ceph/src/client/Dentry.h

   1 #ifndef CEPH_CLIENT_DENTRY_H
   2 #define CEPH_CLIENT_DENTRY_H
   3
   4 #include "include/lru.h"
   5 #include "include/xlist.h"
   6
   7 #include "mds/mdstypes.h"
   8 #include "Inode.h"
   9 #include "InodeRef.h"
  10 #include "Dir.h"
  11
  12 class Dentry : public LRUObject {
  13 public:
  14   explicit Dentry(Dir *_dir, const std::string &_name) :
  15     dir(_dir), name(_name), inode_xlist_link(this)
  16   {
  17     auto r = dir->dentries.insert(make_pair(name, this));
  18     ceph_assert(r.second);
  19     dir->num_null_dentries++;
  20   }
  21   ~Dentry() {
  22     ceph_assert(ref == 0);
  23     ceph_assert(dir == nullptr);
  24   }
  25
  26   /*
  27    * ref==1 -> cached, unused
  28    * ref >1 -> pinned in lru
  29    */
  30   void get() {
  31     ceph_assert(ref > 0);
  32     if (++ref == 2)
  33       lru_pin();
  34     //cout << "dentry.get on " << this << " " << name << " now " << ref << std::endl;
  35   }
  36   void put() {
  37     ceph_assert(ref > 0);
  38     if (--ref == 1)
  39       lru_unpin();
  40     //cout << "dentry.put on " << this << " " << name << " now " << ref << std::endl;
  41     if (ref == 0)
  42       delete this;
  43   }
  44   void link(InodeRef in) {
  45     inode = in;
  46     inode->dentries.push_back(&inode_xlist_link);
  47     if (inode->is_dir()) {
  48       if (inode->dir)
  49         get(); // dir -> dn pin
  50       if (inode->ll_ref)
  51         get(); // ll_ref -> dn pin
  52     }
  53     dir->num_null_dentries--;
  54   }
  55   void unlink(void) {
  56     if (inode->is_dir()) {
  57       if (inode->dir)
  58         put(); // dir -> dn pin
  59       if (inode->ll_ref)
  60         put(); // ll_ref -> dn pin
  61     }
  62     ceph_assert(inode_xlist_link.get_list() == &inode->dentries);
  63     inode_xlist_link.remove_myself();
  64     inode.reset();
  65     dir->num_null_dentries++;
  66   }
  67   void mark_primary() {
  68     if (inode && inode->dentries.front() != this)
  69       inode->dentries.push_front(&inode_xlist_link);
  70   }
  71   void detach(void) {
  72     ceph_assert(!inode);
  73     auto p = dir->dentries.find(name);
  74     ceph_assert(p != dir->dentries.end());
  75     dir->dentries.erase(p);
  76     dir->num_null_dentries--;
  77     dir = nullptr;
  78   }
  79
  80   void dump(Formatter *f) const;
  81   friend std::ostream &operator<<(std::ostream &oss, const Dentry &Dentry);
  82
  83   Dir      *dir;
  84   const string name;
  85   InodeRef inode;
  86   int      ref = 1; // 1 if there's a dir beneath me.
  87   int64_t offset = 0;
  88   mds_rank_t lease_mds = -1;
  89   utime_t lease_ttl;
  90   uint64_t lease_gen = 0;
  91   ceph_seq_t lease_seq = 0;
  92   int cap_shared_gen = 0;
  93   std::string alternate_name;
  94
  95 private:
  96   xlist<Dentry *>::item inode_xlist_link;
  97 };
  98
  99 #endif