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)
48 #define MNT_INTERNAL 0x4000
51 struct list_head mnt_hash;
52 struct vfsmount *mnt_parent; /* fs we are mounted on */
53 struct dentry *mnt_mountpoint; /* dentry of mountpoint */
54 struct dentry *mnt_root; /* root of the mounted tree */
55 struct super_block *mnt_sb; /* pointer to superblock */
56 struct list_head mnt_mounts; /* list of children, anchored here */
57 struct list_head mnt_child; /* and going through their mnt_child */
59 /* 4 bytes hole on 64bits arches without fsnotify */
60 #ifdef CONFIG_FSNOTIFY
61 __u32 mnt_fsnotify_mask;
62 struct hlist_head mnt_fsnotify_marks;
64 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */
65 struct list_head mnt_list;
66 struct list_head mnt_expire; /* link in fs-specific expiry list */
67 struct list_head mnt_share; /* circular list of shared mounts */
68 struct list_head mnt_slave_list;/* list of slave mounts */
69 struct list_head mnt_slave; /* slave list entry */
70 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */
71 struct mnt_namespace *mnt_ns; /* containing namespace */
72 int mnt_id; /* mount identifier */
73 int mnt_group_id; /* peer group identifier */
75 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount
76 * to let these frequently modified fields in a separate cache line
77 * (so that reads of mnt_flags wont ping-pong on SMP machines)
80 int mnt_expiry_mark; /* true if marked for expiry */
84 int __percpu *mnt_writers;
90 static inline int *get_mnt_writers_ptr(struct vfsmount *mnt)
93 return mnt->mnt_writers;
95 return &mnt->mnt_writers;
99 static inline struct vfsmount *mntget(struct vfsmount *mnt)
102 atomic_inc(&mnt->mnt_count);
106 struct file; /* forward dec */
108 extern int mnt_want_write(struct vfsmount *mnt);
109 extern int mnt_want_write_file(struct file *file);
110 extern int mnt_clone_write(struct vfsmount *mnt);
111 extern void mnt_drop_write(struct vfsmount *mnt);
112 extern void mntput_no_expire(struct vfsmount *mnt);
113 extern void mnt_pin(struct vfsmount *mnt);
114 extern void mnt_unpin(struct vfsmount *mnt);
115 extern int __mnt_is_readonly(struct vfsmount *mnt);
117 static inline void mntput(struct vfsmount *mnt)
120 mnt->mnt_expiry_mark = 0;
121 mntput_no_expire(mnt);
125 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
126 const char *name, void *data);
128 struct file_system_type;
129 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
130 int flags, const char *name,
136 extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
137 int mnt_flags, struct list_head *fslist);
139 extern void mark_mounts_for_expiry(struct list_head *mounts);
141 extern dev_t name_to_dev_t(char *name);
143 #endif /* _LINUX_MOUNT_H */