bcachefs: Improve trace_trans_restart_relock

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/btree_iter.c

@@ -1337,7 +1337,7 @@ void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool in
 
 	if (path->should_be_locked &&
 	    !trans->restarted &&
-	    (!dup || !bch2_btree_path_relock_norestart(trans, dup, _THIS_IP_)))
+	    (!dup || !bch2_btree_path_relock_norestart(trans, dup)))
 		return;
 
 	if (dup) {

fs/bcachefs/btree_locking.c

@@ -631,8 +631,7 @@ int bch2_btree_path_relock_intent(struct btree_trans *trans,
 }
 
 __flatten
-bool bch2_btree_path_relock_norestart(struct btree_trans *trans,
-			struct btree_path *path, unsigned long trace_ip)
+bool bch2_btree_path_relock_norestart(struct btree_trans *trans, struct btree_path *path)
 {
 	struct get_locks_fail f;
 
@@ -642,7 +641,7 @@ bool bch2_btree_path_relock_norestart(struct btree_trans *trans,
 int __bch2_btree_path_relock(struct btree_trans *trans,
 			struct btree_path *path, unsigned long trace_ip)
 {
-	if (!bch2_btree_path_relock_norestart(trans, path, trace_ip)) {
+	if (!bch2_btree_path_relock_norestart(trans, path)) {
 		trace_and_count(trans->c, trans_restart_relock_path, trans, trace_ip, path);
 		return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock_path);
 	}
@@ -759,12 +758,39 @@ int bch2_trans_relock(struct btree_trans *trans)
 	if (unlikely(trans->restarted))
 		return -((int) trans->restarted);
 
-	trans_for_each_path(trans, path, i)
+	trans_for_each_path(trans, path, i) {
+		struct get_locks_fail f;
+
 		if (path->should_be_locked &&
-		    !bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) {
-			trace_and_count(trans->c, trans_restart_relock, trans, _RET_IP_, path);
+		    !btree_path_get_locks(trans, path, false, &f)) {
+			if (trace_trans_restart_relock_enabled()) {
+				struct printbuf buf = PRINTBUF;
+
+				bch2_bpos_to_text(&buf, path->pos);
+				prt_printf(&buf, " l=%u seq=%u node seq=",
+					   f.l, path->l[f.l].lock_seq);
+				if (IS_ERR_OR_NULL(f.b)) {
+					prt_str(&buf, bch2_err_str(PTR_ERR(f.b)));
+				} else {
+					prt_printf(&buf, "%u", f.b->c.lock.seq);
+
+					struct six_lock_count c =
+						bch2_btree_node_lock_counts(trans, NULL, &f.b->c, f.l);
+					prt_printf(&buf, " self locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
+
+					c = six_lock_counts(&f.b->c.lock);
+					prt_printf(&buf, " total locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
+				}
+
+				trace_trans_restart_relock(trans, _RET_IP_, buf.buf);
+				printbuf_exit(&buf);
+			}
+
+			count_event(trans->c, trans_restart_relock);
 			return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
 		}
+	}
+
 	return 0;
 }
 
@@ -778,7 +804,7 @@ int bch2_trans_relock_notrace(struct btree_trans *trans)
 
 	trans_for_each_path(trans, path, i)
 		if (path->should_be_locked &&
-		    !bch2_btree_path_relock_norestart(trans, path, _RET_IP_)) {
+		    !bch2_btree_path_relock_norestart(trans, path)) {
 			return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
 		}
 	return 0;

fs/bcachefs/btree_locking.h

@@ -312,8 +312,7 @@ void bch2_btree_node_lock_write_nofail(struct btree_trans *,
 
 /* relock: */
 
-bool bch2_btree_path_relock_norestart(struct btree_trans *,
-				      struct btree_path *, unsigned long);
+bool bch2_btree_path_relock_norestart(struct btree_trans *, struct btree_path *);
 int __bch2_btree_path_relock(struct btree_trans *,
 			     struct btree_path *, unsigned long);
 
@@ -353,12 +352,6 @@ static inline bool bch2_btree_node_relock_notrace(struct btree_trans *trans,
 
 /* upgrade */
 
-
-struct get_locks_fail {
-	unsigned	l;
-	struct btree	*b;
-};
-
 bool bch2_btree_path_upgrade_noupgrade_sibs(struct btree_trans *,
 			       struct btree_path *, unsigned,
 			       struct get_locks_fail *);

fs/bcachefs/btree_types.h

@@ -741,4 +741,9 @@ enum btree_node_sibling {
 	btree_next_sib,
 };
 
+struct get_locks_fail {
+	unsigned	l;
+	struct btree	*b;
+};
+
 #endif /* _BCACHEFS_BTREE_TYPES_H */

fs/bcachefs/trace.h

@@ -528,7 +528,7 @@ TRACE_EVENT(btree_path_relock_fail,
 		__entry->level			= path->level;
 		TRACE_BPOS_assign(pos, path->pos);
 
-		c = bch2_btree_node_lock_counts(trans, NULL, &path->l[level].b->c, level),
+		c = bch2_btree_node_lock_counts(trans, NULL, &path->l[level].b->c, level);
 		__entry->self_read_count	= c.n[SIX_LOCK_read];
 		__entry->self_intent_count	= c.n[SIX_LOCK_intent];
 
@@ -1120,8 +1120,6 @@ DEFINE_EVENT(transaction_restart_iter,	trans_restart_btree_node_split,
 	TP_ARGS(trans, caller_ip, path)
 );
 
-struct get_locks_fail;
-
 TRACE_EVENT(trans_restart_upgrade,
 	TP_PROTO(struct btree_trans *trans,
 		 unsigned long caller_ip,
@@ -1169,11 +1167,9 @@ TRACE_EVENT(trans_restart_upgrade,
 		  __entry->node_seq)
 );
 
-DEFINE_EVENT(transaction_restart_iter,	trans_restart_relock,
-	TP_PROTO(struct btree_trans *trans,
-		 unsigned long caller_ip,
-		 struct btree_path *path),
-	TP_ARGS(trans, caller_ip, path)
+DEFINE_EVENT(trans_str,	trans_restart_relock,
+	TP_PROTO(struct btree_trans *trans, unsigned long caller_ip, const char *str),
+	TP_ARGS(trans, caller_ip, str)
 );
 
 DEFINE_EVENT(transaction_restart_iter,	trans_restart_relock_next_node,