5=EHHQ8XWNzFL=mTXkKMLw@mail.gmail.com
2019-01-02Update copyright for 2019Bruce Momjian
Backpatch-through: certain files through 9.4
2018-12-26Fix portability failure introduced in commits d2b0b60e7 et al.Tom Lane
I made a frontend fprintf() format use %m, forgetting that that's only safe in HEAD not the back branches; prior to 96bf88d52 and d6c55de1f, it would work on glibc platforms but not elsewhere. Revert to using %s ... strerror(errno) as the code did before. We could have left HEAD as-is, but for code consistency across branches, I chose to apply this patch there too. Per Coverity and a few buildfarm members.
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
2018-12-06Improve our response to invalid format strings, and detect more cases.Tom Lane
Places that are testing for *printf failure ought to include the format string in their error reports, since bad-format-string is one of the more likely causes of such failure. This both makes it easier to find and repair the mistake, and provides at least some useful info to the user who stumbles across such a problem. Also, tighten snprintf.c to report EINVAL for an invalid flag or final character in a format %-spec (including the case where the %-spec is missing a final character altogether). This seems like better project policy, and it also allows removing an instruction or two from the hot code path. Back-patch the error reporting change in pvsnprintf, since it should be harmless and may be helpful; but not the snprintf.c change. Per discussion of bug #15511 from Ertuğrul Kahveci, which reported an invalid translated format string. These changes don't fix that error, but they should improve matters next time we make such a mistake. Discussion: https://postgr.es/m/15511-1d8b6a0bc874112f@postgresql.org
2018-10-15Make spelling of "acknowledgment" consistentPeter Eisentraut
I used the preferred U.S. spelling, as we do in other cases.
2018-10-09Make src/common/exec.c's error logging less ugly.Tom Lane
This code used elog where it really ought to use ereport, mainly so that it can report a SQLSTATE different from ERRCODE_INTERNAL_ERROR. There were some other random deviations from typical error report practice too. In addition, we can make some cleanups that were impractical six months ago: * Use one variadic macro, instead of several with different numbers of arguments, reducing the temptation to force-fit messages into particular numbers of arguments; * Use %m, even in the frontend case, simplifying the code. Discussion: https://postgr.es/m/6025.1527351693@sss.pgh.pa.us
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
2018-09-28Build src/common files as a library with -fPIC.Tom Lane
Build a third version of libpgcommon.a, with -fPIC and -DFRONTEND, as commit ea53100d5 did for src/port. Use that in libpq to avoid symlinking+rebuilding source files retail. Also adjust ecpg to use the new src/port and src/common libraries. Arrange to install these libraries, too, to simplify out-of-tree builds of shared libraries that need any of these modules. Discussion: https://postgr.es/m/13022.1538003440@sss.pgh.pa.us Discussion: https://postgr.es/m/E1g5Y8r-0006vs-QA@gemulon.postgresql.org
2018-09-26Implement %m in src/port/snprintf.c, and teach elog.c to rely on that.Tom Lane
I started out with the idea that we needed to detect use of %m format specs in contexts other than elog/ereport calls, because we couldn't rely on that working in *printf calls. But a better answer is to fix things so that it does work. Now that we're using snprintf.c all the time, we can implement %m in that and we've fixed the problem. This requires also adjusting our various printf-wrapping functions so that they ensure "errno" is preserved when they call snprintf.c. Remove elog.c's handmade implementation of %m, and let it rely on snprintf to support the feature. That should provide some performance gain, though I've not attempted to measure it. There are a lot of places where we could now simplify 'printf("%s", strerror(errno))' into 'printf("%m")', but I'm not in any big hurry to make that happen. Patch by me, reviewed by Michael Paquier Discussion: https://postgr.es/m/2975.1526862605@sss.pgh.pa.us
2018-09-14Allow concurrent-safe open() and fopen() in frontend code for WindowsMichael Paquier
PostgreSQL uses a custom wrapper for open() and fopen() which is concurrent-safe, allowing multiple processes to open and work on the same file. This has a couple of advantages: - pg_test_fsync does not handle O_DSYNC correctly otherwise, leading to false claims that disks are unsafe. - TAP tests can run into race conditions when a postmaster and pg_ctl open postmaster.pid, fixing some random failures in the buildfam. pg_upgrade is one frontend tool using workarounds to bypass file locking issues with the log files it generates, however the interactions with pg_ctl are proving to be tedious to get rid of, so this is left for later. Author: Laurenz Albe Reviewed-by: Michael Paquier, Kuntal Ghosh Discussion: https://postgr.es/m/1527846213.2475.31.camel@cybertec.at Discussion: https://postgr.es/m/16922.1520722108@sss.pgh.pa.us
2018-09-09Install a check for mis-linking of src/port and src/common functions.Tom Lane
On ELF-based platforms (and maybe others?) it's possible for a shared library, when dynamically loaded into the backend, to call the backend versions of src/port and src/common functions rather than the frontend versions that are actually linked into the shlib. This is definitely not what we want, because the frontend versions often behave slightly differently. Up to now it's been "slight" enough that nobody noticed; but with the addition of SCRAM support functions in src/common, we're observing crashes due to the difference between palloc and malloc memory allocation rules, as reported in bug #15367 from Jeremy Evans. The purpose of this patch is to create a direct test for this type of mis-linking, so that we know whether any given platform requires extra measures to prevent using the wrong functions. If the test fails, it will lead to connection failures in the contrib/postgres_fdw regression test. At the moment, *BSD platforms using ELF format are known to have the problem and can be expected to fail; but we need to know whether anything else does, and we need a reliable ongoing check for future platforms. Actually fixing the problem will be the subject of later commit(s). Discussion: https://postgr.es/m/153626613985.23143.4743626885618266803@wrigleys.postgresql.org
