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1da177e4 LT |
1 | /* -*- 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. */ | |
57 | struct 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 | ||
77 | struct 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; | |
4dcd00b1 | 87 | atomic_t notified; |
1da177e4 LT |
88 | atomic_t wait_ctr; |
89 | }; | |
90 | ||
91 | #define AUTOFS_SBI_MAGIC 0x6d4a556d | |
92 | ||
93 | struct autofs_sb_info { | |
94 | u32 magic; | |
95 | struct file *pipe; | |
96 | pid_t oz_pgrp; | |
97 | int catatonic; | |
98 | int version; | |
99 | int sub_version; | |
100 | unsigned long exp_timeout; | |
101 | int reghost_enabled; | |
102 | int needs_reghost; | |
103 | struct super_block *sb; | |
104 | struct semaphore wq_sem; | |
3a9720ce | 105 | spinlock_t fs_lock; |
1da177e4 LT |
106 | struct autofs_wait_queue *queues; /* Wait queue pointer */ |
107 | }; | |
108 | ||
109 | static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb) | |
110 | { | |
111 | return (struct autofs_sb_info *)(sb->s_fs_info); | |
112 | } | |
113 | ||
114 | static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) | |
115 | { | |
116 | return (struct autofs_info *)(dentry->d_fsdata); | |
117 | } | |
118 | ||
119 | /* autofs4_oz_mode(): do we see the man behind the curtain? (The | |
120 | processes which do manipulations for us in user space sees the raw | |
121 | filesystem without "magic".) */ | |
122 | ||
123 | static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { | |
124 | return sbi->catatonic || process_group(current) == sbi->oz_pgrp; | |
125 | } | |
126 | ||
127 | /* Does a dentry have some pending activity? */ | |
128 | static inline int autofs4_ispending(struct dentry *dentry) | |
129 | { | |
130 | struct autofs_info *inf = autofs4_dentry_ino(dentry); | |
3a9720ce | 131 | int pending = 0; |
1da177e4 | 132 | |
3a9720ce IK |
133 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) |
134 | return 1; | |
135 | ||
136 | if (inf) { | |
137 | spin_lock(&inf->sbi->fs_lock); | |
138 | pending = inf->flags & AUTOFS_INF_EXPIRING; | |
139 | spin_unlock(&inf->sbi->fs_lock); | |
140 | } | |
141 | ||
142 | return pending; | |
1da177e4 LT |
143 | } |
144 | ||
145 | static inline void autofs4_copy_atime(struct file *src, struct file *dst) | |
146 | { | |
147 | dst->f_dentry->d_inode->i_atime = src->f_dentry->d_inode->i_atime; | |
148 | return; | |
149 | } | |
150 | ||
151 | struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *); | |
152 | void autofs4_free_ino(struct autofs_info *); | |
153 | ||
154 | /* Expiration */ | |
155 | int is_autofs4_dentry(struct dentry *); | |
156 | int autofs4_expire_run(struct super_block *, struct vfsmount *, | |
157 | struct autofs_sb_info *, | |
158 | struct autofs_packet_expire __user *); | |
159 | int autofs4_expire_multi(struct super_block *, struct vfsmount *, | |
160 | struct autofs_sb_info *, int __user *); | |
161 | ||
162 | /* Operations structures */ | |
163 | ||
164 | extern struct inode_operations autofs4_symlink_inode_operations; | |
165 | extern struct inode_operations autofs4_dir_inode_operations; | |
166 | extern struct inode_operations autofs4_root_inode_operations; | |
167 | extern struct file_operations autofs4_dir_operations; | |
168 | extern struct file_operations autofs4_root_operations; | |
169 | ||
170 | /* Initializing function */ | |
171 | ||
172 | int autofs4_fill_super(struct super_block *, void *, int); | |
173 | struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode); | |
174 | ||
175 | /* Queue management functions */ | |
176 | ||
177 | enum autofs_notify | |
178 | { | |
179 | NFY_NONE, | |
180 | NFY_MOUNT, | |
181 | NFY_EXPIRE | |
182 | }; | |
183 | ||
184 | int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify); | |
185 | int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int); | |
186 | void autofs4_catatonic_mode(struct autofs_sb_info *); | |
187 | ||
188 | static inline int simple_positive(struct dentry *dentry) | |
189 | { | |
190 | return dentry->d_inode && !d_unhashed(dentry); | |
191 | } | |
192 | ||
193 | static inline int simple_empty_nolock(struct dentry *dentry) | |
194 | { | |
195 | struct dentry *child; | |
196 | int ret = 0; | |
197 | ||
198 | list_for_each_entry(child, &dentry->d_subdirs, d_child) | |
199 | if (simple_positive(child)) | |
200 | goto out; | |
201 | ret = 1; | |
202 | out: | |
203 | return ret; | |
204 | } |