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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
4 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
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>
18#include <linux/sched/signal.h>
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>
26#include <linux/file.h>
27#include <linux/magic.h>
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
42extern struct file_system_type autofs_fs_type;
43
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 */
52struct 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;
61
62 struct list_head expiring;
63
64 struct autofs_sb_info *sbi;
65 unsigned long last_used;
66 int count;
67
68 kuid_t uid;
69 kgid_t gid;
70 struct rcu_head rcu;
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
84struct 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
103#define AUTOFS_SBI_CATATONIC 0x0001
104#define AUTOFS_SBI_STRICTEXPIRE 0x0002
105#define AUTOFS_SBI_IGNORE 0x0004
106
107struct autofs_sb_info {
108 u32 magic;
109 int pipefd;
110 struct file *pipe;
111 struct pid *oz_pgrp;
112 int version;
113 int sub_version;
114 int min_proto;
115 int max_proto;
116 unsigned int flags;
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
130static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
131{
132 return (struct autofs_sb_info *)(sb->s_fs_info);
133}
134
135static 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 */
144static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
145{
146 return ((sbi->flags & AUTOFS_SBI_CATATONIC) ||
147 task_pgrp(current) == sbi->oz_pgrp);
148}
149
150struct inode *autofs_get_inode(struct super_block *, umode_t);
151void autofs_free_ino(struct autofs_info *);
152
153/* Expiration */
154int is_autofs_dentry(struct dentry *);
155int autofs_expire_wait(const struct path *path, int rcu_walk);
156int autofs_expire_run(struct super_block *, struct vfsmount *,
157 struct autofs_sb_info *,
158 struct autofs_packet_expire __user *);
159int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
160 struct autofs_sb_info *sbi, unsigned int how);
161int autofs_expire_multi(struct super_block *, struct vfsmount *,
162 struct autofs_sb_info *, int __user *);
163
164/* Device node initialization */
165
166int autofs_dev_ioctl_init(void);
167void autofs_dev_ioctl_exit(void);
168
169/* Operations structures */
170
171extern const struct inode_operations autofs_symlink_inode_operations;
172extern const struct inode_operations autofs_dir_inode_operations;
173extern const struct file_operations autofs_dir_operations;
174extern const struct file_operations autofs_root_operations;
175extern const struct dentry_operations autofs_dentry_operations;
176
177/* VFS automount flags management functions */
178static inline void __managed_dentry_set_managed(struct dentry *dentry)
179{
180 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
181}
182
183static 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
190static inline void __managed_dentry_clear_managed(struct dentry *dentry)
191{
192 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
193}
194
195static 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
204int autofs_fill_super(struct super_block *, void *, int);
205struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
206void autofs_clean_ino(struct autofs_info *);
207
208static 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;
216 /* We don't expect -EAGAIN */
217 pipe->f_flags &= ~O_NONBLOCK;
218 return 0;
219}
220
221/* Queue management functions */
222
223int autofs_wait(struct autofs_sb_info *,
224 const struct path *, enum autofs_notify);
225int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
226void autofs_catatonic_mode(struct autofs_sb_info *);
227
228static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
229{
230 return new_encode_dev(sbi->sb->s_dev);
231}
232
233static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
234{
235 return d_inode(sbi->sb->s_root)->i_ino;
236}
237
238static 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
249static 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
262static 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
275void autofs_kill_sb(struct super_block *);
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
4 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
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>
18#include <linux/sched/signal.h>
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>
26#include <linux/file.h>
27#include <linux/magic.h>
28#include <linux/fs_context.h>
29#include <linux/fs_parser.h>
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
44extern struct file_system_type autofs_fs_type;
45
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 */
54struct autofs_info {
55 struct dentry *dentry;
56 int flags;
57
58 struct completion expire_complete;
59
60 struct list_head active;
61
62 struct list_head expiring;
63
64 struct autofs_sb_info *sbi;
65 unsigned long exp_timeout;
66 unsigned long last_used;
67 int count;
68
69 kuid_t uid;
70 kgid_t gid;
71 struct rcu_head rcu;
72};
73
74#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
75#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
76 * for expiry, so RCU_walk is
77 * not permitted. If it progresses to
78 * actual expiry attempt, the flag is
79 * not cleared when EXPIRING is set -
80 * in that case it gets cleared only
81 * when it comes to clearing EXPIRING.
82 */
83#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
84
85#define AUTOFS_INF_EXPIRE_SET (1<<3) /* per-dentry expire timeout set for
86 this mount point.
87 */
88struct autofs_wait_queue {
89 wait_queue_head_t queue;
90 struct autofs_wait_queue *next;
91 autofs_wqt_t wait_queue_token;
92 /* We use the following to see what we are waiting for */
93 struct qstr name;
94 u32 offset;
95 u32 dev;
96 u64 ino;
97 kuid_t uid;
98 kgid_t gid;
99 pid_t pid;
100 pid_t tgid;
101 /* This is for status reporting upon return */
102 int status;
103 unsigned int wait_ctr;
104};
105
106#define AUTOFS_SBI_MAGIC 0x6d4a556d
107
108#define AUTOFS_SBI_CATATONIC 0x0001
109#define AUTOFS_SBI_STRICTEXPIRE 0x0002
110#define AUTOFS_SBI_IGNORE 0x0004
111
112struct autofs_sb_info {
113 u32 magic;
114 int pipefd;
115 struct file *pipe;
116 struct pid *oz_pgrp;
117 int version;
118 int sub_version;
119 int min_proto;
120 int max_proto;
121 unsigned int flags;
122 unsigned long exp_timeout;
123 unsigned int type;
124 struct super_block *sb;
125 struct mutex wq_mutex;
126 struct mutex pipe_mutex;
127 spinlock_t fs_lock;
128 struct autofs_wait_queue *queues; /* Wait queue pointer */
129 spinlock_t lookup_lock;
130 struct list_head active_list;
131 struct list_head expiring_list;
132 struct rcu_head rcu;
133};
134
135static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
136{
137 return (struct autofs_sb_info *)(sb->s_fs_info);
138}
139
140static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
141{
142 return (struct autofs_info *)(dentry->d_fsdata);
143}
144
145/* autofs_oz_mode(): do we see the man behind the curtain? (The
146 * processes which do manipulations for us in user space sees the raw
147 * filesystem without "magic".)
