[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/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 */

#ifdef DEBUG
#define DPRINTK(fmt, args...)				\
do {							\
	printk(KERN_DEBUG "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##args);	\
} while (0)
#else
#define DPRINTK(fmt, args...) do {} while (0)
#endif

#define AUTOFS_WARN(fmt, args...)			\
do {							\
	printk(KERN_WARNING "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##args);	\
} while (0)

#define AUTOFS_ERROR(fmt, args...)			\
do {							\
	printk(KERN_ERR "pid %d: %s: " fmt "\n",	\
		current->pid, __func__, ##args);	\
} while (0)

struct rehash_entry {
	struct task_struct *task;
	struct list_head list;
};

/* 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 rehash_list;

	struct list_head expiring;

	struct autofs_sb_info *sbi;
	unsigned long last_used;
	atomic_t count;

	uid_t uid;
	gid_t gid;

	mode_t	mode;
	size_t	size;

	void (*free)(struct autofs_info *);
	union {
		const char *symlink;
	} u;
};

#define AUTOFS_INF_EXPIRING	(1<<0) /* dentry is in the process of expiring */
#define AUTOFS_INF_MOUNTPOINT	(1<<1) /* mountpoint status for direct expire */
#define AUTOFS_INF_PENDING	(1<<2) /* dentry pending mount */
#define AUTOFS_INF_REHASH	(1<<3) /* dentry in transit to ->lookup() */

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;
	uid_t uid;
	gid_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;
	pid_t 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;
	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;
};

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_nr(current) == sbi->oz_pgrp;
}

/* Does a dentry have some pending activity? */
static inline int autofs4_ispending(struct dentry *dentry)
{
	struct autofs_info *inf = autofs4_dentry_ino(dentry);

	if (inf->flags & AUTOFS_INF_PENDING)
		return 1;

	if (inf->flags & AUTOFS_INF_EXPIRING)
		return 1;

	return 0;
}

static inline void autofs4_copy_atime(struct file *src, struct file *dst)
{
	dst->f_path.dentry->d_inode->i_atime =
		src->f_path.dentry->d_inode->i_atime;
	return;
}

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

/* Expiration */
int is_autofs4_dentry(struct dentry *);
int autofs4_expire_wait(struct dentry *dentry);
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 inode_operations autofs4_root_inode_operations;
extern const struct inode_operations autofs4_indirect_root_inode_operations;
extern const struct inode_operations autofs4_direct_root_inode_operations;
extern const struct file_operations autofs4_dir_operations;
extern const struct file_operations autofs4_root_operations;

/* Initializing function */

int autofs4_fill_super(struct super_block *, void *, int);
struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);

/* 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 int autofs4_follow_mount(struct path *path)
{
	int res = 0;

	while (d_mountpoint(path->dentry)) {
		int followed = follow_down(path);
		if (!followed)
			break;
		res = 1;
	}
	return res;
}

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 sbi->sb->s_root->d_inode->i_ino;
}

static inline int simple_positive(struct dentry *dentry)
{
	return dentry->d_inode && !d_unhashed(dentry);
}

static inline int __simple_empty(struct dentry *dentry)
{
	struct dentry *child;
	int ret = 0;

	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
		if (simple_positive(child))
			goto out;
	ret = 1;
out:
	return ret;
}