2018-09-08Minor cleanup/future-proofing for pg_saslprep().Tom Lane
Ensure that pg_saslprep() initializes its output argument to NULL in all failure paths, and then remove the redundant initialization that some (not all) of its callers did. This does not fix any live bug, but it reduces the odds of future bugs of omission. Also add a comment about why the existing failure-path coding is adequate. Back-patch so as to keep the function's API consistent across branches, again to forestall future bug introduction. Patch by me, reviewed by Michael Paquier Discussion: https://postgr.es/m/16558.1536407783@sss.pgh.pa.us
2018-08-16Require a C99-compliant snprintf(), and remove related workarounds.Tom Lane
Since our substitute snprintf now returns a C99-compliant result, there's no need anymore to have complicated code to cope with pre-C99 behavior. We can just make configure substitute snprintf.c if it finds that the system snprintf() is pre-C99. (Note: I do not believe that there are any platforms where this test will trigger that weren't already being rejected due to our other C99-ish feature requirements for snprintf. But let's add the check for paranoia's sake.) Then, simplify the call sites that had logic to cope with the pre-C99 definition. I also dropped some stuff that was being paranoid about the possibility of snprintf overrunning the given buffer. The only reports we've ever heard of that being a problem were for Solaris 7, which is long dead, and we've sure not heard any reports of these assertions triggering in a long time. So let's drop that complexity too. Likewise, drop some code that wasn't trusting snprintf to set errno when it returns -1. That would be not-per-spec, and again there's no real reason to believe it is a live issue, especially not for snprintfs that pass all of configure's feature checks. Discussion: https://postgr.es/m/17245.1534289329@sss.pgh.pa.us
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
2018-08-11Produce compiler errors if errno is referenced inside elog/ereport calls.Tom Lane
It's often unsafe to reference errno within an elog/ereport call, because there are a lot of sub-functions involved and they might not all preserve errno. (This is why we support the %m format spec: it works off a value of errno captured before we execute any potentially-unsafe functions in the arguments.) Therefore, we have a project policy not to use errno there. This patch adds a hack to cause an (admittedly obscure) compiler error for such unsafe usages. With the current code, the error will only be seen on Linux, macOS, and FreeBSD, but that should certainly be enough to catch mistakes in the buildfarm if they somehow get missed earlier. In addition, fix some places in src/common/exec.c that trip the error. I think these places are actually all safe, but it's simple enough to avoid the error by capturing errno manually, and doing so is good future-proofing in case these call sites get any more complicated. Thomas Munro (exec.c fixes by me) Discussion: https://postgr.es/m/2975.1526862605@sss.pgh.pa.us
2018-07-23Add proper errcodes to new error messages for read() failuresMichael Paquier
Those would use the default ERRCODE_INTERNAL_ERROR, but for foreseeable failures an errcode ought to be set, ERRCODE_DATA_CORRUPTED making the most sense here. While on the way, fix one errcode_for_file_access missing in origin.c since the code has been created, and remove one assignment of errno to 0 before calling read(), as this was around to fit with what was present before 811b6e36 where errno would not be set when not enough bytes are read. I have noticed the first one, and Tom has pinged me about the second one. Author: Michael Paquier Reported-by: Tom Lane Discussion: https://postgr.es/m/27265.1531925836@sss.pgh.pa.us
2018-07-18Rework error messages around file handlingMichael Paquier
Some error messages related to file handling are using the code path context to define their state. For example, 2PC-related errors are referring to "two-phase status files", or "relation mapping file" is used for catalog-to-filenode mapping, however those prove to be difficult to translate, and are not more helpful than just referring to the path of the file being worked on. So simplify all those error messages by just referring to files with their path used. In some cases, like the manipulation of WAL segments, the context is actually helpful so those are kept. Calls to the system function read() have also been rather inconsistent with their error handling sometimes not reporting the number of bytes read, and some other code paths trying to use an errno which has not been set. The in-core functions are using a more consistent pattern with this patch, which checks for both errno if set or if an inconsistent read is happening. So as to care about pluralization when reading an unexpected number of byte(s), "could not read: read %d of %zu" is used as error message, with %d field being the output result of read() and %zu the expected size. This simplifies the work of translators with less variations of the same message. Author: Michael Paquier Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/20180520000522.GB1603@paquier.xyz
2018-07-11Fix more wrong paths in header commentsAlexander Korotkov
It appears that there are more files, whose header comment paths are wrong. So, fix those paths. No backpatching per proposal of Tom Lane. Discussion: https://postgr.es/m/CAPpHfdsJyYbOj59MOQL%2B4XxdcomLSLfLqBtAvwR%2BpsCqj3ELdQ%40mail.gmail.com
2018-06-11Adjust error messagePeter Eisentraut
Makes it look more similar to other ones, and avoids the need for pluralization.
