Linux Kernel  3.7.1
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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 <[email protected]>
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 <linux/seqlock.h>
17 #include <linux/atomic.h>
18 
19 struct super_block;
20 struct vfsmount;
21 struct dentry;
22 struct mnt_namespace;
23 
24 #define MNT_NOSUID 0x01
25 #define MNT_NODEV 0x02
26 #define MNT_NOEXEC 0x04
27 #define MNT_NOATIME 0x08
28 #define MNT_NODIRATIME 0x10
29 #define MNT_RELATIME 0x20
30 #define MNT_READONLY 0x40 /* does the user want this to be r/o? */
31 
32 #define MNT_SHRINKABLE 0x100
33 #define MNT_WRITE_HOLD 0x200
34 
35 #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
36 #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
37 /*
38  * MNT_SHARED_MASK is the set of flags that should be cleared when a
39  * mount becomes shared. Currently, this is only the flag that says a
40  * mount cannot be bind mounted, since this is how we create a mount
41  * that shares events with another mount. If you add a new MNT_*
42  * flag, consider how it interacts with shared mounts.
43  */
44 #define MNT_SHARED_MASK (MNT_UNBINDABLE)
45 #define MNT_PROPAGATION_MASK (MNT_SHARED | MNT_UNBINDABLE)
46 
47 
48 #define MNT_INTERNAL 0x4000
49 
50 struct vfsmount {
51  struct dentry *mnt_root; /* root of the mounted tree */
52  struct super_block *mnt_sb; /* pointer to superblock */
53  int mnt_flags;
54 };
55 
56 struct file; /* forward dec */
57 
58 extern int mnt_want_write(struct vfsmount *mnt);
59 extern int mnt_want_write_file(struct file *file);
60 extern int mnt_clone_write(struct vfsmount *mnt);
61 extern void mnt_drop_write(struct vfsmount *mnt);
62 extern void mnt_drop_write_file(struct file *file);
63 extern void mntput(struct vfsmount *mnt);
64 extern struct vfsmount *mntget(struct vfsmount *mnt);
65 extern void mnt_pin(struct vfsmount *mnt);
66 extern void mnt_unpin(struct vfsmount *mnt);
67 extern int __mnt_is_readonly(struct vfsmount *mnt);
68 
69 struct file_system_type;
70 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
71  int flags, const char *name,
72  void *data);
73 
74 extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
75 extern void mark_mounts_for_expiry(struct list_head *mounts);
76 
77 extern dev_t name_to_dev_t(char *name);
78 
79 #endif /* _LINUX_MOUNT_H */