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autofs_i.h
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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 <[email protected]>
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 
67 
68  struct list_head active;
70 
72 
74  unsigned long last_used;
76 
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 
88  /* We use the following to see what we are waiting for */
89  struct qstr name;
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 
105  int pipefd;
106  struct file *pipe;
109  int version;
113  unsigned long exp_timeout;
114  unsigned int type;
117  struct super_block *sb;
118  struct mutex wq_mutex;
121  struct autofs_wait_queue *queues; /* Wait queue pointer */
125 };
126 
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 
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 
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? */
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 
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 
194 static inline void __managed_dentry_set_automount(struct dentry *dentry)
195 {
196  dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
197 }
198 
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 
206 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
207 {
208  dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
209 }
210 
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 
218 static inline void __managed_dentry_set_transit(struct dentry *dentry)
219 {
220  dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
221 }
222 
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 
230 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
231 {
232  dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
233 }
234 
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 
242 static inline void __managed_dentry_set_managed(struct dentry *dentry)
243 {
245 }
246 
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 
254 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
255 {
257 }
258 
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 
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);
288 
289 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
290 {
291  return new_encode_dev(sbi->sb->s_dev);
292 }
293 
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 
299 static inline int simple_positive(struct dentry *dentry)
300 {
301  return dentry->d_inode && !d_unhashed(dentry);
302 }
303 
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 
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 
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 *);