fs/mount.h

   1 #include <linux/mount.h>
   2 #include <linux/seq_file.h>
   3 #include <linux/poll.h>
   4
   5 struct mnt_namespace {
   6         atomic_t                count;
   7         unsigned int            proc_inum;
   8         struct mount *  root;
   9         struct list_head        list;
  10         struct user_namespace   *user_ns;
  11         u64                     seq;    /* Sequence number to prevent loops */
  12         wait_queue_head_t poll;
  13         int event;
  14 };
  15
  16 struct mnt_pcp {
  17         int mnt_count;
  18         int mnt_writers;
  19 };
  20
  21 struct mountpoint {
  22         struct list_head m_hash;
  23         struct dentry *m_dentry;
  24         int m_count;
  25 };
  26
  27 struct mount {
  28         struct list_head mnt_hash;
  29         struct mount *mnt_parent;
  30         struct dentry *mnt_mountpoint;
  31         struct vfsmount mnt;
  32 #ifdef CONFIG_SMP
  33         struct mnt_pcp __percpu *mnt_pcp;
  34 #else
  35         int mnt_count;
  36         int mnt_writers;
  37 #endif
  38         struct list_head mnt_mounts;    /* list of children, anchored here */
  39         struct list_head mnt_child;     /* and going through their mnt_child */
  40         struct list_head mnt_instance;  /* mount instance on sb->s_mounts */
  41         const char *mnt_devname;        /* Name of device e.g. /dev/dsk/hda1 */
  42         struct list_head mnt_list;
  43         struct list_head mnt_expire;    /* link in fs-specific expiry list */
  44         struct list_head mnt_share;     /* circular list of shared mounts */
  45         struct list_head mnt_slave_list;/* list of slave mounts */
  46         struct list_head mnt_slave;     /* slave list entry */
  47         struct mount *mnt_master;       /* slave is on master->mnt_slave_list */
  48         struct mnt_namespace *mnt_ns;   /* containing namespace */
  49         struct mountpoint *mnt_mp;      /* where is it mounted */
  50 #ifdef CONFIG_FSNOTIFY
  51         struct hlist_head mnt_fsnotify_marks;
  52         __u32 mnt_fsnotify_mask;
  53 #endif
  54         int mnt_id;                     /* mount identifier */
  55         int mnt_group_id;               /* peer group identifier */
  56         int mnt_expiry_mark;            /* true if marked for expiry */
  57         int mnt_pinned;
  58         int mnt_ghosts;
  59 };
  60
  61 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
  62
  63 static inline struct mount *real_mount(struct vfsmount *mnt)
  64 {
  65         return container_of(mnt, struct mount, mnt);
  66 }
  67
  68 static inline int mnt_has_parent(struct mount *mnt)
  69 {
  70         return mnt != mnt->mnt_parent;
  71 }
  72
  73 static inline int is_mounted(struct vfsmount *mnt)
  74 {
  75         /* neither detached nor internal? */
  76         return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
  77 }
  78
  79 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
  80
  81 static inline void get_mnt_ns(struct mnt_namespace *ns)
  82 {
  83         atomic_inc(&ns->count);
  84 }
  85
  86 struct proc_mounts {
  87         struct seq_file m;
  88         struct mnt_namespace *ns;
  89         struct path root;
  90         int (*show)(struct seq_file *, struct vfsmount *);
  91 };
  92
  93 #define proc_mounts(p) (container_of((p), struct proc_mounts, m))
  94
  95 extern const struct seq_operations mounts_op;