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 struct autofs_sb_info {
116 unsigned long exp_timeout;
118 struct super_block *sb;
119 struct mutex wq_mutex;
120 struct mutex pipe_mutex;
122 struct autofs_wait_queue *queues; /* Wait queue pointer */
123 spinlock_t lookup_lock;
124 struct list_head active_list;
125 struct list_head expiring_list;
129 static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
131 return (struct autofs_sb_info *)(sb->s_fs_info);
134 static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
136 return (struct autofs_info *)(dentry->d_fsdata);
139 /* autofs_oz_mode(): do we see the man behind the curtain? (The
140 * processes which do manipulations for us in user space sees the raw
141 * filesystem without "magic".)
143 static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
145 return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
148 struct inode *autofs_get_inode(struct super_block *, umode_t);
149 void autofs_free_ino(struct autofs_info *);
152 int is_autofs_dentry(struct dentry *);
153 int autofs_expire_wait(const struct path *path, int rcu_walk);
154 int autofs_expire_run(struct super_block *, struct vfsmount *,
155 struct autofs_sb_info *,
156 struct autofs_packet_expire __user *);
157 int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
158 struct autofs_sb_info *sbi, unsigned int how);
159 int autofs_expire_multi(struct super_block *, struct vfsmount *,
160 struct autofs_sb_info *, int __user *);
162 /* Device node initialization */
164 int autofs_dev_ioctl_init(void);
165 void autofs_dev_ioctl_exit(void);
167 /* Operations structures */
169 extern const struct inode_operations autofs_symlink_inode_operations;
170 extern const struct inode_operations autofs_dir_inode_operations;
171 extern const struct file_operations autofs_dir_operations;
172 extern const struct file_operations autofs_root_operations;
173 extern const struct dentry_operations autofs_dentry_operations;
175 /* VFS automount flags management functions */
176 static inline void __managed_dentry_set_managed(struct dentry *dentry)
178 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
181 static inline void managed_dentry_set_managed(struct dentry *dentry)
183 spin_lock(&dentry->d_lock);
184 __managed_dentry_set_managed(dentry);
185 spin_unlock(&dentry->d_lock);
188 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
190 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
193 static inline void managed_dentry_clear_managed(struct dentry *dentry)
195 spin_lock(&dentry->d_lock);
196 __managed_dentry_clear_managed(dentry);
197 spin_unlock(&dentry->d_lock);
200 /* Initializing function */
202 int autofs_fill_super(struct super_block *, void *, int);
203 struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
204 void autofs_clean_ino(struct autofs_info *);
206 static inline int autofs_prepare_pipe(struct file *pipe)
208 if (!(pipe->f_mode & FMODE_CAN_WRITE))
210 if (!S_ISFIFO(file_inode(pipe)->i_mode))
212 /* We want a packet pipe */
213 pipe->f_flags |= O_DIRECT;
217 /* Queue management functions */
219 int autofs_wait(struct autofs_sb_info *,
220 const struct path *, enum autofs_notify);
221 int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
222 void autofs_catatonic_mode(struct autofs_sb_info *);
224 static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
226 return new_encode_dev(sbi->sb->s_dev);
229 static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
231 return d_inode(sbi->sb->s_root)->i_ino;
234 static inline void __autofs_add_expiring(struct dentry *dentry)
236 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
237 struct autofs_info *ino = autofs_dentry_ino(dentry);
240 if (list_empty(&ino->expiring))
241 list_add(&ino->expiring, &sbi->expiring_list);
245 static inline void autofs_add_expiring(struct dentry *dentry)
247 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
248 struct autofs_info *ino = autofs_dentry_ino(dentry);
251 spin_lock(&sbi->lookup_lock);
252 if (list_empty(&ino->expiring))
253 list_add(&ino->expiring, &sbi->expiring_list);
254 spin_unlock(&sbi->lookup_lock);
258 static inline void autofs_del_expiring(struct dentry *dentry)
260 struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
261 struct autofs_info *ino = autofs_dentry_ino(dentry);
264 spin_lock(&sbi->lookup_lock);
265 if (!list_empty(&ino->expiring))
266 list_del_init(&ino->expiring);
267 spin_unlock(&sbi->lookup_lock);
271 void autofs_kill_sb(struct super_block *);