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_fs4.h>
13 #include <linux/auto_dev-ioctl.h>
14 #include <linux/mutex.h>
15 #include <linux/spinlock.h>
16 #include <linux/list.h>
17 #include <linux/magic.h>
19 /* This is the range of ioctl() numbers we claim as ours */
20 #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
21 #define AUTOFS_IOC_COUNT 32
23 #define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
24 #define AUTOFS_DEV_IOCTL_IOC_COUNT \
25 (AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/time.h>
30 #include <linux/string.h>
31 #include <linux/wait.h>
32 #include <linux/sched.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <asm/current.h>
36 #include <linux/uaccess.h>
41 #define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
44 * Unified info structure. This is pointed to by both the dentry and
45 * inode structures. Each file in the filesystem has an instance of this
46 * structure. It holds a reference to the dentry, so dentries are never
47 * flushed while the file exists. All name lookups are dealt with at the
48 * dentry level, although the filesystem can interfere in the validation
49 * process. Readdir is implemented by traversing the dentry lists.
52 struct dentry *dentry;
57 struct completion expire_complete;
59 struct list_head active;
62 struct list_head expiring;
64 struct autofs_sb_info *sbi;
65 unsigned long last_used;
72 #define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
73 #define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
74 * for expiry, so RCU_walk is
75 * not permitted. If it progresses to
76 * actual expiry attempt, the flag is
77 * not cleared when EXPIRING is set -
78 * in that case it gets cleared only
79 * when it comes to clearing EXPIRING.
81 #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
83 struct autofs_wait_queue {
84 wait_queue_head_t queue;
85 struct autofs_wait_queue *next;
86 autofs_wqt_t wait_queue_token;
87 /* We use the following to see what we are waiting for */
95 /* This is for status reporting upon return */
97 unsigned int wait_ctr;
100 #define AUTOFS_SBI_MAGIC 0x6d4a556d
102 struct autofs_sb_info {
112 unsigned long exp_timeout;
114 struct super_block *sb;
115 struct mutex wq_mutex;
116 struct mutex pipe_mutex;
118 struct autofs_wait_queue *queues; /* Wait queue pointer */
119 spinlock_t lookup_lock;
120 struct list_head active_list;
121 struct list_head expiring_list;
125 static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
127 return sb->s_magic != AUTOFS_SUPER_MAGIC ?
128 NULL : (struct autofs_sb_info *)(sb->s_fs_info);
131 static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
133 return (struct autofs_info *)(dentry->d_fsdata);
136 /* autofs4_oz_mode(): do we see the man behind the curtain? (The
137 * processes which do manipulations for us in user space sees the raw
138 * filesystem without "magic".)
140 static inline int autofs4_oz_mode(struct autofs_sb_info *sbi)
142 return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
145 struct inode *autofs4_get_inode(struct super_block *, umode_t);
146 void autofs4_free_ino(struct autofs_info *);
149 int is_autofs4_dentry(struct dentry *);
150 int autofs4_expire_wait(struct dentry *dentry, int rcu_walk);
151 int autofs4_expire_run(struct super_block *, struct vfsmount *,
152 struct autofs_sb_info *,
153 struct autofs_packet_expire __user *);
154 int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
155 struct autofs_sb_info *sbi, int when);
156 int autofs4_expire_multi(struct super_block *, struct vfsmount *,
157 struct autofs_sb_info *, int __user *);
158 struct dentry *autofs4_expire_direct(struct super_block *sb,
159 struct vfsmount *mnt,
160 struct autofs_sb_info *sbi, int how);
161 struct dentry *autofs4_expire_indirect(struct super_block *sb,
162 struct vfsmount *mnt,
163 struct autofs_sb_info *sbi, int how);
165 /* Device node initialization */
167 int autofs_dev_ioctl_init(void);
168 void autofs_dev_ioctl_exit(void);
170 /* Operations structures */
172 extern const struct inode_operations autofs4_symlink_inode_operations;
173 extern const struct inode_operations autofs4_dir_inode_operations;
174 extern const struct file_operations autofs4_dir_operations;
175 extern const struct file_operations autofs4_root_operations;
176 extern const struct dentry_operations autofs4_dentry_operations;
178 /* VFS automount flags management functions */
179 static inline void __managed_dentry_set_managed(struct dentry *dentry)
181 dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
184 static inline void managed_dentry_set_managed(struct dentry *dentry)
186 spin_lock(&dentry->d_lock);
187 __managed_dentry_set_managed(dentry);
188 spin_unlock(&dentry->d_lock);
191 static inline void __managed_dentry_clear_managed(struct dentry *dentry)
193 dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
196 static inline void managed_dentry_clear_managed(struct dentry *dentry)
198 spin_lock(&dentry->d_lock);
199 __managed_dentry_clear_managed(dentry);
200 spin_unlock(&dentry->d_lock);
203 /* Initializing function */
205 int autofs4_fill_super(struct super_block *, void *, int);
206 struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
207 void autofs4_clean_ino(struct autofs_info *);
209 static inline int autofs_prepare_pipe(struct file *pipe)
211 if (!(pipe->f_mode & FMODE_CAN_WRITE))
213 if (!S_ISFIFO(file_inode(pipe)->i_mode))
215 /* We want a packet pipe */
216 pipe->f_flags |= O_DIRECT;
220 /* Queue management functions */
222 int autofs4_wait(struct autofs_sb_info *, struct dentry *, enum autofs_notify);
223 int autofs4_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
224 void autofs4_catatonic_mode(struct autofs_sb_info *);
226 static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
228 return new_encode_dev(sbi->sb->s_dev);
231 static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
233 return d_inode(sbi->sb->s_root)->i_ino;
236 static inline void __autofs4_add_expiring(struct dentry *dentry)
238 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
239 struct autofs_info *ino = autofs4_dentry_ino(dentry);
242 if (list_empty(&ino->expiring))
243 list_add(&ino->expiring, &sbi->expiring_list);
247 static inline void autofs4_add_expiring(struct dentry *dentry)
249 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
250 struct autofs_info *ino = autofs4_dentry_ino(dentry);
253 spin_lock(&sbi->lookup_lock);
254 if (list_empty(&ino->expiring))
255 list_add(&ino->expiring, &sbi->expiring_list);
256 spin_unlock(&sbi->lookup_lock);
260 static inline void autofs4_del_expiring(struct dentry *dentry)
262 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
263 struct autofs_info *ino = autofs4_dentry_ino(dentry);
266 spin_lock(&sbi->lookup_lock);
267 if (!list_empty(&ino->expiring))
268 list_del_init(&ino->expiring);
269 spin_unlock(&sbi->lookup_lock);
273 void autofs4_kill_sb(struct super_block *);