Wrap the xns holding a directory listing in a dirns class.

I'll be changing the dirns implementation soon.

Wrap the xns holding a directory listing in a dirns class.
cb7ca72d · Silas Boyd-Wickizer · 91424b90 · cb7ca72d · cb7ca72d · cb7ca72d
--- a/include/dirns.hh
+++ b/include/dirns.hh
+#pragma once
+
+u64 namehash(const strbuf<DIRSIZ>&);
+
+class dirns : public rcu_freed
+{
+public:
+  dirns() : rcu_freed("dirns"), ns_(false) {}
+
+  bool remove(const strbuf<DIRSIZ>& name, const u32* vp = nullptr) {
+    return ns_.remove(name, vp);
+  }
+
+  int  insert(const strbuf<DIRSIZ>& name, const u32& inum) {
+    return ns_.insert(name, inum);
+  }
+
+  u32  lookup(const strbuf<DIRSIZ>& name) {
+    return ns_.lookup(name);
+  }
+
+  template<class CB>
+  void enumerate(CB cb) {
+    return ns_.enumerate(cb);
+  }
+
+  virtual void do_gc(void) {
+    delete this;
+  }
+
+  NEW_DELETE_OPS(dirns);
+
+private:
+  xns<strbuf<DIRSIZ>, u32, namehash> ns_;
+};
--- a/include/file.hh
+++ b/include/file.hh
@@ -6,6 +6,8 @@
 #include "atomic.hh"
 #include "ref.hh"

+class dirns;
+
 u64 namehash(const strbuf<DIRSIZ>&);

 struct file : public referenced, public rcu_freed {
@@ -60,7 +62,7 @@ struct inode : public referenced, public rcu_freed
  struct condvar cv;
  struct spinlock lock;
  char lockname[16];
-  std::atomic<xns<strbuf<DIRSIZ>, u32, namehash>*> dir;
+  std::atomic<dirns*> dir;

  short type;        // copy of disk inode
  short major;

--- a/kernel/fs.cc
+++ b/kernel/fs.cc
@@ -39,6 +39,7 @@
 #include "file.hh"
 #include "cpu.hh"
 #include "kmtrace.hh"
+#include "dirns.hh"

 #define min(a, b) ((a) < (b) ? (a) : (b))
 static void itrunc(struct inode*);
@@ -708,7 +709,7 @@ dir_init(struct inode *dp)
  if (dp->type != T_DIR)
    panic("dir_init not DIR");

-  auto dir = new xns<strbuf<DIRSIZ>, u32, namehash>(false);
+  auto dir = new dirns();
  for (u32 off = 0; off < dp->size; off += BSIZE) {
    struct buf *bp = bread(dp->dev, bmap(dp, off / BSIZE), 0);
    for (struct dirent *de = (struct dirent *) bp->data;

--- a/kernel/sysfile.cc
+++ b/kernel/sysfile.cc
@@ -13,6 +13,7 @@
 #include "net.hh"
 #include "kmtrace.hh"
 #include "sperf.hh"
+#include "dirns.hh"

 static bool
 getfile(int fd, sref<file> *f)