drbd: Removed a race that could cause unexpected execution of w_make_resync_request()
The actual race happened int the drbd_start_resync() function. Where
drbd_resync_finished() -> __drbd_set_state() set STOP_SYNC_TIMER and
armed the timer.
If the timer fired before execution reaches the mod_timer statement
at the end of drbd_start_resync() the latter would cause an
unexpected call to w_make_resync_request().
Removed the STOP_SYNC_TIMER bit, and base it on the connection state.
The STOP_SYNC_TIMER bit probably originates probably the time before
the state engine.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 73c905d..5dd071e 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1052,12 +1052,6 @@
wake_up(&mdev->misc_wait);
wake_up(&mdev->state_wait);
- /* post-state-change actions */
- if (os.conn >= C_SYNC_SOURCE && ns.conn <= C_CONNECTED) {
- set_bit(STOP_SYNC_TIMER, &mdev->flags);
- mod_timer(&mdev->resync_timer, jiffies);
- }
-
/* aborted verify run. log the last position */
if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) &&
ns.conn < C_CONNECTED) {
@@ -1072,22 +1066,14 @@
dev_info(DEV, "Syncer continues.\n");
mdev->rs_paused += (long)jiffies
-(long)mdev->rs_mark_time[mdev->rs_last_mark];
- if (ns.conn == C_SYNC_TARGET) {
- if (!test_and_clear_bit(STOP_SYNC_TIMER, &mdev->flags))
- mod_timer(&mdev->resync_timer, jiffies);
- /* This if (!test_bit) is only needed for the case
- that a device that has ceased to used its timer,
- i.e. it is already in drbd_resync_finished() gets
- paused and resumed. */
- }
+ if (ns.conn == C_SYNC_TARGET)
+ mod_timer(&mdev->resync_timer, jiffies);
}
if ((os.conn == C_SYNC_TARGET || os.conn == C_SYNC_SOURCE) &&
(ns.conn == C_PAUSED_SYNC_T || ns.conn == C_PAUSED_SYNC_S)) {
dev_info(DEV, "Resync suspended\n");
mdev->rs_mark_time[mdev->rs_last_mark] = jiffies;
- if (ns.conn == C_PAUSED_SYNC_T)
- set_bit(STOP_SYNC_TIMER, &mdev->flags);
}
if (os.conn == C_CONNECTED &&