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 <linux/seqlock.h> 17#include <linux/atomic.h> 18 19struct super_block; 20struct vfsmount; 21struct dentry; 22struct 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_USER_SETTABLE_MASK (MNT_NOSUID | MNT_NODEV | MNT_NOEXEC \ 46 | MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME \ 47 | MNT_READONLY) 48#define MNT_ATIME_MASK (MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME ) 49 50#define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ 51 MNT_DOOMED | MNT_SYNC_UMOUNT | MNT_MARKED) 52 53#define MNT_INTERNAL 0x4000 54 55#define MNT_LOCK_ATIME 0x040000 56#define MNT_LOCK_NOEXEC 0x080000 57#define MNT_LOCK_NOSUID 0x100000 58#define MNT_LOCK_NODEV 0x200000 59#define MNT_LOCK_READONLY 0x400000 60#define MNT_LOCKED 0x800000 61#define MNT_DOOMED 0x1000000 62#define MNT_SYNC_UMOUNT 0x2000000 63#define MNT_MARKED 0x4000000 64#define MNT_UMOUNT 0x8000000 65 66struct vfsmount { 67 struct dentry *mnt_root; /* root of the mounted tree */ 68 struct super_block *mnt_sb; /* pointer to superblock */ 69 int mnt_flags; 70}; 71 72struct file; /* forward dec */ 73struct path; 74 75extern int mnt_want_write(struct vfsmount *mnt); 76extern int mnt_want_write_file(struct file *file); 77extern int mnt_clone_write(struct vfsmount *mnt); 78extern void mnt_drop_write(struct vfsmount *mnt); 79extern void mnt_drop_write_file(struct file *file); 80extern void mntput(struct vfsmount *mnt); 81extern struct vfsmount *mntget(struct vfsmount *mnt); 82extern struct vfsmount *mnt_clone_internal(const struct path *path); 83extern int __mnt_is_readonly(struct vfsmount *mnt); 84extern bool mnt_may_suid(struct vfsmount *mnt); 85 86struct path; 87extern struct vfsmount *clone_private_mount(const struct path *path); 88 89struct file_system_type; 90extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 91 int flags, const char *name, 92 void *data); 93extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, 94 struct file_system_type *type, 95 const char *name, void *data); 96 97extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 98extern void mark_mounts_for_expiry(struct list_head *mounts); 99 100extern dev_t name_to_dev_t(const char *name); 101 102extern unsigned int sysctl_mount_max; 103 104extern bool path_is_mountpoint(const struct path *path); 105 106#endif /* _LINUX_MOUNT_H */ 107