[Dovecot] Maildir unreliability

[Matthias Andree]

Timo Sirainen <tss at iki.fi> writes:

> Looks like maildir can't be used very realiably without quite a lot of 
> locking. Writing and scanning the directory would have to be locked, 
> but reading wouldn't (as long as the file hasn't been renamed which 
> would require scanning to find it). So much for "no locks needed"..
>
> The problem is that opendir()/readdir() may temporarily not return some 
> files if there has been changes in the directory since the opendir(). 
> That means Dovecot thinks a message is expunged, while in fact it 
> really isn't, and the next scan would usually show it again.

I'm not sure if the claims are about locking-free scanning (but I
believe DJB of Bold Yet Hollow Announcements fame just touted "no
locks"); one point is locking-free delivery because if opendir/readdir
misses a _new_ file, no harm is done.

qmail is so full of bugs I effectively stopped maintaining my qmail-bugs
page because I grew tired of researching bugs of a system I stopped
using years ago and wackos refuting the bugs
<http://home.pages.de/~mandree/qmail-bugs.html>, I only recently found
out that qmail-pop3d doesn't get article sizes (in LIST) right. Shame on
DJB for claiming efficiency and standards compliance when his nutshell
is rather shipwreck, and has been unmaintained for six years...

-- 
Matthias Andree