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;
}

void autofs4_dentry_release(struct dentry *);
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>
1da177e4 LT	19	#include <linux/list.h>
	20
	21	/* This is the range of ioctl() numbers we claim as ours */
	22	#define AUTOFS_IOC_FIRST AUTOFS_IOC_READY
	23	#define AUTOFS_IOC_COUNT 32
	24
8d7b48e0 IK	25	#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
	26	#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
	27
1da177e4 LT	28	#include <linux/kernel.h>
	29	#include <linux/slab.h>
	30	#include <linux/time.h>
	31	#include <linux/string.h>
	32	#include <linux/wait.h>
	33	#include <linux/sched.h>
	34	#include <linux/mount.h>
	35	#include <linux/namei.h>
	36	#include <asm/current.h>
	37	#include <asm/uaccess.h>
	38
	39	/* #define DEBUG */
	40
	41	#ifdef DEBUG
8d7b48e0 IK	42	#define DPRINTK(fmt, args...) \
	43	do { \
	44	printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \
	45	current->pid, __func__, ##args); \
	46	} while (0)
1da177e4	47	#else
8d7b48e0	48	#define DPRINTK(fmt, args...) do {} while (0)
1da177e4 LT	49	#endif
1da177e4 LT	50
8d7b48e0 IK	51	#define AUTOFS_WARN(fmt, args...) \
	52	do { \
	53	printk(KERN_WARNING "pid %d: %s: " fmt "\n", \
	54	current->pid, __func__, ##args); \
	55	} while (0)
	56
	57	#define AUTOFS_ERROR(fmt, args...) \
	58	do { \
	59	printk(KERN_ERR "pid %d: %s: " fmt "\n", \
	60	current->pid, __func__, ##args); \
	61	} while (0)
	62
213614d5 IK	63	struct rehash_entry {
	64	struct task_struct *task;
	65	struct list_head list;
	66	};
	67
1da177e4 LT	68	/* Unified info structure. This is pointed to by both the dentry and
	69	inode structures. Each file in the filesystem has an instance of this
	70	structure. It holds a reference to the dentry, so dentries are never
	71	flushed while the file exists. All name lookups are dealt with at the
	72	dentry level, although the filesystem can interfere in the validation
	73	process. Readdir is implemented by traversing the dentry lists. */
	74	struct autofs_info {
	75	struct dentry *dentry;
	76	struct inode *inode;
	77
	78	int flags;
	79
6e60a9ab IK	80	struct completion expire_complete;
6e60a9ab IK	81
25767378	82	struct list_head active;
4f8427d1	83	int active_count;
213614d5	84	struct list_head rehash_list;
4f8427d1	85
5f6f4f28	86	struct list_head expiring;
f50b6f86	87
1da177e4 LT	88	struct autofs_sb_info *sbi;
1da177e4 LT	89	unsigned long last_used;
1aff3c8b	90	atomic_t count;
1da177e4	91
c0f54d3e IK	92	uid_t uid;
	93	gid_t gid;
	94
1da177e4 LT	95	mode_t mode;
	96	size_t size;
	97
	98	void (free)(struct autofs_info );
	99	union {
	100	const char *symlink;
	101	} u;
	102	};
	103
	104	#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
6e60a9ab	105	#define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */
aa952eb2	106	#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
213614d5	107	#define AUTOFS_INF_REHASH (1<<3) /* dentry in transit to ->lookup() */
1da177e4 LT	108
	109	struct autofs_wait_queue {
	110	wait_queue_head_t queue;
	111	struct autofs_wait_queue *next;
	112	autofs_wqt_t wait_queue_token;
	113	/* We use the following to see what we are waiting for */
70b52a0a	114	struct qstr name;
5c0a32fc IK	115	u32 dev;
	116	u64 ino;
	117	uid_t uid;
	118	gid_t gid;
	119	pid_t pid;
	120	pid_t tgid;
1da177e4 LT	121	/* This is for status reporting upon return */
1da177e4 LT	122	int status;
296f7bf7	123	unsigned int wait_ctr;
1da177e4 LT	124	};
	125
	126	#define AUTOFS_SBI_MAGIC 0x6d4a556d
	127
	128	struct autofs_sb_info {
	129	u32 magic;
d7c4a5f1	130	int pipefd;
1da177e4 LT	131	struct file *pipe;
	132	pid_t oz_pgrp;
	133	int catatonic;
	134	int version;
	135	int sub_version;
d7c4a5f1 IK	136	int min_proto;
d7c4a5f1 IK	137	int max_proto;
1da177e4	138	unsigned long exp_timeout;
34ca959c	139	unsigned int type;
1da177e4 LT	140	int reghost_enabled;
	141	int needs_reghost;
	142	struct super_block *sb;
1d5599e3	143	struct mutex wq_mutex;
3a9720ce	144	spinlock_t fs_lock;
1da177e4	145	struct autofs_wait_queue queues; / Wait queue pointer */
5f6f4f28	146	spinlock_t lookup_lock;
25767378	147	struct list_head active_list;
5f6f4f28	148	struct list_head expiring_list;
1da177e4 LT	149	};
	150
	151	static inline struct autofs_sb_info autofs4_sbi(struct super_block sb)
	152	{
	153	return (struct autofs_sb_info *)(sb->s_fs_info);
	154	}
	155
	156	static inline struct autofs_info autofs4_dentry_ino(struct dentry dentry)
	157	{
	158	return (struct autofs_info *)(dentry->d_fsdata);
	159	}
	160
	161	/* autofs4_oz_mode(): do we see the man behind the curtain? (The
	162	processes which do manipulations for us in user space sees the raw
	163	filesystem without "magic".) */
	164
	165	static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
a47afb0f	166	return sbi->catatonic \|\| task_pgrp_nr(current) == sbi->oz_pgrp;
