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 int compat_daemon;
114 unsigned long exp_timeout;
115 unsigned int type;
116 int reghost_enabled;
117 int needs_reghost;
118 struct super_block *sb;
119 struct mutex wq_mutex;
120 struct mutex pipe_mutex;
121 spinlock_t fs_lock;
122 struct autofs_wait_queue *queues; /* Wait queue pointer */
123 spinlock_t lookup_lock;
124 struct list_head active_list;
125 struct list_head expiring_list;
126 };
127
autofs4_sbi(struct super_block * sb)128 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
129 {
130 return (struct autofs_sb_info *)(sb->s_fs_info);
131 }
132
autofs4_dentry_ino(struct dentry * dentry)133 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
134 {
135 return (struct autofs_info *)(dentry->d_fsdata);
136 }
137
138 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
139 processes which do manipulations for us in user space sees the raw
140 filesystem without "magic".) */
141
autofs4_oz_mode(struct autofs_sb_info * sbi)142 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
143 return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
144 }
145
146 /* Does a dentry have some pending activity? */
autofs4_ispending(struct dentry * dentry)147 static inline int autofs4_ispending(struct dentry *dentry)
148 {
149 struct autofs_info *inf = autofs4_dentry_ino(dentry);
150
151 if (inf->flags & AUTOFS_INF_PENDING)
152 return 1;
153
154 if (inf->flags & AUTOFS_INF_EXPIRING)
155 return 1;
156
157 return 0;
158 }
159
160 struct inode *autofs4_get_inode(struct super_block *, umode_t);
161 void autofs4_free_ino(struct autofs_info *);
162
163 /* Expiration */
164 int is_autofs4_dentry(struct dentry *);
165 int autofs4_expire_wait(struct dentry *dentry);
166 int autofs4_expire_run(struct super_block *, struct vfsmount *,
167 struct autofs_sb_info *,
168 struct autofs_packet_expire __user *);
169 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
170 struct autofs_sb_info *sbi, int when);
171 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
172 struct autofs_sb_info *, int __user *);
173 struct dentry *autofs4_expire_direct(struct super_block *sb,
174 struct vfsmount *mnt,
175 struct autofs_sb_info *sbi, int how);
176 struct dentry *autofs4_expire_indirect(struct super_block *sb,
177 struct vfsmount *mnt,
178 struct autofs_sb_info *sbi, int how);
179
180 /* Device node initialization */
181
182 int autofs_dev_ioctl_init(void);
183 void autofs_dev_ioctl_exit(void);
184
185 /* Operations structures */
186
187 extern const struct inode_operations autofs4_symlink_inode_operations;
188 extern const struct inode_operations autofs4_dir_inode_operations;
189 extern const struct file_operations autofs4_dir_operations;
190 extern const struct file_operations autofs4_root_operations;
191 extern const struct dentry_operations autofs4_dentry_operations;
192
193 /* VFS automount flags management functions */
194
__managed_dentry_set_automount(struct dentry * dentry)195 static inline void __managed_dentry_set_automount(struct dentry *dentry)
196 {
197 dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
198 }
199
managed_dentry_set_automount(struct dentry * dentry)200 static inline void managed_dentry_set_automount(struct dentry *dentry)
201 {
202 spin_lock(&dentry->d_lock);
203 __managed_dentry_set_automount(dentry);
204 spin_unlock(&dentry->d_lock);
205 }
206
__managed_dentry_clear_automount(struct dentry * dentry)207 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
208 {
209 dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
210 }
211
managed_dentry_clear_automount(struct dentry * dentry)212 static inline void managed_dentry_clear_automount(struct dentry *dentry)
213 {
214 spin_lock(&dentry->d_lock);
215 __managed_dentry_clear_automount(dentry);
216 spin_unlock(&dentry->d_lock);
217 }
218
__managed_dentry_set_transit(struct dentry * dentry)219 static inline void __managed_dentry_set_transit(struct dentry *dentry)
220 {
