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/list.h>
20
21 /* This is the range of ioctl() numbers we claim as ours */
22 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
23 #define AUTOFS_IOC_COUNT 32
24
25 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
26 #define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
27
28 #include <linux/kernel.h>
29 #include <linux/slab.h>
30 #include <linux/time.h>
31 #include <linux/string.h>
32 #include <linux/wait.h>
33 #include <linux/sched.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <asm/current.h>
37 #include <asm/uaccess.h>
38
39 /* #define DEBUG */
40
41 #ifdef DEBUG
42 #define DPRINTK(fmt, args...) \
43 do { \
44 printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \
45 current->pid, __func__, ##args); \
46 } while (0)
47 #else
48 #define DPRINTK(fmt, args...) do {} while (0)
49 #endif
50
51 #define AUTOFS_WARN(fmt, args...) \
52 do { \
53 printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
54 current->pid, __func__, ##args); \
55 } while (0)
56
57 #define AUTOFS_ERROR(fmt, args...) \
58 do { \
59 printk(KERN_ERR "pid %d: %s: " fmt "\n", \
60 current->pid, __func__, ##args); \
61 } while (0)
62
63 /* Unified info structure. This is pointed to by both the dentry and
64 inode structures. Each file in the filesystem has an instance of this
65 structure. It holds a reference to the dentry, so dentries are never
66 flushed while the file exists. All name lookups are dealt with at the
67 dentry level, although the filesystem can interfere in the validation
68 process. Readdir is implemented by traversing the dentry lists. */
69 struct autofs_info {
70 struct dentry *dentry;
71 struct inode *inode;
72
73 int flags;
74
75 struct completion expire_complete;
76
77 struct list_head active;
78 struct list_head expiring;
79
80 struct autofs_sb_info *sbi;
81 unsigned long last_used;
82 atomic_t count;
83
84 uid_t uid;
85 gid_t gid;
86
87 mode_t mode;
88 size_t size;
89
90 void (*free)(struct autofs_info *);
91 union {
92 const char *symlink;
93 } u;
94 };
95
96 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
97 #define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */
98
99 struct autofs_wait_queue {
100 wait_queue_head_t queue;
101 struct autofs_wait_queue *next;
102 autofs_wqt_t wait_queue_token;
103 /* We use the following to see what we are waiting for */
104 struct qstr name;
105 u32 dev;
106 u64 ino;
107 uid_t uid;
108 gid_t gid;
109 pid_t pid;
110 pid_t tgid;
111 /* This is for status reporting upon return */
112 int status;
113 unsigned int wait_ctr;
114 };
115
116 #define AUTOFS_SBI_MAGIC 0x6d4a556d
117
118 struct autofs_sb_info {
119 u32 magic;
120 int pipefd;
121 struct file *pipe;
122 pid_t oz_pgrp;
123 int catatonic;
124 int version;
125 int sub_version;
126 int min_proto;
127 int max_proto;
128 unsigned long exp_timeout;
129 unsigned int type;
130 int reghost_enabled;
131 int needs_reghost;
132 struct super_block *sb;
133 struct mutex wq_mutex;
134 spinlock_t fs_lock;
135 struct autofs_wait_queue *queues; /* Wait queue pointer */
136 spinlock_t lookup_lock;
137 struct list_head active_list;
138 struct list_head expiring_list;
139 };
140
autofs4_sbi(struct super_block * sb)141 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
142 {
143 return (struct autofs_sb_info *)(sb->s_fs_info);
144 }
145
autofs4_dentry_ino(struct dentry * dentry)146 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
147 {
148 return (struct autofs_info *)(dentry->d_fsdata);
149 }
150
151 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
152 processes which do manipulations for us in user space sees the raw
153 filesystem without "magic".) */
154
autofs4_oz_mode(struct autofs_sb_info * sbi)155 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
156 return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
157 }
158
159 /* Does a dentry have some pending activity? */
autofs4_ispending(struct dentry * dentry)160 static inline int autofs4_ispending(struct dentry *dentry)
161 {
162 struct autofs_info *inf = autofs4_dentry_ino(dentry);
163
164 if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
165 return 1;
166
167 if (inf->flags & AUTOFS_INF_EXPIRING)
168 return 1;
169
170 return 0;
171 }
172
autofs4_copy_atime(struct file * src,struct file * dst)173 static inline void autofs4_copy_atime(struct file *src, struct file *dst)
174 {
175 dst->f_path.dentry->d_inode->i_atime =
176 src->f_path.dentry->d_inode->i_atime;
177 return;
178 }
179
180 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
181 void autofs4_free_ino(struct autofs_info *);
182
183 /* Expiration */
184 int is_autofs4_dentry(struct dentry *);
185 int autofs4_expire_wait(struct dentry *dentry);
186 int autofs4_expire_run(struct super_block *, struct vfsmount *,
187 struct autofs_sb_info *,
188 struct autofs_packet_expire __user *);
189 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
190 struct autofs_sb_info *, int __user *);
191 struct dentry *autofs4_expire_direct(struct super_block *sb,
192 struct vfsmount *mnt,
193 struct autofs_sb_info *sbi, int how);
194 struct dentry *autofs4_expire_indirect(struct super_block *sb,
195 struct vfsmount *mnt,
196 struct autofs_sb_info *sbi, int how);
197
198 /* Device node initialization */
199
200 int autofs_dev_ioctl_init(void);
201 void autofs_dev_ioctl_exit(void);
202
203 /* Operations structures */
204
205 extern const struct inode_operations autofs4_symlink_inode_operations;
206 extern const struct inode_operations autofs4_dir_inode_operations;
207 extern const struct inode_operations autofs4_root_inode_operations;
208 extern const struct inode_operations autofs4_indirect_root_inode_operations;
209 extern const struct inode_operations autofs4_direct_root_inode_operations;
210 extern const struct file_operations autofs4_dir_operations;
211 extern const struct file_operations autofs4_root_operations;
212
213 /* Initializing function */
214
215 int autofs4_fill_super(struct super_block *, void *, int);
216 struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
217
218 /* Queue management functions */
219
220 int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
221 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
222 void autofs4_catatonic_mode(struct autofs_sb_info *);
223
autofs4_follow_mount(struct vfsmount ** mnt,struct dentry ** dentry)224 static inline int autofs4_follow_mount(struct vfsmount **mnt, struct dentry **dentry)
225 {
226 int res = 0;
227
228 while (d_mountpoint(*dentry)) {
229 int followed = follow_down(mnt, dentry);
230 if (!followed)
231 break;
232 res = 1;
233 }
234 return res;
235 }
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 sbi->sb->s_root->d_inode->i_ino;
245 }
246
simple_positive(struct dentry * dentry)247 static inline int simple_positive(struct dentry *dentry)
248 {
249 return dentry->d_inode && !d_unhashed(dentry);
250 }
251
__simple_empty(struct dentry * dentry)252 static inline int __simple_empty(struct dentry *dentry)
253 {
254 struct dentry *child;
255 int ret = 0;
256
257 list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
258 if (simple_positive(child))
259 goto out;
260 ret = 1;
261 out:
262 return ret;
263 }
264
265 void autofs4_dentry_release(struct dentry *);
266 extern void autofs4_kill_sb(struct super_block *);
267