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 kuid_t uid;
78 kgid_t gid;
79 };
80
81 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
82 #define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
83 * for expiry, so RCU_walk is
84 * not permitted. If it progresses to
85 * actual expiry attempt, the flag is
86 * not cleared when EXPIRING is set -
87 * in that case it gets cleared only
88 * when it comes to clearing EXPIRING.
89 */
90 #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
91
92 struct autofs_wait_queue {
93 wait_queue_head_t queue;
94 struct autofs_wait_queue *next;
95 autofs_wqt_t wait_queue_token;
96 /* We use the following to see what we are waiting for */
97 struct qstr name;
98 u32 dev;
99 u64 ino;
100 kuid_t uid;
101 kgid_t gid;
102 pid_t pid;
103 pid_t tgid;
104 /* This is for status reporting upon return */
105 int status;
106 unsigned int wait_ctr;
107 };
108
109 #define AUTOFS_SBI_MAGIC 0x6d4a556d
110
111 struct autofs_sb_info {
112 u32 magic;
113 int pipefd;
114 struct file *pipe;
115 struct pid *oz_pgrp;
116 int catatonic;
117 int version;
118 int sub_version;
119 int min_proto;
120 int max_proto;
121 unsigned long exp_timeout;
122 unsigned int type;
123 int reghost_enabled;
124 int needs_reghost;
125 struct super_block *sb;
126 struct mutex wq_mutex;
127 struct mutex pipe_mutex;
128 spinlock_t fs_lock;
129 struct autofs_wait_queue *queues; /* Wait queue pointer */
130 spinlock_t lookup_lock;
131 struct list_head active_list;
132 struct list_head expiring_list;
133 struct rcu_head rcu;
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(current) == sbi->oz_pgrp;
152 }
153
154 struct inode *autofs4_get_inode(struct super_block *, umode_t);
155 void autofs4_free_ino(struct autofs_info *);
156
157 /* Expiration */
158 int is_autofs4_dentry(struct dentry *);
159 int autofs4_expire_wait(struct dentry *dentry, int rcu_walk);
160 int autofs4_expire_run(struct super_block *, struct vfsmount *,
161 struct autofs_sb_info *,
162 struct autofs_packet_expire __user *);
163 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
164 struct autofs_sb_info *sbi, int when);
165 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
166 struct autofs_sb_info *, int __user *);
167 struct dentry *autofs4_expire_direct(struct super_block *sb,
168 struct vfsmount *mnt,
169 struct autofs_sb_info *sbi, int how);
170 struct dentry *autofs4_expire_indirect(struct super_block *sb,
171 struct vfsmount *mnt,
172 struct autofs_sb_info *sbi, int how);
173
174 /* Device node initialization */
175
176 int autofs_dev_ioctl_init(void);
177 void autofs_dev_ioctl_exit(void);
178
179 /* Operations structures */
180
181 extern const struct inode_operations autofs4_symlink_inode_operations;
182 extern const struct inode_operations autofs4_dir_inode_operations;
183 extern const struct file_operations autofs4_dir_operations;
184 extern const struct file_operations autofs4_root_operations;
185 extern const struct dentry_operations autofs4_dentry_operations;
186
187 /* VFS automount flags management functions */
__managed_dentry_set_managed(struct dentry * dentry)188 static inline void __managed_dentry_set_managed(struct dentry *dentry)
189 {
190 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
191 }
192
managed_dentry_set_managed(struct dentry * dentry)193 static 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
__managed_dentry_clear_managed(struct dentry * dentry)200 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
201 {
202 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
203 }
204
managed_dentry_clear_managed(struct dentry * dentry)205 static 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
214 int autofs4_fill_super(struct super_block *, void *, int);
215 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
216 void autofs4_clean_ino(struct autofs_info *);
217
autofs_prepare_pipe(struct file * pipe)218 static inline int autofs_prepare_pipe(struct file *pipe)
219 {
220 if (!pipe->f_op->write)
221 return -EINVAL;
222 if (!S_ISFIFO(file_inode(pipe)->i_mode))
223 return -EINVAL;
224 /* We want a packet pipe */
225 pipe->f_flags |= O_DIRECT;
226 return 0;
227 }
228
229 /* Queue management functions */
230
231 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
232 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
233 void autofs4_catatonic_mode(struct autofs_sb_info *);
234
autofs4_get_dev(struct autofs_sb_info * sbi)235 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
236 {
237 return new_encode_dev(sbi->sb->s_dev);
238 }
239
autofs4_get_ino(struct autofs_sb_info * sbi)240 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
241 {
242 return sbi->sb->s_root->d_inode->i_ino;
243 }
244
simple_positive(struct dentry * dentry)245 static inline int simple_positive(struct dentry *dentry)
246 {
247 return dentry->d_inode && !d_unhashed(dentry);
248 }
249
__autofs4_add_expiring(struct dentry * dentry)250 static inline void __autofs4_add_expiring(struct dentry *dentry)
251 {
252 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
253 struct autofs_info *ino = autofs4_dentry_ino(dentry);
254 if (ino) {
255 if (list_empty(&ino->expiring))
256 list_add(&ino->expiring, &sbi->expiring_list);
257 }
258 return;
259 }
260
autofs4_add_expiring(struct dentry * dentry)261 static inline void autofs4_add_expiring(struct dentry *dentry)
262 {
263 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
264 struct autofs_info *ino = autofs4_dentry_ino(dentry);
265 if (ino) {
266 spin_lock(&sbi->lookup_lock);
267 if (list_empty(&ino->expiring))
268 list_add(&ino->expiring, &sbi->expiring_list);
269 spin_unlock(&sbi->lookup_lock);
270 }
271 return;
272 }
273
autofs4_del_expiring(struct dentry * dentry)274 static inline void autofs4_del_expiring(struct dentry *dentry)
275 {
276 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
277 struct autofs_info *ino = autofs4_dentry_ino(dentry);
278 if (ino) {
279 spin_lock(&sbi->lookup_lock);
280 if (!list_empty(&ino->expiring))
281 list_del_init(&ino->expiring);
282 spin_unlock(&sbi->lookup_lock);
283 }
284 return;
285 }
286
287 extern void autofs4_kill_sb(struct super_block *);
288