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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> |
ebc921ca IK |
28 | |
29 | /* This is the range of ioctl() numbers we claim as ours */ | |
30 | #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY | |
31 | #define AUTOFS_IOC_COUNT 32 | |
32 | ||
33 | #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION) | |
34 | #define AUTOFS_DEV_IOCTL_IOC_COUNT \ | |
35 | (AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD) | |
36 | ||
37 | #ifdef pr_fmt | |
38 | #undef pr_fmt | |
39 | #endif | |
40 | #define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__ | |
41 | ||
55f0d820 IK |
42 | extern struct file_system_type autofs_fs_type; |
43 | ||
ebc921ca IK |
44 | /* |
45 | * Unified info structure. This is pointed to by both the dentry and | |
46 | * inode structures. Each file in the filesystem has an instance of this | |
47 | * structure. It holds a reference to the dentry, so dentries are never | |
48 | * flushed while the file exists. All name lookups are dealt with at the | |
49 | * dentry level, although the filesystem can interfere in the validation | |
50 | * process. Readdir is implemented by traversing the dentry lists. | |
51 | */ | |
52 | struct autofs_info { | |
53 | struct dentry *dentry; | |
54 | struct inode *inode; | |
55 | ||
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; | |
90 | u32 dev; | |
91 | u64 ino; | |
92 | kuid_t uid; | |
93 | kgid_t gid; | |
94 | pid_t pid; | |
95 | pid_t tgid; | |
96 | /* This is for status reporting upon return */ | |
97 | int status; | |
98 | unsigned int wait_ctr; | |
99 | }; | |
100 | ||
101 | #define AUTOFS_SBI_MAGIC 0x6d4a556d | |
102 | ||
9d8719a4 | 103 | #define AUTOFS_SBI_CATATONIC 0x0001 |
f5162216 | 104 | #define AUTOFS_SBI_STRICTEXPIRE 0x0002 |
60d6d04c | 105 | #define AUTOFS_SBI_IGNORE 0x0004 |
9d8719a4 | 106 | |
ebc921ca IK |
107 | struct autofs_sb_info { |
108 | u32 magic; | |
109 | int pipefd; | |
110 | struct file *pipe; | |
111 | struct pid *oz_pgrp; | |
ebc921ca IK |
112 | int version; |
113 | int sub_version; | |
114 | int min_proto; | |
115 | int max_proto; | |
9d8719a4 | 116 | unsigned int flags; |
ebc921ca IK |
117 | unsigned long exp_timeout; |
118 | unsigned int type; | |
119 | struct super_block *sb; | |
120 | struct mutex wq_mutex; | |
121 | struct mutex pipe_mutex; | |
122 | spinlock_t fs_lock; | |
123 | struct autofs_wait_queue *queues; /* Wait queue pointer */ | |
124 | spinlock_t lookup_lock; | |
125 | struct list_head active_list; | |
126 | struct list_head expiring_list; | |
127 | struct rcu_head rcu; | |
128 | }; | |
129 | ||
130 | static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb) | |
131 | { | |
55f0d820 | 132 | return (struct autofs_sb_info *)(sb->s_fs_info); |
ebc921ca IK |
133 | } |
134 | ||
135 | static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry) | |
136 | { | |
137 | return (struct autofs_info *)(dentry->d_fsdata); | |
138 | } | |
139 | ||
140 | /* autofs_oz_mode(): do we see the man behind the curtain? (The | |
141 | * processes which do manipulations for us in user space sees the raw | |
142 | * filesystem without "magic".) | |
143 | */ | |
144 | static inline int autofs_oz_mode(struct autofs_sb_info *sbi) | |
145 | { | |
9d8719a4 IK |
146 | return ((sbi->flags & AUTOFS_SBI_CATATONIC) || |
147 | task_pgrp(current) == sbi->oz_pgrp); | |
ebc921ca IK |
148 | } |
149 | ||
150 | struct inode *autofs_get_inode(struct super_block *, umode_t); | |
151 | void autofs_free_ino(struct autofs_info *); | |
152 | ||
153 | /* Expiration */ | |
154 | int is_autofs_dentry(struct dentry *); | |
155 | int autofs_expire_wait(const struct path *path, int rcu_walk); | |
156 | int autofs_expire_run(struct super_block *, struct vfsmount *, | |
157 | struct autofs_sb_info *, | |
158 | struct autofs_packet_expire __user *); | |
159 | int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, | |
e5c85e1f | 160 | struct autofs_sb_info *sbi, unsigned int how); |
ebc921ca IK |
161 | int autofs_expire_multi(struct super_block *, struct vfsmount *, |
162 | struct autofs_sb_info *, int __user *); | |
