[mirror_ubuntu-artful-kernel.git] / fs / autofs4 / autofs_i.h

/*
 *  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_fs4.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/completion.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)

#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/mount.h>
#include <linux/namei.h>
#include <asm/current.h>
#include <linux/uaccess.h>

#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__

/*
 * 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

struct autofs_sb_info {
	u32 magic;
	int pipefd;
	struct file *pipe;
	struct pid *oz_pgrp;
	int catatonic;
	int version;
	int sub_version;
	int min_proto;
	int max_proto;
	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 *autofs4_sbi(struct super_block *sb)
{
	return (struct autofs_sb_info *)(sb->s_fs_info);
}

static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
{
	return (struct autofs_info *)(dentry->d_fsdata);
}

/* autofs4_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 autofs4_oz_mode(struct autofs_sb_info *sbi)
{
	return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
}

struct inode *autofs4_get_inode(struct super_block *, umode_t);
void autofs4_free_ino(struct autofs_info *);

/* Expiration */
int is_autofs4_dentry(struct dentry *);
int autofs4_expire_wait(const struct path *path, int rcu_walk);
int autofs4_expire_run(struct super_block *, struct vfsmount *,
		       struct autofs_sb_info *,
		       struct autofs_packet_expire __user *);
int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
			    struct autofs_sb_info *sbi, int when);
int autofs4_expire_multi(struct super_block *, struct vfsmount *,
			 struct autofs_sb_info *, int __user *);
struct dentry *autofs4_expire_direct(struct super_block *sb,
				     struct vfsmount *mnt,
				     struct autofs_sb_info *sbi, int how);
struct dentry *autofs4_expire_indirect(struct super_block *sb,
				       struct vfsmount *mnt,
				       struct autofs_sb_info *sbi, int how);

/* Device node initialization */

int autofs_dev_ioctl_init(void);
void autofs_dev_ioctl_exit(void);

/* Operations structures */

extern const struct inode_operations autofs4_symlink_inode_operations;
extern const struct inode_operations autofs4_dir_inode_operations;
extern const struct file_operations autofs4_dir_operations;
extern const struct file_operations autofs4_root_operations;
extern const struct dentry_operations autofs4_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 autofs4_fill_super(struct super_block *, void *, int);
struct autofs_info *autofs4_new_ino(struct autofs_sb_info *);
void autofs4_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;
	return 0;
}

/* Queue management functions */

int autofs4_wait(struct autofs_sb_info *,
		 const struct path *, enum autofs_notify);
int autofs4_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
void autofs4_catatonic_mode(struct autofs_sb_info *);

static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
{
	return new_encode_dev(sbi->sb->s_dev);
}

static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
{
	return d_inode(sbi->sb->s_root)->i_ino;
}

static inline void __autofs4_add_expiring(struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	struct autofs_info *ino = autofs4_dentry_ino(dentry);

	if (ino) {
		if (list_empty(&ino->expiring))
			list_add(&ino->expiring, &sbi->expiring_list);
	}
}

