1 /* -*- c -*- ------------------------------------------------------------- *
2 *
3 * linux/fs/autofs/autofs_i.h
4 *
5 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
6 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
7 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * ----------------------------------------------------------------------- */
13
14 /* Internal header file for autofs */
15
16 #include <linux/auto_fs4.h>
17 #include <linux/auto_dev-ioctl.h>
18 #include <linux/mutex.h>
19 #include <linux/spinlock.h>
20 #include <linux/list.h>
21
22 /* This is the range of ioctl() numbers we claim as ours */
23 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
24 #define AUTOFS_IOC_COUNT 32
25
26 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
27 #define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
28
29 #include <linux/kernel.h>
30 #include <linux/slab.h>
31 #include <linux/time.h>
32 #include <linux/string.h>
33 #include <linux/wait.h>
34 #include <linux/sched.h>
35 #include <linux/mount.h>
36 #include <linux/namei.h>
37 #include <asm/current.h>
38 #include <asm/uaccess.h>
39
40 /* #define DEBUG */
41
42 #define DPRINTK(fmt, ...) \
43 pr_debug("pid %d: %s: " fmt "\n", \
44 current->pid, __func__, ##__VA_ARGS__)
45
46 #define AUTOFS_WARN(fmt, ...) \
47 printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
48 current->pid, __func__, ##__VA_ARGS__)
49
50 #define AUTOFS_ERROR(fmt, ...) \
51 printk(KERN_ERR "pid %d: %s: " fmt "\n", \
52 current->pid, __func__, ##__VA_ARGS__)
53
54 /* Unified info structure. This is pointed to by both the dentry and
55 inode structures. Each file in the filesystem has an instance of this
56 structure. It holds a reference to the dentry, so dentries are never
57 flushed while the file exists. All name lookups are dealt with at the
58 dentry level, although the filesystem can interfere in the validation
59 process. Readdir is implemented by traversing the dentry lists. */
60 struct autofs_info {
61 struct dentry *dentry;
62 struct inode *inode;
63
64 int flags;
65
66 struct completion expire_complete;
67
68 struct list_head active;
69 int active_count;
70
71 struct list_head expiring;
72
73 struct autofs_sb_info *sbi;
74 unsigned long last_used;
75 atomic_t count;
76
77 uid_t uid;
78 gid_t gid;
79 };
80
81 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
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 uid_t uid;
93 gid_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 struct autofs_sb_info {
104 u32 magic;
105 int pipefd;
106 struct file *pipe;
107 pid_t oz_pgrp;
108 int catatonic;
109 int version;
110 int sub_version;
111 int min_proto;
112 int max_proto;
113 unsigned long exp_timeout;
114 unsigned int type;
115 int reghost_enabled;
116 int needs_reghost;
117 struct super_block *sb;
118 struct mutex wq_mutex;
119 struct mutex pipe_mutex;
120 spinlock_t fs_lock;
121 struct autofs_wait_queue *queues; /* Wait queue pointer */
122 spinlock_t lookup_lock;
123 struct list_head active_list;
124 struct list_head expiring_list;
125 };
126
autofs4_sbi(struct super_block * sb)127 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
128 {
129 return (struct autofs_sb_info *)(sb->s_fs_info);
130 }
131
autofs4_dentry_ino(struct dentry * dentry)132 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
133 {
134 return (struct autofs_info *)(dentry->d_fsdata);
135 }
136
137 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
138 processes which do manipulations for us in user space sees the raw
139 filesystem without "magic".) */
140
autofs4_oz_mode(struct autofs_sb_info * sbi)141 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
142 return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
143 }
144
145 /* Does a dentry have some pending activity? */
autofs4_ispending(struct dentry * dentry)146 static inline int autofs4_ispending(struct dentry *dentry)
147 {
148 struct autofs_info *inf = autofs4_dentry_ino(dentry);
149
150 if (inf->flags & AUTOFS_INF_PENDING)
151 return 1;
152
153 if (inf->flags & AUTOFS_INF_EXPIRING)
154 return 1;
155
156 return 0;
157 }
158
159 struct inode *autofs4_get_inode(struct super_block *, umode_t);
160 void autofs4_free_ino(struct autofs_info *);
161
162 /* Expiration */
163 int is_autofs4_dentry(struct dentry *);
164 int autofs4_expire_wait(struct dentry *dentry);
165 int autofs4_expire_run(struct super_block *, struct vfsmount *,
166 struct autofs_sb_info *,
167 struct autofs_packet_expire __user *);
168 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
169 struct autofs_sb_info *sbi, int when);
170 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
171 struct autofs_sb_info *, int __user *);
172 struct dentry *autofs4_expire_direct(struct super_block *sb,
173 struct vfsmount *mnt,
174 struct autofs_sb_info *sbi, int how);
175 struct dentry *autofs4_expire_indirect(struct super_block *sb,
176 struct vfsmount *mnt,
177 struct autofs_sb_info *sbi, int how);
178
179 /* Device node initialization */
180
181 int autofs_dev_ioctl_init(void);
182 void autofs_dev_ioctl_exit(void);
183
184 /* Operations structures */
185
186 extern const struct inode_operations autofs4_symlink_inode_operations;
187 extern const struct inode_operations autofs4_dir_inode_operations;
188 extern const struct file_operations autofs4_dir_operations;
189 extern const struct file_operations autofs4_root_operations;
