/*
* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
* Copyright 2005-2006 Ian Kent <raven@themaw.net>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*/
/* Internal header file for autofs */
#include <linux/auto_fs.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/sched/signal.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/completion.h>
#include <linux/file.h>
#include <linux/magic.h>
/* This is the range of ioctl() numbers we claim as ours */
#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
#define AUTOFS_IOC_COUNT 32
#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
#define AUTOFS_DEV_IOCTL_IOC_COUNT \
(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
extern struct file_system_type autofs_fs_type;
/*
* Unified info structure. This is pointed to by both the dentry and
* inode structures. Each file in the filesystem has an instance of this
* structure. It holds a reference to the dentry, so dentries are never
* flushed while the file exists. All name lookups are dealt with at the
* dentry level, although the filesystem can interfere in the validation
* process. Readdir is implemented by traversing the dentry lists.
*/
struct autofs_info {
struct dentry *dentry;
struct inode *inode;
int flags;
struct completion expire_complete;
struct list_head active;
int active_count;
struct list_head expiring;
struct autofs_sb_info *sbi;
unsigned long last_used;
atomic_t count;
kuid_t uid;
kgid_t gid;
struct rcu_head rcu;
};
#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
* for expiry, so RCU_walk is
* not permitted. If it progresses to
* actual expiry attempt, the flag is
* not cleared when EXPIRING is set -
* in that case it gets cleared only
* when it comes to clearing EXPIRING.
*/
#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
struct autofs_wait_queue {
wait_queue_head_t queue;
struct autofs_wait_queue *next;
autofs_wqt_t wait_queue_token;
/* We use the following to see what we are waiting for */
struct qstr name;
u32 dev;
u64 ino;
kuid_t uid;
kgid_t gid;
pid_t pid;
pid_t tgid;
/* This is for status reporting upon return */
int status;
unsigned int wait_ctr;
};
#define AUTOFS_SBI_MAGIC 0x6d4a556d
#define AUTOFS_SBI_CATATONIC 0x0001
#define AUTOFS_SBI_STRICTEXPIRE 0x0002
#define AUTOFS_SBI_IGNORE 0x0004
struct autofs_sb_info {
u32 magic;
int pipefd;
struct file *pipe;
struct pid *oz_pgrp;
int version;
int sub_version;
int min_proto;
int max_proto;
unsigned int flags;
unsigned long exp_timeout;
unsigned int type;
struct super_block *sb;
struct mutex wq_mutex;
struct mutex pipe_mutex;
spinlock_t fs_lock;
struct autofs_wait_queue *queues; /* Wait queue pointer */
spinlock_t lookup_lock;
struct list_head active_list;
struct list_head expiring_list;
struct rcu_head rcu;
};
static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
{
return (struct autofs_sb_info *)(sb->s_fs_info);
}
static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
{
return (struct autofs_info *)(dentry->d_fsdata);
}
/* autofs_oz_mode(): do we see the man behind the curtain? (The
* processes which do manipulations for us in user space sees the raw
* filesystem without "magic".)
*/
static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
{
return ((sbi->flags & AUTOFS_SBI_CATATONIC) ||
task_pgrp(current) == sbi->oz_pgrp);
}
struct inode *autofs_get_inode(struct super_block *, umode_t);
void autofs_free_ino(struct autofs_info *);
/* Expiration */
int is_autofs_dentry(struct dentry *);
int autofs_expire_wait(const struct path *path, int rcu_walk);
int autofs_expire_run(struct super_block *, struct vfsmount *,
struct autofs_sb_info *,
struct autofs_packet_expire __user *);
int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
struct autofs_sb_info *sbi, unsigned int how);
int autofs_expire_multi(struct super_block *, struct vfsmount *,
struct autofs_sb_info *, int __user *);
/* Device node initialization */
int autofs_dev_ioctl_init(void);
void autofs_dev_ioctl_exit(void);
/* Operations structures */
extern const struct inode_operations autofs_symlink_inode_operations;
extern const struct inode_operations autofs_dir_inode_operations;
extern const struct file_operations autofs_dir_operations;
extern const struct file_operations autofs_root_operations;
extern const struct dentry_operations autofs_dentry_operations;
/* VFS automount flags management functions */
static inline void __managed_dentry_set_managed(struct dentry *dentry)
{
dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
}
static inline void managed_dentry_set_managed(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
__managed_dentry_set_managed(dentry);
spin_unlock(&dentry->d_lock);
}
static inline void __managed_dentry_clear_managed(struct dentry *dentry)
{
dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
}
static inline void managed_dentry_clear_managed(struct dentry *dentry)
{
spin_lock(&dentry->d_lock);
__managed_dentry_clear_managed(dentry);
spin_unlock(&dentry->d_lock);
}
/* Initializing function */
int autofs_fill_super(struct super_block *, void *, int);
struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
void autofs_clean_ino(struct autofs_info *);
static inline int autofs_prepare_pipe(struct file *pipe)
{
if (!(pipe->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
if (!S_ISFIFO(file_inode(pipe)->i_mode))
return -EINVAL;
/* We want a packet pipe */
pipe->f_flags |= O_DIRECT;
/* We don't expect -EAGAIN */
pipe->f_flags &= ~O_NONBLOCK;
return 0;
}
/* Queue management functions */
int autofs_wait(struct autofs_sb_info *,
const struct path *, enum autofs_notify);
int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
void autofs_catatonic_mode(struct autofs_sb_info *);
static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
{
return new_encode_dev(sbi->sb->s_dev);
}
static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
{
return d_inode(sbi->sb->s_root)->i_ino;
}
static inline void __autofs_add_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
if (list_empty(&ino->expiring))
list_add(&ino->expiring, &sbi->expiring_list);
}
}
static inline void autofs_add_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
if (list_empty(&ino->expiring))
list_add(&ino->expiring, &sbi->expiring_list);
spin_unlock(&sbi->lookup_lock);
}
}
static inline void autofs_del_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
struct autofs_info *ino = autofs_dentry_ino(dentry);
if (ino) {
spin_lock(&sbi->lookup_lock);
if (!list_empty(&ino->expiring))
list_del_init(&ino->expiring);
spin_unlock(&sbi->lookup_lock);
}
}
void autofs_kill_sb(struct super_block *);
