[PATCH] pivot_root: add comment
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / mount.h
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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 *
8 * Version: $Id: mount.h,v 2.0 1996/11/17 16:48:14 mvw Exp mvw $
9 *
10 */
11#ifndef _LINUX_MOUNT_H
12#define _LINUX_MOUNT_H
13#ifdef __KERNEL__
14
d53d9f16 15#include <linux/types.h>
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16#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <asm/atomic.h>
19
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20#define MNT_NOSUID 0x01
21#define MNT_NODEV 0x02
22#define MNT_NOEXEC 0x04
03e06e68 23#define MNT_SHARED 0x10 /* if the vfsmount is a shared mount */
9676f0c6 24#define MNT_UNBINDABLE 0x20 /* if the vfsmount is a unbindable mount */
07b20889 25#define MNT_PNODE_MASK 0x30 /* propogation flag mask */
1da177e4 26
07b20889 27struct vfsmount {
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28 struct list_head mnt_hash;
29 struct vfsmount *mnt_parent; /* fs we are mounted on */
30 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
31 struct dentry *mnt_root; /* root of the mounted tree */
32 struct super_block *mnt_sb; /* pointer to superblock */
33 struct list_head mnt_mounts; /* list of children, anchored here */
34 struct list_head mnt_child; /* and going through their mnt_child */
35 atomic_t mnt_count;
36 int mnt_flags;
37 int mnt_expiry_mark; /* true if marked for expiry */
38 char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
39 struct list_head mnt_list;
55e700b9 40 struct list_head mnt_expire; /* link in fs-specific expiry list */
03e06e68 41 struct list_head mnt_share; /* circular list of shared mounts */
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42 struct list_head mnt_slave_list;/* list of slave mounts */
43 struct list_head mnt_slave; /* slave list entry */
44 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
1da177e4 45 struct namespace *mnt_namespace; /* containing namespace */
7b7b1ace 46 int mnt_pinned;
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47};
48
49static inline struct vfsmount *mntget(struct vfsmount *mnt)
50{
51 if (mnt)
52 atomic_inc(&mnt->mnt_count);
53 return mnt;
54}
55
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56extern void mntput_no_expire(struct vfsmount *mnt);
57extern void mnt_pin(struct vfsmount *mnt);
58extern void mnt_unpin(struct vfsmount *mnt);
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59
60static inline void mntput(struct vfsmount *mnt)
61{
62 if (mnt) {
63 mnt->mnt_expiry_mark = 0;
751c404b 64 mntput_no_expire(mnt);
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65 }
66}
67
68extern void free_vfsmnt(struct vfsmount *mnt);
69extern struct vfsmount *alloc_vfsmnt(const char *name);
70extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
71 const char *name, void *data);
72
73struct nameidata;
74
75extern int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
76 int mnt_flags, struct list_head *fslist);
77
78extern void mark_mounts_for_expiry(struct list_head *mounts);
79
80extern spinlock_t vfsmount_lock;
d53d9f16 81extern dev_t name_to_dev_t(char *name);
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82
83#endif
84#endif /* _LINUX_MOUNT_H */