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 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_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 66 struct 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 void *data; 71 }; 72 73 struct file; /* forward dec */ 74 struct path; 75 76 extern int mnt_want_write(struct vfsmount *mnt); 77 extern int mnt_want_write_file(struct file *file); 78 extern int mnt_clone_write(struct vfsmount *mnt); 79 extern void mnt_drop_write(struct vfsmount *mnt); 80 extern void mnt_drop_write_file(struct file *file); 81 extern void mntput(struct vfsmount *mnt); 82 extern struct vfsmount *mntget(struct vfsmount *mnt); 83 extern struct vfsmount *mnt_clone_internal(struct path *path); 84 extern int __mnt_is_readonly(struct vfsmount *mnt); 85 extern bool mnt_may_suid(struct vfsmount *mnt); 86 87 struct path; 88 extern struct vfsmount *clone_private_mount(struct path *path); 89 90 struct file_system_type; 91 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 92 int flags, const char *name, 93 void *data); 94 extern struct vfsmount *vfs_submount(const struct dentry *mountpoint, 95 struct file_system_type *type, 96 const char *name, void *data); 97 98 extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 99 extern void mark_mounts_for_expiry(struct list_head *mounts); 100 101 extern dev_t name_to_dev_t(const char *name); 102 103 extern unsigned int sysctl_mount_max; 104 105 #endif /* _LINUX_MOUNT_H */ 106