Better than POSIX?
Posted Mar 18, 2009 4:11 UTC (Wed) by quotemstr
In reply to: Better than POSIX?
Parent article: Better than POSIX?
Huh? If a program is truly POSIX-compliant, it can't make any assumptions about what happens after a crash. That's undefined by POSIX. There's no sense in playing games with backup files because the backups are undefined by POSIX too!
Really, all a program that depends on nothing more than POSIX can do it take advantage of the atomic rename support on a running system and hope for the best on a crash. POSIX guarantees nothing else.
Clearly, this is not an acceptable state of affairs, so we make further assumptions about the exact behavior fsync and friends. But these assumptions go beyond POSIX.
Now, an ordered rename makes a whole lot more sense than a rename that only preserves contents after an fsync. But don't pretend that either alternative is mandated by POSIX. This whole damn problem has nothing to do with POSIX, so stop bringing it up. (And that means you too, bojan.)
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