ebc921ca IK |
163 | |
164 | /* Device node initialization */ | |
165 | ||
166 | int autofs_dev_ioctl_init(void); | |
167 | void autofs_dev_ioctl_exit(void); | |
168 | ||
169 | /* Operations structures */ | |
170 | ||
171 | extern const struct inode_operations autofs_symlink_inode_operations; | |
172 | extern const struct inode_operations autofs_dir_inode_operations; | |
173 | extern const struct file_operations autofs_dir_operations; | |
174 | extern const struct file_operations autofs_root_operations; | |
175 | extern const struct dentry_operations autofs_dentry_operations; | |
176 | ||
177 | /* VFS automount flags management functions */ | |
178 | static inline void __managed_dentry_set_managed(struct dentry *dentry) | |
179 | { | |
180 | dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT); | |
181 | } | |
182 | ||
183 | static inline void managed_dentry_set_managed(struct dentry *dentry) | |
184 | { | |
185 | spin_lock(&dentry->d_lock); | |
186 | __managed_dentry_set_managed(dentry); | |
187 | spin_unlock(&dentry->d_lock); | |
188 | } | |
189 | ||
190 | static inline void __managed_dentry_clear_managed(struct dentry *dentry) | |
191 | { | |
192 | dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT); | |
193 | } | |
194 | ||
195 | static inline void managed_dentry_clear_managed(struct dentry *dentry) | |
196 | { | |
197 | spin_lock(&dentry->d_lock); | |
198 | __managed_dentry_clear_managed(dentry); | |
199 | spin_unlock(&dentry->d_lock); | |
200 | } | |
201 | ||
202 | /* Initializing function */ | |
203 | ||
204 | int autofs_fill_super(struct super_block *, void *, int); | |
205 | struct autofs_info *autofs_new_ino(struct autofs_sb_info *); | |
206 | void autofs_clean_ino(struct autofs_info *); | |
207 | ||
208 | static inline int autofs_prepare_pipe(struct file *pipe) | |
209 | { | |
210 | if (!(pipe->f_mode & FMODE_CAN_WRITE)) | |
211 | return -EINVAL; | |
212 | if (!S_ISFIFO(file_inode(pipe)->i_mode)) | |
213 | return -EINVAL; | |
214 | /* We want a packet pipe */ | |
215 | pipe->f_flags |= O_DIRECT; | |
660c9fc7 N |
216 | /* We don't expect -EAGAIN */ |
217 | pipe->f_flags &= ~O_NONBLOCK; | |
ebc921ca IK |
218 | return 0; |
219 | } | |
220 | ||
221 | /* Queue management functions */ | |
222 | ||
223 | int autofs_wait(struct autofs_sb_info *, | |
224 | const struct path *, enum autofs_notify); | |
225 | int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int); | |
226 | void autofs_catatonic_mode(struct autofs_sb_info *); | |
227 | ||
228 | static inline u32 autofs_get_dev(struct autofs_sb_info *sbi) | |
229 | { | |
230 | return new_encode_dev(sbi->sb->s_dev); | |
231 | } | |
232 | ||
233 | static inline u64 autofs_get_ino(struct autofs_sb_info *sbi) | |
234 | { | |
235 | return d_inode(sbi->sb->s_root)->i_ino; | |
236 | } | |
237 | ||
238 | static inline void __autofs_add_expiring(struct dentry *dentry) | |
239 | { | |
240 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
241 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
242 | ||
243 | if (ino) { | |
244 | if (list_empty(&ino->expiring)) | |
245 | list_add(&ino->expiring, &sbi->expiring_list); | |
246 | } | |
247 | } | |
248 | ||
249 | static inline void autofs_add_expiring(struct dentry *dentry) | |
250 | { | |
251 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
252 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
253 | ||
254 | if (ino) { | |
255 | spin_lock(&sbi->lookup_lock); | |
256 | if (list_empty(&ino->expiring)) | |
257 | list_add(&ino->expiring, &sbi->expiring_list); | |
258 | spin_unlock(&sbi->lookup_lock); | |
259 | } | |
260 | } | |
261 | ||
262 | static inline void autofs_del_expiring(struct dentry *dentry) | |
263 | { | |
264 | struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); | |
265 | struct autofs_info *ino = autofs_dentry_ino(dentry); | |
266 | ||
267 | if (ino) { | |
268 | spin_lock(&sbi->lookup_lock); | |
269 | if (!list_empty(&ino->expiring)) | |
270 | list_del_init(&ino->expiring); | |
271 | spin_unlock(&sbi->lookup_lock); | |
272 | } | |
273 | } | |
274 | ||
275 | void autofs_kill_sb(struct super_block *); |