Re: More time spending with "delete pending"

Alexander Law <exclusion@gmail.com>

From: Alexander Lakhin <exclusion@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>, Tom Lane <tgl@sss.pgh.pa.us>, Justin Pryzby <pryzby@telsasoft.com>
Date: 2021-07-13T18:00:00Z
Lists: pgsql-hackers

Attachments

Hello Michael,
12.07.2021 08:52, Michael Paquier wrote:
> On Mon, Jul 12, 2021 at 02:09:41PM +0900, Michael Paquier wrote:
>> And fairywren, that uses MinGW, is unhappy:
>> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=fairywren&dt=2021-07-12%2004%3A47%3A13
>> Looking at it now.
> I am not sure what to do here to cool down MinGW, so the patch has
> been reverted for now:
> - Plain stat() is not enough to do a proper detection of the files
> pending for deletion on MSVC, so reverting only the part with
> microsoft_native_stat() is not going to help.
> - We are going to need an evaluation of the stat() implementation in
> MinGW and check if is it possible to rely on it more.  If yes, we
> could get away with more tweaks based on __MINGW32__/__MINGW64__.
I've managed to adapt open/win32stat for MinGW by preventing stat
overriding at the implementation level. Thus, the code that calls stat()
will use the overridden struct/function(s), but inside of
open/win32_stat we could access original stat and reference to
__pgstat64 where we want to use our.
Tested on MSVC, MinGW64 and MinGW32 — the fixed code compiles everywhere.

But when using perl from msys (not ActivePerl) while testing I've got
the same test failure due to another error condition:



In this case CreateFile() fails with ERROR_SHARING_VIOLATION (not
ERROR_ACCESS_DENIED) and it leads to the same "Permission denied" error.
This condition is handled in the pgwin32_open() but not in _pgstat64() yet.

I think I should develop another test for MSVC environment that will
demonstrate a such failure too.
But as it's not related to the DELETE_PENDING state, I wonder whether
this should be fixed in a separate patch.

Best regards,
Alexander

Commits

  1. Revert "Fix issues with Windows' stat() for files pending on deletion"

  2. Fix issues with Windows' stat() for files pending on deletion