fs/aufs/sysaufs.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2005-2019 Junjiro R. Okajima
   4  *
   5  * This program, aufs is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /*
  20  * sysfs interface and mount lifetime management
  21  */
  22
  23 #ifndef __SYSAUFS_H__
  24 #define __SYSAUFS_H__
  25
  26 #ifdef __KERNEL__
  27
  28 #include <linux/sysfs.h>
  29 #include "module.h"
  30
  31 struct super_block;
  32 struct au_sbinfo;
  33
  34 struct sysaufs_si_attr {
  35         struct attribute attr;
  36         int (*show)(struct seq_file *seq, struct super_block *sb);
  37 };
  38
  39 /* ---------------------------------------------------------------------- */
  40
  41 /* sysaufs.c */
  42 extern unsigned long sysaufs_si_mask;
  43 extern struct kset *sysaufs_kset;
  44 extern struct attribute *sysaufs_si_attrs[];
  45 int sysaufs_si_init(struct au_sbinfo *sbinfo);
  46 int __init sysaufs_init(void);
  47 void sysaufs_fin(void);
  48
  49 /* ---------------------------------------------------------------------- */
  50
  51 /* some people doesn't like to show a pointer in kernel */
  52 static inline unsigned long sysaufs_si_id(struct au_sbinfo *sbinfo)
  53 {
  54         return sysaufs_si_mask ^ (unsigned long)sbinfo;
  55 }
  56
  57 #define SysaufsSiNamePrefix     "si_"
  58 #define SysaufsSiNameLen        (sizeof(SysaufsSiNamePrefix) + 16)
  59 static inline void sysaufs_name(struct au_sbinfo *sbinfo, char *name)
  60 {
  61         snprintf(name, SysaufsSiNameLen, SysaufsSiNamePrefix "%lx",
  62                  sysaufs_si_id(sbinfo));
  63 }
  64
  65 struct au_branch;
  66 #ifdef CONFIG_SYSFS
  67 /* sysfs.c */
  68 extern struct attribute_group *sysaufs_attr_group;
  69
  70 int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb);
  71 ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
  72                          char *buf);
  73 long au_brinfo_ioctl(struct file *file, unsigned long arg);
  74 #ifdef CONFIG_COMPAT
  75 long au_brinfo_compat_ioctl(struct file *file, unsigned long arg);
  76 #endif
  77
  78 void sysaufs_br_init(struct au_branch *br);
  79 void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
  80 void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
  81
  82 #define sysaufs_brs_init()      do {} while (0)
  83
  84 #else
  85 #define sysaufs_attr_group      NULL
  86
  87 AuStubInt0(sysaufs_si_xi_path, struct seq_file *seq, struct super_block *sb)
  88 AuStub(ssize_t, sysaufs_si_show, return 0, struct kobject *kobj,
  89        struct attribute *attr, char *buf)
  90 AuStubVoid(sysaufs_br_init, struct au_branch *br)
  91 AuStubVoid(sysaufs_brs_add, struct super_block *sb, aufs_bindex_t bindex)
  92 AuStubVoid(sysaufs_brs_del, struct super_block *sb, aufs_bindex_t bindex)
  93
  94 static inline void sysaufs_brs_init(void)
  95 {
  96         sysaufs_brs = 0;
  97 }
  98
  99 #endif /* CONFIG_SYSFS */
 100
 101 #endif /* __KERNEL__ */
 102 #endif /* __SYSAUFS_H__ */