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
48 struct 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
62 struct autofs_dirhash {
63 struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
64 struct list_head expiry_head;
65 };
66
67 struct 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
80 struct 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
97 struct 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
autofs_sbi(struct super_block * sb)110 static 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
autofs_oz_mode(struct autofs_sb_info * sbi)119 static 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
125 void autofs_initialize_hash(struct autofs_dirhash *);
126 struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
127 void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
128 void autofs_hash_delete(struct autofs_dir_ent *);
129 struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
130 void autofs_hash_dputall(struct autofs_dirhash *);
131 void autofs_hash_nuke(struct autofs_dirhash *);
132
133 /* Expiration-handling functions */
134
135 void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
136 struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
137
138 /* Operations structures */
139
140 extern struct inode_operations autofs_root_inode_operations;
141 extern struct inode_operations autofs_symlink_inode_operations;
142 extern struct inode_operations autofs_dir_inode_operations;
143 extern struct file_operations autofs_root_operations;
144
145 /* Initializing function */
146
147 struct super_block *autofs_read_super(struct super_block *, void *,int);
148
149 /* Queue management functions */
150
151 int autofs_wait(struct autofs_sb_info *,struct qstr *);
152 int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
153 void autofs_catatonic_mode(struct autofs_sb_info *);
154
155 #ifdef DEBUG
156 void autofs_say(const char *name, int len);
157 #else
158 #define autofs_say(n,l) ((void)0)
159 #endif
160