3 * Definitions for mount interface. This describes the in the kernel build
4 * linkedlist with mounted filesystems.
6 * Author: Marco van Wieringen <mvw@planets.elm.net>
10 #define _LINUX_MOUNT_H
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>
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 #define MNT_STRICTATIME 0x80
32 #define MNT_SHRINKABLE 0x100
33 #define MNT_WRITE_HOLD 0x200
35 #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
36 #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
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.
44 #define MNT_SHARED_MASK (MNT_UNBINDABLE)
45 #define MNT_PROPAGATION_MASK (MNT_SHARED | MNT_UNBINDABLE)
49 struct list_head mnt_hash;
50 struct vfsmount *mnt_parent; /* fs we are mounted on */
51 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
52 struct dentry *mnt_root; /* root of the mounted tree */
53 struct super_block *mnt_sb; /* pointer to superblock */
54 struct list_head mnt_mounts; /* list of children, anchored here */
55 struct list_head mnt_child; /* and going through their mnt_child */
57 /* 4 bytes hole on 64bits arches */
58 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
59 struct list_head mnt_list;
60 struct list_head mnt_expire; /* link in fs-specific expiry list */
61 struct list_head mnt_share; /* circular list of shared mounts */
62 struct list_head mnt_slave_list;/* list of slave mounts */
63 struct list_head mnt_slave; /* slave list entry */
64 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
65 struct mnt_namespace *mnt_ns; /* containing namespace */
66 int mnt_id; /* mount identifier */
67 int mnt_group_id; /* peer group identifier */
69 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
70 * to let these frequently modified fields in a separate cache line
71 * (so that reads of mnt_flags wont ping-pong on SMP machines)
74 int mnt_expiry_mark; /* true if marked for expiry */
84 static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
87 return mnt->mnt_writers;
89 return &mnt->mnt_writers;
93 static inline struct vfsmount *mntget(struct vfsmount *mnt)
96 atomic_inc(&mnt->mnt_count);
100 struct file; /* forward dec */
102 extern int mnt_want_write(struct vfsmount *mnt);
103 extern int mnt_want_write_file(struct file *file);
104 extern int mnt_clone_write(struct vfsmount *mnt);
105 extern void mnt_drop_write(struct vfsmount *mnt);
106 extern void mntput_no_expire(struct vfsmount *mnt);
107 extern void mnt_pin(struct vfsmount *mnt);
108 extern void mnt_unpin(struct vfsmount *mnt);
109 extern int __mnt_is_readonly(struct vfsmount *mnt);
111 static inline void mntput(struct vfsmount *mnt)
114 mnt->mnt_expiry_mark = 0;
115 mntput_no_expire(mnt);
119 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
120 const char *name, void *data);
122 struct file_system_type;
123 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
124 int flags, const char *name,
130 extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
131 int mnt_flags, struct list_head *fslist);
133 extern void mark_mounts_for_expiry(struct list_head *mounts);
135 extern spinlock_t vfsmount_lock;
136 extern dev_t name_to_dev_t(char *name);
138 #endif /* _LINUX_MOUNT_H */