[deliverable/linux.git] / include / linux / mount.h

/*
 *
 * Definitions for mount interface. This describes the in the kernel build 
 * linkedlist with mounted filesystems.
 *
 * Author:  Marco van Wieringen <mvw@planets.elm.net>
 *
 */
#ifndef _LINUX_MOUNT_H
#define _LINUX_MOUNT_H

#include <linux/types.h>
#include <linux/list.h>
#include <linux/nodemask.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>

struct super_block;
struct vfsmount;
struct dentry;
struct mnt_namespace;

#define MNT_NOSUID	0x01
#define MNT_NODEV	0x02
#define MNT_NOEXEC	0x04
#define MNT_NOATIME	0x08
#define MNT_NODIRATIME	0x10
#define MNT_RELATIME	0x20
#define MNT_READONLY	0x40	/* does the user want this to be r/o? */
#define MNT_STRICTATIME 0x80

#define MNT_SHRINKABLE	0x100
#define MNT_WRITE_HOLD	0x200

#define MNT_SHARED	0x1000	/* if the vfsmount is a shared mount */
#define MNT_UNBINDABLE	0x2000	/* if the vfsmount is a unbindable mount */
#define MNT_PNODE_MASK	0x3000	/* propagation flag mask */

struct vfsmount {
	struct list_head mnt_hash;
	struct vfsmount *mnt_parent;	/* fs we are mounted on */
	struct dentry *mnt_mountpoint;	/* dentry of mountpoint */
	struct dentry *mnt_root;	/* root of the mounted tree */
	struct super_block *mnt_sb;	/* pointer to superblock */
	struct list_head mnt_mounts;	/* list of children, anchored here */
	struct list_head mnt_child;	/* and going through their mnt_child */
	int mnt_flags;
	/* 4 bytes hole on 64bits arches */
	const char *mnt_devname;	/* Name of device e.g. /dev/dsk/hda1 */
	struct list_head mnt_list;
	struct list_head mnt_expire;	/* link in fs-specific expiry list */
	struct list_head mnt_share;	/* circular list of shared mounts */
	struct list_head mnt_slave_list;/* list of slave mounts */
	struct list_head mnt_slave;	/* slave list entry */
	struct vfsmount *mnt_master;	/* slave is on master->mnt_slave_list */
	struct mnt_namespace *mnt_ns;	/* containing namespace */
	int mnt_id;			/* mount identifier */
	int mnt_group_id;		/* peer group identifier */
	/*
	 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
	 * to let these frequently modified fields in a separate cache line
	 * (so that reads of mnt_flags wont ping-pong on SMP machines)
	 */
	atomic_t mnt_count;
	int mnt_expiry_mark;		/* true if marked for expiry */
	int mnt_pinned;
	int mnt_ghosts;
#ifdef CONFIG_SMP
	int *mnt_writers;
#else
	int mnt_writers;
#endif
};

static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
{
#ifdef CONFIG_SMP
	return mnt->mnt_writers;
#else
	return &mnt->mnt_writers;
#endif
}

static inline struct vfsmount *mntget(struct vfsmount *mnt)
{
	if (mnt)
		atomic_inc(&mnt->mnt_count);
	return mnt;
}

struct file; /* forward dec */

extern int mnt_want_write(struct vfsmount *mnt);
extern int mnt_want_write_file(struct file *file);
extern int mnt_clone_write(struct vfsmount *mnt);
extern void mnt_drop_write(struct vfsmount *mnt);
extern void mntput_no_expire(struct vfsmount *mnt);
extern void mnt_pin(struct vfsmount *mnt);
extern void mnt_unpin(struct vfsmount *mnt);
extern int __mnt_is_readonly(struct vfsmount *mnt);

static inline void mntput(struct vfsmount *mnt)
{
	if (mnt) {
		mnt->mnt_expiry_mark = 0;
		mntput_no_expire(mnt);
	}
}

extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
				      const char *name, void *data);

struct file_system_type;
extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
				      int flags, const char *name,
				      void *data);

struct nameidata;

struct path;
extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
			int mnt_flags, struct list_head *fslist);

extern void mark_mounts_for_expiry(struct list_head *mounts);

extern spinlock_t vfsmount_lock;
extern dev_t name_to_dev_t(char *name);

