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d6910058 | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
ebc921ca IK |
2 | /* |
3 | * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved | |
4 | * Copyright 2005-2006 Ian Kent <raven@themaw.net> | |
ebc921ca IK |
5 | */ |
6 | ||
7 | /* Internal header file for autofs */ | |
8 | ||
9 | #include <linux/auto_fs.h> | |
10 | #include <linux/auto_dev-ioctl.h> | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/time.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/wait.h> | |
17 | #include <linux/sched.h> | |
2c470475 | 18 | #include <linux/sched/signal.h> |
ebc921ca IK |
19 | #include <linux/mount.h> |
20 | #include <linux/namei.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/spinlock.h> | |
24 | #include <linux/list.h> | |
25 | #include <linux/completion.h> | |
6471e938 | 26 | #include <linux/file.h> |
0633da48 | 27 | #include <linux/magic.h> |
e6ec453b IK |
28 | #include <linux/fs_context.h> |
29 | #include <linux/fs_parser.h> | |
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30 | |
31 | /* This is the range of ioctl() numbers we claim as ours */ | |
32 | #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY | |
33 | #define AUTOFS_IOC_COUNT 32 | |
34 | ||
35 | #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION) | |
36 | #define AUTOFS_DEV_IOCTL_IOC_COUNT \ | |
37 | (AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD) | |
38 | ||
39 | #ifdef pr_fmt | |
40 | #undef pr_fmt | |
41 | #endif | |
42 | #define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__ | |
43 | ||
55f0d820 IK |
44 | extern struct file_system_type autofs_fs_type; |
45 | ||
ebc921ca IK |
46 | /* |
47 | * Unified info structure. This is pointed to by both the dentry and | |
48 | * inode structures. Each file in the filesystem has an instance of this | |
49 | * structure. It holds a reference to the dentry, so dentries are never | |
50 | * flushed while the file exists. All name lookups are dealt with at the | |
51 | * dentry level, although the filesystem can interfere in the validation | |
52 | * process. Readdir is implemented by traversing the dentry lists. | |
53 | */ | |
54 | struct autofs_info { | |
55 | struct dentry *dentry; | |
ebc921ca IK |
56 | int flags; |
57 | ||
58 | struct completion expire_complete; | |
59 | ||
60 | struct list_head active; | |
ebc921ca IK |
61 | |
62 | struct list_head expiring; | |
63 | ||
64 | struct autofs_sb_info *sbi; | |
65 | unsigned long last_used; | |
850d71ac | 66 | int count; |
ebc921ca IK |
67 | |
68 | kuid_t uid; | |
69 | kgid_t gid; | |
ce285c26 | 70 | struct rcu_head rcu; |
ebc921ca IK |
71 | }; |
72 | ||
73 | #define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */ | |
74 | #define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered | |
75 | * for expiry, so RCU_walk is | |
76 | * not permitted. If it progresses to | |
77 | * actual expiry attempt, the flag is | |
78 | * not cleared when EXPIRING is set - | |
79 | * in that case it gets cleared only | |
80 | * when it comes to clearing EXPIRING. | |
81 | */ | |
82 | #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */ | |
83 | ||
84 | struct autofs_wait_queue { | |
85 | wait_queue_head_t queue; | |
86 | struct autofs_wait_queue *next; | |
87 | autofs_wqt_t wait_queue_token; | |
88 | /* We use the following to see what we are waiting for */ | |
89 | struct qstr name; | |
2be7828c | 90 | u32 offset; |
ebc921ca IK |
91 | u32 dev; |
92 | u64 ino; | |
93 | kuid_t uid; | |
94 | kgid_t gid; | |
95 | pid_t pid; | |
96 | pid_t tgid; | |
97 | /* This is for status reporting upon return */ | |
98 | int status; | |
