[dovecot] quotas again

[Mark E. Mallett]

A couple of notes about quotas-- I know this has been brought up
before but the negative effects that occur when a user is over quota
are still disconcerting.

Ideally it would be best if a user could at least delete mail when in
an over-quota condition.  One would think it would be enough to simply
ignore errors creating the index files (and use an in-memory index).
However, another problem is that the mere renaming of a file from the
new/ directory to the cur/ directory can cause an over-quota error if
the cur/ directory has to be expanded.  We see these errors in the
maillog followed by an "I/O leak" message, e.g.:

Apr 21 07:42:26 mercury mem[10059]: pop3(someuser): maildir build: rename(/users/3a/someuser/Maildir/new/1049919998.23875.mercury.mv.net, /users/3a/someuser/Maildir/cur/1049919998.23875.mercury.mv.net) failed: Disc quota exceeded
Apr 21 07:42:26 mercury mem[10059]: pop3(someuser): I/O leak: 0x807361c (1)
Apr 21 07:42:26 mercury mem[10059]: pop3(someuser): I/O leak: 0x804a1b8 (0)

and then we get a report about the server dropping the connection.

BTW we seem to see quite a lot of these "I/O leak" messages in other
situations too, and I think it started with the test5 release (but I am
not absolutely sure).  What does this mean?

Yours,
mm