[Pkg-iscsi-maintainers] [SCM] Debian Open-iSCSI Packaging branch, upstream-mnc, updated. 2.0.871.3-1-84-g59f5d1e

[Mike Christie]

The following commit has been merged in the upstream-mnc branch:
commit e362dd2f1ddbb718f06489d0017cf2250079908a
Author: Eddie Wai <eddie.wai at broadcom.com>
Date:   Mon Oct 25 17:52:40 2010 -0700

    ISCSID: Fixed a race condition in the INVALID_HOST path
    
    The race condition can be observed with the following sequence of events:
    - For every active sessions, issue an ISCSI_ERR_CONN_FAILED nl msg
    (This will eventually put all active connections into the actor_list ready
    to execute the session_conn_reopen procedure)
    - Asynchronously after a few seconds, call the iscsi_host_remove procedure
    (This will notify iscsid with the ISCSI_ERR_INVALID_HOST nl message)
    
    The current code actually handles this by advancing the INVALID_HOST
    session_conn_error actor scheduing to the head via the actor_schedule_head
    procedure.  However, if the current actor thread was call-backed from the
    actor_poll loop, then this head scheduling will actually put the INVALID_HOST
    actor onto the poll_list instead of the actor_list.
    
    If there are subsequent elements in the actor_list which triggers the reopen
    path, then the conn_context for the INVALID_HOST for that particular
    connection will get flushed (+ actor_delete).  This will then lockup the
    libiscsi's iscsi_host_remove call as it will wait indefinitely on all
    sessions to be removed.
    
    The fix is to put this head scheduling to the head of the actor_list
    regardless of poll mode or not.  This will allow all INVALID_PATH actors
    to have a chance to get executed before any subsequent reopen actors.
    
    Signed-off-by: Eddie Wai <eddie.wai at broadcom.com>

diff --git a/usr/actor.c b/usr/actor.c
index 00f5c58..b8f8e61 100644
--- a/usr/actor.c
+++ b/usr/actor.c
@@ -113,14 +113,13 @@ actor_schedule_private(actor_t *thread, uint32_t ttschedule, int head)
 		 * state to scheduled, else add current time to ttschedule and
 		 * insert in the queue at the correct point */
 		if (delay_time == 0) {
-			if (poll_in_progress) {
+			/* For head addition, it must go onto the head of the
+			   actor_list regardless if poll is in progress or not
+			 */
+			if (poll_in_progress && !head) {
 				thread->state = ACTOR_POLL_WAITING;
-				if (head)
-					list_add(&thread->list,
-						 &poll_list);
-				else
-					list_add_tail(&thread->list,
-						      &poll_list);
+				list_add_tail(&thread->list,
+					      &poll_list);
 			} else {
 				thread->state = ACTOR_SCHEDULED;
 				if (head)

-- 
Debian Open-iSCSI Packaging