[PATCH 4/6] drbd: Ignore the exit code of a fence-peer handler if it returns too late

From: Philipp Reisner
Date: Fri Jun 14 2013 - 14:56:05 EST


In case the connection was established and lost again before
the a fence-peer handler returns, ignore the exit code of this
instance. (And use the exit code of the later started instance)

Signed-off-by: Andreas Gruenbacher <agruen@xxxxxxxxxx>
Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
---
drivers/block/drbd/drbd_int.h | 1 +
drivers/block/drbd/drbd_nl.c | 15 +++++++++++++--
drivers/block/drbd/drbd_state.c | 4 +++-
3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index f943aac..f104328 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -832,6 +832,7 @@ struct drbd_tconn { /* is a resource from the config file */
unsigned susp_nod:1; /* IO suspended because no data */
unsigned susp_fen:1; /* IO suspended because fence peer handler runs */
struct mutex cstate_mutex; /* Protects graceful disconnects */
+ unsigned int connect_cnt; /* Inc each time a connection is established */

unsigned long flags;
struct net_conf *net_conf; /* content protected by rcu */
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 0936d6a..e25803b 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -417,6 +417,7 @@ static enum drbd_fencing_p highest_fencing_policy(struct drbd_tconn *tconn)

bool conn_try_outdate_peer(struct drbd_tconn *tconn)
{
+ unsigned int connect_cnt;
union drbd_state mask = { };
union drbd_state val = { };
enum drbd_fencing_p fp;
@@ -428,6 +429,10 @@ bool conn_try_outdate_peer(struct drbd_tconn *tconn)
return false;
}

+ spin_lock_irq(&tconn->req_lock);
+ connect_cnt = tconn->connect_cnt;
+ spin_unlock_irq(&tconn->req_lock);
+
fp = highest_fencing_policy(tconn);
switch (fp) {
case FP_NOT_AVAIL:
@@ -492,8 +497,14 @@ bool conn_try_outdate_peer(struct drbd_tconn *tconn)
here, because we might were able to re-establish the connection in the
meantime. */
spin_lock_irq(&tconn->req_lock);
- if (tconn->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &tconn->flags))
- _conn_request_state(tconn, mask, val, CS_VERBOSE);
+ if (tconn->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &tconn->flags)) {
+ if (tconn->connect_cnt != connect_cnt)
+ /* In case the connection was established and droped
+ while the fence-peer handler was running, ignore it */
+ conn_info(tconn, "Ignoring fence-peer exit code\n");
+ else
+ _conn_request_state(tconn, mask, val, CS_VERBOSE);
+ }
spin_unlock_irq(&tconn->req_lock);

return conn_highest_pdsk(tconn) <= D_OUTDATED;
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 90c5be2..216d47b 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1115,8 +1115,10 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
drbd_thread_restart_nowait(&mdev->tconn->receiver);

/* Resume AL writing if we get a connection */
- if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)
+ if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
drbd_resume_al(mdev);
+ mdev->tconn->connect_cnt++;
+ }

/* remember last attach time so request_timer_fn() won't
* kill newly established sessions while we are still trying to thaw
--
1.7.9.5

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