include/linux/mount.h

   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  * 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 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
  31 #define MNT_SHRINKABLE  0x100
  32
  33 #define MNT_SHARED      0x1000  /* if the vfsmount is a shared mount */
  34 #define MNT_UNBINDABLE  0x2000  /* if the vfsmount is a unbindable mount */
  35 #define MNT_PNODE_MASK  0x3000  /* propogation flag mask */
  36
  37 struct vfsmount {
  38         struct list_head mnt_hash;
  39         struct vfsmount *mnt_parent;    /* fs we are mounted on */
  40         struct dentry *mnt_mountpoint;  /* dentry of mountpoint */
  41         struct dentry *mnt_root;        /* root of the mounted tree */
  42         struct super_block *mnt_sb;     /* pointer to superblock */
  43         struct list_head mnt_mounts;    /* list of children, anchored here */
  44         struct list_head mnt_child;     /* and going through their mnt_child */
  45         atomic_t mnt_count;
  46         int mnt_flags;
  47         int mnt_expiry_mark;            /* true if marked for expiry */
  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 namespace *mnt_namespace; /* containing namespace */
  56         int mnt_pinned;
  57 };
  58
  59 static inline struct vfsmount *mntget(struct vfsmount *mnt)
  60 {
  61         if (mnt)
  62                 atomic_inc(&mnt->mnt_count);
  63         return mnt;
  64 }
  65
  66 extern void mntput_no_expire(struct vfsmount *mnt);
  67 extern void mnt_pin(struct vfsmount *mnt);
  68 extern void mnt_unpin(struct vfsmount *mnt);
  69
  70 static inline void mntput(struct vfsmount *mnt)
  71 {
  72         if (mnt) {
  73                 mnt->mnt_expiry_mark = 0;
  74                 mntput_no_expire(mnt);
  75         }
  76 }
  77
  78 extern void free_vfsmnt(struct vfsmount *mnt);
  79 extern struct vfsmount *alloc_vfsmnt(const char *name);
  80 extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
  81                                       const char *name, void *data);
  82
  83 struct file_system_type;
  84 extern struct vfsmount *vfs_kern_mount(struct file_system_type *type,
  85                                       int flags, const char *name,
  86                                       void *data);
  87
  88 struct nameidata;
  89
  90 extern int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
  91                         int mnt_flags, struct list_head *fslist);
  92
  93 extern void mark_mounts_for_expiry(struct list_head *mounts);
  94 extern void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts);
  95
  96 extern spinlock_t vfsmount_lock;
  97 extern dev_t name_to_dev_t(char *name);
  98
  99 #endif
 100 #endif /* _LINUX_MOUNT_H */