static inline void autofs4_add_expiring(struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	struct autofs_info *ino = autofs4_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 autofs4_del_expiring(struct dentry *dentry)
{
	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	struct autofs_info *ino = autofs4_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 autofs4_kill_sb(struct super_block *);
Commit	Line	Data
e9a7c2f1 IK	1	/*
	2	* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
	3	* Copyright 2005-2006 Ian Kent <raven@themaw.net>
1da177e4 LT	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.
e9a7c2f1	8	*/
1da177e4 LT	9
	10	/* Internal header file for autofs */
	11
	12	#include <linux/auto_fs4.h>
8d7b48e0	13	#include <linux/auto_dev-ioctl.h>
1d5599e3	14	#include <linux/mutex.h>
b5c84bf6	15	#include <linux/spinlock.h>
1da177e4	16	#include <linux/list.h>
f9411ebe	17	#include <linux/completion.h>
1da177e4 LT	18
	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
	22
8d7b48e0	23	#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
aa841936 IK	24	#define AUTOFS_DEV_IOCTL_IOC_COUNT \
aa841936 IK	25	(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
8d7b48e0	26
1da177e4 LT	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>
e9a7c2f1	36	#include <linux/uaccess.h>
1da177e4	37
8a78d593 IK	38	#ifdef pr_fmt
	39	#undef pr_fmt
	40	#endif
	41	#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
8d7b48e0	42
e9a7c2f1 IK	43	/*
	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.
	50	*/
1da177e4 LT	51	struct autofs_info {
	52	struct dentry *dentry;
	53	struct inode *inode;
	54
	55	int flags;
	56
6e60a9ab IK	57	struct completion expire_complete;
6e60a9ab IK	58
25767378	59	struct list_head active;
4f8427d1 IK	60	int active_count;
4f8427d1 IK	61
5f6f4f28	62	struct list_head expiring;
f50b6f86	63
1da177e4 LT	64	struct autofs_sb_info *sbi;
1da177e4 LT	65	unsigned long last_used;
1aff3c8b	66	atomic_t count;
1da177e4	67
45634cd8 EB	68	kuid_t uid;
45634cd8 EB	69	kgid_t gid;
1da177e4 LT	70	};
1da177e4 LT	71
e9a7c2f1	72	#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
ea01a184	73	#define AUTOFS_INF_WANT_EXPIRE (1<<1) /* the dentry is being considered
4d885f90	74	* for expiry, so RCU_walk is
ea01a184 AV	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.
4d885f90	80	*/
aa952eb2	81	#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
1da177e4 LT	82
	83	struct autofs_wait_queue {
	84	wait_queue_head_t queue;
	85	struct autofs_wait_queue *next;
7cee9384	86	autofs_wqt_t wait_queue_token;
1da177e4	87	/* We use the following to see what we are waiting for */
70b52a0a	88	struct qstr name;
5c0a32fc IK	89	u32 dev;
5c0a32fc IK	90	u64 ino;
45634cd8 EB	91	kuid_t uid;
45634cd8 EB	92	kgid_t gid;
5c0a32fc IK	93	pid_t pid;
5c0a32fc IK	94	pid_t tgid;
1da177e4 LT	95	/* This is for status reporting upon return */
1da177e4 LT	96	int status;
296f7bf7	97	unsigned int wait_ctr;
1da177e4 LT	98	};
	99
	100	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	101
	102	struct autofs_sb_info {
	103	u32 magic;
d7c4a5f1	104	int pipefd;
1da177e4	105	struct file *pipe;
6eaba35b	106	struct pid *oz_pgrp;
1da177e4 LT	107	int catatonic;
	108	int version;
	109	int sub_version;
d7c4a5f1 IK	110	int min_proto;
d7c4a5f1 IK	111	int max_proto;
1da177e4	112	unsigned long exp_timeout;
34ca959c	113	unsigned int type;
1da177e4	114	struct super_block *sb;
1d5599e3	115	struct mutex wq_mutex;
d668dc56	116	struct mutex pipe_mutex;
3a9720ce	117	spinlock_t fs_lock;
1da177e4	118	struct autofs_wait_queue queues; / Wait queue pointer */
5f6f4f28	119	spinlock_t lookup_lock;
25767378	120	struct list_head active_list;
5f6f4f28	121	struct list_head expiring_list;
baa40671	122	struct rcu_head rcu;
1da177e4 LT	123	};
	124
	125	static inline struct autofs_sb_info autofs4_sbi(struct super_block sb)
	126	{
	127	return (struct autofs_sb_info *)(sb->s_fs_info);
	128	}
	129
	130	static inline struct autofs_info autofs4_dentry_ino(struct dentry dentry)
	131	{
	132	return (struct autofs_info *)(dentry->d_fsdata);
	133	}
	134
	135	/* autofs4_oz_mode(): do we see the man behind the curtain? (The
e9a7c2f1 IK	136	* processes which do manipulations for us in user space sees the raw
	137	* filesystem without "magic".)
	138	*/
	139	static inline int autofs4_oz_mode(struct autofs_sb_info *sbi)
	140	{
6eaba35b	141	return sbi->catatonic \|\| task_pgrp(current) == sbi->oz_pgrp;
1da177e4 LT	142	}
1da177e4 LT	143
030a8ba4	144	struct inode autofs4_get_inode(struct super_block , umode_t);
1da177e4 LT	145	void autofs4_free_ino(struct autofs_info *);
	146
	147	/* Expiration */
	148	int is_autofs4_dentry(struct dentry *);