99 | unsigned int wait_ctr; | |
100 | }; | |
101 | ||
102 | #define AUTOFS_SBI_MAGIC 0x6d4a556d | |
103 | ||
9d8719a4 | 104 | #define AUTOFS_SBI_CATATONIC 0x0001 |
f5162216 | 105 | #define AUTOFS_SBI_STRICTEXPIRE 0x0002 |
60d6d04c | 106 | #define AUTOFS_SBI_IGNORE 0x0004 |
9d8719a4 | 107 | |
ebc921ca IK |
108 | struct autofs_sb_info { |
109 | u32 magic; | |
110 | int pipefd; | |
111 | struct file *pipe; | |
112 | struct pid *oz_pgrp; | |
ebc921ca IK |
113 | int version; |
114 | int sub_version; | |
115 | int min_proto; | |
116 | int max_proto; | |
9d8719a4 | 117 | unsigned int flags; |
ebc921ca IK |
118 | unsigned long exp_timeout; |
119 | unsigned int type; | |
120 | struct super_block *sb; | |
121 | struct mutex wq_mutex; | |
122 | struct mutex pipe_mutex; | |
123 | spinlock_t fs_lock; | |
124 | struct autofs_wait_queue *queues; /* Wait queue pointer */ | |
125 | spinlock_t lookup_lock; | |
126 | struct list_head active_list; | |
127 | struct list_head expiring_list; | |
128 | struct rcu_head rcu; | |
129 | }; | |
130 | ||
131 | static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb) | |
132 | { | |
55f0d820 | 133 | return (struct autofs_sb_info *)(sb->s_fs_info); |
ebc921ca IK |
134 | } |
135 | ||
136 | static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry) | |
137 | { | |
138 | return (struct autofs_info *)(dentry->d_fsdata); | |
139 | } | |
140 | ||
141 | /* autofs_oz_mode(): do we see the man behind the curtain? (The | |
142 | * processes which do manipulations for us in user space sees the raw | |
143 | * filesystem without "magic".) | |
144 | */ | |
145 | static inline int autofs_oz_mode(struct autofs_sb_info *sbi) | |
146 | { | |
9d8719a4 IK |
147 | return ((sbi->flags & AUTOFS_SBI_CATATONIC) || |
148 | task_pgrp(current) == sbi->oz_pgrp); | |
ebc921ca IK |
149 | } |
150 | ||
a4a87303 IK |
151 | static inline bool autofs_empty(struct autofs_info *ino) |
152 | { | |
153 | return ino->count < 2; | |
154 | } | |
155 | ||
ebc921ca IK |
156 | struct inode *autofs_get_inode(struct super_block *, umode_t); |
157 | void autofs_free_ino(struct autofs_info *); | |
158 | ||
159 | /* Expiration */ | |
160 | int is_autofs_dentry(struct dentry *); | |
161 | int autofs_expire_wait(const struct path *path, int rcu_walk); | |
162 | int autofs_expire_run(struct super_block *, struct vfsmount *, | |
163 | struct autofs_sb_info *, | |
164 | struct autofs_packet_expire __user *); | |
165 | int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, | |
e5c85e1f | 166 | struct autofs_sb_info *sbi, unsigned int how); |
ebc921ca IK |
167 | int autofs_expire_multi(struct super_block *, struct vfsmount *, |
168 | struct autofs_sb_info *, int __user *); | |
ebc921ca IK |
169 | |
170 | /* Device node initialization */ | |
171 | ||
172 | int autofs_dev_ioctl_init(void); | |
173 | void autofs_dev_ioctl_exit(void); | |
174 | ||
175 | /* Operations structures */ | |
176 | ||
177 | extern const struct inode_operations autofs_symlink_inode_operations; | |
178 | extern const struct inode_operations autofs_dir_inode_operations; | |
179 | extern const struct file_operations autofs_dir_operations; | |
180 | extern const struct file_operations autofs_root_operations; | |
181 | extern const struct dentry_operations autofs_dentry_operations; | |
182 | ||
183 | /* VFS automount flags management functions */ | |
184 | static inline void __managed_dentry_set_managed(struct dentry *dentry) | |
185 | { | |
186 | dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT); | |
187 | } | |
188 | ||
189 | static inline void managed_dentry_set_managed(struct dentry *dentry) | |
190 | { | |
191 | spin_lock(&dentry->d_lock); | |
