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 #ifdef DEBUG
43 #define DPRINTK(fmt, args...) \
44 do { \
45 printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \
46 current->pid, __func__, ##args); \
47 } while (0)
48 #else
49 #define DPRINTK(fmt, args...) do {} while (0)
50 #endif
51
52 #define AUTOFS_WARN(fmt, args...) \
53 do { \
54 printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
55 current->pid, __func__, ##args); \
56 } while (0)
57
58 #define AUTOFS_ERROR(fmt, args...) \
59 do { \
60 printk(KERN_ERR "pid %d: %s: " fmt "\n", \
61 current->pid, __func__, ##args); \
62 } while (0)
63
64 /* Unified info structure. This is pointed to by both the dentry and
65 inode structures. Each file in the filesystem has an instance of this
66 structure. It holds a reference to the dentry, so dentries are never
67 flushed while the file exists. All name lookups are dealt with at the
68 dentry level, although the filesystem can interfere in the validation
69 process. Readdir is implemented by traversing the dentry lists. */
70 struct autofs_info {
71 struct dentry *dentry;
72 struct inode *inode;
73
74 int flags;
75
76 struct completion expire_complete;
77
78 struct list_head active;
79 int active_count;
80
81 struct list_head expiring;
82
83 struct autofs_sb_info *sbi;
84 unsigned long last_used;
85 atomic_t count;
86
87 uid_t uid;
88 gid_t gid;
89 };
90
91 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
92 #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
93
94 struct autofs_wait_queue {
95 wait_queue_head_t queue;
96 struct autofs_wait_queue *next;
97 autofs_wqt_t wait_queue_token;
98 /* We use the following to see what we are waiting for */
99 struct qstr name;
100 u32 dev;
101 u64 ino;
102 uid_t uid;
103 gid_t gid;
104 pid_t pid;
105 pid_t tgid;
106 /* This is for status reporting upon return */
107 int status;
108 unsigned int wait_ctr;
109 };
110
111 #define AUTOFS_SBI_MAGIC 0x6d4a556d
112
113 struct autofs_sb_info {
114 u32 magic;
115 int pipefd;
116 struct file *pipe;
117 pid_t oz_pgrp;
118 int catatonic;
119 int version;
120 int sub_version;
121 int min_proto;
122 int max_proto;
123 unsigned long exp_timeout;
124 unsigned int type;
125 int reghost_enabled;
126 int needs_reghost;
127 struct super_block *sb;
128 struct mutex wq_mutex;
129 spinlock_t fs_lock;
130 struct autofs_wait_queue *queues; /* Wait queue pointer */
131 spinlock_t lookup_lock;
132 struct list_head active_list;
133 struct list_head expiring_list;
134 };
135
autofs4_sbi(struct super_block * sb)136 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
137 {
138 return (struct autofs_sb_info *)(sb->s_fs_info);
139 }
140
autofs4_dentry_ino(struct dentry * dentry)141 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
142 {
143 return (struct autofs_info *)(dentry->d_fsdata);
144 }
145
146 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
147 processes which do manipulations for us in user space sees the raw
148 filesystem without "magic".) */
149
autofs4_oz_mode(struct autofs_sb_info * sbi)150 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
151 return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
152 }
153
154 /* Does a dentry have some pending activity? */
autofs4_ispending(struct dentry * dentry)155 static inline int autofs4_ispending(struct dentry *dentry)
156 {
157 struct autofs_info *inf = autofs4_dentry_ino(dentry);
158
159 if (inf->flags & AUTOFS_INF_PENDING)
160 return 1;
161
162 if (inf->flags & AUTOFS_INF_EXPIRING)
163 return 1;
164
165 return 0;
166 }
167
168 struct inode *autofs4_get_inode(struct super_block *, mode_t);
169 void autofs4_free_ino(struct autofs_info *);
170
171 /* Expiration */
172 int is_autofs4_dentry(struct dentry *);
173 int autofs4_expire_wait(struct dentry *dentry);
174 int autofs4_expire_run(struct super_block *, struct vfsmount *,
175 struct autofs_sb_info *,
176 struct autofs_packet_expire __user *);
177 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
178 struct autofs_sb_info *sbi, int when);
179 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
180 struct autofs_sb_info *, int __user *);
181 struct dentry *autofs4_expire_direct(struct super_block *sb,
182 struct vfsmount *mnt,
183 struct autofs_sb_info *sbi, int how);
184 struct dentry *autofs4_expire_indirect(struct super_block *sb,
185 struct vfsmount *mnt,
186 struct autofs_sb_info *sbi, int how);
187
188 /* Device node initialization */
189
190 int autofs_dev_ioctl_init(void);
191 void autofs_dev_ioctl_exit(void);
192
193 /* Operations structures */
194
195 extern const struct inode_operations autofs4_symlink_inode_operations;
196 extern const struct inode_operations autofs4_dir_inode_operations;
197 extern const struct file_operations autofs4_dir_operations;
198 extern const struct file_operations autofs4_root_operations;
199 extern const struct dentry_operations autofs4_dentry_operations;
200
201 /* VFS automount flags management functions */
