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
15 #include <linux/types.h>
16 #include <linux/list.h>
17 #include <linux/spinlock.h>
18 #include <asm/atomic.h>
19
20 struct super_block;
21 struct vfsmount;
22 struct dentry;
23 struct namespace;
24
25 #define MNT_NOSUID 0x01
26 #define MNT_NODEV 0x02
27 #define MNT_NOEXEC 0x04
28 #define MNT_NOATIME 0x08
29 #define MNT_NODIRATIME 0x10
30
31 #define MNT_SHRINKABLE 0x100
32
33 #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
34 #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
35 #define MNT_PNODE_MASK 0x3000 /* propogation flag mask */
36
37 struct vfsmount {
38 struct list_head mnt_hash;
39 struct vfsmount *mnt_parent; /* fs we are mounted on */
40 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
41 struct dentry *mnt_root; /* root of the mounted tree */
42 struct super_block *mnt_sb; /* pointer to superblock */
43 struct list_head mnt_mounts; /* list of children, anchored here */
44 struct list_head mnt_child; /* and going through their mnt_child */
45 atomic_t mnt_count;
46 int mnt_flags;
47 int mnt_expiry_mark; /* true if marked for expiry */
48 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 namespace *mnt_namespace; /* containing namespace */
56 int mnt_pinned;
57 };
58
mntget(struct vfsmount * mnt)59 static inline struct vfsmount *mntget(struct vfsmount *mnt)
60 {
61 if (mnt)
62 atomic_inc(&mnt->mnt_count);
63 return mnt;
64 }
65
66 extern void mntput_no_expire(struct vfsmount *mnt);
67 extern void mnt_pin(struct vfsmount *mnt);
68 extern void mnt_unpin(struct vfsmount *mnt);
69
mntput(struct vfsmount * mnt)70 static inline void mntput(struct vfsmount *mnt)
71 {
72 if (mnt) {
73 mnt->mnt_expiry_mark = 0;
74 mntput_no_expire(mnt);
75 }
76 }
77
78 extern void free_vfsmnt(struct vfsmount *mnt);
79 extern struct vfsmount *alloc_vfsmnt(const char *name);
80 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
81 const char *name, void *data);
82
83 struct file_system_type;
84 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
85 int flags, const char *name,
86 void *data);
87
88 struct nameidata;
89
90 extern int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
91 int mnt_flags, struct list_head *fslist);
92
93 extern void mark_mounts_for_expiry(struct list_head *mounts);
94 extern void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts);
95
96 extern spinlock_t vfsmount_lock;
97 extern dev_t name_to_dev_t(char *name);
98
99 #endif
100 #endif /* _LINUX_MOUNT_H */
101