X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Ffilesys%2Ffilesys.c;h=5df0d9d6b01145d7b132fab8cfa4577c039097da;hb=c0206643b024b6f0e6cde1cbb5e7d37abbc84c69;hp=2cc07217aa19dddb75d8f188bcb77e7a579d8db5;hpb=621963e2a383d53b2c5eca627102625421b46545;p=pintos-anon

diff --git a/src/filesys/filesys.c b/src/filesys/filesys.c
index 2cc0721..5df0d9d 100644
--- a/src/filesys/filesys.c
+++ b/src/filesys/filesys.c
@@ -1,227 +1,163 @@
-#include "filesys.h"
-#include "bitmap.h"
-#include "debug.h"
-#include "directory.h"
-#include "disk.h"
-#include "file.h"
-#include "filehdr.h"
-#include "lib.h"
-
-#define FREE_MAP_SECTOR 0
-#define ROOT_DIR_SECTOR 1
-
-#define NUM_DIR_ENTRIES 10
-#define ROOT_DIR_FILE_SIZE (sizeof (struct dir_entry) * NUM_DIR_ENTRIES)
-
+#include "filesys/filesys.h"
+#include <debug.h>
+#include <stdio.h>
+#include <string.h>
+#include "filesys/file.h"
+#include "filesys/free-map.h"
+#include "filesys/inode.h"
+#include "filesys/directory.h"
+#include "devices/disk.h"
+
+/* The disk that contains the file system. */
 struct disk *filesys_disk;
 
-static struct file free_map_file, root_dir_file;
-
-static void
-do_format (void)
-{
-  struct bitmap free_map;
-  struct filehdr *map_hdr, *dir_hdr;
-  struct dir dir;
-
-  /* Create the initial bitmap and reserve sectors for the
-     free map and root directory file headers. */
-  if (!bitmap_init (&free_map, disk_size (filesys_disk)))
-    panic ("bitmap creation failed--disk is too large");
-  bitmap_mark (&free_map, FREE_MAP_SECTOR);
-  bitmap_mark (&free_map, ROOT_DIR_SECTOR);
-
-  /* Allocate data sector(s) for the free map file
-     and write its file header to disk. */
-  map_hdr = filehdr_allocate (&free_map, bitmap_storage_size (&free_map));
-  if (map_hdr == NULL)
-    panic ("free map creation failed--disk is too large");
-  filehdr_write (map_hdr, FREE_MAP_SECTOR);
-  filehdr_destroy (map_hdr);
-
-  /* Allocate data sector(s) for the root directory file
-     and write its file header to disk. */
-  dir_hdr = filehdr_allocate (&free_map, ROOT_DIR_FILE_SIZE);
-  if (dir_hdr == NULL)
-    panic ("root directory creation failed");
-  filehdr_write (dir_hdr, ROOT_DIR_SECTOR);
-  filehdr_destroy (dir_hdr);
-
-  /* Write out the free map now that we have space reserved
-     for it. */
-  file_open (&free_map_file, FREE_MAP_SECTOR);
-  bitmap_write (&free_map, &free_map_file);
-  bitmap_destroy (&free_map);
-  file_close (&free_map_file);
-
-  /* Write out the root directory in the same way. */
-  if (!file_open (&root_dir_file, ROOT_DIR_SECTOR))
-    panic ("can't open root directory");
-  if (!dir_init (&dir, NUM_DIR_ENTRIES))
-    panic ("can't initialize root directory");
-  dir_write (&dir, &root_dir_file);
-  dir_destroy (&dir);
-  file_close (&free_map_file);
-}
+static void do_format (void);
 
+/* Initializes the file system module.
+   If FORMAT is true, reformats the file system. */
 void
 filesys_init (bool format) 
 {
-  filesys_disk = disk_get (1);
+  filesys_disk = disk_get (0, 1);
   if (filesys_disk == NULL)
-    panic ("ide1:1 not present, filesystem initialization failed");
+    PANIC ("hd0:1 (hdb) not present, file system initialization failed");
+
+  inode_init ();
+  free_map_init ();
 
   if (format) 
     do_format ();
-  
-  file_open (&free_map_file, FREE_MAP_SECTOR);
-  file_open (&root_dir_file, ROOT_DIR_SECTOR);
+
+  free_map_open ();
 }
 
