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_PROPAGATION_MASK (MNT_SHARED | MNT_UNBINDABLE) 46 47 #define MNT_INTERNAL_FLAGS (MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL | \ 48 MNT_MARKED) 49 50 #define MNT_INTERNAL 0x4000 51 52 #define MNT_LOCK_READONLY 0x400000 53 #define MNT_MARKED 0x4000000 54 55 struct vfsmount { 56 struct dentry *mnt_root; /* root of the mounted tree */ 57 struct super_block *mnt_sb; /* pointer to superblock */ 58 int mnt_flags; 59 void *data; 60 }; 61 62 struct file; /* forward dec */ 63 64 extern int mnt_want_write(struct vfsmount *mnt); 65 extern int mnt_want_write_file(struct file *file); 66 extern int mnt_clone_write(struct vfsmount *mnt); 67 extern void mnt_drop_write(struct vfsmount *mnt); 68 extern void mnt_drop_write_file(struct file *file); 69 extern void mntput(struct vfsmount *mnt); 70 extern struct vfsmount *mntget(struct vfsmount *mnt); 71 extern void mnt_pin(struct vfsmount *mnt); 72 extern void mnt_unpin(struct vfsmount *mnt); 73 extern int __mnt_is_readonly(struct vfsmount *mnt); 74 75 struct file_system_type; 76 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 77 int flags, const char *name, 78 void *data); 79 80 extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 81 extern void mark_mounts_for_expiry(struct list_head *mounts); 82 83 extern dev_t name_to_dev_t(char *name); 84 85 #endif /* _LINUX_MOUNT_H */ 86