Re: [HACKERS] pg_archivecleanup bug (invalid filename input)
On Wed, Jun 10, 2015 at 12:29 PM, Joshua D. Drake wrote: > > On 06/09/2015 05:54 PM, Michael Paquier wrote: > >> Looking at the documentation what is expected is not a path to a >> segment file, but only a segment file name: >> http://www.postgresql.org/docs/devel/static/pgarchivecleanup.html >> So the current behavior is correct, it is actually what >> SetWALFileNameForCleanup@pg_archivecleanup.c checks in the code. > > > O.k so I would say: Should we adjust this behavior? It seems to me that > it should accept a path. Perhaps others have a different opinion, but I don't see much the point. First, archive_cleanup_command uses %r with only a segment file name. Then, in the case where pg_archivecleanup is called within a script and that the segment name is retrieved from a given path that you may want to append, this script is going to scan this directory to fetch the segment file name anyway, actually killing the purpose of appending a path. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug (invalid filename input)
On 06/09/2015 05:54 PM, Michael Paquier wrote: Looking at the documentation what is expected is not a path to a segment file, but only a segment file name: http://www.postgresql.org/docs/devel/static/pgarchivecleanup.html So the current behavior is correct, it is actually what SetWALFileNameForCleanup@pg_archivecleanup.c checks in the code. O.k so I would say: Should we adjust this behavior? It seems to me that it should accept a path. JD -- Command Prompt, Inc. - http://www.commandprompt.com/ 503-667-4564 PostgreSQL Centered full stack support, consulting and development. Announcing "I'm offended" is basically telling the world you can't control your own emotions, so everyone else should do it for you. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug (invalid filename input)
On Wed, Jun 10, 2015 at 7:27 AM, Joshua D. Drake wrote: > Trying to use pg_archivecleanup as a: > > "standalone archive cleaner" > > Results in an error of: > > pg_archivecleanup: invalid filename input > Try "pg_archivecleanup --help" for more information. > > /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive > 0001074800B1.00015838.backup > Works. Yes. > /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive > ./0001074800B1.00015838.backup > Or > /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive > /backups/db1/archive/0001074800B1.00015838.backup > Do not and present with the error mentioned above. Looking at the documentation what is expected is not a path to a segment file, but only a segment file name: http://www.postgresql.org/docs/devel/static/pgarchivecleanup.html So the current behavior is correct, it is actually what SetWALFileNameForCleanup@pg_archivecleanup.c checks in the code. Speaking of which, 179cdd09 has forgotten pg_archivecleanup.c, making XLOG_DATA_FNAME_LEN not needed. XLOG_BACKUP_FNAME_LEN could be removed as well and IsBackupHistoryFileName() should be made smarter by checking that the length of the backup file name is actually 40... Regards, -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] pg_archivecleanup bug (invalid filename input)
Hello, Trying to use pg_archivecleanup as a: "standalone archive cleaner" Results in an error of: pg_archivecleanup: invalid filename input Try "pg_archivecleanup --help" for more information. /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive 0001074800B1.00015838.backup Works. /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive ./0001074800B1.00015838.backup Or /usr/pgsql-9.4/bin/pg_archivecleanup /backups/db1/archive /backups/db1/archive/0001074800B1.00015838.backup Do not and present with the error mentioned above. CentOS 6.6 with PGDG rpms. Sincerely, JD -- Command Prompt, Inc. - http://www.commandprompt.com/ 503-667-4564 PostgreSQL Centered full stack support, consulting and development. Announcing "I'm offended" is basically telling the world you can't control your own emotions, so everyone else should do it for you. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Wed, Mar 19, 2014 at 02:02:50PM -0400, Bruce Momjian wrote: > The attached patch is slightly updated. I will apply it to head and all > the back branches, including the stylistic change to pg_resetxlog (for > consistency) and remove the MinGW block in head. Patch applied back through 8.4. I had the closedir() tests backwards and that was fixed. I also went over all the readdir/closedir() calls in all back branches to make sure they were properly handled. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Wed, Mar 19, 2014 at 09:59:19AM +0200, Heikki Linnakangas wrote:
> >Would people accept?
> >
> > for (errno = 0; (dirent = readdir(dir)) != NULL; errno = 0)
> >
> >That would keep the errno's together and avoid the 'continue' additions.
>
> That's clever. A less clever way would be:
>
> for (;;)
> {
> errno = 0;
> if ((dirent = readdir(dir)) != NULL)
> break;
>
> ...
> }
>
> I'm fine with either, but that's how I would naturally write it.
>
> Yet another way would be to have a wrapper function for readdir that
> resets errno, and just replace the current readdir() calls with
> that.
>
> And now that I look at initdb.c, walkdir is using the comma
> expression for this already. So there's some precedence, and it
> doesn't actually look that bad. So I withdraw my objection for that
> approach; I'm fine with any of the discussed alternatives, really.
OK, let's go with the comma. Ironically, the for() loop would be an odd
way to avoid commas as 'for' uses commas often:
for (i = 0, j = 1; i < 10; i++, j++)
The attached patch is slightly updated. I will apply it to head and all
the back branches, including the stylistic change to pg_resetxlog (for
consistency) and remove the MinGW block in head.
--
Bruce Momjian http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
diff --git a/contrib/pg_archivecleanup/pg_archivecleanup.c b/contrib/pg_archivecleanup/pg_archivecleanup.c
new file mode 100644
index 7b5484b..4f4d507
*** a/contrib/pg_archivecleanup/pg_archivecleanup.c
--- b/contrib/pg_archivecleanup/pg_archivecleanup.c
*** CleanupPriorWALFiles(void)
*** 106,112
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while ((xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
--- 106,112
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
*** CleanupPriorWALFiles(void)
*** 164,170
}
}
}
! closedir(xldir);
}
else
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
--- 164,182
}
}
}
!
