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 #include <linux/magic.h>
22
23 /* This is the range of ioctl() numbers we claim as ours */
24 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
25 #define AUTOFS_IOC_COUNT 32
26
27 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
28 #define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
29
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/time.h>
33 #include <linux/string.h>
34 #include <linux/wait.h>
35 #include <linux/sched.h>
36 #include <linux/mount.h>
37 #include <linux/namei.h>
38 #include <asm/current.h>
39 #include <asm/uaccess.h>
40
41 /* #define DEBUG */
42
43 #define DPRINTK(fmt, ...) \
44 pr_debug("pid %d: %s: " fmt "\n", \
45 current->pid, __func__, ##__VA_ARGS__)
46
47 #define AUTOFS_WARN(fmt, ...) \
48 printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
49 current->pid, __func__, ##__VA_ARGS__)
50
51 #define AUTOFS_ERROR(fmt, ...) \
52 printk(KERN_ERR "pid %d: %s: " fmt "\n", \
53 current->pid, __func__, ##__VA_ARGS__)
54
55 /* Unified info structure. This is pointed to by both the dentry and
56 inode structures. Each file in the filesystem has an instance of this
57 structure. It holds a reference to the dentry, so dentries are never
58 flushed while the file exists. All name lookups are dealt with at the
59 dentry level, although the filesystem can interfere in the validation
60 process. Readdir is implemented by traversing the dentry lists. */
61 struct autofs_info {
62 struct dentry *dentry;
63 struct inode *inode;
64
65 int flags;
66
67 struct completion expire_complete;
68
69 struct list_head active;
70 int active_count;
71
72 struct list_head expiring;
73
74 struct autofs_sb_info *sbi;
75 unsigned long last_used;
76 atomic_t count;
77
78 kuid_t uid;
79 kgid_t gid;
80 };
81
82 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
83 #define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
84 * for expiry, so RCU_walk is
85 * not permitted. If it progresses to
86 * actual expiry attempt, the flag is
87 * not cleared when EXPIRING is set -
88 * in that case it gets cleared only
89 * when it comes to clearing EXPIRING.
90 */
91 #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
92
93 struct autofs_wait_queue {
94 wait_queue_head_t queue;
95 struct autofs_wait_queue *next;
96 autofs_wqt_t wait_queue_token;
97 /* We use the following to see what we are waiting for */
98 struct qstr name;
99 u32 dev;
100 u64 ino;
101 kuid_t uid;
102 kgid_t gid;
103 pid_t pid;
104 pid_t tgid;
105 /* This is for status reporting upon return */
106 int status;
107 unsigned int wait_ctr;
108 };
109
110 #define AUTOFS_SBI_MAGIC 0x6d4a556d
111
112 struct autofs_sb_info {
113 u32 magic;
114 int pipefd;
115 struct file *pipe;
116 struct pid *oz_pgrp;
117 int catatonic;
118 int version;
119 int sub_version;
120 int min_proto;
121 int max_proto;
122 unsigned long exp_timeout;
123 unsigned int type;
124 int reghost_enabled;
125 int needs_reghost;
126 struct super_block *sb;
127 struct mutex wq_mutex;
128 struct mutex pipe_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 struct rcu_head rcu;
135 };
136
autofs4_sbi(struct super_block * sb)137 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
138 {
139 return sb->s_magic != AUTOFS_SUPER_MAGIC ?