+/* Shuts down the file system module, writing any unwritten data
+   to disk. */
+void
+filesys_done (void) 
+{
+  free_map_close ();
+}
+
+/* Creates a file named NAME with the given INITIAL_SIZE.
+   Returns true if successful, false otherwise.
+   Fails if a file named NAME already exists,
+   or if internal memory allocation fails. */
 bool
 filesys_create (const char *name, off_t initial_size) 
 {
-  struct dir dir;
-  struct bitmap free_map;
-  disk_sector_no hdr_sector;
-  struct filehdr *filehdr;
-  bool success = false;
-
-  /* Read the root directory. */
-  dir_init (&dir, NUM_DIR_ENTRIES);
-  dir_read (&dir, &root_dir_file);
-  if (dir_lookup (&dir, name, NULL)) 
-    goto exit1;
-
-  /* Allocate a block for the file header. */
-  if (!bitmap_init (&free_map, disk_size (filesys_disk)))
-    goto exit1;
-  bitmap_read (&free_map, &free_map_file);
-  hdr_sector = bitmap_find_and_set (&free_map);
-  if (hdr_sector == BITMAP_ERROR)
-    goto exit2;
-
-  /* Add the file to the directory. */
-  if (!dir_add (&dir, name, hdr_sector))
-    goto exit2;
-
-  /* Allocate space for the file. */
-  filehdr = filehdr_allocate (&free_map, initial_size);
-  if (filehdr == NULL)
-    goto exit2;
-
-  /* Write everything back. */
-  filehdr_write (filehdr, hdr_sector);
-  dir_write (&dir, &root_dir_file);
-  bitmap_write (&free_map, &free_map_file);
-
-  success = true;
-
-  /* Clean up. */
-  filehdr_destroy (filehdr);
- exit2:
-  bitmap_destroy (&free_map);
- exit1:
-  dir_destroy (&dir);
+  disk_sector_t inode_sector = 0;
+  struct dir *dir = dir_open_root ();
+  bool success = (dir != NULL
+                  && free_map_allocate (1, &inode_sector)
+                  && inode_create (inode_sector, initial_size)
+                  && dir_add (dir, name, inode_sector));
+  if (!success && inode_sector != 0) 
+    free_map_release (inode_sector, 1);
+  dir_close (dir);
 
   return success;
 }
 
-bool
-filesys_open (const char *name, struct file *file)
+/* Opens the file with the given NAME.
+   Returns the new file if successful or a null pointer
+   otherwise.
+   Fails if no file named NAME exists,
+   or if an internal memory allocation fails. */
+struct file *
+filesys_open (const char *name)
 {
-  struct dir dir;
-  disk_sector_no hdr_sector;
-  bool success = false;
-
-  dir_init (&dir, NUM_DIR_ENTRIES);
-  dir_read (&dir, &root_dir_file);
-  if (dir_lookup (&dir, name, &hdr_sector))
-    success = file_open (file, hdr_sector);
-  
-  dir_destroy (&dir);
-  return success;
+  struct dir *dir = dir_open_root ();
+  struct inode *inode = NULL;
+
+  if (dir != NULL)
+    dir_lookup (dir, name, &inode);
+  dir_close (dir);
+
+  return file_open (inode);
 }
 
+/* Deletes the file named NAME.
+   Returns true if successful, false on failure.
+   Fails if no file named NAME exists,
+   or if an internal memory allocation fails. */
 bool
 filesys_remove (const char *name) 
 {
-  struct dir dir;
-  disk_sector_no hdr_sector;
-  struct filehdr *filehdr;
-  struct bitmap free_map;
-  bool success = false;
-
-  /* Read the root directory. */
-  dir_init (&dir, NUM_DIR_ENTRIES);
-  dir_read (&dir, &root_dir_file);
-  if (!dir_lookup (&dir, name, &hdr_sector))
-    goto exit1;
-
-  /* Read the file header. */
-  filehdr = filehdr_read (hdr_sector);
-  if (filehdr == NULL)
-    goto exit1;
-
-  /* Allocate a block for the file header. */
-  if (!bitmap_init (&free_map, disk_size (filesys_disk)))
-    goto exit2;
-  bitmap_read (&free_map, &free_map_file);
-
-  /* Deallocate. */
-  filehdr_deallocate (filehdr, &free_map);
-  bitmap_reset (&free_map, hdr_sector);
-  dir_remove (&dir, name);
-
-  /* Write everything back. */
-  bitmap_write (&free_map, &free_map_file);
-  dir_write (&dir, &root_dir_file);
-
-  success = true;
-
-  /* Clean up. */
-  bitmap_destroy (&free_map);
- exit2:
-  filehdr_destroy (filehdr);
- exit1:
-  dir_destroy (&dir);
+  struct dir *dir = dir_open_root ();
+  bool success = dir != NULL && dir_remove (dir, name);
+  dir_close (dir); 
 
