summaryrefslogtreecommitdiffstats
path: root/fs/autofs/autofs_i.h
blob: 9dc40922a441a8e8b541aad17108f03e1b7cd7b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/* -*- linux-c -*- ------------------------------------------------------- *
 *   
 * linux/fs/autofs/autofs_i.h
 *
 *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
 *
 * This file is part of the Linux kernel and is made available under
 * the terms of the GNU General Public License, version 2, or at your
 * option, any later version, incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/* Internal header file for autofs */

#include <linux/auto_fs.h>

/* This is the range of ioctl() numbers we claim as ours */
#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
#define AUTOFS_IOC_COUNT     32

#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/wait.h>
#include <asm/uaccess.h>

#ifdef DEBUG
#define DPRINTK(D) (printk D)
#else
#define DPRINTK(D) ((void)0)
#endif

#define AUTOFS_SUPER_MAGIC 0x0187

/*
 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
 * kernel will keep the negative response cached for up to the time given
 * here, although the time can be shorter if the kernel throws the dcache
 * entry away.  This probably should be settable from user space.
 */
#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ)	/* 1 minute */

/* Structures associated with the root directory hash table */

#define AUTOFS_HASH_SIZE 67

struct autofs_dir_ent {
	int hash;
	char *name;
	int len;
	ino_t ino;
	struct dentry *dentry;
	/* Linked list of entries */
	struct autofs_dir_ent *next;
	struct autofs_dir_ent **back;
	/* The following entries are for the expiry system */
	unsigned long last_usage;
	struct list_head exp;
};

struct autofs_dirhash {
	struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
	struct list_head expiry_head;
};

struct autofs_wait_queue {
	wait_queue_head_t queue;
	struct autofs_wait_queue *next;
	autofs_wqt_t wait_queue_token;
	/* We use the following to see what we are waiting for */
	int hash;
	int len;
	char *name;
	/* This is for status reporting upon return */
	int status;
	int wait_ctr;
};

struct autofs_symlink {
	char *data;
	int len;
	time_t mtime;
};

#define AUTOFS_MAX_SYMLINKS 256

#define AUTOFS_ROOT_INO      1
#define AUTOFS_FIRST_SYMLINK 2
#define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)

#define AUTOFS_SYMLINK_BITMAP_LEN ((AUTOFS_MAX_SYMLINKS+31)/32)

#define AUTOFS_SBI_MAGIC 0x6d4a556d

struct autofs_sb_info {
	u32 magic;
	struct file *pipe;
	pid_t oz_pgrp;
	int catatonic;
	unsigned long exp_timeout;
	ino_t next_dir_ino;
	struct autofs_wait_queue *queues; /* Wait queue pointer */
	struct autofs_dirhash dirhash; /* Root directory hash */
	struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
	u32 symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
};

extern inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
{
	return (struct autofs_sb_info *)(sb->u.generic_sbp);
}

/* autofs_oz_mode(): do we see the man behind the curtain?  (The
   processes which do manipulations for us in user space sees the raw
   filesystem without "magic".) */

static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
}

/* Hash operations */

void autofs_initialize_hash(struct autofs_dirhash *);
struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
void autofs_hash_delete(struct autofs_dir_ent *);
struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
void autofs_hash_dputall(struct autofs_dirhash *);
void autofs_hash_nuke(struct autofs_dirhash *);

/* Expiration-handling functions */

void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);

/* Operations structures */

extern struct inode_operations autofs_root_inode_operations;
extern struct inode_operations autofs_symlink_inode_operations;
extern struct inode_operations autofs_dir_inode_operations;
extern struct file_operations autofs_root_operations;
extern struct file_operations autofs_dir_operations;

/* Initializing function */

struct super_block *autofs_read_super(struct super_block *, void *,int);

/* Queue management functions */

int autofs_wait(struct autofs_sb_info *,struct qstr *);
int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
void autofs_catatonic_mode(struct autofs_sb_info *);

#ifdef DEBUG
void autofs_say(const char *name, int len);
#else
#define autofs_say(n,l) ((void)0)
#endif