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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> | |
1d5599e3 | 16 | #include <linux/mutex.h> |
1da177e4 LT |
17 | #include <linux/list.h> |
18 | ||
19 | /* This is the range of ioctl() numbers we claim as ours */ | |
20 | #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY | |
21 | #define AUTOFS_IOC_COUNT 32 | |
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/time.h> | |
26 | #include <linux/string.h> | |
27 | #include <linux/wait.h> | |
28 | #include <linux/sched.h> | |
29 | #include <linux/mount.h> | |
30 | #include <linux/namei.h> | |
31 | #include <asm/current.h> | |
32 | #include <asm/uaccess.h> | |
33 | ||
34 | /* #define DEBUG */ | |
35 | ||
36 | #ifdef DEBUG | |
37 | #define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0) | |
38 | #else | |
39 | #define DPRINTK(fmt,args...) do {} while(0) | |
40 | #endif | |
41 | ||
42 | #define AUTOFS_SUPER_MAGIC 0x0187 | |
43 | ||
44 | /* | |
45 | * If the daemon returns a negative response (AUTOFS_IOC_FAIL) then the | |
46 | * kernel will keep the negative response cached for up to the time given | |
47 | * here, although the time can be shorter if the kernel throws the dcache | |
48 | * entry away. This probably should be settable from user space. | |
49 | */ | |
50 | #define AUTOFS_NEGATIVE_TIMEOUT (60*HZ) /* 1 minute */ | |
51 | ||
52 | /* Unified info structure. This is pointed to by both the dentry and | |
53 | inode structures. Each file in the filesystem has an instance of this | |
54 | structure. It holds a reference to the dentry, so dentries are never | |
55 | flushed while the file exists. All name lookups are dealt with at the | |
56 | dentry level, although the filesystem can interfere in the validation | |
57 | process. Readdir is implemented by traversing the dentry lists. */ | |
58 | struct autofs_info { | |
59 | struct dentry *dentry; | |
60 | struct inode *inode; | |
61 | ||
62 | int flags; | |
63 | ||
64 | struct autofs_sb_info *sbi; | |
65 | unsigned long last_used; | |
66 | ||
67 | mode_t mode; | |
68 | size_t size; | |
69 | ||
70 | void (*free)(struct autofs_info *); | |
71 | union { | |
72 | const char *symlink; | |
73 | } u; | |
74 | }; | |
75 | ||
76 | #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */ | |
77 | ||
78 | struct autofs_wait_queue { | |
79 | wait_queue_head_t queue; | |
80 | struct autofs_wait_queue *next; | |
81 | autofs_wqt_t wait_queue_token; | |
82 | /* We use the following to see what we are waiting for */ | |
83 | int hash; | |
84 | int len; | |
85 | char *name; | |
86 | /* This is for status reporting upon return */ | |
87 | int status; | |
4dcd00b1 | 88 | atomic_t notified; |
1da177e4 LT |
89 | atomic_t wait_ctr; |
90 | }; | |
91 | ||
92 | #define AUTOFS_SBI_MAGIC 0x6d4a556d | |
93 | ||
94 | struct autofs_sb_info { | |
95 | u32 magic; | |
104e49fc | 96 | struct dentry *root; |
1da177e4 LT |
97 | struct file *pipe; |
98 | pid_t oz_pgrp; | |
99 | int catatonic; | |
100 | int version; | |
101 | int sub_version; | |
102 | unsigned long exp_timeout; | |
103 | int reghost_enabled; | |
104 | int needs_reghost; | |
105 | struct super_block *sb; | |
1d5599e3 | 106 | struct mutex wq_mutex; |
3a9720ce | 107 | spinlock_t fs_lock; |
1da177e4 LT |
108 | struct autofs_wait_queue *queues; /* Wait queue pointer */ |
109 | }; | |
110 | ||
111 | static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb) | |
112 | { | |
113 | return (struct autofs_sb_info *)(sb->s_fs_info); | |
114 | } | |
115 | ||
116 | static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) | |
117 | { | |
