1 files changed, 144 insertions, 2 deletions

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 09668ec..ab986df 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -82,10 +82,13 @@ static int send_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int mode);
 static int send_lookup(struct dlm_rsb *r, struct dlm_lkb *lkb);
 static int send_remove(struct dlm_rsb *r);
 static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
+static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb);
 static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
 				    struct dlm_message *ms);
 static int receive_extralen(struct dlm_message *ms);
 static void do_purge(struct dlm_ls *ls, int nodeid, int pid);
+static void del_timeout(struct dlm_lkb *lkb);
+void dlm_timeout_warn(struct dlm_lkb *lkb);
 
 /*
  * Lock compatibilty matrix - thanks Steve
@@ -286,8 +289,17 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
 	if (is_master_copy(lkb))
 		return;
 
+	del_timeout(lkb);
+
 	DLM_ASSERT(lkb->lkb_lksb, dlm_print_lkb(lkb););
 
+	/* if the operation was a cancel, then return -DLM_ECANCEL, if a
+	   timeout caused the cancel then return -ETIMEDOUT */
+	if (rv == -DLM_ECANCEL && (lkb->lkb_flags & DLM_IFL_TIMEOUT_CANCEL)) {
+		lkb->lkb_flags &= ~DLM_IFL_TIMEOUT_CANCEL;
+		rv = -ETIMEDOUT;
+	}
+
 	lkb->lkb_lksb->sb_status = rv;
 	lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
 
@@ -581,6 +593,7 @@ static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 	kref_init(&lkb->lkb_ref);
 	INIT_LIST_HEAD(&lkb->lkb_ownqueue);
 	INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);
+	INIT_LIST_HEAD(&lkb->lkb_time_list);
 
 	get_random_bytes(&bucket, sizeof(bucket));
 	bucket &= (ls->ls_lkbtbl_size - 1);
@@ -993,6 +1006,125 @@ void dlm_scan_rsbs(struct dlm_ls *ls)
 	}
 }
 
+static void add_timeout(struct dlm_lkb *lkb)
+{
+	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+
+	if (is_master_copy(lkb))
+		return;
+
+	if (lkb->lkb_exflags & DLM_LKF_TIMEOUT)
+		goto add_it;
+
+	if (test_bit(LSFL_TIMEWARN, &ls->ls_flags) &&
+	    !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
+		lkb->lkb_flags |= DLM_IFL_WATCH_TIMEWARN;
+		goto add_it;
+	}
+	return;
+
+ add_it:
+	DLM_ASSERT(list_empty(&lkb->lkb_time_list), dlm_print_lkb(lkb););
+	mutex_lock(&ls->ls_timeout_mutex);
+	hold_lkb(lkb);
+	lkb->lkb_timestamp = jiffies;
+	list_add_tail(&lkb->lkb_time_list, &ls->ls_timeout);
+	mutex_unlock(&ls->ls_timeout_mutex);
+}
+
+static void del_timeout(struct dlm_lkb *lkb)
+{
+	struct dlm_ls *ls = lkb->lkb_resource->res_ls;
+
+	mutex_lock(&ls->ls_timeout_mutex);
+	if (!list_empty(&lkb->lkb_time_list)) {
+		list_del_init(&lkb->lkb_time_list);
+		unhold_lkb(lkb);
+	}
+	mutex_unlock(&ls->ls_timeout_mutex);
+}
+
+/* FIXME: is it safe to look at lkb_exflags, lkb_flags, lkb_timestamp, and
+   lkb_lksb_timeout without lock_rsb?  Note: we can't lock timeout_mutex
+   and then lock rsb because of lock ordering in add_timeout.  We may need
+   to specify some special timeout-related bits in the lkb that are just to
+   be accessed under the timeout_mutex. */
+
+void dlm_scan_timeout(struct dlm_ls *ls)
+{
+	struct dlm_rsb *r;
+	struct dlm_lkb *lkb;
+	int do_cancel, do_warn;
+
+	for (;;) {
+		if (dlm_locking_stopped(ls))
+			break;
+
+		do_cancel = 0;
+		do_warn = 0;
+		mutex_lock(&ls->ls_timeout_mutex);
+		list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list) {
+
+			if ((lkb->lkb_exflags & DLM_LKF_TIMEOUT) &&
+			    time_after_eq(jiffies, lkb->lkb_timestamp +
+					  lkb->lkb_timeout_cs * HZ/100))
+				do_cancel = 1;
+
+			if ((lkb->lkb_flags & DLM_IFL_WATCH_TIMEWARN) &&
+			    time_after_eq(jiffies, lkb->lkb_timestamp +
+				   	   dlm_config.ci_timewarn_cs * HZ/100))
+				do_warn = 1;
+
+			if (!do_cancel && !do_warn)
+				continue;
+			hold_lkb(lkb);
+			break;
+		}
+		mutex_unlock(&ls->ls_timeout_mutex);
+
+		if (!do_cancel && !do_warn)
+			break;
+
+		r = lkb->lkb_resource;
+		hold_rsb(r);
+		lock_rsb(r);
+
+		if (do_warn) {
+			/* clear flag so we only warn once */
+			lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
+			if (!(lkb->lkb_exflags & DLM_LKF_TIMEOUT))
+				del_timeout(lkb);
+			dlm_timeout_warn(lkb);
+		}
+
+		if (do_cancel) {
+			lkb->lkb_flags &= ~DLM_IFL_WATCH_TIMEWARN;
+			lkb->lkb_flags |= DLM_IFL_TIMEOUT_CANCEL;
+			del_timeout(lkb);
+			_cancel_lock(r, lkb);
+		}
+
+		unlock_rsb(r);
+		unhold_rsb(r);
+		dlm_put_lkb(lkb);
+	}
+}
+
+/* This is only called by dlm_recoverd, and we rely on dlm_ls_stop() stopping
+   dlm_recoverd before checking/setting ls_recover_begin. */
+
+void dlm_adjust_timeouts(struct dlm_ls *ls)
+{
+	struct dlm_lkb *lkb;
+	long adj = jiffies - ls->ls_recover_begin;
+
+	ls->ls_recover_begin = 0;
+	mutex_lock(&ls->ls_timeout_mutex);
+	list_for_each_entry(lkb, &ls->ls_timeout, lkb_time_list)
+		lkb->lkb_timestamp += adj;
+	mutex_unlock(&ls->ls_timeout_mutex);
+}
+
 /* lkb is master or local copy */
 
