Root/fs/autofs/autofs_i.h

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/time.h>
24#include <linux/string.h>
25#include <linux/wait.h>
26#include <linux/dcache.h>
27#include <linux/namei.h>
28#include <linux/mount.h>
29#include <linux/sched.h>
30
31#include <asm/current.h>
32#include <asm/uaccess.h>
33
34#ifdef DEBUG
35#define DPRINTK(D) (printk D)
36#else
37#define DPRINTK(D) ((void)0)
38#endif
39
40/*
41 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
42 * kernel will keep the negative response cached for up to the time given
43 * here, although the time can be shorter if the kernel throws the dcache
44 * entry away. This probably should be settable from user space.
45 */
46#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ) /* 1 minute */
47
48/* Structures associated with the root directory hash table */
49
50#define AUTOFS_HASH_SIZE 67
51
52struct autofs_dir_ent {
53    int hash;
54    char *name;
55    int len;
56    ino_t ino;
57    struct dentry *dentry;
58    /* Linked list of entries */
59    struct autofs_dir_ent *next;
60    struct autofs_dir_ent **back;
61    /* The following entries are for the expiry system */
62    unsigned long last_usage;
63    struct list_head exp;
64};
65
66struct autofs_dirhash {
67    struct autofs_dir_ent *h[AUTOFS_HASH_SIZE];
68    struct list_head expiry_head;
69};
70
71struct autofs_wait_queue {
72    wait_queue_head_t queue;
73    struct autofs_wait_queue *next;
74    autofs_wqt_t wait_queue_token;
75    /* We use the following to see what we are waiting for */
76    int hash;
77    int len;
78    char *name;
79    /* This is for status reporting upon return */
80    int status;
81    int wait_ctr;
82};
83
84struct autofs_symlink {
85    char *data;
86    int len;
87    time_t mtime;
88};
89
90#define AUTOFS_MAX_SYMLINKS 256
91
92#define AUTOFS_ROOT_INO 1
93#define AUTOFS_FIRST_SYMLINK 2
94#define AUTOFS_FIRST_DIR_INO (AUTOFS_FIRST_SYMLINK+AUTOFS_MAX_SYMLINKS)
95
96#define AUTOFS_SYMLINK_BITMAP_LEN \
97    ((AUTOFS_MAX_SYMLINKS+((sizeof(long)*1)-1))/(sizeof(long)*8))
98
99#define AUTOFS_SBI_MAGIC 0x6d4a556d
100
101struct autofs_sb_info {
102    u32 magic;
103    struct file *pipe;
104    struct pid *oz_pgrp;
105    int catatonic;
106    struct super_block *sb;
107    unsigned long exp_timeout;
108    ino_t next_dir_ino;
109    struct autofs_wait_queue *queues; /* Wait queue pointer */
110    struct autofs_dirhash dirhash; /* Root directory hash */
111    struct autofs_symlink symlink[AUTOFS_MAX_SYMLINKS];
112    unsigned long symlink_bitmap[AUTOFS_SYMLINK_BITMAP_LEN];
113};
114
115static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
116{
117    return (struct autofs_sb_info *)(sb->s_fs_info);
118}
119
120/* autofs_oz_mode(): do we see the man behind the curtain? (The
121   processes which do manipulations for us in user space sees the raw
122   filesystem without "magic".) */
123
124static inline int autofs_oz_mode(struct autofs_sb_info *sbi) {
125    return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
126}
127
128/* Hash operations */
129
130void autofs_initialize_hash(struct autofs_dirhash *);
131struct autofs_dir_ent *autofs_hash_lookup(const struct autofs_dirhash *,struct qstr *);
132void autofs_hash_insert(struct autofs_dirhash *,struct autofs_dir_ent *);
133void autofs_hash_delete(struct autofs_dir_ent *);
134struct autofs_dir_ent *autofs_hash_enum(const struct autofs_dirhash *,off_t *,struct autofs_dir_ent *);
135void autofs_hash_dputall(struct autofs_dirhash *);
136void autofs_hash_nuke(struct autofs_sb_info *);
137
138/* Expiration-handling functions */
139
140void autofs_update_usage(struct autofs_dirhash *,struct autofs_dir_ent *);
141struct autofs_dir_ent *autofs_expire(struct super_block *,struct autofs_sb_info *, struct vfsmount *mnt);
142
143/* Operations structures */
144
145extern const struct inode_operations autofs_root_inode_operations;
146extern const struct inode_operations autofs_symlink_inode_operations;
147extern const struct file_operations autofs_root_operations;
148
149/* Initializing function */
150
151int autofs_fill_super(struct super_block *, void *, int);
152void autofs_kill_sb(struct super_block *sb);
153struct inode *autofs_iget(struct super_block *, unsigned long);
154
155/* Queue management functions */
156
157int autofs_wait(struct autofs_sb_info *,struct qstr *);
158int autofs_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
159void autofs_catatonic_mode(struct autofs_sb_info *);
160
161#ifdef DEBUG
162void autofs_say(const char *name, int len);
163#else
164#define autofs_say(n,l) ((void)0)
165#endif
166

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