140 NULL : (struct autofs_sb_info *)(sb->s_fs_info);
141 }
142
autofs4_dentry_ino(struct dentry * dentry)143 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
144 {
145 return (struct autofs_info *)(dentry->d_fsdata);
146 }
147
148 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
149 processes which do manipulations for us in user space sees the raw
150 filesystem without "magic".) */
151
autofs4_oz_mode(struct autofs_sb_info * sbi)152 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
153 return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
154 }
155
156 struct inode *autofs4_get_inode(struct super_block *, umode_t);
157 void autofs4_free_ino(struct autofs_info *);
158
159 /* Expiration */
160 int is_autofs4_dentry(struct dentry *);
161 int autofs4_expire_wait(struct dentry *dentry, int rcu_walk);
162 int autofs4_expire_run(struct super_block *, struct vfsmount *,
163 struct autofs_sb_info *,
164 struct autofs_packet_expire __user *);
165 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
166 struct autofs_sb_info *sbi, int when);
167 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
168 struct autofs_sb_info *, int __user *);
169 struct dentry *autofs4_expire_direct(struct super_block *sb,
170 struct vfsmount *mnt,
171 struct autofs_sb_info *sbi, int how);
172 struct dentry *autofs4_expire_indirect(struct super_block *sb,
173 struct vfsmount *mnt,
174 struct autofs_sb_info *sbi, int how);
175
176 /* Device node initialization */
177
178 int autofs_dev_ioctl_init(void);
179 void autofs_dev_ioctl_exit(void);
180
181 /* Operations structures */
182
183 extern const struct inode_operations autofs4_symlink_inode_operations;
184 extern const struct inode_operations autofs4_dir_inode_operations;
185 extern const struct file_operations autofs4_dir_operations;
186 extern const struct file_operations autofs4_root_operations;
187 extern const struct dentry_operations autofs4_dentry_operations;
188
189 /* VFS automount flags management functions */
__managed_dentry_set_managed(struct dentry * dentry)190 static inline void __managed_dentry_set_managed(struct dentry *dentry)
191 {
192 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
193 }
194
managed_dentry_set_managed(struct dentry * dentry)195 static inline void managed_dentry_set_managed(struct dentry *dentry)
196 {
197 spin_lock(&dentry->d_lock);
198 __managed_dentry_set_managed(dentry);
199 spin_unlock(&dentry->d_lock);
200 }
201
__managed_dentry_clear_managed(struct dentry * dentry)202 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
203 {
204 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
205 }
206
managed_dentry_clear_managed(struct dentry * dentry)207 static inline void managed_dentry_clear_managed(struct dentry *dentry)
208 {
209 spin_lock(&dentry->d_lock);
210 __managed_dentry_clear_managed(dentry);
211 spin_unlock(&dentry->d_lock);
212 }
213
214 /* Initializing function */
215
216 int autofs4_fill_super(struct super_block *, void *, int);
217 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
218 void autofs4_clean_ino(struct autofs_info *);
219
autofs_prepare_pipe(struct file * pipe)220 static inline int autofs_prepare_pipe(struct file *pipe)
221 {
222 if (!(pipe->f_mode & FMODE_CAN_WRITE))
223 return -EINVAL;
224 if (!S_ISFIFO(file_inode(pipe)->i_mode))
225 return -EINVAL;
226 /* We want a packet pipe */
227 pipe->f_flags |= O_DIRECT;
228 return 0;
229 }
230
231 /* Queue management functions */
232
233 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
234 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
235 void autofs4_catatonic_mode(struct autofs_sb_info *);
236
autofs4_get_dev(struct autofs_sb_info * sbi)237 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
238 {
239 return new_encode_dev(sbi->sb->s_dev);
240 }
241
autofs4_get_ino(struct autofs_sb_info * sbi)242 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
243 {
244 return d_inode(sbi->sb->s_root)->i_ino;
245 }
246
__autofs4_add_expiring(struct dentry * dentry)247 static inline void __autofs4_add_expiring(struct dentry *dentry)
248 {
249 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
250 struct autofs_info *ino = autofs4_dentry_ino(dentry);
251 if (ino) {
252 if (list_empty(&ino->expiring))
253 list_add(&ino->expiring, &sbi->expiring_list);
254 }
255 return;
256 }
257
autofs4_add_expiring(struct dentry * dentry)258 static inline void autofs4_add_expiring(struct dentry *dentry)
259 {
260 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
261 struct autofs_info *ino = autofs4_dentry_ino(dentry);
262 if (ino) {
263 spin_lock(&sbi->lookup_lock);
264 if (list_empty(&ino->expiring))
265 list_add(&ino->expiring, &sbi->expiring_list);
266 spin_unlock(&sbi->lookup_lock);
267 }
268 return;
269 }
270
autofs4_del_expiring(struct dentry * dentry)271 static inline void autofs4_del_expiring(struct dentry *dentry)
272 {
273 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
274 struct autofs_info *ino = autofs4_dentry_ino(dentry);
275 if (ino) {
276 spin_lock(&sbi->lookup_lock);
277 if (!list_empty(&ino->expiring))
278 list_del_init(&ino->expiring);
279 spin_unlock(&sbi->lookup_lock);
280 }
281 return;
282 }
283
284 extern void autofs4_kill_sb(struct super_block *);
285