 static void set_lvb_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -1902,6 +2034,9 @@ static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
 		if (is_overlap(lkb))
 			goto out;
 
+		/* don't let scand try to do a cancel */
+		del_timeout(lkb);
+
 		if (lkb->lkb_flags & DLM_IFL_RESEND) {
 			lkb->lkb_flags |= DLM_IFL_OVERLAP_CANCEL;
 			rv = -EBUSY;
@@ -1933,6 +2068,9 @@ static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
 		if (is_overlap_unlock(lkb))
 			goto out;
 
+		/* don't let scand try to do a cancel */
+		del_timeout(lkb);
+
 		if (lkb->lkb_flags & DLM_IFL_RESEND) {
 			lkb->lkb_flags |= DLM_IFL_OVERLAP_UNLOCK;
 			rv = -EBUSY;
@@ -1993,6 +2131,7 @@ static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
 		error = -EINPROGRESS;
 		add_lkb(r, lkb, DLM_LKSTS_WAITING);
 		send_blocking_asts(r, lkb);
+		add_timeout(lkb);
 		goto out;
 	}
 
@@ -2040,6 +2179,7 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
 		del_lkb(r, lkb);
 		add_lkb(r, lkb, DLM_LKSTS_CONVERT);
 		send_blocking_asts(r, lkb);
+		add_timeout(lkb);
 		goto out;
 	}
 
@@ -3110,9 +3250,10 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
 		lkb->lkb_remid = ms->m_lkid;
 		if (is_altmode(lkb))
 			munge_altmode(lkb, ms);
-		if (result)
+		if (result) {
 			add_lkb(r, lkb, DLM_LKSTS_WAITING);
-		else {
+			add_timeout(lkb);
+		} else {
 			grant_lock_pc(r, lkb, ms);
 			queue_cast(r, lkb, 0);
 		}
@@ -3178,6 +3319,7 @@ static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
 			munge_demoted(lkb, ms);
 		del_lkb(r, lkb);
 		add_lkb(r, lkb, DLM_LKSTS_CONVERT);
+		add_timeout(lkb);
 		break;
 
 	case 0: