[linux-2.6-block.git] / fs / autofs4 / autofs_i.h

/* -*- c -*- ------------------------------------------------------------- *
 *   
 * linux/fs/autofs/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>

/* 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_IOC_COUNT - 11)

#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 <asm/uaccess.h>

/* #define DEBUG */

#define DPRINTK(fmt, ...)				\
	pr_debug("pid %d: %s: " fmt "\n",		\
		current->pid, __func__, ##__VA_ARGS__)

#define AUTOFS_WARN(fmt, ...)				\
	printk(KERN_WARNING "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##__VA_ARGS__)

#define AUTOFS_ERROR(fmt, ...)				\
	printk(KERN_ERR "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##__VA_ARGS__)

/* 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 is in the process of expiring */
#define AUTOFS_INF_NO_RCU	(1<<1) /* the dentry is being considered
					* for expiry, so RCU_walk is
					* not permitted
					*/
#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;
	int reghost_enabled;
	int needs_reghost;
	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(struct dentry *dentry, 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 *,struct dentry *, 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 int simple_positive(struct dentry *dentry)
{
	return d_really_is_positive(dentry) && !d_unhashed(dentry);
}

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);
	}
	return;
}

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);
	}
	return;
}

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);
	}
	return;
}

extern void autofs4_kill_sb(struct super_block *);
Commit	Line	Data
1da177e4 LT	1	/* -- c -- ------------------------------------------------------------- *
	2	*
	3	* linux/fs/autofs/autofs_i.h
	4	*
	5	* Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
34ca959c	6	* Copyright 2005-2006 Ian Kent <raven@themaw.net>
1da177e4 LT	7	*
	8	* This file is part of the Linux kernel and is made available under
	9	* the terms of the GNU General Public License, version 2, or at your
	10	* option, any later version, incorporated herein by reference.
	11	*
	12	* ----------------------------------------------------------------------- */
	13
	14	/* Internal header file for autofs */
	15
	16	#include <linux/auto_fs4.h>
8d7b48e0	17	#include <linux/auto_dev-ioctl.h>
1d5599e3	18	#include <linux/mutex.h>
b5c84bf6	19	#include <linux/spinlock.h>
1da177e4 LT	20	#include <linux/list.h>
	21
	22	/* This is the range of ioctl() numbers we claim as ours */
	23	#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
	24	#define AUTOFS_IOC_COUNT 32
	25
8d7b48e0 IK	26	#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
	27	#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
	28
1da177e4 LT	29	#include <linux/kernel.h>
	30	#include <linux/slab.h>
	31	#include <linux/time.h>
	32	#include <linux/string.h>
	33	#include <linux/wait.h>
	34	#include <linux/sched.h>
	35	#include <linux/mount.h>
	36	#include <linux/namei.h>
	37	#include <asm/current.h>
	38	#include <asm/uaccess.h>
	39
	40	/* #define DEBUG */
	41
c3ad9962 LT	42	#define DPRINTK(fmt, ...) \
	43	pr_debug("pid %d: %s: " fmt "\n", \
	44	current->pid, __func__, ##__VA_ARGS__)
1da177e4	45
c3ad9962	46	#define AUTOFS_WARN(fmt, ...) \
8d7b48e0	47	printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
c3ad9962	48	current->pid, __func__, ##__VA_ARGS__)
8d7b48e0	49
c3ad9962	50	#define AUTOFS_ERROR(fmt, ...) \
8d7b48e0	51	printk(KERN_ERR "pid %d: %s: " fmt "\n", \
c3ad9962	52	current->pid, __func__, ##__VA_ARGS__)
8d7b48e0	53
1da177e4 LT	54	/* Unified info structure. This is pointed to by both the dentry and
	55	inode structures. Each file in the filesystem has an instance of this
	56	structure. It holds a reference to the dentry, so dentries are never
	57	flushed while the file exists. All name lookups are dealt with at the
	58	dentry level, although the filesystem can interfere in the validation
	59	process. Readdir is implemented by traversing the dentry lists. */
	60	struct autofs_info {
	61	struct dentry *dentry;
	62	struct inode *inode;
	63
	64	int flags;
	65
6e60a9ab IK	66	struct completion expire_complete;
6e60a9ab IK	67
25767378	68	struct list_head active;
4f8427d1 IK	69	int active_count;
4f8427d1 IK	70
5f6f4f28	71	struct list_head expiring;
f50b6f86	72
1da177e4 LT	73	struct autofs_sb_info *sbi;
1da177e4 LT	74	unsigned long last_used;
1aff3c8b	75	atomic_t count;
1da177e4	76
45634cd8 EB	77	kuid_t uid;
45634cd8 EB	78	kgid_t gid;
1da177e4 LT	79	};
	80
	81	#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
4d885f90 N	82	#define AUTOFS_INF_NO_RCU (1<<1) /* the dentry is being considered
	83	* for expiry, so RCU_walk is
	84	* not permitted
	85	*/
aa952eb2	86	#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
1da177e4 LT	87
	88	struct autofs_wait_queue {
	89	wait_queue_head_t queue;
	90	struct autofs_wait_queue *next;
	91	autofs_wqt_t wait_queue_token;
	92	/* We use the following to see what we are waiting for */
70b52a0a	93	struct qstr name;
5c0a32fc IK	94	u32 dev;
5c0a32fc IK	95	u64 ino;
45634cd8 EB	96	kuid_t uid;
45634cd8 EB	97	kgid_t gid;
5c0a32fc IK	98	pid_t pid;
5c0a32fc IK	99	pid_t tgid;
1da177e4 LT	100	/* This is for status reporting upon return */
1da177e4 LT	101	int status;
296f7bf7	102	unsigned int wait_ctr;
1da177e4 LT	103	};
	104
	105	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	106
	107	struct autofs_sb_info {
	108	u32 magic;
d7c4a5f1	109	int pipefd;
1da177e4	110	struct file *pipe;
6eaba35b	111	struct pid *oz_pgrp;
1da177e4 LT	112	int catatonic;
	113	int version;
	114	int sub_version;
d7c4a5f1 IK	115	int min_proto;
d7c4a5f1 IK	116	int max_proto;
1da177e4	117	unsigned long exp_timeout;
34ca959c	118	unsigned int type;
1da177e4 LT	119	int reghost_enabled;
	120	int needs_reghost;
	121	struct super_block *sb;
1d5599e3	122	struct mutex wq_mutex;
d668dc56	123	struct mutex pipe_mutex;
3a9720ce	124	spinlock_t fs_lock;
1da177e4	125	struct autofs_wait_queue queues; / Wait queue pointer */
5f6f4f28	126	spinlock_t lookup_lock;
25767378	127	struct list_head active_list;
5f6f4f28	128	struct list_head expiring_list;
baa40671	129	struct rcu_head rcu;
1da177e4 LT	130	};
	131
	132	static inline struct autofs_sb_info autofs4_sbi(struct super_block sb)
	133	{
	134	return (struct autofs_sb_info *)(sb->s_fs_info);
	135	}
	136
	137	static inline struct autofs_info autofs4_dentry_ino(struct dentry dentry)
	138	{
	139	return (struct autofs_info *)(dentry->d_fsdata);
	140	}
	141
	142	/* autofs4_oz_mode(): do we see the man behind the curtain? (The
	143	processes which do manipulations for us in user space sees the raw
	144	filesystem without "magic".) */
	145
	146	static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
6eaba35b	147	return sbi->catatonic \|\| task_pgrp(current) == sbi->oz_pgrp;
1da177e4 LT	148	}
1da177e4 LT	149
030a8ba4	150	struct inode autofs4_get_inode(struct super_block , umode_t);
1da177e4 LT	151	void autofs4_free_ino(struct autofs_info *);
	152
	153	/* Expiration */
	154	int is_autofs4_dentry(struct dentry *);
23bfc2a2	155	int autofs4_expire_wait(struct dentry *dentry, int rcu_walk);
1da177e4 LT	156	int autofs4_expire_run(struct super_block , struct vfsmount ,
	157	struct autofs_sb_info *,
	158	struct autofs_packet_expire __user *);
56fcef75 IK	159	int autofs4_do_expire_multi(struct super_block sb, struct vfsmount mnt,
56fcef75 IK	160	struct autofs_sb_info *sbi, int when);
1da177e4 LT	161	int autofs4_expire_multi(struct super_block , struct vfsmount ,
1da177e4 LT	162	struct autofs_sb_info , int __user );
8d7b48e0 IK	163	struct dentry autofs4_expire_direct(struct super_block sb,
	164	struct vfsmount *mnt,
	165	struct autofs_sb_info *sbi, int how);
	166	struct dentry autofs4_expire_indirect(struct super_block sb,
	167	struct vfsmount *mnt,
	168	struct autofs_sb_info *sbi, int how);
	169
	170	/* Device node initialization */
	171
	172	int autofs_dev_ioctl_init(void);
	173	void autofs_dev_ioctl_exit(void);
1da177e4 LT	174
	175	/* Operations structures */
	176
754661f1 AV	177	extern const struct inode_operations autofs4_symlink_inode_operations;
754661f1 AV	178	extern const struct inode_operations autofs4_dir_inode_operations;
4b6f5d20 AV	179	extern const struct file_operations autofs4_dir_operations;
4b6f5d20 AV	180	extern const struct file_operations autofs4_root_operations;
71e469db	181	extern const struct dentry_operations autofs4_dentry_operations;
10584211 IK	182
10584211 IK	183	/* VFS automount flags management functions */
b5b80177 IK	184	static inline void __managed_dentry_set_managed(struct dentry *dentry)
	185	{
	186	dentry->d_flags \|= (DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	187	}
	188
	189	static inline void managed_dentry_set_managed(struct dentry *dentry)
	190	{
	191	spin_lock(&dentry->d_lock);
	192	__managed_dentry_set_managed(dentry);
	193	spin_unlock(&dentry->d_lock);
	194	}
	195
	196	static inline void __managed_dentry_clear_managed(struct dentry *dentry)
	197	{
	198	dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT\|DCACHE_MANAGE_TRANSIT);
	199	}
	200
	201	static inline void managed_dentry_clear_managed(struct dentry *dentry)
	202	{
	203	spin_lock(&dentry->d_lock);
	204	__managed_dentry_clear_managed(dentry);
	205	spin_unlock(&dentry->d_lock);
	206	}
	207
1da177e4 LT	208	/* Initializing function */
	209
	210	int autofs4_fill_super(struct super_block , void , int);
26e6c910 AV	211	struct autofs_info autofs4_new_ino(struct autofs_sb_info );
26e6c910 AV	212	void autofs4_clean_ino(struct autofs_info *);
1da177e4	213
64f371bc LT	214	static inline int autofs_prepare_pipe(struct file *pipe)
64f371bc LT	215	{
a35fb914	216	if (!(pipe->f_mode & FMODE_CAN_WRITE))
64f371bc	217	return -EINVAL;
496ad9aa	218	if (!S_ISFIFO(file_inode(pipe)->i_mode))
64f371bc LT	219	return -EINVAL;
	220	/* We want a packet pipe */
	221	pipe->f_flags \|= O_DIRECT;
	222	return 0;
	223	}
	224
1da177e4 LT	225	/* Queue management functions */
1da177e4 LT	226
1da177e4 LT	227	int autofs4_wait(struct autofs_sb_info ,struct dentry , enum autofs_notify);
	228	int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
	229	void autofs4_catatonic_mode(struct autofs_sb_info *);
	230
5c0a32fc IK	231	static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
	232	{
	233	return new_encode_dev(sbi->sb->s_dev);
	234	}
	235
	236	static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
	237	{
2b0143b5	238	return d_inode(sbi->sb->s_root)->i_ino;
5c0a32fc IK	239	}
5c0a32fc IK	240
1da177e4 LT	241	static inline int simple_positive(struct dentry *dentry)
1da177e4 LT	242	{
2b0143b5	243	return d_really_is_positive(dentry) && !d_unhashed(dentry);
1da177e4 LT	244	}
1da177e4 LT	245
2fd6b7f5 NP	246	static inline void __autofs4_add_expiring(struct dentry *dentry)
	247	{
	248	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	249	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	250	if (ino) {
	251	if (list_empty(&ino->expiring))
	252	list_add(&ino->expiring, &sbi->expiring_list);
	253	}
	254	return;
	255	}
	256
c4cd70b3 IK	257	static inline void autofs4_add_expiring(struct dentry *dentry)
	258	{
	259	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	260	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	261	if (ino) {
	262	spin_lock(&sbi->lookup_lock);
	263	if (list_empty(&ino->expiring))
	264	list_add(&ino->expiring, &sbi->expiring_list);
	265	spin_unlock(&sbi->lookup_lock);
	266	}
	267	return;
	268	}
	269
	270	static inline void autofs4_del_expiring(struct dentry *dentry)
	271	{
	272	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	273	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	274	if (ino) {
	275	spin_lock(&sbi->lookup_lock);
	276	if (!list_empty(&ino->expiring))
	277	list_del_init(&ino->expiring);
	278	spin_unlock(&sbi->lookup_lock);
	279	}
	280	return;
	281	}
	282
6ce31523	283	extern void autofs4_kill_sb(struct super_block *);