Commit 43279e53 authored by David Teigland's avatar David Teigland
Browse files

dlm: clear defunct cancel state 



When a conversion completes successfully and finds that a cancel
of the convert is still in progress (which is now a moot point),
preemptively clear the state associated with outstanding cancel.
That state could cause a subsequent conversion to be ignored.

Also, improve the consistency and content of error and debug
messages in this area.

Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 5e9ccc37

fs/dlm/lock.c

+45 −8
Original line number Diff line number Diff line
@@ -835,7 +835,7 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) 
		lkb->lkb_wait_count++;

		hold_lkb(lkb);



		log_debug(ls, "add overlap %x cur %d new %d count %d flags %x",

		log_debug(ls, "addwait %x cur %d overlap %d count %d f %x",

			  lkb->lkb_id, lkb->lkb_wait_type, mstype,

			  lkb->lkb_wait_count, lkb->lkb_flags);

		goto out;
@@ -851,7 +851,7 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) 
	list_add(&lkb->lkb_wait_reply, &ls->ls_waiters);

 out:

	if (error)

		log_error(ls, "add_to_waiters %x error %d flags %x %d %d %s",

		log_error(ls, "addwait error %x %d flags %x %d %d %s",

			  lkb->lkb_id, error, lkb->lkb_flags, mstype,

			  lkb->lkb_wait_type, lkb->lkb_resource->res_name);

	mutex_unlock(&ls->ls_waiters_mutex);
@@ -863,23 +863,55 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) 
   request reply on the requestqueue) between dlm_recover_waiters_pre() which

   set RESEND and dlm_recover_waiters_post() */



static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype)

static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype,

				struct dlm_message *ms)

{

	struct dlm_ls *ls = lkb->lkb_resource->res_ls;

	int overlap_done = 0;



	if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) {

		log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id);

		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK;

		overlap_done = 1;

		goto out_del;

	}



	if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) {

		log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id);

		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;

		overlap_done = 1;

		goto out_del;

	}



	/* Cancel state was preemptively cleared by a successful convert,

	   see next comment, nothing to do. */



	if ((mstype == DLM_MSG_CANCEL_REPLY) &&

	    (lkb->lkb_wait_type != DLM_MSG_CANCEL)) {

		log_debug(ls, "remwait %x cancel_reply wait_type %d",

			  lkb->lkb_id, lkb->lkb_wait_type);

		return -1;

	}



	/* Remove for the convert reply, and premptively remove for the

	   cancel reply.  A convert has been granted while there's still

	   an outstanding cancel on it (the cancel is moot and the result

	   in the cancel reply should be 0).  We preempt the cancel reply

	   because the app gets the convert result and then can follow up

	   with another op, like convert.  This subsequent op would see the

	   lingering state of the cancel and fail with -EBUSY. */



	if ((mstype == DLM_MSG_CONVERT_REPLY) &&

	    (lkb->lkb_wait_type == DLM_MSG_CONVERT) &&

	    is_overlap_cancel(lkb) && ms && !ms->m_result) {

		log_debug(ls, "remwait %x convert_reply zap overlap_cancel",

			  lkb->lkb_id);

		lkb->lkb_wait_type = 0;

		lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL;

		lkb->lkb_wait_count--;

		goto out_del;

	}



	/* N.B. type of reply may not always correspond to type of original

	   msg due to lookup->request optimization, verify others? */
@@ -888,8 +920,8 @@ static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) 
		goto out_del;

	}



	log_error(ls, "remove_from_waiters lkid %x flags %x types %d %d",

		  lkb->lkb_id, lkb->lkb_flags, mstype, lkb->lkb_wait_type);

	log_error(ls, "remwait error %x reply %d flags %x no wait_type",

		  lkb->lkb_id, mstype, lkb->lkb_flags);

	return -1;



 out_del:
@@ -899,7 +931,7 @@ static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) 
	   this would happen */



	if (overlap_done && lkb->lkb_wait_type) {

		log_error(ls, "remove_from_waiters %x reply %d give up on %d",

		log_error(ls, "remwait error %x reply %d wait_type %d overlap",

			  lkb->lkb_id, mstype, lkb->lkb_wait_type);

		lkb->lkb_wait_count--;

		lkb->lkb_wait_type = 0;
@@ -921,7 +953,7 @@ static int remove_from_waiters(struct dlm_lkb *lkb, int mstype) 
	int error;



	mutex_lock(&ls->ls_waiters_mutex);

	error = _remove_from_waiters(lkb, mstype);

	error = _remove_from_waiters(lkb, mstype, NULL);

	mutex_unlock(&ls->ls_waiters_mutex);

	return error;

}
@@ -936,7 +968,7 @@ static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms) 


	if (ms != &ls->ls_stub_ms)

		mutex_lock(&ls->ls_waiters_mutex);

	error = _remove_from_waiters(lkb, ms->m_type);

	error = _remove_from_waiters(lkb, ms->m_type, ms);

	if (ms != &ls->ls_stub_ms)

		mutex_unlock(&ls->ls_waiters_mutex);

	return error;
@@ -2083,6 +2115,11 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, 
	lkb->lkb_timeout_cs = args->timeout;

	rv = 0;

 out:

	if (rv)

		log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s",

			  rv, lkb->lkb_id, lkb->lkb_flags, args->flags,

			  lkb->lkb_status, lkb->lkb_wait_type,

			  lkb->lkb_resource->res_name);

	return rv;

}

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