   return success;
 }
-
-static void must_succeed_function (int, int) ATTRIBUTE((noinline));
-
-static void 
-must_succeed_function (int line_no, int success) 
-{
-  if (!success)
-    panic ("filesys_self_test: operation failed on line %d", line_no);
-}
-
+
+static void must_succeed_function (int, bool) NO_INLINE;
 #define MUST_SUCCEED(EXPR) must_succeed_function (__LINE__, EXPR)
 
+/* Performs basic sanity checks on the file system.
+   The file system should not contain a file named `foo' when
+   called. */
 void
 filesys_self_test (void)
 {
   static const char s[] = "This is a test string.";
-  struct file file;
+  static const char zeros[sizeof s] = {0};
+  struct file *file;
   char s2[sizeof s];
+  int i;
+
+  filesys_remove ("foo");
+  for (i = 0; i < 2; i++) 
+    {
+      /* Create file and check that it contains zeros
+         throughout the created length. */
+      MUST_SUCCEED (filesys_create ("foo", sizeof s));
+      MUST_SUCCEED ((file = filesys_open ("foo")) != NULL);
+      MUST_SUCCEED (file_read (file, s2, sizeof s2) == sizeof s2);
+      MUST_SUCCEED (memcmp (s2, zeros, sizeof s) == 0);
+      MUST_SUCCEED (file_tell (file) == sizeof s);
+      MUST_SUCCEED (file_length (file) == sizeof s);
+      file_close (file);
+
+      /* Reopen file and write to it. */
+      MUST_SUCCEED ((file = filesys_open ("foo")) != NULL);
+      MUST_SUCCEED (file_write (file, s, sizeof s) == sizeof s);
+      MUST_SUCCEED (file_tell (file) == sizeof s);
+      MUST_SUCCEED (file_length (file) == sizeof s);
+      file_close (file);
+
+      /* Reopen file and verify that it reads back correctly.
+         Delete file while open to check proper semantics. */
+      MUST_SUCCEED ((file = filesys_open ("foo")) != NULL);
+      MUST_SUCCEED (filesys_remove ("foo"));
+      MUST_SUCCEED (filesys_open ("foo") == NULL);
+      MUST_SUCCEED (file_read (file, s2, sizeof s) == sizeof s);
+      MUST_SUCCEED (memcmp (s, s2, sizeof s) == 0);
+      MUST_SUCCEED (file_tell (file) == sizeof s);
+      MUST_SUCCEED (file_length (file) == sizeof s);
+      file_close (file);
+    }
+  
+  printf ("filesys: self test ok\n");
+}
 
-  MUST_SUCCEED (filesys_create ("foo", sizeof s));
-  MUST_SUCCEED (filesys_open ("foo", &file));
-  MUST_SUCCEED (file_write (&file, s, sizeof s) == sizeof s);
-  MUST_SUCCEED (file_tell (&file) == sizeof s);
-  MUST_SUCCEED (file_length (&file) == sizeof s);
-  file_close (&file);
-
-  MUST_SUCCEED (filesys_open ("foo", &file));
-  MUST_SUCCEED (file_read (&file, s2, sizeof s2) == sizeof s2);
-  MUST_SUCCEED (memcmp (s, s2, sizeof s) == 0);
-  MUST_SUCCEED (file_tell (&file) == sizeof s2);
-  MUST_SUCCEED (file_length (&file) == sizeof s2);
-  file_close (&file);
-
-  MUST_SUCCEED (filesys_remove ("foo"));
-
-  printk ("filesys: self test ok\n");
+/* If SUCCESS is false, panics with an error complaining about
+   LINE_NO. */
+static void 
+must_succeed_function (int line_no, bool success) 
+{
+  if (!success)
+    PANIC ("filesys_self_test: operation failed on line %d", line_no);
+}
+
+/* Formats the file system. */
+static void
+do_format (void)
+{
+  printf ("Formatting file system...");
+  free_map_create ();
+  if (!dir_create (ROOT_DIR_SECTOR, 16))
+    PANIC ("root directory creation failed");
+  free_map_close ();
+  printf ("done.\n");
 }