[PATCH v3 1/5] wal: preallocate disk space before writing rows

[Konstantin Osipov]

* Vladimir Davydov <vdavydov.dev at gmail.com> [18/10/24 16:43]:
> This function introduces a new xlog method xlog_fallocate() that makes
> sure that the requested amount of disk space is available at the current
> write position. It does that with posix_fallocate(). The new method is
> called before writing anything to WAL, see wal_fallocate(). In order not
> to invoke the system call too often, wal_fallocate() allocates disk
> space in big chunks (1 MB).
> 
> The reason why I'm doing this is that I want to have a single and
> clearly defined point in the code to handle ENOSPC errors, where
> I could delete old WALs and retry (this is what #3397 is about).
> 
> Needed for #3397

Thank you for taking into account the comments. Please push.


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Konstantin Osipov, Moscow, Russia, +7 903 626 22 32
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