! #ifdef WIN32
! /* Bug in old Mingw dirent.c; fixed in mingw-runtime-3.2, 2003-10-10 */
! if (GetLastError() == ERROR_NO_MORE_FILES)
! errno = 0;
! #endif
!
! if (errno)
! fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
! if (!closedir(xldir))
! fprintf(stderr, "%s: could not close archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
}
else
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
new file mode 100644
index 8ddd486..70fb387
*** a/contrib/pg_standby/pg_standby.c
--- b/contrib/pg_standby/pg_standby.c
*** CustomizableCleanupPriorWALFiles(void)
*** 245,251
*/
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while ((xlde = readdir(xldir)) != NULL)
{
/*
* We ignore the timeline part of the XLOG segment identifiers
--- 245,251
*/
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
/*
* We ignore the timeline part of the XLOG segment identifiers
*** CustomizableCleanupPriorWALFiles(void)
*** 283,288
--- 283,298
}
}
}
+
+ #ifdef WIN32
+ /* Bug in old Mingw dirent.c; fixed in mingw-runtime-3.2, 2003-10-10 */
+ if (GetLastError() == ERROR_NO_MORE_FILES)
+ errno = 0;
+ #endif
+
+ if (errno)
+ fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
+ progname, archiveLocation, strerror(errno));
if (debug)
fprintf(stderr, "\n");
}
*** CustomizableCleanupPriorWALFiles(void)
*** 290,296
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
progname, archiveLocation, strerror(errno));
! closedir(xldir);
fflush(stderr);
}
}
--- 300,309
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
progname, archiveLocation, strerror(errno));
! if (!closedir(xldir))
! fprintf(stderr, "%s: could not close archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
!
fflush(stderr);
}
}
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
new file mode 100644
index 4dc809d..5158cfe
*** a/src/backend/storage/file/fd.c
--- b/src/backend/storage/file/fd.c
*** ReadDir(DIR *dir, const char *dirname)
*** 1957,1966
return dent;
#ifdef WIN32
! /*
! * This fix is in mingw c
Re: [HACKERS] pg_archivecleanup bug
On 03/19/2014 02:30 AM, Bruce Momjian wrote:
On Tue, Mar 18, 2014 at 09:13:28PM +0200, Heikki Linnakangas wrote:
On 03/18/2014 09:04 PM, Simon Riggs wrote:
On 18 March 2014 18:55, Alvaro Herrera wrote:
That said, I don't find comma expression to be particularly "not
simple".
Maybe, but we've not used it before anywhere in Postgres, so I don't
see a reason to start now. Especially since C is not the native
language of many people these days and people just won't understand
it.
Agreed. The psqlODBC code is littered with comma expressions, and
the first time I saw it, it took me a really long time to figure out
what "if (foo = malloc(...), foo) { } " meant. And I consider myself
quite experienced with C.
I can see how the comma syntax would be confusing, though it does the
job well. Attached is a patch that does the double-errno. However,
some of these loops are large, and there are 'continue' calls in there,
causing the addition of many new errno locations. I am not totally
comfortable that this new coding layout will stay unbroken.
Would people accept?
for (errno = 0; (dirent = readdir(dir)) != NULL; errno = 0)
That would keep the errno's together and avoid the 'continue' additions.
That's clever. A less clever way would be:
for (;;)
{
errno = 0;
if ((dirent = readdir(dir)) != NULL)
break;
...
}
I'm fine with either, but that's how I would naturally write it.
Yet another way would be to have a wrapper function for readdir that
resets errno, and just replace the current readdir() calls with that.
And now that I look at initdb.c, walkdir is using the comma expression
for this already. So there's some precedence, and it doesn't actually
look that bad. So I withdraw my objection for that approach; I'm fine
with any of the discussed alternatives, really.
- Heikki
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Re: [HACKERS] pg_archivecleanup bug
Bruce Momjian writes: > Would people accept? > for (errno = 0; (dirent = readdir(dir)) != NULL; errno = 0) It's a bit weird looking, but I agree that there's value in only needing the errno-zeroing in precisely one place. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 09:13:28PM +0200, Heikki Linnakangas wrote:
> On 03/18/2014 09:04 PM, Simon Riggs wrote:
> >On 18 March 2014 18:55, Alvaro Herrera wrote:
> >
> >>That said, I don't find comma expression to be particularly "not
> >>simple".
> >
> >Maybe, but we've not used it before anywhere in Postgres, so I don't
> >see a reason to start now. Especially since C is not the native
> >language of many people these days and people just won't understand
> >it.
>
> Agreed. The psqlODBC code is littered with comma expressions, and
> the first time I saw it, it took me a really long time to figure out
> what "if (foo = malloc(...), foo) { } " meant. And I consider myself
> quite experienced with C.
I can see how the comma syntax would be confusing, though it does the
job well. Attached is a patch that does the double-errno. However,
some of these loops are large, and there are 'continue' calls in there,
causing the addition of many new errno locations. I am not totally
comfortable that this new coding layout will stay unbroken.
Would people accept?
for (errno = 0; (dirent = readdir(dir)) != NULL; errno = 0)
That would keep the errno's together and avoid the 'continue' additions.
--
Bruce Momjian http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
diff --git a/contrib/pg_archivecleanup/pg_archivecleanup.c b/contrib/pg_archivecleanup/pg_archivecleanup.c
new file mode 100644
index 7b5484b..405ec48
*** a/contrib/pg_archivecleanup/pg_archivecleanup.c
--- b/contrib/pg_archivecleanup/pg_archivecleanup.c
*** CleanupPriorWALFiles(void)
*** 106,111
--- 106,112
if ((xldir = opendir(archiveLocation)) != NULL)
{
+ errno = 0;
while ((xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
*** CleanupPriorWALFiles(void)
*** 148,153
--- 149,155
fprintf(stderr,
"%s: file \"%s\" would be removed\n",
progname, WALFilePath);
+ errno = 0;
continue;
}
*** CleanupPriorWALFiles(void)
*** 163,170
break;
}
}
}
! closedir(xldir);
}
else
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
--- 165,185
break;
}
}
+ errno = 0;
}
!
