bcachefs: Improve bucket_alloc_fail tracepoint

Also include the number of buckets available, and the number of buckets
awaiting journal commit - and add a sysfs counter, too.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

4 files changed, 41 insertions, 7 deletions

diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index e0dc585b50da..178d7c058597 100644
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -432,7 +432,7 @@ static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
 	}
 	bch2_trans_iter_exit(trans, &iter);
 
-	return ob ?: ERR_PTR(ret ?: -FREELIST_EMPTY);
+	return ob ?: ERR_PTR(ret);
 }
 
 /**
@@ -471,8 +471,8 @@ again:
 		if (!c->blocked_allocate)
 			c->blocked_allocate = local_clock();
 
-		trace_bucket_alloc_fail(ca, reserve);
-		return ERR_PTR(-FREELIST_EMPTY);
+		ob = ERR_PTR(-FREELIST_EMPTY);
+		goto err;
 	}
 
 	ret = bch2_trans_do(c, NULL, NULL, 0,
@@ -482,8 +482,16 @@ again:
 
 	if (need_journal_commit * 2 > avail)
 		bch2_journal_flush_async(&c->journal, NULL);
+err:
+	if (!ob)
+		ob = ERR_PTR(ret ?: -FREELIST_EMPTY);
 
-	return ob ?: ERR_PTR(ret ?: -FREELIST_EMPTY);
+	if (ob == ERR_PTR(-FREELIST_EMPTY)) {
+		trace_bucket_alloc_fail(ca, reserve, avail, need_journal_commit);
+		atomic_long_inc(&c->bucket_alloc_fail);
+	}
+
+	return ob;
 }
 
 static int __dev_stripe_cmp(struct dev_stripe_state *stripe,
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 2d185d22d78e..a4ef9aabf274 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -897,6 +897,7 @@ struct bch_fs {
 	atomic_long_t		read_realloc_races;
 	atomic_long_t		extent_migrate_done;
 	atomic_long_t		extent_migrate_raced;
+	atomic_long_t		bucket_alloc_fail;
 
 	unsigned		btree_gc_periodic:1;
 	unsigned		copy_gc_enabled:1;
diff --git a/fs/bcachefs/sysfs.c b/fs/bcachefs/sysfs.c
index 1b5ed7adc261..bed48afb4ac9 100644
--- a/fs/bcachefs/sysfs.c
+++ b/fs/bcachefs/sysfs.c
@@ -188,6 +188,7 @@ read_attribute(alloc_debug);
 read_attribute(read_realloc_races);
 read_attribute(extent_migrate_done);
 read_attribute(extent_migrate_raced);
+read_attribute(bucket_alloc_fail);
 
 rw_attribute(discard);
 rw_attribute(label);
@@ -374,6 +375,8 @@ SHOW(bch2_fs)
 		    atomic_long_read(&c->extent_migrate_done));
 	sysfs_print(extent_migrate_raced,
 		    atomic_long_read(&c->extent_migrate_raced));
+	sysfs_print(bucket_alloc_fail,
+		    atomic_long_read(&c->bucket_alloc_fail));
 
 	sysfs_printf(btree_gc_periodic, "%u",	(int) c->btree_gc_periodic);
 
@@ -570,6 +573,7 @@ struct attribute *bch2_fs_internal_files[] = {
 	&sysfs_read_realloc_races,
 	&sysfs_extent_migrate_done,
 	&sysfs_extent_migrate_raced,
+	&sysfs_bucket_alloc_fail,
 
 	&sysfs_gc_gens_pos,
 
diff --git a/include/trace/events/bcachefs.h b/include/trace/events/bcachefs.h
index 0596887959d3..832e9f191409 100644
--- a/include/trace/events/bcachefs.h
+++ b/include/trace/events/bcachefs.h
@@ -491,9 +491,30 @@ DEFINE_EVENT(bucket_alloc, bucket_alloc,
 	TP_ARGS(ca, reserve)
 );
 
-DEFINE_EVENT(bucket_alloc, bucket_alloc_fail,
-	TP_PROTO(struct bch_dev *ca, enum alloc_reserve reserve),
-	TP_ARGS(ca, reserve)
+TRACE_EVENT(bucket_alloc_fail,
+	TP_PROTO(struct bch_dev *ca, enum alloc_reserve reserve,
+		 u64 avail, u64 need_journal_commit),
+	TP_ARGS(ca, reserve, avail, need_journal_commit),
+
+	TP_STRUCT__entry(
+		__field(dev_t,			dev	)
+		__field(enum alloc_reserve,	reserve	)
+		__field(u64,			avail	)
+		__field(u64,			need_journal_commit )
+	),
+
+	TP_fast_assign(
+		__entry->dev		= ca->dev;
+		__entry->reserve	= reserve;
+		__entry->avail		= avail;
+		__entry->need_journal_commit = need_journal_commit;
+	),
+
+	TP_printk("%d,%d reserve %d avail %llu need_journal_commit %llu",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->reserve,
+		  __entry->avail,
+		  __entry->need_journal_commit)
 );
 
 DEFINE_EVENT(bucket_alloc, open_bucket_alloc_fail,