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 <asm/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 48 #define MNT_INTERNAL 0x4000 49 50 struct mnt_pcp { 51 int mnt_count; 52 int mnt_writers; 53 }; 54 55 struct vfsmount { 56 struct list_head mnt_hash; 57 struct vfsmount *mnt_parent; /* fs we are mounted on */ 58 struct dentry *mnt_mountpoint; /* dentry of mountpoint */ 59 struct dentry *mnt_root; /* root of the mounted tree */ 60 struct super_block *mnt_sb; /* pointer to superblock */ 61 #ifdef CONFIG_SMP 62 struct mnt_pcp __percpu *mnt_pcp; 63 atomic_t mnt_longterm; /* how many of the refs are longterm */ 64 #else 65 int mnt_count; 66 int mnt_writers; 67 #endif 68 struct list_head mnt_mounts; /* list of children, anchored here */ 69 struct list_head mnt_child; /* and going through their mnt_child */ 70 int mnt_flags; 71 /* 4 bytes hole on 64bits arches without fsnotify */ 72 #ifdef CONFIG_FSNOTIFY 73 __u32 mnt_fsnotify_mask; 74 struct hlist_head mnt_fsnotify_marks; 75 #endif 76 const char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 77 struct list_head mnt_list; 78 struct list_head mnt_expire; /* link in fs-specific expiry list */ 79 struct list_head mnt_share; /* circular list of shared mounts */ 80 struct list_head mnt_slave_list;/* list of slave mounts */ 81 struct list_head mnt_slave; /* slave list entry */ 82 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */ 83 struct mnt_namespace *mnt_ns; /* containing namespace */ 84 int mnt_id; /* mount identifier */ 85 int mnt_group_id; /* peer group identifier */ 86 int mnt_expiry_mark; /* true if marked for expiry */ 87 int mnt_pinned; 88 int mnt_ghosts; 89 }; 90 91 struct file; /* forward dec */ 92 93 extern int mnt_want_write(struct vfsmount *mnt); 94 extern int mnt_want_write_file(struct file *file); 95 extern int mnt_clone_write(struct vfsmount *mnt); 96 extern void mnt_drop_write(struct vfsmount *mnt); 97 extern void mntput(struct vfsmount *mnt); 98 extern struct vfsmount *mntget(struct vfsmount *mnt); 99 extern void mnt_pin(struct vfsmount *mnt); 100 extern void mnt_unpin(struct vfsmount *mnt); 101 extern int __mnt_is_readonly(struct vfsmount *mnt); 102 103 extern struct vfsmount *do_kern_mount(const char *fstype, int flags, 104 const char *name, void *data); 105 106 struct file_system_type; 107 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, 108 int flags, const char *name, 109 void *data); 110 111 extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list); 112 extern void mark_mounts_for_expiry(struct list_head *mounts); 113 114 extern dev_t name_to_dev_t(char *name); 115 116 #endif /* _LINUX_MOUNT_H */ 117