Upstream: http://lists.gnu.org/archive/html/grub-devel/2009-09/msg00210.html
Description: If you set root after running loopback, any attempts to open
files on the loopback device resolve the loopback file name relative to the
*new* root, not the root at the time loopback was invoked, and so the above
recurses until it runs out of stack. This causes problems for Wubi. I think
it's fairly clear that only the root that was in place when you ran
loopback should be relevant to the loopback file name.
diff -Nur -x '*.orig' -x '*~' grub2-1.97~beta2/disk/loopback.c grub2-1.97~beta2.new/disk/loopback.c
--- grub2-1.97~beta2/disk/loopback.c 2009-06-10 22:04:23.000000000 +0100
+++ grub2-1.97~beta2.new/disk/loopback.c 2009-09-10 21:42:56.000000000 +0100
@@ -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