fs/aufs/sysaufs.h

   1 /*
   2  * Copyright (C) 2005-2017 Junjiro R. Okajima
   3  *
   4  * This program, aufs is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * sysfs interface and mount lifetime management
  20  */
  21
  22 #ifndef __SYSAUFS_H__
  23 #define __SYSAUFS_H__
  24
  25 #ifdef __KERNEL__
  26
  27 #include <linux/sysfs.h>
  28 #include "module.h"
  29
  30 struct super_block;
  31 struct au_sbinfo;
  32
  33 struct sysaufs_si_attr {
  34         struct attribute attr;
  35         int (*show)(struct seq_file *seq, struct super_block *sb);
  36 };
  37
  38 /* ---------------------------------------------------------------------- */
  39
  40 /* sysaufs.c */
  41 extern unsigned long sysaufs_si_mask;
  42 extern struct kset *sysaufs_kset;
  43 extern struct attribute *sysaufs_si_attrs[];
  44 int sysaufs_si_init(struct au_sbinfo *sbinfo);
  45 int __init sysaufs_init(void);
  46 void sysaufs_fin(void);
  47
  48 /* ---------------------------------------------------------------------- */
  49
  50 /* some people doesn't like to show a pointer in kernel */
  51 static inline unsigned long sysaufs_si_id(struct au_sbinfo *sbinfo)
  52 {
  53         return sysaufs_si_mask ^ (unsigned long)sbinfo;
  54 }
  55
  56 #define SysaufsSiNamePrefix     "si_"
  57 #define SysaufsSiNameLen        (sizeof(SysaufsSiNamePrefix) + 16)
  58 static inline void sysaufs_name(struct au_sbinfo *sbinfo, char *name)
  59 {
  60         snprintf(name, SysaufsSiNameLen, SysaufsSiNamePrefix "%lx",
  61                  sysaufs_si_id(sbinfo));
  62 }
  63
  64 struct au_branch;
  65 #ifdef CONFIG_SYSFS
  66 /* sysfs.c */
  67 extern struct attribute_group *sysaufs_attr_group;
  68
  69 int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb);
  70 ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
  71                          char *buf);
  72 long au_brinfo_ioctl(struct file *file, unsigned long arg);
  73 #ifdef CONFIG_COMPAT
  74 long au_brinfo_compat_ioctl(struct file *file, unsigned long arg);
  75 #endif
  76
  77 void sysaufs_br_init(struct au_branch *br);
  78 void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
  79 void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
  80
  81 #define sysaufs_brs_init()      do {} while (0)
  82
  83 #else
  84 #define sysaufs_attr_group      NULL
  85
  86 AuStubInt0(sysaufs_si_xi_path, struct seq_file *seq, struct super_block *sb)
  87 AuStub(ssize_t, sysaufs_si_show, return 0, struct kobject *kobj,
  88        struct attribute *attr, char *buf)
  89 AuStubVoid(sysaufs_br_init, struct au_branch *br)
  90 AuStubVoid(sysaufs_brs_add, struct super_block *sb, aufs_bindex_t bindex)
  91 AuStubVoid(sysaufs_brs_del, struct super_block *sb, aufs_bindex_t bindex)
  92
  93 static inline void sysaufs_brs_init(void)
  94 {
  95         sysaufs_brs = 0;
  96 }
  97
  98 #endif /* CONFIG_SYSFS */
  99
 100 #endif /* __KERNEL__ */
 101 #endif /* __SYSAUFS_H__ */