2 * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
3 * Copyright 2005-2006 Ian Kent <raven@themaw.net>
5 * This file is part of the Linux kernel and is made available under
6 * the terms of the GNU General Public License, version 2, or at your
7 * option, any later version, incorporated herein by reference.
10 /* Internal header file for autofs */
12 #include <linux/auto_fs.h>
13 #include <linux/auto_dev-ioctl.h>
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/time.h>
18 #include <linux/string.h>
19 #include <linux/wait.h>
20 #include <linux/sched.h>
21 #include <linux/sched/signal.h>
22 #include <linux/mount.h>
23 #include <linux/namei.h>
24 #include <linux/uaccess.h>
25 #include <linux/mutex.h>
26 #include <linux/spinlock.h>
27 #include <linux/list.h>
28 #include <linux/completion.h>
29 #include <linux/file.h>
30 #include <linux/magic.h>
32 /* This is the range of ioctl() numbers we claim as ours */
33 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
34 #define AUTOFS_IOC_COUNT 32
36 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
37 #define AUTOFS_DEV_IOCTL_IOC_COUNT \
38 (AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
43 #define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
45 extern struct file_system_type autofs_fs_type;
48 * Unified info structure. This is pointed to by both the dentry and
49 * inode structures. Each file in the filesystem has an instance of this
50 * structure. It holds a reference to the dentry, so dentries are never
51 * flushed while the file exists. All name lookups are dealt with at the
52 * dentry level, although the filesystem can interfere in the validation
53 * process. Readdir is implemented by traversing the dentry lists.
56 struct dentry *dentry;
61 struct completion expire_complete;
63 struct list_head active;
66 struct list_head expiring;
68 struct autofs_sb_info *sbi;
69 unsigned long last_used;
76 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
77 #define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
78 * for expiry, so RCU_walk is
79 * not permitted. If it progresses to
80 * actual expiry attempt, the flag is
81 * not cleared when EXPIRING is set -
82 * in that case it gets cleared only
83 * when it comes to clearing EXPIRING.
85 #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
87 struct autofs_wait_queue {
88 wait_queue_head_t queue;
89 struct autofs_wait_queue *next;
90 autofs_wqt_t wait_queue_token;
91 /* We use the following to see what we are waiting for */
99 /* This is for status reporting upon return */
101 unsigned int wait_ctr;
104 #define AUTOFS_SBI_MAGIC 0x6d4a556d
106 #define AUTOFS_SBI_CATATONIC 0x0001
107 #define AUTOFS_SBI_STRICTEXPIRE 0x0002
109 struct autofs_sb_info {
119 unsigned long exp_timeout;
121 struct super_block *sb;
122 struct mutex wq_mutex;
123 struct mutex pipe_mutex;
125 struct autofs_wait_queue *queues; /* Wait queue pointer */
126 spinlock_t lookup_lock;
127 struct list_head active_list;
128 struct list_head expiring_list;
132 static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
134 return (struct autofs_sb_info *)(sb->s_fs_info);
137 static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
139 return (struct autofs_info *)(dentry->d_fsdata);
142 /* autofs_oz_mode(): do we see the man behind the curtain? (The
143 * processes which do manipulations for us in user space sees the raw
144 * filesystem without "magic".)
146 static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
148 return ((sbi->flags & AUTOFS_SBI_CATATONIC) ||
149 task_pgrp(current) == sbi->oz_pgrp);
152 struct inode *autofs_get_inode(struct super_block *, umode_t);
153 void autofs_free_ino(struct autofs_info *);
156 int is_autofs_dentry(struct dentry *);
157 int autofs_expire_wait(const struct path *path, int rcu_walk);
158 int autofs_expire_run(struct super_block *, struct vfsmount *,
159 struct autofs_sb_info *,
160 struct autofs_packet_expire __user *);
161 int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
162 struct autofs_sb_info *sbi, unsigned int how);
163 int autofs_expire_multi(struct super_block *, struct vfsmount *,
164 struct autofs_sb_info *, int __user *);
166 /* Device node initialization */
168 int autofs_dev_ioctl_init(void);
169 void autofs_dev_ioctl_exit(void);
171 /* Operations structures */
173 extern const struct inode_operations autofs_symlink_inode_operations;
174 extern const struct inode_operations autofs_dir_inode_operations;
175 extern const struct file_operations autofs_dir_operations;
176 extern const struct file_operations autofs_root_operations;
177 extern const struct dentry_operations autofs_dentry_operations;
179 /* VFS automount flags management functions */
180 static inline void __managed_dentry_set_managed(struct dentry *dentry)
182 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
185 static inline void managed_dentry_set_managed(struct dentry *dentry)
187 spin_lock(&dentry->d_lock);
188 __managed_dentry_set_managed(dentry);
189 spin_unlock(&dentry->d_lock);
192 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
194 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
197 static inline void managed_dentry_clear_managed(struct dentry *dentry)
199 spin_lock(&dentry->d_lock);
200 __managed_dentry_clear_managed(dentry);
201 spin_unlock(&dentry->d_lock);
204 /* Initializing function */
206 int autofs_fill_super(struct super_block *, void *, int);
207 struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
208 void autofs_clean_ino(struct autofs_info *);
210 static inline int autofs_prepare_pipe(struct file *pipe)
212 if (!(pipe->f_mode & FMODE_CAN_WRITE))
214 if (!S_ISFIFO(file_inode(pipe)->i_mode))
216 /* We want a packet pipe */
217 pipe->f_flags |= O_DIRECT;
221 /* Queue management functions */
223 int autofs_wait(struct autofs_sb_info *,
224 const struct path *, enum autofs_notify);
225 int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
226 void autofs_catatonic_mode(struct autofs_sb_info *);
228 static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
230 return new_encode_dev(sbi->sb->s_dev);
233 static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
235 return d_inode(sbi->sb->s_root)->i_ino;
238 static inline void __autofs_add_expiring(struct dentry *dentry)
240 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
241 struct autofs_info *ino = autofs_dentry_ino(dentry);
244 if (list_empty(&ino->expiring))
245 list_add(&ino->expiring, &sbi->expiring_list);
249 static inline void autofs_add_expiring(struct dentry *dentry)
251 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
252 struct autofs_info *ino = autofs_dentry_ino(dentry);
255 spin_lock(&sbi->lookup_lock);
256 if (list_empty(&ino->expiring))
257 list_add(&ino->expiring, &sbi->expiring_list);
258 spin_unlock(&sbi->lookup_lock);
262 static inline void autofs_del_expiring(struct dentry *dentry)
264 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
265 struct autofs_info *ino = autofs_dentry_ino(dentry);
268 spin_lock(&sbi->lookup_lock);
269 if (!list_empty(&ino->expiring))
270 list_del_init(&ino->expiring);
271 spin_unlock(&sbi->lookup_lock);
275 void autofs_kill_sb(struct super_block *);