#endif /* _LINUX_MOUNT_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	*
	3	* Definitions for mount interface. This describes the in the kernel build
	4	* linkedlist with mounted filesystems.
	5	*
	6	* Author: Marco van Wieringen <mvw@planets.elm.net>
	7	*
1da177e4 LT	8	*/
	9	#ifndef _LINUX_MOUNT_H
	10	#define _LINUX_MOUNT_H
1da177e4	11
d53d9f16	12	#include <linux/types.h>
1da177e4	13	#include <linux/list.h>
3d733633	14	#include <linux/nodemask.h>
1da177e4 LT	15	#include <linux/spinlock.h>
	16	#include <asm/atomic.h>
	17
726c3342 DH	18	struct super_block;
	19	struct vfsmount;
	20	struct dentry;
6b3286ed	21	struct mnt_namespace;
726c3342	22
07b20889 RP	23	#define MNT_NOSUID 0x01
	24	#define MNT_NODEV 0x02
	25	#define MNT_NOEXEC 0x04
fc33a7bb CH	26	#define MNT_NOATIME 0x08
fc33a7bb CH	27	#define MNT_NODIRATIME 0x10
47ae32d6	28	#define MNT_RELATIME 0x20
2e4b7fcd	29	#define MNT_READONLY 0x40 /* does the user want this to be r/o? */
d0adde57	30	#define MNT_STRICTATIME 0x80
bf066c7d	31
5528f911	32	#define MNT_SHRINKABLE 0x100
d3ef3d73	33	#define MNT_WRITE_HOLD 0x200
5528f911	34
fc33a7bb CH	35	#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
fc33a7bb CH	36	#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
beb7dd86	37	#define MNT_PNODE_MASK 0x3000 /* propagation flag mask */
1da177e4	38
07b20889	39	struct vfsmount {
1da177e4 LT	40	struct list_head mnt_hash;
	41	struct vfsmount mnt_parent; / fs we are mounted on */
	42	struct dentry mnt_mountpoint; / dentry of mountpoint */
	43	struct dentry mnt_root; / root of the mounted tree */
	44	struct super_block mnt_sb; / pointer to superblock */
	45	struct list_head mnt_mounts; /* list of children, anchored here */
	46	struct list_head mnt_child; /* and going through their mnt_child */
1da177e4	47	int mnt_flags;
4ba4d4c0	48	/* 4 bytes hole on 64bits arches */
88b38782	49	const char mnt_devname; / Name of device e.g. /dev/dsk/hda1 */
1da177e4	50	struct list_head mnt_list;
55e700b9	51	struct list_head mnt_expire; /* link in fs-specific expiry list */
03e06e68	52	struct list_head mnt_share; /* circular list of shared mounts */
a58b0eb8 RP	53	struct list_head mnt_slave_list;/* list of slave mounts */
	54	struct list_head mnt_slave; /* slave list entry */
	55	struct vfsmount mnt_master; / slave is on master->mnt_slave_list */
6b3286ed	56	struct mnt_namespace mnt_ns; / containing namespace */
73cd49ec	57	int mnt_id; /* mount identifier */
719f5d7f	58	int mnt_group_id; /* peer group identifier */
4ba4d4c0 ED	59	/*
	60	* We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
	61	* to let these frequently modified fields in a separate cache line
	62	* (so that reads of mnt_flags wont ping-pong on SMP machines)
	63	*/
	64	atomic_t mnt_count;
	65	int mnt_expiry_mark; /* true if marked for expiry */
7b7b1ace	66	int mnt_pinned;
7c4b93d8	67	int mnt_ghosts;
d3ef3d73	68	#ifdef CONFIG_SMP
	69	int *mnt_writers;
	70	#else
	71	int mnt_writers;
	72	#endif
1da177e4 LT	73	};
1da177e4 LT	74
d3ef3d73	75	static inline int get_mnt_writers_ptr(struct vfsmount mnt)
	76	{
	77	#ifdef CONFIG_SMP
	78	return mnt->mnt_writers;
	79	#else
	80	return &mnt->mnt_writers;
	81	#endif
	82	}
	83
1da177e4 LT	84	static inline struct vfsmount mntget(struct vfsmount mnt)
	85	{
	86	if (mnt)
	87	atomic_inc(&mnt->mnt_count);
	88	return mnt;
	89	}
	90
96029c4e	91	struct file; /* forward dec */
96029c4e	92
8366025e	93	extern int mnt_want_write(struct vfsmount *mnt);
96029c4e	94	extern int mnt_want_write_file(struct file *file);
96029c4e	95	extern int mnt_clone_write(struct vfsmount *mnt);
8366025e	96	extern void mnt_drop_write(struct vfsmount *mnt);
7b7b1ace AV	97	extern void mntput_no_expire(struct vfsmount *mnt);
	98	extern void mnt_pin(struct vfsmount *mnt);
	99	extern void mnt_unpin(struct vfsmount *mnt);
8366025e	100	extern int __mnt_is_readonly(struct vfsmount *mnt);
1da177e4 LT	101
	102	static inline void mntput(struct vfsmount *mnt)
	103	{
	104	if (mnt) {
	105	mnt->mnt_expiry_mark = 0;
751c404b	106	mntput_no_expire(mnt);
1da177e4 LT	107	}
	108	}
	109
1da177e4 LT	110	extern struct vfsmount do_kern_mount(const char fstype, int flags,
	111	const char name, void data);
	112
bb4a58bf TM	113	struct file_system_type;
	114	extern struct vfsmount vfs_kern_mount(struct file_system_type type,
	115	int flags, const char *name,
	116	void *data);
	117
1da177e4 LT	118	struct nameidata;
1da177e4 LT	119
8d66bf54 AV	120	struct path;
8d66bf54 AV	121	extern int do_add_mount(struct vfsmount newmnt, struct path path,
1da177e4 LT	122	int mnt_flags, struct list_head *fslist);
	123
	124	extern void mark_mounts_for_expiry(struct list_head *mounts);
	125
	126	extern spinlock_t vfsmount_lock;
d53d9f16	127	extern dev_t name_to_dev_t(char *name);
1da177e4	128
1da177e4	129	#endif /* _LINUX_MOUNT_H */