148 */
149static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
150{
151 return ((sbi->flags & AUTOFS_SBI_CATATONIC) ||
152 task_pgrp(current) == sbi->oz_pgrp);
153}
154
155static inline bool autofs_empty(struct autofs_info *ino)
156{
157 return ino->count < 2;
158}
159
160struct inode *autofs_get_inode(struct super_block *, umode_t);
161void autofs_free_ino(struct autofs_info *);
162
163/* Expiration */
164int is_autofs_dentry(struct dentry *);
165int autofs_expire_wait(const struct path *path, int rcu_walk);
166int autofs_expire_run(struct super_block *, struct vfsmount *,
167 struct autofs_sb_info *,
168 struct autofs_packet_expire __user *);
169int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
170 struct autofs_sb_info *sbi, unsigned int how);
171int autofs_expire_multi(struct super_block *, struct vfsmount *,
172 struct autofs_sb_info *, int __user *);
173
174/* Device node initialization */
175
176int autofs_dev_ioctl_init(void);
177void autofs_dev_ioctl_exit(void);
178
179/* Operations structures */
180
181extern const struct inode_operations autofs_symlink_inode_operations;
182extern const struct inode_operations autofs_dir_inode_operations;
183extern const struct file_operations autofs_dir_operations;
184extern const struct file_operations autofs_root_operations;
185extern const struct dentry_operations autofs_dentry_operations;
186
187/* VFS automount flags management functions */
188static inline void __managed_dentry_set_managed(struct dentry *dentry)
189{
190 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
191}
192
193static inline void managed_dentry_set_managed(struct dentry *dentry)
194{
195 spin_lock(&dentry->d_lock);
196 __managed_dentry_set_managed(dentry);
197 spin_unlock(&dentry->d_lock);
198}
199
200static inline void __managed_dentry_clear_managed(struct dentry *dentry)
201{
202 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
203}
204
205static inline void managed_dentry_clear_managed(struct dentry *dentry)
206{
207 spin_lock(&dentry->d_lock);
208 __managed_dentry_clear_managed(dentry);
209 spin_unlock(&dentry->d_lock);
210}
211
212/* Initializing function */
213
214extern const struct fs_parameter_spec autofs_param_specs[];
215int autofs_init_fs_context(struct fs_context *fc);
216struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
217void autofs_clean_ino(struct autofs_info *);
218
219static inline int autofs_check_pipe(struct file *pipe)
220{
221 if (!(pipe->f_mode & FMODE_CAN_WRITE))
222 return -EINVAL;
223 if (!S_ISFIFO(file_inode(pipe)->i_mode))
224 return -EINVAL;
225 return 0;
226}
227
228static inline void autofs_set_packet_pipe_flags(struct file *pipe)
229{
230 /* We want a packet pipe */
231 pipe->f_flags |= O_DIRECT;
232 /* We don't expect -EAGAIN */
233 pipe->f_flags &= ~O_NONBLOCK;
234}
235
236static inline int autofs_prepare_pipe(struct file *pipe)
237{
238 int ret = autofs_check_pipe(pipe);
239 if (ret < 0)
240 return ret;
241 autofs_set_packet_pipe_flags(pipe);
242 return 0;
243}
244
245/* Queue management functions */
246
247int autofs_wait(struct autofs_sb_info *,
248 const struct path *, enum autofs_notify);
249int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
250void autofs_catatonic_mode(struct autofs_sb_info *);
251
252static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
253{
254 return new_encode_dev(sbi->sb->s_dev);
255}
256
257static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
258{
259 return d_inode(sbi->sb->s_root)->i_ino;
260}
261
262static inline void __autofs_add_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 if (list_empty(&ino->expiring))
269 list_add(&ino->expiring, &sbi->expiring_list);
270 }
271}
272
273static inline void autofs_add_expiring(struct dentry *dentry)
274{
275 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
276 struct autofs_info *ino = autofs_dentry_ino(dentry);
277
278 if (ino) {
279 spin_lock(&sbi->lookup_lock);
280 if (list_empty(&ino->expiring))
281 list_add(&ino->expiring, &sbi->expiring_list);
282 spin_unlock(&sbi->lookup_lock);
283 }
284}
285
286static inline void autofs_del_expiring(struct dentry *dentry)
287{
288 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
289 struct autofs_info *ino = autofs_dentry_ino(dentry);
290
291 if (ino) {
292 spin_lock(&sbi->lookup_lock);
293 if (!list_empty(&ino->expiring))
294 list_del_init(&ino->expiring);
295 spin_unlock(&sbi->lookup_lock);
296 }
297}
298
299void autofs_kill_sb(struct super_block *);