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Commit c02abda2 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
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drbd: mutex_unlock "... must no be used in interrupt context" 



Documentation of mutex_unlock says
we must not use it in interrupt context.
So do not call it while holding the spin_lock_irq,
but give up the spinlock temporarily.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent c1fd29a1

drivers/block/drbd/drbd_state.c

+39 −35
Original line number Diff line number Diff line
@@ -1721,38 +1721,6 @@ _conn_rq_cond(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state 
	return rv;

}



static enum drbd_state_rv

conn_cl_wide(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,

	     enum chg_state_flags f)

{

	enum drbd_state_rv rv;



	spin_unlock_irq(&tconn->req_lock);

	mutex_lock(&tconn->cstate_mutex);



	set_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);

	if (conn_send_state_req(tconn, mask, val)) {

		clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);

		/* if (f & CS_VERBOSE)

		   print_st_err(mdev, os, ns, rv); */

		mutex_unlock(&tconn->cstate_mutex);

		spin_lock_irq(&tconn->req_lock);

		return SS_CW_FAILED_BY_PEER;

	}



	if (val.conn == C_DISCONNECTING)

		set_bit(DISCONNECT_SENT, &tconn->flags);



	spin_lock_irq(&tconn->req_lock);



	wait_event_lock_irq(tconn->ping_wait, (rv = _conn_rq_cond(tconn, mask, val)), tconn->req_lock,);

	clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);



	mutex_unlock(&tconn->cstate_mutex);



	return rv;

}



enum drbd_state_rv

_conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state val,

		    enum chg_state_flags flags)
@@ -1761,6 +1729,7 @@ _conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_ 
	struct after_conn_state_chg_work *acscw;

	enum drbd_conns oc = tconn->cstate;

	union drbd_state ns_max, ns_min, os;

	bool have_mutex = false;



	rv = is_valid_conn_transition(oc, val.conn);

	if (rv < SS_SUCCESS)
@@ -1772,7 +1741,35 @@ _conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_ 


	if (oc == C_WF_REPORT_PARAMS && val.conn == C_DISCONNECTING &&

	    !(flags & (CS_LOCAL_ONLY | CS_HARD))) {

		rv = conn_cl_wide(tconn, mask, val, flags);



		/* This will be a cluster-wide state change.

		 * Need to give up the spinlock, grab the mutex,

		 * then send the state change request, ... */

		spin_unlock_irq(&tconn->req_lock);

		mutex_lock(&tconn->cstate_mutex);

		have_mutex = true;



		set_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);

		if (conn_send_state_req(tconn, mask, val)) {

			/* sending failed. */

			clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);

			rv = SS_CW_FAILED_BY_PEER;

			/* need to re-aquire the spin lock, though */

			goto abort_unlocked;

		}



		if (val.conn == C_DISCONNECTING)

			set_bit(DISCONNECT_SENT, &tconn->flags);



		/* ... and re-aquire the spinlock.

		 * If _conn_rq_cond() returned >= SS_SUCCESS, we must call

		 * conn_set_state() within the same spinlock. */

		spin_lock_irq(&tconn->req_lock);

		wait_event_lock_irq(tconn->ping_wait,

				(rv = _conn_rq_cond(tconn, mask, val)),

				tconn->req_lock,

				);

		clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);

		if (rv < SS_SUCCESS)

			goto abort;

	}
@@ -1796,9 +1793,16 @@ _conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_ 
		conn_err(tconn, "Could not kmalloc an acscw\n");

	}



	return rv;

 abort:

	if (flags & CS_VERBOSE) {

	if (have_mutex) {

		/* mutex_unlock() "... must not be used in interrupt context.",

		 * so give up the spinlock, then re-aquire it */

		spin_unlock_irq(&tconn->req_lock);

 abort_unlocked:

		mutex_unlock(&tconn->cstate_mutex);

		spin_lock_irq(&tconn->req_lock);

	}

	if (rv < SS_SUCCESS && flags & CS_VERBOSE) {

		conn_err(tconn, "State change failed: %s\n", drbd_set_st_err_str(rv));

		conn_err(tconn, " state = { cs:%s }\n", drbd_conn_str(oc));

		conn_err(tconn, "wanted = { cs:%s }\n", drbd_conn_str(val.conn));