fs/debugfs/internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  internal.h - declarations internal to debugfs
   4  *
   5  *  Copyright (C) 2016 Nicolai Stange <nicstange@gmail.com>
   6  */
   7
   8 #ifndef _DEBUGFS_INTERNAL_H_
   9 #define _DEBUGFS_INTERNAL_H_
  10 #include <linux/list.h>
  11
  12 struct file_operations;
  13
  14 /* declared over in file.c */
  15 extern const struct file_operations debugfs_noop_file_operations;
  16 extern const struct file_operations debugfs_open_proxy_file_operations;
  17 extern const struct file_operations debugfs_full_proxy_file_operations;
  18
  19 struct debugfs_fsdata {
  20         const struct file_operations *real_fops;
  21         const struct debugfs_short_fops *short_fops;
  22         union {
  23                 /* automount_fn is used when real_fops is NULL */
  24                 debugfs_automount_t automount;
  25                 struct {
  26                         refcount_t active_users;
  27                         struct completion active_users_drained;
  28
  29                         /* protect cancellations */
  30                         struct mutex cancellations_mtx;
  31                         struct list_head cancellations;
  32                 };
  33         };
  34 };
  35
  36 /*
  37  * A dentry's ->d_fsdata either points to the real fops or to a
  38  * dynamically allocated debugfs_fsdata instance.
  39  * In order to distinguish between these two cases, a real fops
  40  * pointer gets its lowest bit set.
  41  */
  42 #define DEBUGFS_FSDATA_IS_REAL_FOPS_BIT BIT(0)
  43 /*
  44  * A dentry's ->d_fsdata, when pointing to real fops, is with
  45  * short fops instead of full fops.
  46  */
  47 #define DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT BIT(1)
  48
  49 /* Access BITS */
  50 #define DEBUGFS_ALLOW_API       BIT(0)
  51 #define DEBUGFS_ALLOW_MOUNT     BIT(1)
  52
  53 #ifdef CONFIG_DEBUG_FS_ALLOW_ALL
  54 #define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_MOUNT | DEBUGFS_ALLOW_API)
  55 #endif
  56 #ifdef CONFIG_DEBUG_FS_DISALLOW_MOUNT
  57 #define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_API)
  58 #endif
  59 #ifdef CONFIG_DEBUG_FS_ALLOW_NONE
  60 #define DEFAULT_DEBUGFS_ALLOW_BITS (0)
  61 #endif
  62
  63 #endif /* _DEBUGFS_INTERNAL_H_ */