1da177e4 LT	167	}
	168
	169	/* Does a dentry have some pending activity? */
	170	static inline int autofs4_ispending(struct dentry *dentry)
	171	{
	172	struct autofs_info *inf = autofs4_dentry_ino(dentry);
	173
aa952eb2	174	if (inf->flags & AUTOFS_INF_PENDING)
3a9720ce IK	175	return 1;
3a9720ce IK	176
97e7449a IK	177	if (inf->flags & AUTOFS_INF_EXPIRING)
97e7449a IK	178	return 1;
3a9720ce	179
97e7449a	180	return 0;
1da177e4 LT	181	}
	182
	183	static inline void autofs4_copy_atime(struct file src, struct file dst)
	184	{
a4669ed8 JJS	185	dst->f_path.dentry->d_inode->i_atime =
a4669ed8 JJS	186	src->f_path.dentry->d_inode->i_atime;
1da177e4 LT	187	return;
	188	}
	189
	190	struct inode autofs4_get_inode(struct super_block , struct autofs_info *);
	191	void autofs4_free_ino(struct autofs_info *);
	192
	193	/* Expiration */
	194	int is_autofs4_dentry(struct dentry *);
06a35985	195	int autofs4_expire_wait(struct dentry *dentry);
1da177e4 LT	196	int autofs4_expire_run(struct super_block , struct vfsmount ,
	197	struct autofs_sb_info *,
	198	struct autofs_packet_expire __user *);
56fcef75 IK	199	int autofs4_do_expire_multi(struct super_block sb, struct vfsmount mnt,
56fcef75 IK	200	struct autofs_sb_info *sbi, int when);
1da177e4 LT	201	int autofs4_expire_multi(struct super_block , struct vfsmount ,
1da177e4 LT	202	struct autofs_sb_info , int __user );
8d7b48e0 IK	203	struct dentry autofs4_expire_direct(struct super_block sb,
	204	struct vfsmount *mnt,
	205	struct autofs_sb_info *sbi, int how);
	206	struct dentry autofs4_expire_indirect(struct super_block sb,
	207	struct vfsmount *mnt,
	208	struct autofs_sb_info *sbi, int how);
	209
	210	/* Device node initialization */
	211
	212	int autofs_dev_ioctl_init(void);
	213	void autofs_dev_ioctl_exit(void);
1da177e4 LT	214
	215	/* Operations structures */
	216
754661f1 AV	217	extern const struct inode_operations autofs4_symlink_inode_operations;
	218	extern const struct inode_operations autofs4_dir_inode_operations;
	219	extern const struct inode_operations autofs4_root_inode_operations;
	220	extern const struct inode_operations autofs4_indirect_root_inode_operations;
	221	extern const struct inode_operations autofs4_direct_root_inode_operations;
4b6f5d20 AV	222	extern const struct file_operations autofs4_dir_operations;
4b6f5d20 AV	223	extern const struct file_operations autofs4_root_operations;
1da177e4 LT	224
	225	/* Initializing function */
	226
	227	int autofs4_fill_super(struct super_block , void , int);
	228	struct autofs_info autofs4_init_ino(struct autofs_info , struct autofs_sb_info *sbi, mode_t mode);
	229
	230	/* Queue management functions */
	231
1da177e4 LT	232	int autofs4_wait(struct autofs_sb_info ,struct dentry , enum autofs_notify);
	233	int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
	234	void autofs4_catatonic_mode(struct autofs_sb_info *);
	235
9393bd07	236	static inline int autofs4_follow_mount(struct path *path)
9b1e3afd IK	237	{
	238	int res = 0;
	239
9393bd07 AV	240	while (d_mountpoint(path->dentry)) {
9393bd07 AV	241	int followed = follow_down(path);
9b1e3afd IK	242	if (!followed)
	243	break;
	244	res = 1;
	245	}
	246	return res;
	247	}
	248
5c0a32fc IK	249	static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
	250	{
	251	return new_encode_dev(sbi->sb->s_dev);
	252	}
	253
	254	static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
	255	{
	256	return sbi->sb->s_root->d_inode->i_ino;
	257	}
	258
1da177e4 LT	259	static inline int simple_positive(struct dentry *dentry)
	260	{
	261	return dentry->d_inode && !d_unhashed(dentry);
	262	}
	263
90a59c7c	264	static inline int __simple_empty(struct dentry *dentry)
1da177e4 LT	265	{
	266	struct dentry *child;
	267	int ret = 0;
	268
5160ee6f	269	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
1da177e4 LT	270	if (simple_positive(child))
	271	goto out;
	272	ret = 1;
	273	out:
	274	return ret;
	275	}
f5b95ff0	276
c4cd70b3 IK	277	static inline void autofs4_add_expiring(struct dentry *dentry)
	278	{
	279	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	280	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	281	if (ino) {
	282	spin_lock(&sbi->lookup_lock);
	283	if (list_empty(&ino->expiring))
	284	list_add(&ino->expiring, &sbi->expiring_list);
	285	spin_unlock(&sbi->lookup_lock);
	286	}
	287	return;
	288	}
	289
	290	static inline void autofs4_del_expiring(struct dentry *dentry)
	291	{
	292	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
	293	struct autofs_info *ino = autofs4_dentry_ino(dentry);
	294	if (ino) {
	295	spin_lock(&sbi->lookup_lock);
	296	if (!list_empty(&ino->expiring))
	297	list_del_init(&ino->expiring);
	298	spin_unlock(&sbi->lookup_lock);
	299	}
	300	return;
	301	}
	302
f5b95ff0	303	void autofs4_dentry_release(struct dentry *);
6ce31523	304	extern void autofs4_kill_sb(struct super_block *);