1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * linux/fs/autofs/autofs_i.h
4 *
5 *   Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
6 *
7 * This file is part of the Linux kernel and is made available under
8 * the terms of the GNU General Public License, version 2, or at your
9 * option, any later version, incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/* Internal header file for autofs */
14
15#include <linux/auto_fs.h>
16
17/* This is the range of ioctl() numbers we claim as ours */
18#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
19#define AUTOFS_IOC_COUNT     32
20
21#include <linux/kernel.h>
22#include <linux/slab.h>
23#include <linux/sched.h>
24#include <linux/string.h>
25#include <linux/wait.h>
26#include <asm/uaccess.h>
27
28#ifdef DEBUG
29#define DPRINTK(D) (printk D)
30#else
31#define DPRINTK(D) ((void)0)
32#endif
33
34#define AUTOFS_SUPER_MAGIC 0x0187
35
36/*
37 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
38 * kernel will keep the negative response cached for up to the time given
39 * here, although the time can be shorter if the kernel throws the dcache
40 * entry away.  This probably should be settable from user space.
41 */
42#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ)	/* 1 minute */
43
44/* Structures associated with the root directory hash table */
45
46#define AUTOFS_HASH_SIZE 67
47
48struct autofs_dir_ent {
49	int hash;
50	char *name;
51	int len;
52	ino_t ino;
53	struct dentry *dentry;
54	/* Linked list of entries */
55	struct autofs_dir_ent *next;
56	struct autofs_dir_ent **back;
57	/* The following entries are for the expiry system */
58	unsigned long last_usage;
59	struct list_head exp;
60};
61
62struct autofs_dirhash {
63	struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
64	struct list_head expiry_head;
65};
66
67struct autofs_wait_queue {
68	wait_queue_head_t queue;
69	struct autofs_wait_queue *next;
70	autofs_wqt_t wait_queue_token;
71	/* We use the following to see what we are waiting for */
72	int hash;
73	int len;
74	char *name;
75	/* This is for status reporting upon return */
76	int status;
77	int wait_ctr;
78};
79
80struct autofs_symlink {
81	char *data;
82	int len;
83	time_t mtime;
84};
85
86#define AUTOFS_MAX_SYMLINKS 256
87
88#define AUTOFS_ROOT_INO      1
89#define AUTOFS_FIRST_SYMLINK 2
90#define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)
91
92#define AUTOFS_SYMLINK_BITMAP_LEN \
93	((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8))
94
95#define AUTOFS_SBI_MAGIC 0x6d4a556d
96
97struct autofs_sb_info {
98	u32 magic;
99	struct file *pipe;
100	pid_t oz_pgrp;
101	int catatonic;
102	unsigned long exp_timeout;
103	ino_t next_dir_ino;
104	struct autofs_wait_queue *queues; /* Wait queue pointer */
105	struct autofs_dirhash dirhash; /* Root directory hash */
106	struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
107	unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
108};
109
110static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
111{
112	return (struct autofs_sb_info *)(sb->u.generic_sbp);
113}
114
115/* autofs_oz_mode(): do we see the man behind the curtain?  (The
116   processes which do manipulations for us in user space sees the raw
117   filesystem without "magic".) */
118
119static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
120	return sbi->catatonic || current->pgrp == sbi->oz_pgrp;
121}
122
123/* Hash operations */
124
125void autofs_initialize_hash(struct autofs_dirhash *);
126struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
127void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
128void autofs_hash_delete(struct autofs_dir_ent *);
129struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
130void autofs_hash_dputall(struct autofs_dirhash *);
131void autofs_hash_nuke(struct autofs_dirhash *);
132
133/* Expiration-handling functions */
134
135void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
136struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
137
138/* Operations structures */
139
140extern struct inode_operations autofs_root_inode_operations;
141extern struct inode_operations autofs_symlink_inode_operations;
142extern struct inode_operations autofs_dir_inode_operations;
143extern struct file_operations autofs_root_operations;
144
145/* Initializing function */
146
147struct super_block *autofs_read_super(struct super_block *, void *,int);
148
149/* Queue management functions */
150
151int autofs_wait(struct autofs_sb_info *,struct qstr *);
152int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
153void autofs_catatonic_mode(struct autofs_sb_info *);
154
155#ifdef DEBUG
156void autofs_say(const char *name, int len);
157#else
158#define autofs_say(n,l) ((void)0)
159#endif
160