Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 */
9#ifndef _LINUX_MOUNT_H
10#define _LINUX_MOUNT_H
11
12#include <linux/types.h>
13#include <linux/list.h>
14#include <linux/nodemask.h>
15#include <linux/spinlock.h>
16#include <asm/atomic.h>
17
18struct super_block;
19struct vfsmount;
20struct dentry;
21struct mnt_namespace;
22
23#define MNT_NOSUID 0x01
24#define MNT_NODEV 0x02
25#define MNT_NOEXEC 0x04
26#define MNT_NOATIME 0x08
27#define MNT_NODIRATIME 0x10
28#define MNT_RELATIME 0x20
29#define MNT_READONLY 0x40 /* does the user want this to be r/o? */
30
31#define MNT_SHRINKABLE 0x100
32#define MNT_IMBALANCED_WRITE_COUNT 0x200 /* just for debugging */
33
34#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
35#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
36#define MNT_PNODE_MASK 0x3000 /* propagation flag mask */
37
38struct vfsmount {
39 struct list_head mnt_hash;
40 struct vfsmount *mnt_parent; /* fs we are mounted on */
41 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
42 struct dentry *mnt_root; /* root of the mounted tree */
43 struct super_block *mnt_sb; /* pointer to superblock */
44 struct list_head mnt_mounts; /* list of children, anchored here */
45 struct list_head mnt_child; /* and going through their mnt_child */
46 int mnt_flags;
47 /* 4 bytes hole on 64bits arches */
48 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
49 struct list_head mnt_list;
50 struct list_head mnt_expire; /* link in fs-specific expiry list */
51 struct list_head mnt_share; /* circular list of shared mounts */
52 struct list_head mnt_slave_list;/* list of slave mounts */
53 struct list_head mnt_slave; /* slave list entry */
54 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
55 struct mnt_namespace *mnt_ns; /* containing namespace */
56 int mnt_id; /* mount identifier */
57 int mnt_group_id; /* peer group identifier */
58 /*
59 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
60 * to let these frequently modified fields in a separate cache line
61 * (so that reads of mnt_flags wont ping-pong on SMP machines)
62 */
63 atomic_t mnt_count;
64 int mnt_expiry_mark; /* true if marked for expiry */
65 int mnt_pinned;
66 int mnt_ghosts;
67 /*
68 * This value is not stable unless all of the mnt_writers[] spinlocks
69 * are held, and all mnt_writer[]s on this mount have 0 as their ->count
70 */
71 atomic_t __mnt_writers;
72};
73
74static inline struct vfsmount *mntget(struct vfsmount *mnt)
75{
76 if (mnt)
77 atomic_inc(&mnt->mnt_count);
78 return mnt;
79}
80
81extern int mnt_want_write(struct vfsmount *mnt);
82extern void mnt_drop_write(struct vfsmount *mnt);
83extern void mntput_no_expire(struct vfsmount *mnt);
84extern void mnt_pin(struct vfsmount *mnt);
85extern void mnt_unpin(struct vfsmount *mnt);
86extern int __mnt_is_readonly(struct vfsmount *mnt);
87
88static inline void mntput(struct vfsmount *mnt)
89{
90 if (mnt) {
91 mnt->mnt_expiry_mark = 0;
92 mntput_no_expire(mnt);
93 }
94}
95
96extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
97 const char *name, void *data);
98
99struct file_system_type;
100extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
101 int flags, const char *name,
102 void *data);
103
104struct nameidata;
105
106struct path;
107extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
108 int mnt_flags, struct list_head *fslist);
109
110extern void mark_mounts_for_expiry(struct list_head *mounts);
111
112extern spinlock_t vfsmount_lock;
113extern dev_t name_to_dev_t(char *name);
114
115#endif /* _LINUX_MOUNT_H */