Btrfs: add tracepoints for flush events

We want to track when we're triggering flushing from our reservation code and
what flushing is being done when we start flushing.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 82 insertions, 0 deletions

diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 985e01b6c849..226c7f283247 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -784,6 +784,88 @@ TRACE_EVENT(btrfs_space_reservation,
 		  __entry->bytes)
 );
 
+#define show_flush_action(action)						\
+	__print_symbolic(action,						\
+		{ BTRFS_RESERVE_NO_FLUSH,	"BTRFS_RESERVE_NO_FLUSH"},	\
+		{ BTRFS_RESERVE_FLUSH_LIMIT,	"BTRFS_RESERVE_FLUSH_LIMIT"},	\
+		{ BTRFS_RESERVE_FLUSH_ALL,	"BTRFS_RESERVE_FLUSH_ALL"})
+
+TRACE_EVENT(btrfs_trigger_flush,
+
+	TP_PROTO(struct btrfs_fs_info *fs_info, u64 flags, u64 bytes,
+		 int flush, char *reason),
+
+	TP_ARGS(fs_info, flags, bytes, flush, reason),
+
+	TP_STRUCT__entry(
+		__array(	u8,	fsid,	BTRFS_UUID_SIZE	)
+		__field(	u64,	flags			)
+		__field(	u64,	bytes			)
+		__field(	int,	flush			)
+		__string(	reason,	reason			)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->fsid, fs_info->fsid, BTRFS_UUID_SIZE);
+		__entry->flags	= flags;
+		__entry->bytes	= bytes;
+		__entry->flush	= flush;
+		__assign_str(reason, reason)
+	),
+
+	TP_printk("%pU: %s: flush = %d(%s), flags = %llu(%s), bytes = %llu",
+		  __entry->fsid, __get_str(reason), __entry->flush,
+		  show_flush_action(__entry->flush),
+		  (unsigned long long)__entry->flags,
+		  __print_flags((unsigned long)__entry->flags, "|",
+				BTRFS_GROUP_FLAGS),
+		  (unsigned long long)__entry->bytes)
+);
+
+#define show_flush_state(state)							\
+	__print_symbolic(state,							\
+		{ FLUSH_DELAYED_ITEMS_NR,	"FLUSH_DELAYED_ITEMS_NR"},	\
+		{ FLUSH_DELAYED_ITEMS,		"FLUSH_DELAYED_ITEMS"},		\
+		{ FLUSH_DELALLOC,		"FLUSH_DELALLOC"},		\
+		{ FLUSH_DELALLOC_WAIT,		"FLUSH_DELALLOC_WAIT"},		\
+		{ ALLOC_CHUNK,			"ALLOC_CHUNK"},			\
+		{ COMMIT_TRANS,			"COMMIT_TRANS"})
+
+TRACE_EVENT(btrfs_flush_space,
+
+	TP_PROTO(struct btrfs_fs_info *fs_info, u64 flags, u64 num_bytes,
+		 u64 orig_bytes, int state, int ret),
+
+	TP_ARGS(fs_info, flags, num_bytes, orig_bytes, state, ret),
+
+	TP_STRUCT__entry(
+		__array(	u8,	fsid,	BTRFS_UUID_SIZE	)
+		__field(	u64,	flags			)
+		__field(	u64,	num_bytes		)
+		__field(	u64,	orig_bytes		)
+		__field(	int,	state			)
+		__field(	int,	ret			)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->fsid, fs_info->fsid, BTRFS_UUID_SIZE);
+		__entry->flags		=	flags;
+		__entry->num_bytes	=	num_bytes;
+		__entry->orig_bytes	=	orig_bytes;
+		__entry->state		=	state;
+		__entry->ret		=	ret;
+	),
+
+	TP_printk("%pU: state = %d(%s), flags = %llu(%s), num_bytes = %llu, "
+		  "orig_bytes = %llu, ret = %d", __entry->fsid, __entry->state,
+		  show_flush_state(__entry->state),
+		  (unsigned long long)__entry->flags,
+		  __print_flags((unsigned long)__entry->flags, "|",
+				BTRFS_GROUP_FLAGS),
+		  (unsigned long long)__entry->num_bytes,
+		  (unsigned long long)__entry->orig_bytes, __entry->ret)
+);
+
 DECLARE_EVENT_CLASS(btrfs__reserved_extent,
 
 	TP_PROTO(struct btrfs_root *root, u64 start, u64 len),