! #ifdef WIN32
! /* Bug in old Mingw dirent.c; fixed in mingw-runtime-3.2, 2003-10-10 */
! if (GetLastError() == ERROR_NO_MORE_FILES)
! errno = 0;
! #endif
!
! if (errno)
! fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
! if (!closedir(xldir))
! fprintf(stderr, "%s: could not close archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
}
else
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
new file mode 100644
index 8ddd486..d4731d7
*** a/contrib/pg_standby/pg_standby.c
--- b/contrib/pg_standby/pg_standby.c
*** CustomizableCleanupPriorWALFiles(void)
*** 245,250
--- 245,251
*/
if ((xldir = opendir(archiveLocation)) != NULL)
{
+ errno = 0;
while ((xlde = readdir(xldir)) != NULL)
{
/*
*** CustomizableCleanupPriorWALFiles(void)
*** 282,288
--- 283,300
break;
}
}
+ errno = 0;
}
+
+ #ifdef WIN32
+ /* Bug in old Mingw dirent.c; fixed in mingw-runtime-3.2, 2003-10-10 */
+ if (GetLastError() == ERROR_NO_MORE_FILES)
+ errno = 0;
+ #endif
+
+ if (errno)
+ fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
+ progname, archiveLocation, strerror(errno));
if (debug)
fprintf(stderr, "\n");
}
*** CustomizableCleanupPriorWALFiles(void)
*** 290,296
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
progname, archiveLocation, strerror(errno));
! closedir(xldir);
fflush(stderr);
}
}
--- 302,311
fprintf(stderr, "%s: could not open archive location \"%s\": %s\n",
progname, archiveLocation, strerror(errno));
! if (!closedir(xldir))
! fprintf(stderr, "%s: could not close archive location \"%s\": %s\n",
! progname, archiveLocation, strerror(errno));
!
fflush(stderr);
}
}
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
new file mode 100644
index 4dc809d..5158cfe
*** a/src/backend/storage/file/fd.c
--- b/src/backend/storage/file/fd.c
*** ReadDir(DIR *dir, const char *dirname)
*** 1957,1966
return dent;
#ifdef WIN32
! /*
! * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
! * released version
! */
if (GetLastError() == ERROR_NO_MORE_FILES)
errno = 0;
#endif
--- 1957,1963
return dent;
#ifdef WIN32
! /* Bug in old Mingw
Re: [HACKERS] pg_archivecleanup bug
On 03/18/2014 09:04 PM, Simon Riggs wrote:
On 18 March 2014 18:55, Alvaro Herrera wrote:
That said, I don't find comma expression to be particularly "not
simple".
Maybe, but we've not used it before anywhere in Postgres, so I don't
see a reason to start now. Especially since C is not the native
language of many people these days and people just won't understand
it.
Agreed. The psqlODBC code is littered with comma expressions, and the
first time I saw it, it took me a really long time to figure out what
"if (foo = malloc(...), foo) { } " meant. And I consider myself quite
experienced with C.
- Heikki
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 18 March 2014 18:55, Alvaro Herrera wrote: > That said, I don't find comma expression to be particularly "not > simple". Maybe, but we've not used it before anywhere in Postgres, so I don't see a reason to start now. Especially since C is not the native language of many people these days and people just won't understand it. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Simon Riggs escribió: > On 18 March 2014 18:18, Bruce Momjian wrote: > > On Tue, Mar 18, 2014 at 06:11:30PM +, Simon Riggs wrote: > >> Why make style changes at all? A patch with no style changes would > >> mean backpatch and HEAD versions would be the same. > > > > The old style had errno set in two places in the loop, while the new > > style has it set in only one place. > > Seems better to leave the previously-good coding in place. ISTM to be > clearer to use simple C. If you're saying we should use that style in all readdir loops, with the errno=0 before the loop and at the bottom of it, I don't disagree. Let's just make sure they're all safe though (i.e. watch out for "continue" for instance). That said, I don't find comma expression to be particularly "not simple". -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 18 March 2014 18:18, Bruce Momjian wrote: > On Tue, Mar 18, 2014 at 06:11:30PM +, Simon Riggs wrote: >> On 18 March 2014 18:01, Bruce Momjian wrote: >> > On Tue, Mar 18, 2014 at 04:17:53PM +, Simon Riggs wrote: >> >> > While I am not a fan of backpatching, the fact we are ignoring errors in >> >> > some critical cases seems the non-cosmetic parts should be backpatched. >> >> >> >> pg_resetxlog was not an offender here; its coding was sound. >> >> >> >> We shouldn't be discussing backpatching a patch that contains changes >> >> to coding style. >> > >> > I was going to remove the coding style changes to pg_resetxlog from the >> > backpatched portion. >> >> Why make style changes at all? A patch with no style changes would >> mean backpatch and HEAD versions would be the same. > > The old style had errno set in two places in the loop, while the new > style has it set in only one place. Seems better to leave the previously-good coding in place. ISTM to be clearer to use simple C. You're doing this anyway for the backpatch, so I'm not causing you any more work. Better one patch than two. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Bruce Momjian escribió: > On Tue, Mar 18, 2014 at 06:11:30PM +, Simon Riggs wrote: > > On 18 March 2014 18:01, Bruce Momjian wrote: > > > On Tue, Mar 18, 2014 at 04:17:53PM +, Simon Riggs wrote: > > >> > While I am not a fan of backpatching, the fact we are ignoring errors > > >> > in > > >> > some critical cases seems the non-cosmetic parts should be backpatched. > > >> > > >> pg_resetxlog was not an offender here; its coding was sound. > > >> > > >> We shouldn't be discussing backpatching a patch that contains changes > > >> to coding style. > > > > > > I was going to remove the coding style changes to pg_resetxlog from the > > > backpatched portion. > > > > Why make style changes at all? A patch with no style changes would > > mean backpatch and HEAD versions would be the same. > > The old style had errno set in two places in the loop, while the new > style has it set in only one place. I think it makes more sense to have all callsites look the same in all supported branches. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 06:11:30PM +, Simon Riggs wrote: > On 18 March 2014 18:01, Bruce Momjian wrote: > > On Tue, Mar 18, 2014 at 04:17:53PM +, Simon Riggs wrote: > >> > While I am not a fan of backpatching, the fact we are ignoring errors in > >> > some critical cases seems the non-cosmetic parts should be backpatched. > >> > >> pg_resetxlog was not an offender here; its coding was sound. > >> > >> We shouldn't be discussing backpatching a patch that contains changes > >> to coding style. > > > > I was going to remove the coding style changes to pg_resetxlog from the > > backpatched portion. > > Why make style changes at all? A patch with no style changes would > mean backpatch and HEAD versions would be the same. The old style had errno set in two places in the loop, while the new style has it set in only one place. