btrfs: tracepoints: add trace event for btrfs_log_new_name()

btrfs_log_new_name() is an important function that affects inode logging
and is called during link and rename operations. Add trace events for when
entering and exiting that function.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -8058,6 +8058,8 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	bool log_pinned = false;
 	int ret;
 
+	trace_btrfs_log_new_name_enter(trans, inode, old_dir, old_dir_index);
+
 	/* The inode has a new name (ref/extref), so make sure we log it. */
 	set_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
 
@@ -8080,7 +8082,7 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 		goto out;
 	} else if (ret == 0) {
 		if (!old_dir)
-			return;
+			goto out;
 		/*
 		 * If the inode was not logged and we are doing a rename (old_dir is not
 		 * NULL), check if old_dir was logged - if it was not we can return and
@@ -8090,7 +8092,7 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 		if (ret < 0)
 			goto out;
 		else if (ret == 0)
-			return;
+			goto out;
 	}
 	ret = 0;
 
@@ -8189,6 +8191,7 @@ void btrfs_log_new_name(struct btrfs_trans_handle *trans,
 	btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
 	ASSERT(list_empty(&ctx.conflict_inodes));
 out:
+	trace_btrfs_log_new_name_exit(trans, inode, old_dir, ret);
 	/*
 	 * If an error happened mark the log for a full commit because it's not
 	 * consistent and up to date or we couldn't find out if one of the

include/trace/events/btrfs.h

@@ -1481,6 +1481,72 @@ TRACE_EVENT(btrfs_record_new_subvolume,
 			__entry->dir)
 );
 
+TRACE_EVENT(btrfs_log_new_name_enter,
+
+	TP_PROTO(const struct btrfs_trans_handle *trans,
+		 const struct btrfs_inode *inode,
+		 const struct btrfs_inode *old_dir,
+		 u64 old_dir_index),
+
+	TP_ARGS(trans, inode, old_dir, old_dir_index),
+
+	TP_STRUCT__entry_btrfs(
+		__field(	u64,     	root_objectid		)
+		__field(	u64,		transid			)
+		__field(	u64,	 	ino			)
+		__field(	umode_t,	mode			)
+		__field(	u64,	 	old_dir_ino		)
+		__field(	u64,		old_dir_index		)
+	),
+
+	TP_fast_assign(
+		TP_fast_assign_fsid(trans->fs_info);
+		__entry->root_objectid		= btrfs_root_id(inode->root);
+		__entry->transid		= trans->transid;
+		__entry->ino			= btrfs_ino(inode);
+		__entry->mode			= inode->vfs_inode.i_mode;
+		__entry->old_dir_ino		= old_dir ? btrfs_ino(old_dir) : 0;
+		__entry->old_dir_index		= old_dir_index;
+	),
+
+	TP_printk_btrfs("root=%llu(%s) transid=%llu ino=%llu type=%s"
+			" old_dir=%llu old_dir_index=%llu",
+			show_root_type(__entry->root_objectid), __entry->transid,
+			__entry->ino, show_inode_type(__entry->mode),
+			__entry->old_dir_ino, __entry->old_dir_index)
+);
+
+TRACE_EVENT(btrfs_log_new_name_exit,
+
+	TP_PROTO(const struct btrfs_trans_handle *trans,
+		 const struct btrfs_inode *inode,
+		 const struct btrfs_inode *old_dir,
+		 int ret),
+
+	TP_ARGS(trans, inode, old_dir, ret),
+
+	TP_STRUCT__entry_btrfs(
+		__field(	u64,     	root_objectid		)
+		__field(	u64,		transid			)
+		__field(	u64,	 	ino			)
+		__field(	u64,	 	old_dir_ino		)
+		__field(	int,		ret			)
+	),
+
+	TP_fast_assign(
+		TP_fast_assign_fsid(trans->fs_info);
+		__entry->root_objectid		= btrfs_root_id(inode->root);
+		__entry->transid		= trans->transid;
+		__entry->ino			= btrfs_ino(inode);
+		__entry->old_dir_ino		= old_dir ? btrfs_ino(old_dir) : 0;
+		__entry->ret			= ret;
+	),
+
+	TP_printk_btrfs("root=%llu(%s) transid=%llu ino=%llu old_dir=%llu ret=%d",
+			show_root_type(__entry->root_objectid), __entry->transid,
+			__entry->ino, __entry->old_dir_ino, __entry->ret)
+);
+
 TRACE_EVENT(btrfs_sync_fs,
 
 	TP_PROTO(const struct btrfs_fs_info *fs_info, int wait),