linux/fs/debugfs/internal.h
Johannes Berg f4acfcd4de debugfs: annotate debugfs handlers vs. removal with lockdep
When you take a lock in a debugfs handler but also try
to remove the debugfs file under that lock, things can
deadlock since the removal has to wait for all users
to finish.

Add lockdep annotations in debugfs_file_get()/_put()
to catch such issues.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-11-27 11:24:50 +01:00

58 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* internal.h - declarations internal to debugfs
*
* Copyright (C) 2016 Nicolai Stange <nicstange@gmail.com>
*/
#ifndef _DEBUGFS_INTERNAL_H_
#define _DEBUGFS_INTERNAL_H_
#include <linux/lockdep.h>
struct file_operations;
/* declared over in file.c */
extern const struct file_operations debugfs_noop_file_operations;
extern const struct file_operations debugfs_open_proxy_file_operations;
extern const struct file_operations debugfs_full_proxy_file_operations;
struct debugfs_fsdata {
const struct file_operations *real_fops;
union {
/* automount_fn is used when real_fops is NULL */
debugfs_automount_t automount;
struct {
refcount_t active_users;
struct completion active_users_drained;
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
struct lock_class_key key;
char *lock_name;
#endif
};
};
};
/*
* A dentry's ->d_fsdata either points to the real fops or to a
* dynamically allocated debugfs_fsdata instance.
* In order to distinguish between these two cases, a real fops
* pointer gets its lowest bit set.
*/
#define DEBUGFS_FSDATA_IS_REAL_FOPS_BIT BIT(0)
/* Access BITS */
#define DEBUGFS_ALLOW_API BIT(0)
#define DEBUGFS_ALLOW_MOUNT BIT(1)
#ifdef CONFIG_DEBUG_FS_ALLOW_ALL
#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_MOUNT | DEBUGFS_ALLOW_API)
#endif
#ifdef CONFIG_DEBUG_FS_DISALLOW_MOUNT
#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_API)
#endif
#ifdef CONFIG_DEBUG_FS_ALLOW_NONE
#define DEFAULT_DEBUGFS_ALLOW_BITS (0)
#endif
#endif /* _DEBUGFS_INTERNAL_H_ */