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 18 March 2014 18:01, Bruce Momjian wrote: > On Tue, Mar 18, 2014 at 04:17:53PM +, Simon Riggs wrote: >> > While I am not a fan of backpatching, the fact we are ignoring errors in >> > some critical cases seems the non-cosmetic parts should be backpatched. >> >> pg_resetxlog was not an offender here; its coding was sound. >> >> We shouldn't be discussing backpatching a patch that contains changes >> to coding style. > > I was going to remove the coding style changes to pg_resetxlog from the > backpatched portion. Why make style changes at all? A patch with no style changes would mean backpatch and HEAD versions would be the same. >> ISTM we should change the code with missing checks to adopt the coding >> style of pg_resetxlog, not the other way around. >> >> I assume you or Kevin have this in hand and you don't want me to apply >> the patch? (Since it was originally my bug) > > I know the email subject says pg_archivecleanup but the problem is all > over our code. Yes, understood. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 04:17:53PM +, Simon Riggs wrote: > > While I am not a fan of backpatching, the fact we are ignoring errors in > > some critical cases seems the non-cosmetic parts should be backpatched. > > pg_resetxlog was not an offender here; its coding was sound. > > We shouldn't be discussing backpatching a patch that contains changes > to coding style. I was going to remove the coding style changes to pg_resetxlog from the backpatched portion. > ISTM we should change the code with missing checks to adopt the coding > style of pg_resetxlog, not the other way around. > > I assume you or Kevin have this in hand and you don't want me to apply > the patch? (Since it was originally my bug) I know the email subject says pg_archivecleanup but the problem is all over our code. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 13 March 2014 05:48, Bruce Momjian wrote: > On Mon, Dec 9, 2013 at 11:27:28AM -0500, Robert Haas wrote: >> On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: >> > But the other usages seem to be in assorted utilities, which >> > will need to do it right for themselves. initdb.c's walkdir() seems to >> > have it right and might be a reasonable model to follow. Or maybe we >> > should invent a frontend-friendly version of ReadDir() rather than >> > duplicating all the error checking code in ten-and-counting places? >> >> If there's enough uniformity in all of those places to make that >> feasible, it certainly seems wise to do it that way. I don't know if >> that's the case, though - e.g. maybe some callers want to exit and >> others do not. pg_resetxlog wants to exit; pg_archivecleanup and >> pg_standby most likely want to print an error and carry on. > > I have developed the attached patch which fixes all cases where > readdir() wasn't checking for errno, and cleaned up the syntax in other > cases to be consistent. > > While I am not a fan of backpatching, the fact we are ignoring errors in > some critical cases seems the non-cosmetic parts should be backpatched. pg_resetxlog was not an offender here; its coding was sound. We shouldn't be discussing backpatching a patch that contains changes to coding style. ISTM we should change the code with missing checks to adopt the coding style of pg_resetxlog, not the other way around. I assume you or Kevin have this in hand and you don't want me to apply the patch? (Since it was originally my bug) -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 18 March 2014 15:50, Robert Haas wrote: > On Tue, Mar 18, 2014 at 11:36 AM, Simon Riggs wrote: >> Given the above, this means we've run for about 7 years without a >> reported issue on this. If we are going to "make this better" by >> actually having it throw errors in places that didn't throw errors >> before, are we sure that is going to make people happier? The archive >> cleanup isn't exactly critical in most cases, so dynamic errors don't >> matter much. > > We report errors returned by system calls in many other places. I > can't see why this place should be any different. Sure. Just wanted to make sure it's a conscious, explicit choice to do so. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 11:36 AM, Simon Riggs wrote: > Given the above, this means we've run for about 7 years without a > reported issue on this. If we are going to "make this better" by > actually having it throw errors in places that didn't throw errors > before, are we sure that is going to make people happier? The archive > cleanup isn't exactly critical in most cases, so dynamic errors don't > matter much. We report errors returned by system calls in many other places. I can't see why this place should be any different. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On 18 March 2014 14:15, Alvaro Herrera wrote: > Bruce Momjian escribió: >> On Tue, Mar 18, 2014 at 10:03:46AM -0400, Robert Haas wrote: >> > On Tue, Mar 18, 2014 at 9:56 AM, Tom Lane wrote: >> > > Bruce Momjian writes: >> > >> Very good point. I have modified the patch to add this block in all >> > >> cases where it was missing. I started to wonder about the comment and >> > >> if the Mingw fix was released. Based on some research, I see this as >> > >> fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old. >> > > >> > > Yeah. I would vote for removing that code in all branches. There is no >> > > reason to suppose somebody is going to install 8.4.22 on a machine that >> > > they haven't updated mingw on since 2003. Or, if you prefer, just remove >> > > it in HEAD --- but going around and *adding* more copies seems like >> > > make-work. The fact that we've not heard complaints about the omissions >> > > is good evidence that nobody's using the buggy mingw versions anymore. >> > >> > I don't think it is. Right now we're not checking errno *at all* in a >> > bunch of these places, so we're sure not going to get complaints about >> > doing it incorrectly in those places. Or do I need more caffeine? >> >> You are correct. This code is seriously broken and I am susprised we >> have not gotten more complaints. Good thing readdir/closedir rarely >> fail. > back-patching Some commentary on this... Obviously, all errors are mine. If pg_archivecleanup is a problem, then so is pg_standby a problem. Given the above, this means we've run for about 7 years without a reported issue on this. If we are going to "make this better" by actually having it throw errors in places that didn't throw errors before, are we sure that is going to make people happier? The archive cleanup isn't exactly critical in most cases, so dynamic errors don't matter much. Also, the programs were originally written to work as standalone program as well as an archive_cleanup_command. So we can't use PostgreSQL infrastructure (can we?). That aspect is needed to allow testing the program before it goes live. