[PATCH v3 1/2] include/linux/watch_queue: Improve documentation

[Siddh Raman Pant]

Introduce kerneldoc-style comments, and document a couple of things
explicitly.

Signed-off-by: Siddh Raman Pant <code at siddh.me>
---
 include/linux/watch_queue.h | 102 ++++++++++++++++++++++++++----------
 1 file changed, 75 insertions(+), 27 deletions(-)

diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
index fc6bba20273b..7f6eea4a33a6 100644
--- a/include/linux/watch_queue.h
+++ b/include/linux/watch_queue.h
@@ -18,57 +18,103 @@
 
 struct cred;
 
+/**
+ * struct watch_type_filter - Filter on watch type
+ *
+ * @type: Type of watch_notification
+ * @subtype_filter: Bitmask of subtypes to filter on
+ * @info_filter: Filter on watch_notification::info
+ * @info_mask: Mask of relevant bits in info_filter
+ */
 struct watch_type_filter {
 	enum watch_notification_type type;
-	__u32		subtype_filter[1];	/* Bitmask of subtypes to filter on */
-	__u32		info_filter;		/* Filter on watch_notification::info */
-	__u32		info_mask;		/* Mask of relevant bits in info_filter */
+	__u32		subtype_filter[1];
+	__u32		info_filter;
+	__u32		info_mask;
 };
 
+/**
+ * struct watch_filter - Filter on watch
+ *
+ * @rcu: RCU head (in union with type_filter)
+ * @type_filter: Bitmask of accepted types (in union with rcu)
+ * @nr_filters: Number of filters
+ * @filters: Array of watch_type_filter
+ */
 struct watch_filter {
 	union {
 		struct rcu_head	rcu;
-		/* Bitmask of accepted types */
 		DECLARE_BITMAP(type_filter, WATCH_TYPE__NR);
 	};
-	u32			nr_filters;	/* Number of filters */
+	u32			 nr_filters;
 	struct watch_type_filter filters[];
 };
 
+/**
+ * struct watch_queue - General notification queue
+ *
+ * @rcu: RCU head
+ * @filter: Filter to use on watches
+ * @pipe: The pipe we're using as a buffer
+ * @watches: Contributory watches
+ * @notes: Preallocated notifications
+ * @notes_bitmap: Allocation bitmap for notes
+ * @usage: Object usage count
+ * @lock: To serialize accesses and removes
+ * @nr_notes: Number of notes
+ * @nr_pages: Number of pages in notes[]
+ * @defunct: True when queues closed
+ */
 struct watch_queue {
 	struct rcu_head		rcu;
 	struct watch_filter __rcu *filter;
-	struct pipe_inode_info	*pipe;		/* The pipe we're using as a buffer */
-	struct hlist_head	watches;	/* Contributory watches */
-	struct page		**notes;	/* Preallocated notifications */
-	unsigned long		*notes_bitmap;	/* Allocation bitmap for notes */
-	struct kref		usage;		/* Object usage count */
+	struct pipe_inode_info	*pipe;
+	struct hlist_head	watches;
+	struct page		**notes;
+	unsigned long		*notes_bitmap;
+	struct kref		usage;
 	spinlock_t		lock;
-	unsigned int		nr_notes;	/* Number of notes */
-	unsigned int		nr_pages;	/* Number of pages in notes[] */
-	bool			defunct;	/* T when queues closed */
+	unsigned int		nr_notes;
+	unsigned int		nr_pages;
+	bool			defunct;
 };
 
-/*
- * Representation of a watch on an object.
+/**
+ * struct watch - Representation of a watch on an object
+ *
+ * @rcu: RCU head (in union with info_id)
+ * @info_id: ID to be OR'd in to info field (in union with rcu)
+ * @queue: Queue to post events to
+ * @queue_node: Link in queue->watches
+ * @watch_list: The watch list containing this watch
+ * @list_node: Link in watch_list->watchers
+ * @cred: Creds of the owner of the watch
+ * @private: Private data for the watched object
+ * @id: Internal identifier
+ * @usage: Object usage count
  */
 struct watch {
 	union {
 		struct rcu_head	rcu;
-		u32		info_id;	/* ID to be OR'd in to info field */
+		u32		info_id;
 	};
-	struct watch_queue __rcu *queue;	/* Queue to post events to */
-	struct hlist_node	queue_node;	/* Link in queue->watches */
+	struct watch_queue __rcu *queue;
+	struct hlist_node	queue_node;
 	struct watch_list __rcu	*watch_list;
-	struct hlist_node	list_node;	/* Link in watch_list->watchers */
-	const struct cred	*cred;		/* Creds of the owner of the watch */
-	void			*private;	/* Private data for the watched object */
-	u64			id;		/* Internal identifier */
-	struct kref		usage;		/* Object usage count */
+	struct hlist_node	list_node;
+	const struct cred	*cred;
+	void			*private;
+	u64			id;
+	struct kref		usage;
 };
 
-/*
- * List of watches on an object.
+/**
+ * struct watch_list - List of watches on an object
+ *
+ * @rcu: RCU head
+ * @watchers: List head
+ * @release_watch: Function to release watch
+ * @lock: To protect addition and removal of watches
  */
 struct watch_list {
 	struct rcu_head		rcu;
@@ -118,8 +164,10 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
 }
 
 /**
- * watch_sizeof - Calculate the information part of the size of a watch record,
- * given the structure size.
+ * watch_sizeof() - Calculate the information part of the size of a watch
+ *		    record, given the structure size.
+ *
+ * @STRUCT: The structure whose size is to be given
  */
 #define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)
 
-- 
2.39.0