118 | return (struct autofs_info *)(dentry->d_fsdata); | |
119 | } | |
120 | ||
121 | /* autofs4_oz_mode(): do we see the man behind the curtain? (The | |
122 | processes which do manipulations for us in user space sees the raw | |
123 | filesystem without "magic".) */ | |
124 | ||
125 | static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { | |
126 | return sbi->catatonic || process_group(current) == sbi->oz_pgrp; | |
127 | } | |
128 | ||
129 | /* Does a dentry have some pending activity? */ | |
130 | static inline int autofs4_ispending(struct dentry *dentry) | |
131 | { | |
132 | struct autofs_info *inf = autofs4_dentry_ino(dentry); | |
3a9720ce | 133 | int pending = 0; |
1da177e4 | 134 | |
3a9720ce IK |
135 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) |
136 | return 1; | |
137 | ||
138 | if (inf) { | |
139 | spin_lock(&inf->sbi->fs_lock); | |
140 | pending = inf->flags & AUTOFS_INF_EXPIRING; | |
141 | spin_unlock(&inf->sbi->fs_lock); | |
142 | } | |
143 | ||
144 | return pending; | |
1da177e4 LT |
145 | } |
146 | ||
147 | static inline void autofs4_copy_atime(struct file *src, struct file *dst) | |
148 | { | |
149 | dst->f_dentry->d_inode->i_atime = src->f_dentry->d_inode->i_atime; | |
150 | return; | |
151 | } | |
152 | ||
153 | struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *); | |
154 | void autofs4_free_ino(struct autofs_info *); | |
155 | ||
156 | /* Expiration */ | |
157 | int is_autofs4_dentry(struct dentry *); | |
158 | int autofs4_expire_run(struct super_block *, struct vfsmount *, | |
159 | struct autofs_sb_info *, | |
160 | struct autofs_packet_expire __user *); | |
161 | int autofs4_expire_multi(struct super_block *, struct vfsmount *, | |
162 | struct autofs_sb_info *, int __user *); | |
163 | ||
164 | /* Operations structures */ | |
165 | ||
166 | extern struct inode_operations autofs4_symlink_inode_operations; | |
167 | extern struct inode_operations autofs4_dir_inode_operations; | |
168 | extern struct inode_operations autofs4_root_inode_operations; | |
169 | extern struct file_operations autofs4_dir_operations; | |
170 | extern struct file_operations autofs4_root_operations; | |
171 | ||
172 | /* Initializing function */ | |
173 | ||
174 | int autofs4_fill_super(struct super_block *, void *, int); | |
175 | struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode); | |
176 | ||
177 | /* Queue management functions */ | |
178 | ||
179 | enum autofs_notify | |
180 | { | |
181 | NFY_NONE, | |
182 | NFY_MOUNT, | |
183 | NFY_EXPIRE | |
184 | }; | |
185 | ||
186 | int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify); | |
187 | int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int); | |
188 | void autofs4_catatonic_mode(struct autofs_sb_info *); | |
189 | ||
9b1e3afd IK |
190 | static inline int autofs4_follow_mount(struct vfsmount **mnt, struct dentry **dentry) |
191 | { | |
192 | int res = 0; | |
193 | ||
194 | while (d_mountpoint(*dentry)) { | |
195 | int followed = follow_down(mnt, dentry); | |
196 | if (!followed) | |
197 | break; | |
198 | res = 1; | |
199 | } | |
200 | return res; | |
201 | } | |
202 | ||
1da177e4 LT |
203 | static inline int simple_positive(struct dentry *dentry) |
204 | { | |
205 | return dentry->d_inode && !d_unhashed(dentry); | |
206 | } | |
207 | ||
208 | static inline int simple_empty_nolock(struct dentry *dentry) | |
209 | { | |
210 | struct dentry *child; | |
211 | int ret = 0; | |
212 | ||
5160ee6f | 213 | list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) |
1da177e4 LT |
214 | if (simple_positive(child)) |
215 | goto out; | |
216 | ret = 1; | |
217 | out: | |
218 | return ret; | |
219 | } |