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Bruce Momjian escribió: > On Tue, Mar 18, 2014 at 10:03:46AM -0400, Robert Haas wrote: > > On Tue, Mar 18, 2014 at 9:56 AM, Tom Lane wrote: > > > Bruce Momjian writes: > > >> Very good point. I have modified the patch to add this block in all > > >> cases where it was missing. I started to wonder about the comment and > > >> if the Mingw fix was released. Based on some research, I see this as > > >> fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old. > > > > > > Yeah. I would vote for removing that code in all branches. There is no > > > reason to suppose somebody is going to install 8.4.22 on a machine that > > > they haven't updated mingw on since 2003. Or, if you prefer, just remove > > > it in HEAD --- but going around and *adding* more copies seems like > > > make-work. The fact that we've not heard complaints about the omissions > > > is good evidence that nobody's using the buggy mingw versions anymore. > > > > I don't think it is. Right now we're not checking errno *at all* in a > > bunch of these places, so we're sure not going to get complaints about > > doing it incorrectly in those places. Or do I need more caffeine? > > You are correct. This code is seriously broken and I am susprised we > have not gotten more complaints. Good thing readdir/closedir rarely > fail. I think we need to keep the check for old mingw runtime in older branches; it seems reasonable to keep updating Postgres when new versions come out but keep mingw the same if it doesn't break. A good criterion here, to me, is: would we make it a runtime error if an old mingw version is detected? If we would, then let's go and remove all those errno checks. Then we force everyone to update to a sane mingw. But if we're not adding such a check, then we might cause subtle trouble just because we think running old mingw is unlikely. On another note, please let's not make the code dissimilar in some branches just because of source code embellishments are not back-ported out of fear. I mean, if we want them in master, let them be in older branches as well. Otherwise we end up with slightly different versions that make back-patching future fixes a lot harder, for no gain. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 10:03:46AM -0400, Robert Haas wrote: > On Tue, Mar 18, 2014 at 9:56 AM, Tom Lane wrote: > > Bruce Momjian writes: > >> Very good point. I have modified the patch to add this block in all > >> cases where it was missing. I started to wonder about the comment and > >> if the Mingw fix was released. Based on some research, I see this as > >> fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old. > > > > Yeah. I would vote for removing that code in all branches. There is no > > reason to suppose somebody is going to install 8.4.22 on a machine that > > they haven't updated mingw on since 2003. Or, if you prefer, just remove > > it in HEAD --- but going around and *adding* more copies seems like > > make-work. The fact that we've not heard complaints about the omissions > > is good evidence that nobody's using the buggy mingw versions anymore. > > I don't think it is. Right now we're not checking errno *at all* in a > bunch of these places, so we're sure not going to get complaints about > doing it incorrectly in those places. Or do I need more caffeine? You are correct. This code is seriously broken and I am susprised we have not gotten more complaints. Good thing readdir/closedir rarely fail. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 9:56 AM, Tom Lane wrote: > Bruce Momjian writes: >> Very good point. I have modified the patch to add this block in all >> cases where it was missing. I started to wonder about the comment and >> if the Mingw fix was released. Based on some research, I see this as >> fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old. > > Yeah. I would vote for removing that code in all branches. There is no > reason to suppose somebody is going to install 8.4.22 on a machine that > they haven't updated mingw on since 2003. Or, if you prefer, just remove > it in HEAD --- but going around and *adding* more copies seems like > make-work. The fact that we've not heard complaints about the omissions > is good evidence that nobody's using the buggy mingw versions anymore. I don't think it is. Right now we're not checking errno *at all* in a bunch of these places, so we're sure not going to get complaints about doing it incorrectly in those places. Or do I need more caffeine? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Bruce Momjian writes: > Very good point. I have modified the patch to add this block in all > cases where it was missing. I started to wonder about the comment and > if the Mingw fix was released. Based on some research, I see this as > fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old. Yeah. I would vote for removing that code in all branches. There is no reason to suppose somebody is going to install 8.4.22 on a machine that they haven't updated mingw on since 2003. Or, if you prefer, just remove it in HEAD --- but going around and *adding* more copies seems like make-work. The fact that we've not heard complaints about the omissions is good evidence that nobody's using the buggy mingw versions anymore. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Tue, Mar 18, 2014 at 11:25:46AM +0530, Amit Kapila wrote:
> On Thu, Mar 13, 2014 at 11:18 AM, Bruce Momjian wrote:
> >
> > I have developed the attached patch which fixes all cases where
> > readdir() wasn't checking for errno, and cleaned up the syntax in other
> > cases to be consistent.
>
>
> 1. One common thing missed wherever handling for errno is added
> is below check which is present in all existing cases where errno
> is used (initdb.c, pg_resetxlog.c, ReadDir, ..)
