Initial revision

kern/fs.c

@@ -0,0 +1,224 @@
+/* fs.c - filesystem manager */
+/*
+ *  PUPA  --  Preliminary Universal Programming Architecture for GRUB
+ *  Copyright (C) 2002 Yoshinori K. Okuji <okuji@enbug.org>
+ *
+ *  PUPA is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with PUPA; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <pupa/disk.h>
+#include <pupa/net.h>
+#include <pupa/fs.h>
+#include <pupa/file.h>
+#include <pupa/err.h>
+#include <pupa/misc.h>
+#include <pupa/types.h>
+#include <pupa/mm.h>
+#include <pupa/term.h>
+
+static pupa_fs_t pupa_fs_list;
+
+void
+pupa_fs_register (pupa_fs_t fs)
+{
+  fs->next = pupa_fs_list;
+  pupa_fs_list = fs;
+}
+
+void
+pupa_fs_unregister (pupa_fs_t fs)
+{
+  pupa_fs_t *p, q;
+
+  for (p = &pupa_fs_list, q = *p; q; p = &(q->next), q = q->next)
+    if (q == fs)
+      {
+	*p = q->next;
+	break;
+      }
+}
+
+void
+pupa_fs_iterate (int (*hook) (const pupa_fs_t fs))
+{
+  pupa_fs_t p;
+
+  for (p = pupa_fs_list; p; p = p->next)
+    if (hook (p))
+      break;
+}
+
+pupa_fs_t
+pupa_fs_probe (pupa_device_t device)
+{
+  pupa_fs_t p;
+  auto int dummy_func (const char *filename, int dir);
+
+  int dummy_func (const char *filename __attribute__ ((unused)),
+		  int dir __attribute__ ((unused)))
+    {
+      return 1;
+    }
+
+  if (device->disk)
+    {
+      for (p = pupa_fs_list; p; p = p->next)
+	{
+	  (p->dir) (device, "/", dummy_func);
+	  if (pupa_errno == PUPA_ERR_NONE)
+	    return p;
+	  
+	  if (pupa_errno != PUPA_ERR_BAD_FS)
+	    return 0;
+	  
+	  pupa_errno = PUPA_ERR_NONE;
+	}
+    }
+  else if (device->net->fs)
+    return device->net->fs;
+
+  pupa_error (PUPA_ERR_UNKNOWN_FS, "unknown filesystem");
+  return 0;
+}
+
+
+
+/* Block list support routines.  */
+
+struct pupa_fs_block
+{
+  unsigned long offset;
+  unsigned long length;
+};
+
+static pupa_err_t
+pupa_fs_blocklist_open (pupa_file_t file, const char *name)
+{
+  char *p = (char *) name;
+  unsigned num = 0;
+  unsigned i;
+  pupa_disk_t disk = file->device->disk;
+  struct pupa_fs_block *blocks;
+  
+  /* First, count the number of blocks.  */
+  do
+    {
+      num++;
+      p = pupa_strchr (p, ',');
+    }
+  while (p);
+
+  /* Allocate a block list.  */
+  blocks = pupa_malloc (sizeof (struct pupa_fs_block) * (num + 1));
+  if (! blocks)
+    return 0;
+
+  file->size = 0;
+  p = (char *) name;
+  for (i = 0; i < num; i++)
+    {
+      if (*p != '+')
+	{
+	  blocks[i].offset = pupa_strtoul (p, &p, 0);
+	  if (pupa_errno != PUPA_ERR_NONE || *p != '+')
+	    {
+	      pupa_error (PUPA_ERR_BAD_FILENAME,
+			  "invalid file name `%s'", name);
+	      goto fail;
+	    }
+	}
+      else
+	blocks[i].offset = 0;
+
+      p++;
+      blocks[i].length = pupa_strtoul (p, &p, 0);
+      if (pupa_errno != PUPA_ERR_NONE
+	  || blocks[i].length == 0
+	  || (*p && *p != ',' && ! pupa_isspace (*p)))
+	{
+	  pupa_error (PUPA_ERR_BAD_FILENAME,
+		      "invalid file name `%s'", name);
+	  goto fail;
+	}
+
+      if (disk->total_sectors < blocks[i].offset + blocks[i].length)
+	{
+	  pupa_error (PUPA_ERR_BAD_FILENAME, "beyond the total sectors");
+	  goto fail;
+	}
+      
+      file->size += (blocks[i].length << PUPA_DISK_SECTOR_BITS);
+      p++;
+    }
+
+  blocks[i].length = 0;
+  file->data = blocks;
+  
+  return PUPA_ERR_NONE;
+
+ fail:
+  pupa_free (blocks);
+  return pupa_errno;
+}
+
+static pupa_ssize_t
+pupa_fs_blocklist_read (pupa_file_t file, char *buf, pupa_ssize_t len)
+{
+  struct pupa_fs_block *p;
+  unsigned long sector;
+  unsigned long offset;
+  pupa_ssize_t ret = 0;
+
+  if (len > file->size - file->offset)
+    len = file->size - file->offset;
+
+  sector = (file->offset >> PUPA_DISK_SECTOR_BITS);
+  offset = (file->offset & (PUPA_DISK_SECTOR_SIZE - 1));
+  for (p = file->data; p->length && len > 0; p++)
+    {
+      if (sector < p->length)
+	{
+	  pupa_ssize_t size;
+
+	  size = len;
+	  if (((size + offset + PUPA_DISK_SECTOR_SIZE - 1)
+	       >> PUPA_DISK_SECTOR_BITS) > p->length - sector)
+	    size = ((p->length - sector) << PUPA_DISK_SECTOR_BITS) - offset;
+	  
+	  if (pupa_disk_read (file->device->disk, p->offset + sector, offset,
+			      size, buf) != PUPA_ERR_NONE)
+	    return -1;
+	  
+	  ret += size;
+	  len -= size;
+	  sector -= ((size + offset) >> PUPA_DISK_SECTOR_BITS);
+	  offset = ((size + offset) & (PUPA_DISK_SECTOR_SIZE - 1));
+	}
+      else
+	sector -= p->length;
+    }
+
+  return ret;
+}
+
+struct pupa_fs pupa_fs_blocklist =
+  {
+    .name = "blocklist",
+    .dir = 0,
+    .open = pupa_fs_blocklist_open,
+    .read = pupa_fs_blocklist_read,
+    .close = 0,
+    .next = 0
+  };