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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- 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_fs4.h>
16#include <linux/list.h>
17
18/* This is the range of ioctl() numbers we claim as ours */
19#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
20#define AUTOFS_IOC_COUNT 32
21
22#include <linux/kernel.h>
23#include <linux/slab.h>
24#include <linux/time.h>
25#include <linux/string.h>
26#include <linux/wait.h>
27#include <linux/sched.h>
28#include <linux/mount.h>
29#include <linux/namei.h>
30#include <asm/current.h>
31#include <asm/uaccess.h>
32
33/* #define DEBUG */
34
35#ifdef DEBUG
36#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0)
37#else
38#define DPRINTK(fmt,args...) do {} while(0)
39#endif
40
41#define AUTOFS_SUPER_MAGIC 0x0187
42
43/*
44 * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the
45 * kernel will keep the negative response cached for up to the time given
46 * here, although the time can be shorter if the kernel throws the dcache
47 * entry away. This probably should be settable from user space.
48 */
49#define AUTOFS_NEGATIVE_TIMEOUT (60*HZ) /* 1 minute */
50
51/* Unified info structure. This is pointed to by both the dentry and
52 inode structures. Each file in the filesystem has an instance of this
53 structure. It holds a reference to the dentry, so dentries are never
54 flushed while the file exists. All name lookups are dealt with at the
55 dentry level, although the filesystem can interfere in the validation
56 process. Readdir is implemented by traversing the dentry lists. */
57struct autofs_info {
58 struct dentry *dentry;
59 struct inode *inode;
60
61 int flags;
62
63 struct autofs_sb_info *sbi;
64 unsigned long last_used;
65
66 mode_t mode;
67 size_t size;
68
69 void (*free)(struct autofs_info *);
70 union {
71 const char *symlink;
72 } u;
73};
74
75#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
76
77struct autofs_wait_queue {
78 wait_queue_head_t queue;
79 struct autofs_wait_queue *next;
80 autofs_wqt_t wait_queue_token;
81 /* We use the following to see what we are waiting for */
82 int hash;
83 int len;
84 char *name;
85 /* This is for status reporting upon return */
86 int status;
Ian Kent4dcd00b2005-05-01 08:59:16 -070087 atomic_t notified;
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 atomic_t wait_ctr;
89};
90
91#define AUTOFS_SBI_MAGIC 0x6d4a556d
92
93struct autofs_sb_info {
94 u32 magic;
Ian Kent104e49f2005-07-27 11:43:45 -070095 struct dentry *root;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 struct file *pipe;
97 pid_t oz_pgrp;
98 int catatonic;
99 int version;
100 int sub_version;
101 unsigned long exp_timeout;
102 int reghost_enabled;
103 int needs_reghost;
104 struct super_block *sb;
105 struct semaphore wq_sem;
Ian Kent3a9720c2005-05-01 08:59:17 -0700106 spinlock_t fs_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 struct autofs_wait_queue *queues; /* Wait queue pointer */
108};
109
110static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
111{
112 return (struct autofs_sb_info *)(sb->s_fs_info);
113}
114
115static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
116{
117 return (struct autofs_info *)(dentry->d_fsdata);
118}
119
120/* autofs4_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 autofs4_oz_mode(struct autofs_sb_info *sbi) {
125 return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
126}
127
128/* Does a dentry have some pending activity? */
129static inline int autofs4_ispending(struct dentry *dentry)
130{
131 struct autofs_info *inf = autofs4_dentry_ino(dentry);
Ian Kent3a9720c2005-05-01 08:59:17 -0700132 int pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Ian Kent3a9720c2005-05-01 08:59:17 -0700134 if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
135 return 1;
136
137 if (inf) {
138 spin_lock(&inf->sbi->fs_lock);
139 pending = inf->flags & AUTOFS_INF_EXPIRING;
140 spin_unlock(&inf->sbi->fs_lock);
141 }
142
143 return pending;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144}
145
146static inline void autofs4_copy_atime(struct file *src, struct file *dst)
147{
148 dst->f_dentry->d_inode->i_atime = src->f_dentry->d_inode->i_atime;
149 return;
150}
151
152struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
153void autofs4_free_ino(struct autofs_info *);
154
155/* Expiration */
156int is_autofs4_dentry(struct dentry *);
157int autofs4_expire_run(struct super_block *, struct vfsmount *,
158 struct autofs_sb_info *,
159 struct autofs_packet_expire __user *);
160int autofs4_expire_multi(struct super_block *, struct vfsmount *,
161 struct autofs_sb_info *, int __user *);
162
163/* Operations structures */
164
165extern struct inode_operations autofs4_symlink_inode_operations;
166extern struct inode_operations autofs4_dir_inode_operations;
167extern struct inode_operations autofs4_root_inode_operations;
168extern struct file_operations autofs4_dir_operations;
169extern struct file_operations autofs4_root_operations;
170
171/* Initializing function */
172
173int autofs4_fill_super(struct super_block *, void *, int);
174struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
175
176/* Queue management functions */
177
178enum autofs_notify
179{
180 NFY_NONE,
181 NFY_MOUNT,
182 NFY_EXPIRE
183};
184
185int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
186int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
187void autofs4_catatonic_mode(struct autofs_sb_info *);
188
Ian Kent9b1e3af2005-06-21 17:16:38 -0700189static inline int autofs4_follow_mount(struct vfsmount **mnt, struct dentry **dentry)
190{
191 int res = 0;
192
193 while (d_mountpoint(*dentry)) {
194 int followed = follow_down(mnt, dentry);
195 if (!followed)
196 break;
197 res = 1;
198 }
199 return res;
200}
201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202static inline int simple_positive(struct dentry *dentry)
203{
204 return dentry->d_inode && !d_unhashed(dentry);
205}
206
207static inline int simple_empty_nolock(struct dentry *dentry)
208{
209 struct dentry *child;
210 int ret = 0;
211
212 list_for_each_entry(child, &dentry->d_subdirs, d_child)
213 if (simple_positive(child))
214 goto out;
215 ret = 1;
216out:
217 return ret;
218}