>
> #ifdef WIN32
> /*
> * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
> * released version
> */
> if (GetLastError() == ERROR_NO_MORE_FILES)
> errno = 0;
> #endif
Very good point. I have modified the patch to add this block in all
cases where it was missing. I started to wonder about the comment and
if the Mingw fix was released. Based on some research, I see this as
fixed in mingw-runtime-3.2, released 2003-10-10. That's pretty old.
(What I don't know is when that was paired with Msys in a bundled
release.) Here is the Mingw fixed code:
http://ftp.ntua.gr/mirror/mingw/OldFiles/mingw-runtime-3.2-src.tar.gz
{
/* Get the next search entry. */
if (_tfindnext (dirp->dd_handle, &(dirp->dd_dta)))
{
/* We are off the end or otherwise error.
_findnext sets errno to ENOENT if no more file
Undo this. */
DWORD winerr = GetLastError();
if (winerr == ERROR_NO_MORE_FILES)
errno = 0;
The current code has a better explanation:
http://sourceforge.net/p/mingw/mingw-org-wsl/ci/master/tree/src/libcrt/tchar/dirent.c
if( dirp->dd_private.dd_stat++ > 0 )
{
/* Otherwise...
*
* Get the next search entry. POSIX mandates that this must
* return NULL after the last entry has been read, but that it
* MUST NOT change errno in this case. MS-Windows _findnext()
* DOES change errno (to ENOENT) after the last entry has been
* read, so we must be prepared to restore it to its previous
* value, when no actual error has occurred.
*/
int prev_errno = errno;
if( DIRENT_UPDATE( dirp->dd_private ) != 0 )
{
/* May be an error, or just the case described above...
*/
if( GetLastError() == ERROR_NO_MORE_FILES )
/*
* ...which requires us to reset errno.
*/
errno = prev_errno;
but it is basically doing the same thing. I am wondering if we should
back-patch the PG code block where it was missing, and remove it from
head in all places on the logic that everyone running 9.4 will have a
post-3.1 version of Mingw. Postgres 8.4 was released in 2009 and it is
possible some people are still using pre-3.2 Mingw versions with that PG
release.
> 2.
> ! if (errno || closedir(chkdir) == -1)
> result = -1; /* some kind of I/O error? */
>
> Is there a special need to check return value of closedir in this
> function, as all other uses (initdb.c, pg_resetxlog.c, pgfnames.c)
> of it in similar context doesn't check the same?
>
> One thing I think for which this code needs change is to check
> errno before closedir as is done in initdb.c or pg_resetxlog.c
Yes, good point. Patch adjusted to add this.
> > While I am not a fan of backpatching, the fact we are ignoring errors in
> > some critical cases seems the non-cosmetic parts should be backpatched.
>
> +1
The larger the patch gets, the more worried I am about backpatching.
--
Bruce Momjian http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
--
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Re: [HACKERS] pg_archivecleanup bug
On Thu, Mar 13, 2014 at 11:18 AM, Bruce Momjian wrote: > > I have developed the attached patch which fixes all cases where > readdir() wasn't checking for errno, and cleaned up the syntax in other > cases to be consistent. 1. One common thing missed wherever handling for errno is added is below check which is present in all existing cases where errno is used (initdb.c, pg_resetxlog.c, ReadDir, ..) #ifdef WIN32 /* * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in * released version */ if (GetLastError() == ERROR_NO_MORE_FILES) errno = 0; #endif 2. ! if (errno || closedir(chkdir) == -1) result = -1; /* some kind of I/O error? */ Is there a special need to check return value of closedir in this function, as all other uses (initdb.c, pg_resetxlog.c, pgfnames.c) of it in similar context doesn't check the same? One thing I think for which this code needs change is to check errno before closedir as is done in initdb.c or pg_resetxlog.c > While I am not a fan of backpatching, the fact we are ignoring errors in > some critical cases seems the non-cosmetic parts should be backpatched. +1 With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Thu, Mar 13, 2014 at 1:48 AM, Bruce Momjian wrote: > On Mon, Dec 9, 2013 at 11:27:28AM -0500, Robert Haas wrote: >> On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: >> > But the other usages seem to be in assorted utilities, which >> > will need to do it right for themselves. initdb.c's walkdir() seems to >> > have it right and might be a reasonable model to follow. Or maybe we >> > should invent a frontend-friendly version of ReadDir() rather than >> > duplicating all the error checking code in ten-and-counting places? >> >> If there's enough uniformity in all of those places to make that >> feasible, it certainly seems wise to do it that way. I don't know if >> that's the case, though - e.g. maybe some callers want to exit and >> others do not. pg_resetxlog wants to exit; pg_archivecleanup and >> pg_standby most likely want to print an error and carry on. > > I have developed the attached patch which fixes all cases where > readdir() wasn't checking for errno, and cleaned up the syntax in other > cases to be consistent. Thanks! > While I am not a fan of backpatching, the fact we are ignoring errors in > some critical cases seems the non-cosmetic parts should be backpatched. While I haven't read the patch, I agree that this is a back-patchable bug fix. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Mon, Dec 9, 2013 at 11:27:28AM -0500, Robert Haas wrote:
> On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote:
> > But the other usages seem to be in assorted utilities, which
> > will need to do it right for themselves. initdb.c's walkdir() seems to
> > have it right and might be a reasonable model to follow. Or maybe we
> > should invent a frontend-friendly version of ReadDir() rather than
> > duplicating all the error checking code in ten-and-counting places?
>
> If there's enough uniformity in all of those places to make that
> feasible, it certainly seems wise to do it that way. I don't know if
> that's the case, though - e.g. maybe some callers want to exit and
> others do not. pg_resetxlog wants to exit; pg_archivecleanup and
> pg_standby most likely want to print an error and carry on.
I have developed the attached patch which fixes all cases where
readdir() wasn't checking for errno, and cleaned up the syntax in other
cases to be consistent.