202
__managed_dentry_set_automount(struct dentry * dentry)203 static inline void __managed_dentry_set_automount(struct dentry *dentry)
204 {
205 dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
206 }
207
managed_dentry_set_automount(struct dentry * dentry)208 static inline void managed_dentry_set_automount(struct dentry *dentry)
209 {
210 spin_lock(&dentry->d_lock);
211 __managed_dentry_set_automount(dentry);
212 spin_unlock(&dentry->d_lock);
213 }
214
__managed_dentry_clear_automount(struct dentry * dentry)215 static inline void __managed_dentry_clear_automount(struct dentry *dentry)
216 {
217 dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
218 }
219
managed_dentry_clear_automount(struct dentry * dentry)220 static inline void managed_dentry_clear_automount(struct dentry *dentry)
221 {
222 spin_lock(&dentry->d_lock);
223 __managed_dentry_clear_automount(dentry);
224 spin_unlock(&dentry->d_lock);
225 }
226
__managed_dentry_set_transit(struct dentry * dentry)227 static inline void __managed_dentry_set_transit(struct dentry *dentry)
228 {
229 dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
230 }
231
managed_dentry_set_transit(struct dentry * dentry)232 static inline void managed_dentry_set_transit(struct dentry *dentry)
233 {
234 spin_lock(&dentry->d_lock);
235 __managed_dentry_set_transit(dentry);
236 spin_unlock(&dentry->d_lock);
237 }
238
__managed_dentry_clear_transit(struct dentry * dentry)239 static inline void __managed_dentry_clear_transit(struct dentry *dentry)
240 {
241 dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
242 }
243
managed_dentry_clear_transit(struct dentry * dentry)244 static inline void managed_dentry_clear_transit(struct dentry *dentry)
245 {
246 spin_lock(&dentry->d_lock);
247 __managed_dentry_clear_transit(dentry);
248 spin_unlock(&dentry->d_lock);
249 }
250
__managed_dentry_set_managed(struct dentry * dentry)251 static inline void __managed_dentry_set_managed(struct dentry *dentry)
252 {
253 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
254 }
255
managed_dentry_set_managed(struct dentry * dentry)256 static inline void managed_dentry_set_managed(struct dentry *dentry)
257 {
258 spin_lock(&dentry->d_lock);
259 __managed_dentry_set_managed(dentry);
260 spin_unlock(&dentry->d_lock);
261 }
262
__managed_dentry_clear_managed(struct dentry * dentry)263 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
264 {
265 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
266 }
267
managed_dentry_clear_managed(struct dentry * dentry)268 static inline void managed_dentry_clear_managed(struct dentry *dentry)
269 {
270 spin_lock(&dentry->d_lock);
271 __managed_dentry_clear_managed(dentry);
272 spin_unlock(&dentry->d_lock);
273 }
274
275 /* Initializing function */
276
277 int autofs4_fill_super(struct super_block *, void *, int);
278 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
279 void autofs4_clean_ino(struct autofs_info *);
280
281 /* Queue management functions */
282
283 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
284 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
285 void autofs4_catatonic_mode(struct autofs_sb_info *);
286
autofs4_get_dev(struct autofs_sb_info * sbi)287 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
288 {
289 return new_encode_dev(sbi->sb->s_dev);
290 }
291
autofs4_get_ino(struct autofs_sb_info * sbi)292 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
293 {
294 return sbi->sb->s_root->d_inode->i_ino;
295 }
296
simple_positive(struct dentry * dentry)297 static inline int simple_positive(struct dentry *dentry)
298 {
299 return dentry->d_inode && !d_unhashed(dentry);
300 }
301
__autofs4_add_expiring(struct dentry * dentry)302 static inline void __autofs4_add_expiring(struct dentry *dentry)
303 {
304 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
305 struct autofs_info *ino = autofs4_dentry_ino(dentry);
306 if (ino) {
307 if (list_empty(&ino->expiring))
308 list_add(&ino->expiring, &sbi->expiring_list);
309 }
310 return;
311 }
312
autofs4_add_expiring(struct dentry * dentry)313 static inline void autofs4_add_expiring(struct dentry *dentry)
314 {
315 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
316 struct autofs_info *ino = autofs4_dentry_ino(dentry);
317 if (ino) {
318 spin_lock(&sbi->lookup_lock);
319 if (list_empty(&ino->expiring))
320 list_add(&ino->expiring, &sbi->expiring_list);
321 spin_unlock(&sbi->lookup_lock);
322 }
323 return;
324 }
325
autofs4_del_expiring(struct dentry * dentry)326 static inline void autofs4_del_expiring(struct dentry *dentry)
327 {
328 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
329 struct autofs_info *ino = autofs4_dentry_ino(dentry);
330 if (ino) {
331 spin_lock(&sbi->lookup_lock);
332 if (!list_empty(&ino->expiring))
333 list_del_init(&ino->expiring);
334 spin_unlock(&sbi->lookup_lock);
335 }
336 return;
337 }
338
339 extern void autofs4_kill_sb(struct super_block *);
340