add lab answers

labcodes_answer/lab8_result/kern/fs/fs.h

@@ -0,0 +1,61 @@
+#ifndef __KERN_FS_FS_H__
+#define __KERN_FS_FS_H__
+
+#include <defs.h>
+#include <mmu.h>
+#include <sem.h>
+#include <atomic.h>
+
+#define SECTSIZE            512
+#define PAGE_NSECT          (PGSIZE / SECTSIZE)
+
+#define SWAP_DEV_NO         1
+#define DISK0_DEV_NO        2
+#define DISK1_DEV_NO        3
+
+void fs_init(void);
+void fs_cleanup(void);
+
+struct inode;
+struct file;
+
+/*
+ * process's file related informaction
+ */
+struct files_struct {
+    struct inode *pwd;      // inode of present working directory
+    struct file *fd_array;  // opened files array
+    int files_count;        // the number of opened files
+    semaphore_t files_sem;  // lock protect sem
+};
+
+#define FILES_STRUCT_BUFSIZE                       (PGSIZE - sizeof(struct files_struct))
+#define FILES_STRUCT_NENTRY                        (FILES_STRUCT_BUFSIZE / sizeof(struct file))
+
+void lock_files(struct files_struct *filesp);
+void unlock_files(struct files_struct *filesp);
+
+struct files_struct *files_create(void);
+void files_destroy(struct files_struct *filesp);
+void files_closeall(struct files_struct *filesp);
+int dup_files(struct files_struct *to, struct files_struct *from);
+
+static inline int
+files_count(struct files_struct *filesp) {
+    return filesp->files_count;
+}
+
+static inline int
+files_count_inc(struct files_struct *filesp) {
+    filesp->files_count += 1;
+    return filesp->files_count;
+}
+
+static inline int
+files_count_dec(struct files_struct *filesp) {
+    filesp->files_count -= 1;
+    return filesp->files_count;
+}
+
+#endif /* !__KERN_FS_FS_H__ */
+