192 | __managed_dentry_set_managed(dentry); | |
193 | spin_unlock(&dentry->d_lock); | |
194 | } | |
195 | ||
196 | static inline void __managed_dentry_clear_managed(struct dentry *dentry) | |
197 | { | |
198 | dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT); | |
199 | } | |
200 | ||
201 | static inline void managed_dentry_clear_managed(struct dentry *dentry) | |
202 | { | |
203 | spin_lock(&dentry->d_lock); | |
204 | __managed_dentry_clear_managed(dentry); | |
205 | spin_unlock(&dentry->d_lock); | |
206 | } | |
207 | ||
208 | /* Initializing function */ | |
209 | ||
e6ec453b IK |
210 | extern const struct fs_parameter_spec autofs_param_specs[]; |
211 | int autofs_init_fs_context(struct fs_context *fc); | |
ebc921ca IK |
212 | struct autofs_info *autofs_new_ino(struct autofs_sb_info *); |
213 | void autofs_clean_ino(struct autofs_info *); | |
214 | ||
bc69fdde | 215 | static inline int autofs_check_pipe(struct file *pipe) |
ebc921ca IK |
216 | { |
217 | if (!(pipe->f_mode & FMODE_CAN_WRITE)) | |
218 | return -EINVAL; | |
219 | if (!S_ISFIFO(file_inode(pipe)->i_mode)) | |
220 | return -EINVAL; | |
bc69fdde IK |
221 | return 0; |
222 | } | |
223 | ||
d3c50061 | 224 | static inline void autofs_set_packet_pipe_flags(struct file *pipe) |
bc69fdde | 225 | { |
ebc921ca IK |
226 | /* We want a packet pipe */ |
227 | pipe->f_flags |= O_DIRECT; | |
660c9fc7 N |
228 | /* We don't expect -EAGAIN */ |
229 | pipe->f_flags &= ~O_NONBLOCK; | |
d3c50061 IK |
230 | } |
231 | ||
232 | static inline int autofs_prepare_pipe(struct file *pipe) | |
233 | { | |
234 | int ret = autofs_check_pipe(pipe); | |
235 | if (ret < 0) | |
236 | return ret; | |
237 | autofs_set_packet_pipe_flags(pipe); | |
ebc921ca IK |
238 | return 0; |
239 | } | |
240 | ||
241 | /* Queue management functions */ | |
242 | ||
243 | int autofs_wait(struct autofs_sb_info *, | |
244 | const struct path *, enum autofs_notify); | |
245 | int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int); | |
246 | void autofs_catatonic_mode(struct autofs_sb_info *); | |
247 | ||
248 | static inline u32 autofs_get_dev(struct autofs_sb_info *sbi) | |
249 | { | |
250 | return new_encode_dev(sbi->sb->s_dev); | |
251 | } | |
252 | ||
253 | static inline u64 autofs_get_ino(struct autofs_sb_info *sbi) | |
254 | { | |
255 | return d_inode(sbi->sb->s_root)->i_ino; | |
256 | } | |
257 | ||
258 | static inline void __autofs_add_expiring(struct dentry *dentry) | |
259 | { | |
260 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
261 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
262 | ||
263 | if (ino) { | |
264 | if (list_empty(&ino->expiring)) | |
265 | list_add(&ino->expiring, &sbi->expiring_list); | |
266 | } | |
267 | } | |
268 | ||
269 | static inline void autofs_add_expiring(struct dentry *dentry) | |
270 | { | |
271 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
272 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
273 | ||
274 | if (ino) { | |
275 | spin_lock(&sbi->lookup_lock); | |
276 | if (list_empty(&ino->expiring)) | |
277 | list_add(&ino->expiring, &sbi->expiring_list); | |
278 | spin_unlock(&sbi->lookup_lock); | |
279 | } | |
280 | } | |
281 | ||
282 | static inline void autofs_del_expiring(struct dentry *dentry) | |
283 | { | |
284 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
285 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
286 | ||
287 | if (ino) { | |
288 | spin_lock(&sbi->lookup_lock); | |
289 | if (!list_empty(&ino->expiring)) | |
290 | list_del_init(&ino->expiring); | |
291 | spin_unlock(&sbi->lookup_lock); | |
292 | } | |
293 | } | |
294 | ||
295 | void autofs_kill_sb(struct super_block *); |