Repeat recovers on databases

[Michael Bacon]

--On June 19, 2009 9:57:03 AM +1000 Bron Gondwana <brong at fastmail.fm> wrote:

> On Thu, Jun 18, 2009 at 05:44:19PM -0400, Michael Bacon wrote:
>> Another one stomped here.  This time, it's a 32/64 bit issue.  myinit in
>>  cyrusdb_skiplist.c assumes that type_t is 4 bytes long, and writes out
>> that many from the current timestamp when creating
>> $confdir/db/skipstamp.
>
> Actually, reading the code, that's not strictly true:
>
>>        a = htonl(global_recovery);
>> -       if (r != -1) r = write(fd, &a, 4);
>> +       if (r != -1) r = write(fd, &a, sizeof(time_t));
>
> It writes "a", which is the result of calling htonl on global_recovery.
>
> If htonl isn't returning a 32 bit value of the lower order bytes of the
> value that it's given, then this bug is going to be causing a LOT more
> problems than just this.  We assume this works in quite a few other
> places in the code, including the timestamp value in the skiplist header
> itself, and in places throughout the mailbox code too.
>
> "htonl" => "host to net long" by my reading.  There's also htonll for 64
> bit values.  Is your platform creating net longlongs?

Good question -- this may be a Solaris bug after all.  Solaris clearly 
defines in the man page that htonl is supposed to return a uint32_t from 
htonl, but looking at sys/byteorder.h, that's um, not being enforced...

#if defined(_BIG_ENDIAN) && !defined(ntohl) && !defined(__lint)
/* big-endian */
#define ntohl(x)        (x)
#define ntohs(x)        (x)
#define htonl(x)        (x)
#define htons(x)        (x)

#elif !defined(ntohl) /* little-endian */

I think I may give our friends out in CA a call here...

-Michael