While I am not a fan of backpatching, the fact we are ignoring errors in
some critical cases seems the non-cosmetic parts should be backpatched.
--
Bruce Momjian http://momjian.us
EnterpriseDB http://enterprisedb.com
+ Everyone has their own god. +
diff --git a/contrib/pg_archivecleanup/pg_archivecleanup.c b/contrib/pg_archivecleanup/pg_archivecleanup.c
new file mode 100644
index 7b5484b..fbc3e5a
*** a/contrib/pg_archivecleanup/pg_archivecleanup.c
--- b/contrib/pg_archivecleanup/pg_archivecleanup.c
*** CleanupPriorWALFiles(void)
*** 106,112
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while ((xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
--- 106,112
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
*** CleanupPriorWALFiles(void)
*** 164,169
--- 164,172
}
}
}
+ if (errno)
+ fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
+ progname, archiveLocation, strerror(errno));
closedir(xldir);
}
else
diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
new file mode 100644
index 8ddd486..be4d31f
*** a/contrib/pg_standby/pg_standby.c
--- b/contrib/pg_standby/pg_standby.c
*** CustomizableCleanupPriorWALFiles(void)
*** 245,251
*/
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while ((xlde = readdir(xldir)) != NULL)
{
/*
* We ignore the timeline part of the XLOG segment identifiers
--- 245,251
*/
if ((xldir = opendir(archiveLocation)) != NULL)
{
! while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
/*
* We ignore the timeline part of the XLOG segment identifiers
*** CustomizableCleanupPriorWALFiles(void)
*** 283,288
--- 283,291
}
}
}
+ if (errno)
+ fprintf(stderr, "%s: could not read archive location \"%s\": %s\n",
+ progname, archiveLocation, strerror(errno));
if (debug)
fprintf(stderr, "\n");
}
diff --git a/src/bin/pg_basebackup/pg_receivexlog.c b/src/bin/pg_basebackup/pg_receivexlog.c
new file mode 100644
index 2478789..e252405
*** a/src/bin/pg_basebackup/pg_receivexlog.c
--- b/src/bin/pg_basebackup/pg_receivexlog.c
*** FindStreamingStart(uint32 *tli)
*** 139,145
disconnect_and_exit(1);
}
! while ((dirent = readdir(dir)) != NULL)
{
uint32 tli;
XLogSegNo segno;
--- 139,145
disconnect_and_exit(1);
}
! while (errno = 0, (dirent = readdir(dir)) != NULL)
{
uint32 tli;
XLogSegNo segno;
*** FindStreamingStart(uint32 *tli)
*** 209,214
--- 209,221
}
}
+ if (errno)
+ {
+ fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+ progname, basedir, strerror(errno));
+ disconnect_and_exit(1);
+ }
+
closedir(dir);
if (high_segno > 0)
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
new file mode 100644
index 1bed8a9..c24f7e3
*** a/src/bin/pg_dump/pg_backup_directory.c
--- b/src/bin/pg_dump/pg_backup_directory.c
*** InitArchiveFmt_Directory(ArchiveHandle *
*** 177,183
struct dirent *d;
is_empty = true;
! while ((d = readdir(dir)))
{
if (strcmp(d->d_name, ".") != 0 && strcmp(d->d_name, "..") != 0)
{
--- 177,183
struct dirent *d;
is_empty = true;
! while (errno = 0, (d = readdir(dir)))
{
if (strcmp(d->d_name, ".") != 0 && strcmp(d->d_name, "..") != 0)
{
*** InitArchiveFmt_Directory(ArchiveHandle *
*** 185,190
--- 185,193
break;
}
}
+ if (errno)
+ exit_horribly(modulename, "c
Re: [HACKERS] pg_archivecleanup bug
On Thu, Dec 5, 2013 at 12:06:07PM -0800, Kevin Grittner wrote: > An EDB customer reported a problem with pg_archivecleanup which I > have looked into and found a likely cause. It is, in any event, a > bug which I think should be fixed. It has to do with our use of > the readdir() function: > > http://pubs.opengroup.org/onlinepubs/7908799/xsh/readdir_r.html > > These are the relevant bits: > > | Applications wishing to check for error situations should set > | errno to 0 before calling readdir(). If errno is set to non-zero > | on return, an error occurred. > > | Upon successful completion, readdir() returns a pointer to an > | object of type struct dirent. When an error is encountered, a > | null pointer is returned and errno is set to indicate the error. > | When the end of the directory is encountered, a null pointer is > | returned and errno is not changed. Wow, another case where errno clearing is necessary. We were just looking this requirement for getpwuid() last week. -- Bruce Momjian http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: > But the other usages seem to be in assorted utilities, which > will need to do it right for themselves. initdb.c's walkdir() seems to > have it right and might be a reasonable model to follow. Or maybe we > should invent a frontend-friendly version of ReadDir() rather than > duplicating all the error checking code in ten-and-counting places? If there's enough uniformity in all of those places to make that feasible, it certainly seems wise to do it that way. I don't know if that's the case, though - e.g. maybe some callers want to exit and others do not. pg_resetxlog wants to exit; pg_archivecleanup and pg_standby most likely want to print an error and carry on. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Fri, Dec 6, 2013 at 11:10 AM, Tom Lane wrote: > Robert Haas writes: >> On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: >>> In general, I think there is no excuse for code in the backend to use >>> readdir() directly; it should be using ReadDir(), which takes care of this >>> as well as error reporting. > >> My understanding is that the fd.c infrastructure can't be used in the >> postmaster. > > Say what? See ParseConfigDirectory for code that certainly runs in the > postmaster, and uses ReadDir(). Gosh, I could have sworn that I had calls into fd.c that were crashing and burning during development because they happened too early in postmaster startup. But it seems to work fine now, so I've pushed a fix for this and a few related issues. Please let me know if you think there are remaining issues. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Robert Haas writes: > On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: >> In general, I think there is no excuse for code in the backend to use >> readdir() directly; it should be using ReadDir(), which takes care of this >> as well as error reporting. > My understanding is that the fd.c infrastructure can't be used in the > postmaster. Say what? See ParseConfigDirectory for code that certainly runs in the postmaster, and uses ReadDir(). regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Thu, Dec 5, 2013 at 6:15 PM, Tom Lane wrote: > In general, I think there is no excuse for code in the backend to use > readdir() directly; it should be using ReadDir(), which takes care of this > as well as error reporting. My understanding is that the fd.c infrastructure can't be used in the postmaster. I agree that sucks. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
