2009-09-10  Colin Watson  <address@hidden>

	* disk/loopback.c (struct grub_loopback): Add `file' member.
	(delete_loopback): Close `dev->file'.
	(grub_cmd_loopback): Keep `file' open unless this command fails.
	Save it in the loopback structure for later.
	(grub_loopback_open): Use the saved file handle rather than opening
	the loopback file again.
	(grub_loopback_close): Remove.
	(grub_loopback_dev): Remove `close' member.

Index: disk/loopback.c
===================================================================
--- disk/loopback.c	(revision 2584)
+++ disk/loopback.c	(working copy)
@@ -28,6 +28,7 @@
 {
   char *devname;
   char *filename;
+  grub_file_t file;
   int has_partitions;
   struct grub_loopback *next;
 };
@@ -61,6 +62,7 @@
   /* Remove the device from the list.  */
   *prev = dev->next;
 
+  grub_file_close (dev->file);
   grub_free (dev->devname);
   grub_free (dev->filename);
   grub_free (dev);
@@ -90,9 +92,6 @@
   if (! file)
     return grub_errno;
 
-  /* Close the file, the only reason for opening it is validation.  */
-  grub_file_close (file);
-
   /* First try to replace the old device.  */
   for (newdev = loopback_list; newdev; newdev = newdev->next)
     if (grub_strcmp (newdev->devname, args[0]) == 0)
@@ -102,10 +101,12 @@
     {
       char *newname = grub_strdup (args[1]);
       if (! newname)
-	return grub_errno;
+	goto fail;
 
       grub_free (newdev->filename);
       newdev->filename = newname;
+      grub_file_close (newdev->file);
+      newdev->file = file;
 
       /* Set has_partitions when `--partitions' was used.  */
       newdev->has_partitions = state[1].set;
@@ -116,13 +117,13 @@
   /* Unable to replace it, make a new entry.  */
   newdev = grub_malloc (sizeof (struct grub_loopback));
   if (! newdev)
-    return grub_errno;
+    goto fail;
 
   newdev->devname = grub_strdup (args[0]);
   if (! newdev->devname)
     {
       grub_free (newdev);
-      return grub_errno;
+      goto fail;
     }
 
   newdev->filename = grub_strdup (args[1]);
@@ -130,9 +131,11 @@
     {
       grub_free (newdev->devname);
       grub_free (newdev);
-      return grub_errno;
+      goto fail;
     }
 
+  newdev->file = file;
+
   /* Set has_partitions when `--partitions' was used.  */
   newdev->has_partitions = state[1].set;
 
@@ -141,6 +144,10 @@
   loopback_list = newdev;
 
   return 0;
+
+fail:
+  grub_file_close (file);
+  return grub_errno;
 }
 
 
@@ -159,7 +166,6 @@
 static grub_err_t
 grub_loopback_open (const char *name, grub_disk_t disk)
 {
-  grub_file_t file;
   struct grub_loopback *dev;
 
   for (dev = loopback_list; dev; dev = dev->next)
@@ -169,29 +175,17 @@
   if (! dev)
     return grub_error (GRUB_ERR_UNKNOWN_DEVICE, "Can't open device");
 
-  file = grub_file_open (dev->filename);
-  if (! file)
-    return grub_errno;
-
   /* Use the filesize for the disk size, round up to a complete sector.  */
-  disk->total_sectors = ((file->size + GRUB_DISK_SECTOR_SIZE - 1)
+  disk->total_sectors = ((dev->file->size + GRUB_DISK_SECTOR_SIZE - 1)
 			 / GRUB_DISK_SECTOR_SIZE);
   disk->id = (unsigned long) dev;
 
   disk->has_partitions = dev->has_partitions;
-  disk->data = file;
+  disk->data = dev->file;
 
   return 0;
 }
 
-static void
-grub_loopback_close (grub_disk_t disk)
-{
-  grub_file_t file = (grub_file_t) disk->data;
-
-  grub_file_close (file);
-}
-
 static grub_err_t
 grub_loopback_read (grub_disk_t disk, grub_disk_addr_t sector,
 		    grub_size_t size, char *buf)
@@ -233,7 +227,6 @@
     .id = GRUB_DISK_DEVICE_LOOPBACK_ID,
     .iterate = grub_loopback_iterate,
     .open = grub_loopback_open,
-    .close = grub_loopback_close,
     .read = grub_loopback_read,
     .write = grub_loopback_write,
     .next = 0