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 mount {
  22         struct list_head mnt_hash;
  23         struct mount *mnt_parent;
  24         struct dentry *mnt_mountpoint;
  25         struct vfsmount mnt;
  26 #ifdef CONFIG_SMP
  27         struct mnt_pcp __percpu *mnt_pcp;
  28 #else
  29         int mnt_count;
  30         int mnt_writers;
  31 #endif
  32         struct list_head mnt_mounts;    /* list of children, anchored here */
  33         struct list_head mnt_child;     /* and going through their mnt_child */
  34         struct list_head mnt_instance;  /* mount instance on sb->s_mounts */
  35         const char *mnt_devname;        /* Name of device e.g. /dev/dsk/hda1 */
  36         struct list_head mnt_list;
  37         struct list_head mnt_expire;    /* link in fs-specific expiry list */
  38         struct list_head mnt_share;     /* circular list of shared mounts */
  39         struct list_head mnt_slave_list;/* list of slave mounts */
  40         struct list_head mnt_slave;     /* slave list entry */
  41         struct mount *mnt_master;       /* slave is on master->mnt_slave_list */
  42         struct mnt_namespace *mnt_ns;   /* containing namespace */
  43 #ifdef CONFIG_FSNOTIFY
  44         struct hlist_head mnt_fsnotify_marks;
  45         __u32 mnt_fsnotify_mask;
  46 #endif
  47         int mnt_id;                     /* mount identifier */
  48         int mnt_group_id;               /* peer group identifier */
  49         int mnt_expiry_mark;            /* true if marked for expiry */
  50         int mnt_pinned;
  51         int mnt_ghosts;
  52 };
  53
  54 #define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
  55
  56 static inline struct mount *real_mount(struct vfsmount *mnt)
  57 {
  58         return container_of(mnt, struct mount, mnt);
  59 }
  60
  61 static inline int mnt_has_parent(struct mount *mnt)
  62 {
  63         return mnt != mnt->mnt_parent;
  64 }
  65
  66 static inline int is_mounted(struct vfsmount *mnt)
  67 {
  68         /* neither detached nor internal? */
  69         return !IS_ERR_OR_NULL(real_mount(mnt));
  70 }
  71
  72 extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
  73
  74 static inline void get_mnt_ns(struct mnt_namespace *ns)
  75 {
  76         atomic_inc(&ns->count);
  77 }
  78
  79 struct proc_mounts {
  80         struct seq_file m;
  81         struct mnt_namespace *ns;
  82         struct path root;
  83         int (*show)(struct seq_file *, struct vfsmount *);
  84 };
  85
  86 #define proc_mounts(p) (container_of((p), struct proc_mounts, m))
  87
  88 extern const struct seq_operations mounts_op;