[Dovecot] Broken physical size caching in Dovecot 2.1.10

[Rob Redpath]

Hi,

I'm encountering two, probably related, errors in my Dovecot 2.1.10
install. The issue relates to compressed email stored in Maildir format
directories.

In some cases, a mailbox will become inaccessible, and the following
will be logged from a doveadm fetch:-

doveadm(info at example.com): Error: Corrupted index cache file
/var/spool/virtual_mail/info_example.com_d/dovecot.index.cache: Broken
physical size for mail UID 2777
doveadm(info at example.com): Error: Cached message size smaller than
expected (18996 < 64624)
doveadm(info at example.com): Error: Maildir filename has wrong S value,
renamed the file from
/var/spool/virtual_mail/info_example.com_d/cur/1277451630.H877760P14612.mailserver.example.com,S=18996:2,Z
to
/var/spool/virtual_mail/info_example.com_d/cur/1277451630.H877760P14612.mailserver.example.com,S=18996:2,Z

Interestingly, the file mentioned in the error (
/var/spool/virtual_mail/info_example.com_d/dovecot.index.cache ) doesn't
exist.

The uncompressed size of the file is 64624 bytes, the compressed size is
18996.

My attempts to debug the issue myself didn't get very far - the function
that appears to return the wrong value is in
/src/lib-storage/index/maildir/maildir-mail.c in the 2.1.13 source; it's
do_fix_size() and appears to not consider whether a file is compressed
or not when reporting it's size for S= value purposes.

Can anyone help? I'm happy to provide parts of dovecot -n output if
required, but I'd rather not post configuration in a public forum if
it's not required.

--
Rob Redpath
Systems Administrator
Heart Internet Ltd
E: rob.redpath at heartinternet.co.uk
DDI: 0115 845 6643
www.heartinternet.co.uk<http://www.heartinternet.co.uk>

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