CVSROOT: /cvs/cluster
Module name: cluster
Branch: RHEL4
Changes by: [EMAIL PROTECTED] 2007-11-07 15:22:31
Modified files:
dlm-kernel/src : lockqueue.c
Log message:
bz 349001
For the entire life of the dlm, there's been an annoying issue that
we've
worked around and not "fixed" directly. It's the source of all these
messages:
process_lockqueue_reply id 2c0224 state 0
The problem that a lock master sends an async "granted" message for a
convert request *before* actually sending the reply for the original
convert. The work-around is that the requesting node just takes the
granted message as an implicit reply to the conversion and ignores the
convert reply when it arrives later (the message above is printed when
it gets the out-of-order reply for its convert). Apart from the
annoying
messages, it's never been a problem.
Now we've found a case where it's a real problem:
1. nodeA: send convert PR->CW to nodeB
nodeB: send granted message to nodeA
nodeB: send convert reply to nodeA
2. nodeA: receive granted message for conversion
complete request, sending ast to gfs
3. nodeA: send convert CW->EX to nodeB
4. nodeA: receive reply for convert in step 1, which we ordinarily
ignore, but since another convert has been sent, we mistake this
message as the reply for the convert in step 3, and complete
the convert request which is *not* really completed yet
5. nodeA: send unlock to nodeB
nodeB: complains about an unlock during a conversion
The fix is to have nodeB not send a convert reply if it has already
sent a
granted message. (We already do this for cases where the conversion is
granted when first processing it, but we don't in cases where the grant
is done after processing the convert.)
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/dlm-kernel/src/lockqueue.c.diff?cvsroot=cluster&only_with_tag=RHEL4&r1=1.37.2.9&r2=1.37.2.10
--- cluster/dlm-kernel/src/Attic/lockqueue.c 2006/01/24 14:38:19 1.37.2.9
+++ cluster/dlm-kernel/src/Attic/lockqueue.c 2007/11/07 15:22:31
1.37.2.10
@@ -590,6 +590,14 @@
req->rr_lvbseq = lkb->lkb_lvbseq;
add_request_lvb(lkb, req);
+ /* prevent a convert reply that hasn't been sent yet, the grant message
+ will serve as an implicit convert reply */
+ if (lkb->lkb_request) {
+ log_debug(lkb->lkb_resource->res_ls, "skip convert reply %x "
+ "gr %d\n", lkb->lkb_id, lkb->lkb_grmode);
+ lkb->lkb_request = NULL;
+ }
+
midcomms_send_buffer(&req->rr_header, e);
}