2018-05-23Fix incorrect ordering of operations in pg_resetwal and pg_rewind.Tom Lane
Commit c37b3d08c dropped its added GetDataDirectoryCreatePerm call into the wrong place in pg_resetwal.c, namely after the chdir to DataDir. That broke invocations using a relative path, as reported by Tushar Ahuja. We could have left it where it was and changed the argument to be ".", but that'd result in a rather confusing error message in event of a failure, so re-ordering seems like a better solution. Similarly reorder operations in pg_rewind.c. The issue there is that it doesn't seem like a good idea to do any actual operations before the not-root check (on Unix) or the restricted token acquisition (on Windows). I don't know that this is an actual bug, but I'm definitely not convinced that it isn't, either. Assorted other code review for c37b3d08c and da9b580d8: fix some misspelled or otherwise badly worded comments, put the #include for <sys/stat.h> where it actually belongs, etc. Discussion: https://postgr.es/m/aeb9c3a7-3c3f-a57f-1a18-c8d4fcdc2a1f@enterprisedb.com
2018-05-18Fix error message on short read of pg_controlMagnus Hagander
Instead of saying "error: success", indicate that we got a working read but it was too short.
2018-04-19Enlarge find_other_exec's meager fgets bufferAlvaro Herrera
The buffer was 100 bytes long, which is barely sufficient when the version string gets longer (such as by configure --with-extra-version). Set it to MAXPGPATH. Author: Nikhil Sontakke Discussion: https://postgr.es/m/CAMGcDxfLfpYU_Jru++L6ARPCOyxr0W+2O3Q54TDi5XdYeU36ow@mail.gmail.com
2018-04-09Fix partial-build problems introduced by having more generated headers.Tom Lane
Commit 372728b0d created some problems for usages like building a subdirectory without having first done "make all" at the top level, or for proceeding directly to "make install" without "make all". The only reasonably clean way to fix this seems to be to force the submake-generated-headers rule to fire in *any* "make all" or "make install" command anywhere in the tree. To avoid lots of redundant work, as well as parallel make jobs possibly clobbering each others' output, we still need to be sure that the rule fires only once in a recursive build. For that, adopt the same MAKELEVEL hack previously used for "temp-install". But try to document it a bit better. The submake-errcodes mechanism previously used in src/port/ and src/common/ is subsumed by this, so we can get rid of those special cases. It was inadequate for src/common/ anyway after the aforesaid commit, and it always risked parallel attempts to build errcodes.h. Discussion: https://postgr.es/m/E1f5FAB-0006LU-MB@gemulon.postgresql.org
2018-04-09Further cleanup of client dependencies on src/include/catalog headers.Tom Lane
In commit 9c0a0de4c, I'd failed to notice that catalog/catalog.h should also be considered a frontend-unsafe header, because it includes (and needs) the full form of pg_class.h, not to mention relcache.h. However, various frontend code was depending on it to get TABLESPACE_VERSION_DIRECTORY, so refactoring of some sort is called for. The cleanest answer seems to be to move TABLESPACE_VERSION_DIRECTORY, as well as the OIDCHARS symbol, to common/relpath.h. Do that, and mop up inclusions as necessary. (I found that quite a few current users of catalog/catalog.h don't seem to need it at all anymore, apparently as a result of the refactorings that created common/relpath.[hc]. And initdb.c needed it only as a route to pg_class_d.h.) Discussion: https://postgr.es/m/6629.1523294509@sss.pgh.pa.us
2018-04-08Switch client-side code to include catalog/pg_foo_d.h not pg_foo.h.Tom Lane
Everything of use to frontend code should now appear in the _d.h files, and making this change frees us from needing to worry about whether the catalog header files proper are frontend-safe. Remove src/interfaces/ecpg/ecpglib/pg_type.h entirely, as the previous commit reduced it to a confusingly-named wrapper around pg_type_d.h. In passing, make test_rls_hooks.c follow project convention of including our own files with #include "" not <>. Discussion: https://postgr.es/m/23690.1523031777@sss.pgh.pa.us
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