[linux.git] / fs / autofs / autofs_i.h

/*
 *  Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
 *  Copyright 2005-2006 Ian Kent <[email protected]>
 *
 * 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;
};

#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 *);
Commit	Line	Data
ebc921ca IK	1	/*
	2	* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
	3	* Copyright 2005-2006 Ian Kent <[email protected]>
	4	*
	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.
	8	*/
	9
	10	/* Internal header file for autofs */
	11
	12	#include <linux/auto_fs.h>
	13	#include <linux/auto_dev-ioctl.h>
	14
	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>
2c470475	21	#include <linux/sched/signal.h>
ebc921ca IK	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>
6471e938	29	#include <linux/file.h>
0633da48	30	#include <linux/magic.h>
ebc921ca IK	31
	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
	35
	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)
	39
	40	#ifdef pr_fmt
	41	#undef pr_fmt
	42	#endif
	43	#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
	44
55f0d820 IK	45	extern struct file_system_type autofs_fs_type;
55f0d820 IK	46
ebc921ca IK	47	/*
	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.
	54	*/
	55	struct autofs_info {
	56	struct dentry *dentry;
	57	struct inode *inode;
	58
	59	int flags;
	60
	61	struct completion expire_complete;
	62
	63	struct list_head active;
	64	int active_count;
	65
	66	struct list_head expiring;
	67
	68	struct autofs_sb_info *sbi;
	69	unsigned long last_used;
	70	atomic_t count;
	71
	72	kuid_t uid;
	73	kgid_t gid;
	74	};
	75
	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.
	84	*/
	85	#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
	86
	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 */
	92	struct qstr name;
	93	u32 dev;
	94	u64 ino;
	95	kuid_t uid;
	96	kgid_t gid;
	97	pid_t pid;
	98	pid_t tgid;
	99	/* This is for status reporting upon return */
	100	int status;
	101	unsigned int wait_ctr;
	102	};
	103
	104	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	105
9d8719a4	106	#define AUTOFS_SBI_CATATONIC 0x0001
f5162216	107	#define AUTOFS_SBI_STRICTEXPIRE 0x0002
60d6d04c	108	#define AUTOFS_SBI_IGNORE 0x0004
9d8719a4	109
ebc921ca IK	110	struct autofs_sb_info {
	111	u32 magic;
	112	int pipefd;
	113	struct file *pipe;
	114	struct pid *oz_pgrp;
ebc921ca IK	115	int version;
	116	int sub_version;
	117	int min_proto;
	118	int max_proto;
9d8719a4	119	unsigned int flags;
ebc921ca IK	120	unsigned long exp_timeout;
	121	unsigned int type;
	122	struct super_block *sb;
	123	struct mutex wq_mutex;
	124	struct mutex pipe_mutex;
	125	spinlock_t fs_lock;
	126	struct autofs_wait_queue queues; / Wait queue pointer */
	127	spinlock_t lookup_lock;
	128	struct list_head active_list;
	129	struct list_head expiring_list;
	130	struct rcu_head rcu;
	131	};
	132
	133	static inline struct autofs_sb_info autofs_sbi(struct super_block sb)
	134	{
55f0d820	135	return (struct autofs_sb_info *)(sb->s_fs_info);
ebc921ca IK	136	}
	137
	138	static inline struct autofs_info autofs_dentry_ino(struct dentry dentry)
	139	{
	140	return (struct autofs_info *)(dentry->d_fsdata);
	141	}
	142
	143	/* autofs_oz_mode(): do we see the man behind the curtain? (The
	144	* processes which do manipulations for us in user space sees the raw
	145	* filesystem without "magic".)
