/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TRACEFS_INTERNAL_H
#define _TRACEFS_INTERNAL_H

enum {
        TRACEFS_EVENT_INODE             = BIT(1),
        TRACEFS_GID_PERM_SET            = BIT(2),
        TRACEFS_UID_PERM_SET            = BIT(3),
        TRACEFS_INSTANCE_INODE          = BIT(4),
};

struct tracefs_inode {
        struct inode            vfs_inode;
        /* The below gets initialized with memset_after(ti, 0, vfs_inode) */
        struct list_head        list;
        unsigned long           flags;
        void                    *private;
};

/*
 * struct eventfs_attr - cache the mode and ownership of a eventfs entry
 * @mode:       saved mode plus flags of what is saved
 * @uid:        saved uid if changed
 * @gid:        saved gid if changed
 */
struct eventfs_attr {
        int                             mode;
        kuid_t                          uid;
        kgid_t                          gid;
};

/*
 * 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
 * @entry_attrs: Saved mode and ownership of the @d_children
 * @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 {
        union {
                struct list_head        list;
                struct rcu_head         rcu;
        };
        struct list_head                children;
        const struct eventfs_entry      *entries;
        const char                      *name;
        struct eventfs_attr             *entry_attrs;
        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;
};

static inline struct tracefs_inode *get_tracefs(const struct inode *inode)
{
        return container_of(inode, struct tracefs_inode, vfs_inode);
}

struct dentry *tracefs_start_creating(const char *name, struct dentry *parent);
struct dentry *tracefs_end_creating(struct dentry *dentry);
struct dentry *tracefs_failed_creating(struct dentry *dentry);
struct inode *tracefs_get_inode(struct super_block *sb);

void eventfs_remount(struct tracefs_inode *ti, bool update_uid, bool update_gid);
void eventfs_d_release(struct dentry *dentry);

#endif /* _TRACEFS_INTERNAL_H */