sequential du

bfdbe916 · Nickolai Zeldovich · 9cc8199d · bfdbe916 · bfdbe916 · bfdbe916
--- a/bin/Makefrag
+++ b/bin/Makefrag
 UPROGS= \
 	cat \
+        du \
 	echo \
 	init \
 	forkexectree \

--- a/bin/du.cc
+++ b/bin/du.cc
+#include "types.h"
+#include "stat.h"
+#include "user.h"
+#include "fs.h"
+static int
+du(int fd)
+{
+  struct stat st;
+  if (fstat(fd, &st) < 0) {
+    fprintf(2, "du: cannot stat\n");
+    close(fd);
+    return 0;
+  }
+  int size = st.size;
+  if (st.type == T_DIR) {
+    struct dirent de;
+    while (read(fd, &de, sizeof(de)) == sizeof(de)) {
+      if (de.inum == 0)
+        continue;
+      char buf[DIRSIZ+1];
+      memmove(buf, de.name, DIRSIZ);
+      buf[DIRSIZ] = 0;
+      if (!strcmp(buf, ".") || !strcmp(buf, ".."))
+        continue;
+      int nfd = openat(fd, buf, 0);
+      if (nfd >= 0)
+        size += du(nfd);  // should go into work queue
+    }
+  }
+  close(fd);
+  return size;
+}
+int
+main(int ac, char **av)
+{
+  printf("%d\n", du(open(".", 0)));
+  exit();
+}
--- a/kernel/file.cc
+++ b/kernel/file.cc
@@ -15,6 +15,7 @@ filealloc(void)
 {
  struct file *f = (file*) kmalloc(sizeof(struct file));
  f->ref = 1;
+  f->type = file::FD_NONE;
  return f;
 }
@@ -40,7 +41,7 @@ fileclose(struct file *f)
    iput(f->ip);
  else if(f->type == file::FD_SOCKET)
    netclose(f->socket);
-  else
+  else if(f->type != file::FD_NONE)
    panic("fileclose bad type");
  kmfree(f, sizeof(struct file));
 }