221 dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
222 }
223
managed_dentry_set_transit(struct dentry * dentry)224 static inline void managed_dentry_set_transit(struct dentry *dentry)
225 {
226 spin_lock(&dentry->d_lock);
227 __managed_dentry_set_transit(dentry);
228 spin_unlock(&dentry->d_lock);
229 }
230
__managed_dentry_clear_transit(struct dentry * dentry)231 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
232 {
233 dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
234 }
235
managed_dentry_clear_transit(struct dentry * dentry)236 static inline void managed_dentry_clear_transit(struct dentry *dentry)
237 {
238 spin_lock(&dentry->d_lock);
239 __managed_dentry_clear_transit(dentry);
240 spin_unlock(&dentry->d_lock);
241 }
242
__managed_dentry_set_managed(struct dentry * dentry)243 static inline void __managed_dentry_set_managed(struct dentry *dentry)
244 {
245 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
246 }
247
managed_dentry_set_managed(struct dentry * dentry)248 static inline void managed_dentry_set_managed(struct dentry *dentry)
249 {
250 spin_lock(&dentry->d_lock);
251 __managed_dentry_set_managed(dentry);
252 spin_unlock(&dentry->d_lock);
253 }
254
__managed_dentry_clear_managed(struct dentry * dentry)255 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
256 {
257 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
258 }
259
managed_dentry_clear_managed(struct dentry * dentry)260 static inline void managed_dentry_clear_managed(struct dentry *dentry)
261 {
262 spin_lock(&dentry->d_lock);
263 __managed_dentry_clear_managed(dentry);
264 spin_unlock(&dentry->d_lock);
265 }
266
267 /* Initializing function */
268
269 int autofs4_fill_super(struct super_block *, void *, int);
270 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
271 void autofs4_clean_ino(struct autofs_info *);
272
273 /* Queue management functions */
274
275 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
276 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
277 void autofs4_catatonic_mode(struct autofs_sb_info *);
278
autofs4_get_dev(struct autofs_sb_info * sbi)279 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
280 {
281 return new_encode_dev(sbi->sb->s_dev);
282 }
283
autofs4_get_ino(struct autofs_sb_info * sbi)284 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
285 {
286 return sbi->sb->s_root->d_inode->i_ino;
287 }
288
simple_positive(struct dentry * dentry)289 static inline int simple_positive(struct dentry *dentry)
290 {
291 return dentry->d_inode && !d_unhashed(dentry);
292 }
293
__autofs4_add_expiring(struct dentry * dentry)294 static inline void __autofs4_add_expiring(struct dentry *dentry)
295 {
296 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
297 struct autofs_info *ino = autofs4_dentry_ino(dentry);
298 if (ino) {
299 if (list_empty(&ino->expiring))
300 list_add(&ino->expiring, &sbi->expiring_list);
301 }
302 return;
303 }
304
autofs4_add_expiring(struct dentry * dentry)305 static inline void autofs4_add_expiring(struct dentry *dentry)
306 {
307 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
308 struct autofs_info *ino = autofs4_dentry_ino(dentry);
309 if (ino) {
310 spin_lock(&sbi->lookup_lock);
311 if (list_empty(&ino->expiring))
312 list_add(&ino->expiring, &sbi->expiring_list);
313 spin_unlock(&sbi->lookup_lock);
314 }
315 return;
316 }
317
autofs4_del_expiring(struct dentry * dentry)318 static inline void autofs4_del_expiring(struct dentry *dentry)
319 {
320 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
321 struct autofs_info *ino = autofs4_dentry_ino(dentry);
322 if (ino) {
323 spin_lock(&sbi->lookup_lock);
324 if (!list_empty(&ino->expiring))
325 list_del_init(&ino->expiring);
326 spin_unlock(&sbi->lookup_lock);
327 }
328 return;
329 }
330
331 extern void autofs4_kill_sb(struct super_block *);
332