On Mon, Sep 29, 2008 at 12:37:12PM +0100, Mark Cave-Ayland wrote:
> What happens is that periodically (maybe around once a month?) we have
> one particular user who contacts us complaining that they are unable
> access their mailbox. Generally we always find the same thing: there is
> an imapd process accessing his seen DB which is running at 100% CPU.
> Once this process is killed then things go back to normal and the user
> can log in.
The following patch fixes your issue and has the syslog line added as
well.
https://bugzilla.andrew.cmu.edu/show_bug.cgi?id=3088
Ken, Wes - I think this is a candidate for 2.3.13 since we haven't
released yet. It's trivial, and infinite loops are bad!
Regards,
Bron ( also attaching the patch with this email )
Check for infinite loop on corrupted index files
Mark Cave-Ayland reported a corrupted index file
causing 100% CPU usage by imapd.
This patch checks for the cause (last_uid being
less than the current uid) and syslogs a warning
while dropping out of the loop.
Index: cyrus-imapd-2.3.12p2/imap/index.c
===================================================================
--- cyrus-imapd-2.3.12p2.orig/imap/index.c 2008-09-29 22:39:03.000000000 +1000
+++ cyrus-imapd-2.3.12p2/imap/index.c 2008-09-30 21:50:12.000000000 +1000
@@ -584,7 +584,16 @@
else {
oldseen = (*old == ':');
oldnext = 0;
- if (!*old) oldnext = mailbox->last_uid+1;
+ if (!*old) {
+ oldnext = mailbox->last_uid+1;
+ /* just in case the index is corrupted, don't
+ * loop forever */
+ if (oldnext < uid) {
+ syslog(LOG_ERR, "index corrupted, needs reconstruct %s",
+ mailbox->name);
+ oldnext = uid;
+ }
+ }
else old++;
while (cyrus_isdigit((int) *old)) {
oldnext = oldnext * 10 + *old++ - '0';
@@ -602,6 +611,13 @@
newnext = 0;
if (!*new) {
newnext = mailbox->last_uid+1;
+ /* just in case the index is corrupted, don't
+ * loop forever */
+ if (newnext < uid) {
+ syslog(LOG_ERR, "index corrupted, needs reconstruct %s",
+ mailbox->name);
+ newnext = uid;
+ }
neweof++;
}
else new++;
----
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