74f504cf	149	int autofs4_expire_wait(const struct path *path, int rcu_walk);
1da177e4	150	int autofs4_expire_run(struct super_block , struct vfsmount ,
e9a7c2f1 IK	151	struct autofs_sb_info *,
e9a7c2f1 IK	152	struct autofs_packet_expire __user *);
56fcef75 IK	153	int autofs4_do_expire_multi(struct super_block sb, struct vfsmount mnt,
56fcef75 IK	154	struct autofs_sb_info *sbi, int when);
1da177e4	155	int autofs4_expire_multi(struct super_block , struct vfsmount ,
e9a7c2f1	156	struct autofs_sb_info , int __user );
8d7b48e0 IK	157	struct dentry autofs4_expire_direct(struct super_block sb,
	158	struct vfsmount *mnt,
	159	struct autofs_sb_info *sbi, int how);
	160	struct dentry autofs4_expire_indirect(struct super_block sb,
	161	struct vfsmount *mnt,
	162	struct autofs_sb_info *sbi, int how);
	163
	164	/* Device node initialization */
	165
	166	int autofs_dev_ioctl_init(void);
	167	void autofs_dev_ioctl_exit(void);
1da177e4 LT	168
	169	/* Operations structures */
	170
754661f1 AV	171	extern const struct inode_operations autofs4_symlink_inode_operations;
754661f1 AV	172	extern const struct inode_operations autofs4_dir_inode_operations;
4b6f5d20 AV	173	extern const struct file_operations autofs4_dir_operations;
4b6f5d20 AV	174	extern const struct file_operations autofs4_root_operations;
71e469db	175	extern const struct dentry_operations autofs4_dentry_operations;
10584211 IK	176
10584211 IK	177	/* VFS automount flags management functions */
b5b80177 IK	178	static inline void __managed_dentry_set_managed(struct dentry *dentry)
	179	{
	180	dentry->d_flags \|= (DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	181	}
	182
	183	static inline void managed_dentry_set_managed(struct dentry *dentry)
	184	{
	185	spin_lock(&dentry->d_lock);
	186	__managed_dentry_set_managed(dentry);
	187	spin_unlock(&dentry->d_lock);
	188	}
	189
	190	static inline void __managed_dentry_clear_managed(struct dentry *dentry)
	191	{
	192	dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	193	}
	194
	195	static inline void managed_dentry_clear_managed(struct dentry *dentry)
	196	{
	197	spin_lock(&dentry->d_lock);
	198	__managed_dentry_clear_managed(dentry);
	199	spin_unlock(&dentry->d_lock);
	200	}
	201
1da177e4 LT	202	/* Initializing function */
	203
	204	int autofs4_fill_super(struct super_block , void , int);
26e6c910 AV	205	struct autofs_info autofs4_new_ino(struct autofs_sb_info );
26e6c910 AV	206	void autofs4_clean_ino(struct autofs_info *);
1da177e4	207
64f371bc LT	208	static inline int autofs_prepare_pipe(struct file *pipe)
64f371bc LT	209	{
a35fb914	210	if (!(pipe->f_mode & FMODE_CAN_WRITE))
64f371bc	211	return -EINVAL;
496ad9aa	212	if (!S_ISFIFO(file_inode(pipe)->i_mode))
64f371bc LT	213	return -EINVAL;
	214	/* We want a packet pipe */
	215	pipe->f_flags \|= O_DIRECT;
	216	return 0;
	217	}
	218
1da177e4 LT	219	/* Queue management functions */
1da177e4 LT	220
dd36a882 IK	221	int autofs4_wait(struct autofs_sb_info *,
dd36a882 IK	222	const struct path *, enum autofs_notify);
e9a7c2f1	223	int autofs4_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
1da177e4 LT	224	void autofs4_catatonic_mode(struct autofs_sb_info *);
1da177e4 LT	225
5c0a32fc IK	226	static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
	227	{
	228	return new_encode_dev(sbi->sb->s_dev);
	229	}
	230
	231	static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
	232	{
2b0143b5	233	return d_inode(sbi->sb->s_root)->i_ino;
5c0a32fc IK	234	}
5c0a32fc IK	235
2fd6b7f5 NP	236	static inline void __autofs4_add_expiring(struct dentry *dentry)
	237	{
	238	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	239	struct autofs_info *ino = autofs4_dentry_ino(dentry);
e9a7c2f1	240
2fd6b7f5 NP	241	if (ino) {
	242	if (list_empty(&ino->expiring))
	243	list_add(&ino->expiring, &sbi->expiring_list);
	244	}
2fd6b7f5 NP	245	}
2fd6b7f5 NP	246
c4cd70b3 IK	247	static inline void autofs4_add_expiring(struct dentry *dentry)
	248	{
	249	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	250	struct autofs_info *ino = autofs4_dentry_ino(dentry);
e9a7c2f1	251
c4cd70b3 IK	252	if (ino) {
	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);
	257	}
c4cd70b3 IK	258	}
	259
	260	static inline void autofs4_del_expiring(struct dentry *dentry)
	261	{
	262	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	263	struct autofs_info *ino = autofs4_dentry_ino(dentry);
e9a7c2f1	264
c4cd70b3 IK	265	if (ino) {
	266	spin_lock(&sbi->lookup_lock);
	267	if (!list_empty(&ino->expiring))
	268	list_del_init(&ino->expiring);
	269	spin_unlock(&sbi->lookup_lock);
	270	}
c4cd70b3 IK	271	}
c4cd70b3 IK	272
4a44c185	273	void autofs4_kill_sb(struct super_block *);