eventfs: Restructure eventfs_inode structure to be more condensed

Some of the eventfs_inode structure has holes in it. Rework the structure
to be a bit more condensed, and also remove the no longer used llist
field.

Link: https://lore.kernel.org/linux-trace-kernel/20240201161617.002321438@goodmis.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Ajay Kaher <ajay.kaher@broadcom.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
index 1886f18..beb3dcd 100644 (file)
--- a/fs/tracefs/internal.h
+++ b/fs/tracefs/internal.h
@@ -32,40 +32,37 @@ struct eventfs_attr {
 /*
  * struct eventfs_inode - hold the properties of the eventfs directories.
  * @list:      link list into the parent directory
+ * @rcu:       Union with @list for freeing
+ * @children:  link list into the child eventfs_inode
  * @entries:   the array of entries representing the files in the directory
  * @name:      the name of the directory to create
- * @children:  link list into the child eventfs_inode
  * @events_dir: the dentry of the events directory
  * @entry_attrs: Saved mode and ownership of the @d_children
- * @attr:      Saved mode and ownership of eventfs_inode itself
  * @data:      The private data to pass to the callbacks
+ * @attr:      Saved mode and ownership of eventfs_inode itself
  * @is_freed:  Flag set if the eventfs is on its way to be freed
  *                Note if is_freed is set, then dentry is corrupted.
+ * @is_events: Flag set for only the top level "events" directory
  * @nr_entries: The number of items in @entries
+ * @ino:       The saved inode number
  */
 struct eventfs_inode {
-       struct kref                     kref;
-       struct list_head                list;
+       union {
+               struct list_head        list;
+               struct rcu_head         rcu;
+       };
+       struct list_head                children;
        const struct eventfs_entry      *entries;
        const char                      *name;
-       struct list_head                children;
        struct dentry                   *events_dir;
        struct eventfs_attr             *entry_attrs;
-       struct eventfs_attr             attr;
        void                            *data;
+       struct eventfs_attr             attr;
+       struct kref                     kref;
        unsigned int                    is_freed:1;
        unsigned int                    is_events:1;
        unsigned int                    nr_entries:30;
        unsigned int                    ino;
-       /*
-        * Union - used for deletion
-        * @llist:      for calling dput() if needed after RCU
-        * @rcu:        eventfs_inode to delete in RCU
-        */
-       union {
-               struct llist_node       llist;
-               struct rcu_head         rcu;
-       };
 };
 
 static inline struct tracefs_inode *get_tracefs(const struct inode *inode)