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 <[email protected]> 7 * 8 * Version: $Id: mount.h,v 2.0 1996/11/17 16:48:14 mvw Exp mvw $ 9 * 10 */ 11 #ifndef _LINUX_MOUNT_H 12 #define _LINUX_MOUNT_H 13 #ifdef __KERNEL__ 14 15 #include <linux/types.h> 16 #include <linux/list.h> 17 #include <linux/spinlock.h> 18 #include <asm/atomic.h> 19 20 struct super_block; 21 struct vfsmount; 22 struct dentry; 23 struct mnt_namespace; 24 25 #define MNT_NOSUID 0x01 26 #define MNT_NODEV 0x02 27 #define MNT_NOEXEC 0x04 28 #define MNT_NOATIME 0x08 29 #define MNT_NODIRATIME 0x10 30 #define MNT_RELATIME 0x20 31 32 #define MNT_SHRINKABLE 0x100 33 34 #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ 35 #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ 36 #define MNT_PNODE_MASK 0x3000 /* propagation flag mask */ 37 38 struct vfsmount { 39 struct list_head mnt_hash; 40 struct vfsmount *mnt_parent; /* fs we are mounted on */ 41 struct dentry *mnt_mountpoint; /* dentry of mountpoint */ 42 struct dentry *mnt_root; /* root of the mounted tree */ 43 struct super_block *mnt_sb; /* pointer to superblock */ 44 struct list_head mnt_mounts; /* list of children, anchored here */ 45 struct list_head mnt_child; /* and going through their mnt_child */ 46 int mnt_flags; 47 /* 4 bytes hole on 64bits arches */ 48 char *mnt_devname; /* Name of device e.g. /dev/dsk/hda1 */ 49 struct list_head mnt_list; 50 struct list_head mnt_expire; /* link in fs-specific expiry list */ 51 struct list_head mnt_share; /* circular list of shared mounts */ 52 struct list_head mnt_slave_list;/* list of slave mounts */ 53 struct list_head mnt_slave; /* slave list entry */ 54 struct vfsmount *mnt_master; /* slave is on master->mnt_slave_list */ 55 struct mnt_namespace *mnt_ns; /* containing namespace */ 56 /* 57 * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount 58 * to let these frequently modified fields in a separate cache line 59 * (so that reads of mnt_flags wont ping-pong on SMP machines) 60 */ 61 atomic_t mnt_count; 62 int mnt_expiry_mark; /* true if marked for expiry */ 63 int mnt_pinned; 64 }; 65 66 static inline struct vfsmount *mntget(struct vfsmount *mnt) 67 { 68 if (mnt) 69 atomic_inc(&mnt->mnt_count); 70 return mnt; 71 } 72 73 extern void mntput_no_expire(struct vfsmount *mnt); 74 extern void mnt_pin(struct vfsmount *mnt); 75 extern void mnt_unpin(struct vfsmount *mnt); 76 77 static inline void mntput(struct vfsmount *mnt) 78 { 79 if (mnt) { 80 mnt->mnt_expiry_mark = 0; 81 mntput_no_expire(mnt); 82 } 83 } 84 85 extern void free_vfsmnt(struct vfsmount *mnt); 86 extern struct vfsmount *alloc_vfsmnt(const char *name); 87 extern struct vfsmount *do_kern_mount(const char *fstype, int flags, 88 const char *name, void *data); 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 95 struct nameidata; 96 97 extern int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd, 98 int mnt_flags, struct list_head *fslist); 99 100 extern void mark_mounts_for_expiry(struct list_head *mounts); 101 extern void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts); 102 103 extern spinlock_t vfsmount_lock; 104 extern dev_t name_to_dev_t(char *name); 105 106 #endif 107 #endif /* _LINUX_MOUNT_H */ 108