Kevin Grittner writes: > | Applications wishing to check for error situations should set > | errno to 0 before calling readdir(). If errno is set to non-zero > | on return, an error occurred. > So an error in scanning the directory will not be reported; the > cleanup will quietly terminate the WAL deletions without processing > the remainder of the directory. Attached is the simplest fix, > which would report the error, stop looking for WAL files, and > continue with other clean-ups. I'm not sure we should keep the fix > that simple. We could set a flag so that we would exit with a > non-zero code, or we could try a new directory scan as long as the > last scan found and deleted at least one WAL file. Perhaps we want > to back-patch the simple fix and do something fancier for 9.4? A quick grep shows about ten other readdir() usages, most of which have a similar disease. In general, I think there is no excuse for code in the backend to use readdir() directly; it should be using ReadDir(), which takes care of this as well as error reporting. It appears that src/backend/storage/ipc/dsm.c didn't get that memo; it certainly is innocent of any error checking concerns. But the other usages seem to be in assorted utilities, which will need to do it right for themselves. initdb.c's walkdir() seems to have it right and might be a reasonable model to follow. Or maybe we should invent a frontend-friendly version of ReadDir() rather than duplicating all the error checking code in ten-and-counting places? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pg_archivecleanup bug
On Thu, Dec 5, 2013 at 3:06 PM, Kevin Grittner wrote: > An EDB customer reported a problem with pg_archivecleanup which I > have looked into and found a likely cause. It is, in any event, a > bug which I think should be fixed. It has to do with our use of > the readdir() function: > > http://pubs.opengroup.org/onlinepubs/7908799/xsh/readdir_r.html > > These are the relevant bits: > > | Applications wishing to check for error situations should set > | errno to 0 before calling readdir(). If errno is set to non-zero > | on return, an error occurred. > > | Upon successful completion, readdir() returns a pointer to an > | object of type struct dirent. When an error is encountered, a > | null pointer is returned and errno is set to indicate the error. > | When the end of the directory is encountered, a null pointer is > | returned and errno is not changed. > > Here is our current usage: > > http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=contrib/pg_archivecleanup/pg_archivecleanup.c;h=8f77998de12f95f41bb95c3e05a14de6cdf18047;hb=7800229b36d0444cf2c61f5c5895108ee5e8ee2a#l110 > > So an error in scanning the directory will not be reported; the > cleanup will quietly terminate the WAL deletions without processing > the remainder of the directory. Attached is the simplest fix, > which would report the error, stop looking for WAL files, and > continue with other clean-ups. I'm not sure we should keep the fix > that simple. We could set a flag so that we would exit with a > non-zero code, or we could try a new directory scan as long as the > last scan found and deleted at least one WAL file. Perhaps we want > to back-patch the simple fix and do something fancier for 9.4? A directory that you can't read sounds like a pretty bad thing. I'd be inclined to print an error message and exit forthwith. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] pg_archivecleanup bug
An EDB customer reported a problem with pg_archivecleanup which I
have looked into and found a likely cause. It is, in any event, a
bug which I think should be fixed. It has to do with our use of
the readdir() function:
http://pubs.opengroup.org/onlinepubs/7908799/xsh/readdir_r.html
These are the relevant bits:
| Applications wishing to check for error situations should set
| errno to 0 before calling readdir(). If errno is set to non-zero
| on return, an error occurred.
| Upon successful completion, readdir() returns a pointer to an
| object of type struct dirent. When an error is encountered, a
| null pointer is returned and errno is set to indicate the error.
| When the end of the directory is encountered, a null pointer is
| returned and errno is not changed.
Here is our current usage:
http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=contrib/pg_archivecleanup/pg_archivecleanup.c;h=8f77998de12f95f41bb95c3e05a14de6cdf18047;hb=7800229b36d0444cf2c61f5c5895108ee5e8ee2a#l110
So an error in scanning the directory will not be reported; the
cleanup will quietly terminate the WAL deletions without processing
the remainder of the directory. Attached is the simplest fix,
which would report the error, stop looking for WAL files, and
continue with other clean-ups. I'm not sure we should keep the fix
that simple. We could set a flag so that we would exit with a
non-zero code, or we could try a new directory scan as long as the
last scan found and deleted at least one WAL file. Perhaps we want
to back-patch the simple fix and do something fancier for 9.4?
I would also add a few comment lines before committing this, if we
decide to go with the simple approach -- this is for purposes of
illustration; to facilitate discussion.
Thoughts?
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Companydiff --git a/contrib/pg_archivecleanup/pg_archivecleanup.c b/contrib/pg_archivecleanup/pg_archivecleanup.c
index f12331a..3e47f3c 100644
--- a/contrib/pg_archivecleanup/pg_archivecleanup.c
+++ b/contrib/pg_archivecleanup/pg_archivecleanup.c
@@ -117,7 +117,7 @@ CleanupPriorWALFiles(void)
if ((xldir = opendir(archiveLocation)) != NULL)
{
- while ((xlde = readdir(xldir)) != NULL)
+ while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
strncpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
@@ -175,6 +175,11 @@ CleanupPriorWALFiles(void)
}
}
}
+
+ if (errno)
+ fprintf(stderr, "%s: ERROR: could not read next directory entry: %s\n",
+ progname, strerror(errno));
+
closedir(xldir);
}
else
--
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