190 extern const struct dentry_operations autofs4_dentry_operations;
191
192 /* VFS automount flags management functions */
193
__managed_dentry_set_automount(struct dentry * dentry)194 static inline void __managed_dentry_set_automount(struct dentry *dentry)
195 {
196 dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
197 }
198
managed_dentry_set_automount(struct dentry * dentry)199 static inline void managed_dentry_set_automount(struct dentry *dentry)
200 {
201 spin_lock(&dentry->d_lock);
202 __managed_dentry_set_automount(dentry);
203 spin_unlock(&dentry->d_lock);
204 }
205
__managed_dentry_clear_automount(struct dentry * dentry)206 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
207 {
208 dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
209 }
210
managed_dentry_clear_automount(struct dentry * dentry)211 static inline void managed_dentry_clear_automount(struct dentry *dentry)
212 {
213 spin_lock(&dentry->d_lock);
214 __managed_dentry_clear_automount(dentry);
215 spin_unlock(&dentry->d_lock);
216 }
217
__managed_dentry_set_transit(struct dentry * dentry)218 static inline void __managed_dentry_set_transit(struct dentry *dentry)
219 {
220 dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
221 }
222
managed_dentry_set_transit(struct dentry * dentry)223 static inline void managed_dentry_set_transit(struct dentry *dentry)
224 {
225 spin_lock(&dentry->d_lock);
226 __managed_dentry_set_transit(dentry);
227 spin_unlock(&dentry->d_lock);
228 }
229
__managed_dentry_clear_transit(struct dentry * dentry)230 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
231 {
232 dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
233 }
234
managed_dentry_clear_transit(struct dentry * dentry)235 static inline void managed_dentry_clear_transit(struct dentry *dentry)
236 {
237 spin_lock(&dentry->d_lock);
238 __managed_dentry_clear_transit(dentry);
239 spin_unlock(&dentry->d_lock);
240 }
241
__managed_dentry_set_managed(struct dentry * dentry)242 static inline void __managed_dentry_set_managed(struct dentry *dentry)
243 {
244 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
245 }
246
managed_dentry_set_managed(struct dentry * dentry)247 static inline void managed_dentry_set_managed(struct dentry *dentry)
248 {
249 spin_lock(&dentry->d_lock);
250 __managed_dentry_set_managed(dentry);
251 spin_unlock(&dentry->d_lock);
252 }
253
__managed_dentry_clear_managed(struct dentry * dentry)254 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
255 {
256 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
257 }
258
managed_dentry_clear_managed(struct dentry * dentry)259 static inline void managed_dentry_clear_managed(struct dentry *dentry)
260 {
261 spin_lock(&dentry->d_lock);
262 __managed_dentry_clear_managed(dentry);
263 spin_unlock(&dentry->d_lock);
264 }
265
266 /* Initializing function */
267
268 int autofs4_fill_super(struct super_block *, void *, int);
269 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
270 void autofs4_clean_ino(struct autofs_info *);
271
autofs_prepare_pipe(struct file * pipe)272 static inline int autofs_prepare_pipe(struct file *pipe)
273 {
274 if (!pipe->f_op || !pipe->f_op->write)
275 return -EINVAL;
276 if (!S_ISFIFO(pipe->f_dentry->d_inode->i_mode))
277 return -EINVAL;
278 /* We want a packet pipe */
279 pipe->f_flags |= O_DIRECT;
280 return 0;
281 }
282
283 /* Queue management functions */
284
285 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
286 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
287 void autofs4_catatonic_mode(struct autofs_sb_info *);
288
autofs4_get_dev(struct autofs_sb_info * sbi)289 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
290 {
291 return new_encode_dev(sbi->sb->s_dev);
292 }
293
autofs4_get_ino(struct autofs_sb_info * sbi)294 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
295 {
296 return sbi->sb->s_root->d_inode->i_ino;
297 }
298
simple_positive(struct dentry * dentry)299 static inline int simple_positive(struct dentry *dentry)
300 {
301 return dentry->d_inode && !d_unhashed(dentry);
302 }
303
__autofs4_add_expiring(struct dentry * dentry)304 static inline void __autofs4_add_expiring(struct dentry *dentry)
305 {
306 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
307 struct autofs_info *ino = autofs4_dentry_ino(dentry);
308 if (ino) {
309 if (list_empty(&ino->expiring))
310 list_add(&ino->expiring, &sbi->expiring_list);
311 }
312 return;
313 }
314
autofs4_add_expiring(struct dentry * dentry)315 static inline void autofs4_add_expiring(struct dentry *dentry)
316 {
317 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
318 struct autofs_info *ino = autofs4_dentry_ino(dentry);
319 if (ino) {
320 spin_lock(&sbi->lookup_lock);
321 if (list_empty(&ino->expiring))
322 list_add(&ino->expiring, &sbi->expiring_list);
323 spin_unlock(&sbi->lookup_lock);
324 }
325 return;
326 }
327
autofs4_del_expiring(struct dentry * dentry)328 static inline void autofs4_del_expiring(struct dentry *dentry)
329 {
330 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
331 struct autofs_info *ino = autofs4_dentry_ino(dentry);
332 if (ino) {
333 spin_lock(&sbi->lookup_lock);
334 if (!list_empty(&ino->expiring))
335 list_del_init(&ino->expiring);
336 spin_unlock(&sbi->lookup_lock);
337 }
338 return;
339 }
340
341 extern void autofs4_kill_sb(struct super_block *);
342