	146	*/
	147	static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
	148	{
9d8719a4 IK	149	return ((sbi->flags & AUTOFS_SBI_CATATONIC) \|\|
9d8719a4 IK	150	task_pgrp(current) == sbi->oz_pgrp);
ebc921ca IK	151	}
	152
	153	struct inode autofs_get_inode(struct super_block , umode_t);
	154	void autofs_free_ino(struct autofs_info *);
	155
	156	/* Expiration */
	157	int is_autofs_dentry(struct dentry *);
	158	int autofs_expire_wait(const struct path *path, int rcu_walk);
	159	int autofs_expire_run(struct super_block , struct vfsmount ,
	160	struct autofs_sb_info *,
	161	struct autofs_packet_expire __user *);
	162	int autofs_do_expire_multi(struct super_block sb, struct vfsmount mnt,
e5c85e1f	163	struct autofs_sb_info *sbi, unsigned int how);
ebc921ca IK	164	int autofs_expire_multi(struct super_block , struct vfsmount ,
ebc921ca IK	165	struct autofs_sb_info , int __user );
ebc921ca IK	166
	167	/* Device node initialization */
	168
	169	int autofs_dev_ioctl_init(void);
	170	void autofs_dev_ioctl_exit(void);
	171
	172	/* Operations structures */
	173
	174	extern const struct inode_operations autofs_symlink_inode_operations;
	175	extern const struct inode_operations autofs_dir_inode_operations;
	176	extern const struct file_operations autofs_dir_operations;
	177	extern const struct file_operations autofs_root_operations;
	178	extern const struct dentry_operations autofs_dentry_operations;
	179
	180	/* VFS automount flags management functions */
	181	static inline void __managed_dentry_set_managed(struct dentry *dentry)
	182	{
	183	dentry->d_flags \|= (DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	184	}
	185
	186	static inline void managed_dentry_set_managed(struct dentry *dentry)
	187	{
	188	spin_lock(&dentry->d_lock);
	189	__managed_dentry_set_managed(dentry);
	190	spin_unlock(&dentry->d_lock);
	191	}
	192
	193	static inline void __managed_dentry_clear_managed(struct dentry *dentry)
	194	{
	195	dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	196	}
	197
	198	static inline void managed_dentry_clear_managed(struct dentry *dentry)
	199	{
	200	spin_lock(&dentry->d_lock);
	201	__managed_dentry_clear_managed(dentry);
	202	spin_unlock(&dentry->d_lock);
	203	}
	204
	205	/* Initializing function */
	206
	207	int autofs_fill_super(struct super_block , void , int);
	208	struct autofs_info autofs_new_ino(struct autofs_sb_info );
	209	void autofs_clean_ino(struct autofs_info *);
	210
	211	static inline int autofs_prepare_pipe(struct file *pipe)
	212	{
	213	if (!(pipe->f_mode & FMODE_CAN_WRITE))
	214	return -EINVAL;
	215	if (!S_ISFIFO(file_inode(pipe)->i_mode))
	216	return -EINVAL;
	217	/* We want a packet pipe */
	218	pipe->f_flags \|= O_DIRECT;
660c9fc7 N	219	/* We don't expect -EAGAIN */
660c9fc7 N	220	pipe->f_flags &= ~O_NONBLOCK;
ebc921ca IK	221	return 0;
	222	}
	223
	224	/* Queue management functions */
	225
	226	int autofs_wait(struct autofs_sb_info *,
	227	const struct path *, enum autofs_notify);
	228	int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
	229	void autofs_catatonic_mode(struct autofs_sb_info *);
	230
	231	static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
	232	{
	233	return new_encode_dev(sbi->sb->s_dev);
	234	}
	235
	236	static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
	237	{
	238	return d_inode(sbi->sb->s_root)->i_ino;
	239	}
	240
	241	static inline void __autofs_add_expiring(struct dentry *dentry)
	242	{
	243	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
	244	struct autofs_info *ino = autofs_dentry_ino(dentry);
	245
	246	if (ino) {
	247	if (list_empty(&ino->expiring))
	248	list_add(&ino->expiring, &sbi->expiring_list);
	249	}
	250	}
	251
	252	static inline void autofs_add_expiring(struct dentry *dentry)
	253	{
	254	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
	255	struct autofs_info *ino = autofs_dentry_ino(dentry);
	256
	257	if (ino) {
	258	spin_lock(&sbi->lookup_lock);
	259	if (list_empty(&ino->expiring))
	260	list_add(&ino->expiring, &sbi->expiring_list);
	261	spin_unlock(&sbi->lookup_lock);
	262	}
	263	}
	264
	265	static inline void autofs_del_expiring(struct dentry *dentry)
	266	{
	267	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
	268	struct autofs_info *ino = autofs_dentry_ino(dentry);
	269
	270	if (ino) {
	271	spin_lock(&sbi->lookup_lock);
	272	if (!list_empty(&ino->expiring))
	273	list_del_init(&ino->expiring);
	274	spin_unlock(&sbi->lookup_lock);
	275	}
	276	}
	277
	278	void autofs_kill_sb(struct super_block *);