LXR linux/fs/mount.h

   1#include <linux/mount.h>
   2#include <linux/seq_file.h>
   3#include <linux/poll.h>
   4#include <linux/ns_common.h>
   5#include <linux/fs_pin.h>
   6
   7struct mnt_namespace {
   8        atomic_t                count;
   9        struct ns_common        ns;
  10        struct mount *  root;
  11        struct list_head        list;
  12        struct user_namespace   *user_ns;
  13        struct ucounts          *ucounts;
  14        u64                     seq;    /* Sequence number to prevent loops */
  15        wait_queue_head_t poll;
  16        u64 event;
  17        unsigned int            mounts; /* # of mounts in the namespace */
  18        unsigned int            pending_mounts;
  19};
  20
  21struct mnt_pcp {
  22        int mnt_count;
  23        int mnt_writers;
  24};
  25
  26struct mountpoint {
  27        struct hlist_node m_hash;
  28        struct dentry *m_dentry;
  29        struct hlist_head m_list;
  30        int m_count;
  31};
  32
  33struct mount {
  34        struct hlist_node mnt_hash;
  35        struct mount *mnt_parent;
  36        struct dentry *mnt_mountpoint;
  37        struct vfsmount mnt;
  38        union {
  39                struct rcu_head mnt_rcu;
  40                struct llist_node mnt_llist;
  41        };
  42#ifdef CONFIG_SMP
  43        struct mnt_pcp __percpu *mnt_pcp;
  44#else
  45        int mnt_count;
  46        int mnt_writers;
  47#endif
  48        struct list_head mnt_mounts;    /* list of children, anchored here */
  49        struct list_head mnt_child;     /* and going through their mnt_child */
  50        struct list_head mnt_instance;  /* mount instance on sb->s_mounts */
  51        const char *mnt_devname;        /* Name of device e.g. /dev/dsk/hda1 */
  52        struct list_head mnt_list;
  53        struct list_head mnt_expire;    /* link in fs-specific expiry list */
  54        struct list_head mnt_share;     /* circular list of shared mounts */
  55        struct list_head mnt_slave_list;/* list of slave mounts */
  56        struct list_head mnt_slave;     /* slave list entry */
  57        struct mount *mnt_master;       /* slave is on master->mnt_slave_list */
  58        struct mnt_namespace *mnt_ns;   /* containing namespace */
  59        struct mountpoint *mnt_mp;      /* where is it mounted */
  60        struct hlist_node mnt_mp_list;  /* list mounts with the same mountpoint */
  61#ifdef CONFIG_FSNOTIFY
  62        struct fsnotify_mark_connector __rcu *mnt_fsnotify_marks;
  63        __u32 mnt_fsnotify_mask;
  64#endif
  65        int mnt_id;                     /* mount identifier */
  66        int mnt_group_id;               /* peer group identifier */
  67        int mnt_expiry_mark;            /* true if marked for expiry */
  68        struct hlist_head mnt_pins;
  69        struct fs_pin mnt_umount;
  70        struct dentry *mnt_ex_mountpoint;
  71};
  72
  73#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */
  74
  75static inline struct mount *real_mount(struct vfsmount *mnt)
  76{
  77        return container_of(mnt, struct mount, mnt);
  78}
  79
  80static inline int mnt_has_parent(struct mount *mnt)
  81{
  82        return mnt != mnt->mnt_parent;
  83}
  84
  85static inline int is_mounted(struct vfsmount *mnt)
  86{
  87        /* neither detached nor internal? */
  88        return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
  89}
  90
  91extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
  92
  93extern int __legitimize_mnt(struct vfsmount *, unsigned);
  94extern bool legitimize_mnt(struct vfsmount *, unsigned);
  95
  96static inline bool __path_is_mountpoint(const struct path *path)
  97{
  98        struct mount *m = __lookup_mnt(path->mnt, path->dentry);
  99        return m && likely(!(m->mnt.mnt_flags & MNT_SYNC_UMOUNT));
 100}
 101
 102extern void __detach_mounts(struct dentry *dentry);
 103
 104static inline void detach_mounts(struct dentry *dentry)
 105{
 106        if (!d_mountpoint(dentry))
 107                return;
 108        __detach_mounts(dentry);
 109}
 110
 111static inline void get_mnt_ns(struct mnt_namespace *ns)
 112{
 113        atomic_inc(&ns->count);
 114}
 115
 116extern seqlock_t mount_lock;
 117
 118static inline void lock_mount_hash(void)
 119{
 120        write_seqlock(&mount_lock);
 121}
 122
 123static inline void unlock_mount_hash(void)
 124{
 125        write_sequnlock(&mount_lock);
 126}
 127
 128struct proc_mounts {
 129        struct mnt_namespace *ns;
 130        struct path root;
 131        int (*show)(struct seq_file *, struct vfsmount *);
 132        void *cached_mount;
 133        u64 cached_event;
 134        loff_t cached_index;
 135};
 136
 137extern const struct seq_operations mounts_op;
 138
 139extern bool __is_local_mountpoint(struct dentry *dentry);
 140static inline bool is_local_mountpoint(struct dentry *dentry)
 141{
 142        if (!d_mountpoint(dentry))
 143                return false;
 144
 145        return __is_local_mountpoint(dentry);
 146}
 147