Ok, let's try this: We refuse to install on a partition UNLESS:
- A filesystem can be identified in it.
- This filesystem is known to reserve the first block for DOS-style
chainload.
If these conditions aren't met, user will have to override our check.
Patch attached. Also in people/robertmh/grub-setup-fs-probe.
--
Robert Millan
The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
how) you may access your data; but nobody's threatening your freedom: we
still allow you to remove your data and not access it at all."
=== modified file 'ChangeLog'
--- ChangeLog 2009-10-24 23:13:27 +0000
+++ ChangeLog 2009-10-24 23:57:58 +0000
@@ -1,5 +1,15 @@
2009-10-25 Robert Millan <[email protected]>
+ * include/grub/fs.h (struct grub_fs): Add `reserved_first_sector'
+ member.
+ * fs/ext2.c (grub_ext2_fs): Initialize `reserved_first_sector' to 1.
+ * util/i386/pc/grub-setup.c (setup): Add safety check that probes for
+ filesystems which begin at first sector.
+ (options): New option --skip-fs-probe.
+ (main): Handle --skip-fs-probe and pass it to setup().
+
+2009-10-25 Robert Millan <[email protected]>
+
* fs/cpio.c [MODE_USTAR]: Finish `tar' module instead of
`cpio'.
[! MODE_USTAR]: Finish `cpio' module instead of `tar'.
=== modified file 'fs/ext2.c'
--- fs/ext2.c 2009-07-19 13:59:21 +0000
+++ fs/ext2.c 2009-10-24 23:57:58 +0000
@@ -924,6 +924,7 @@
.label = grub_ext2_label,
.uuid = grub_ext2_uuid,
.mtime = grub_ext2_mtime,
+ .reserved_first_sector = 1,
.next = 0
};
=== modified file 'include/grub/fs.h'
--- include/grub/fs.h 2009-06-10 21:04:23 +0000
+++ include/grub/fs.h 2009-10-24 23:57:58 +0000
@@ -68,6 +68,11 @@
/* Get writing time of filesystem. */
grub_err_t (*mtime) (grub_device_t device, grub_int32_t *timebuf);
+#ifdef GRUB_UTIL
+ /* Whether this filesystem reserves first sector for DOS-style boot. */
+ int reserved_first_sector;
+#endif
+
/* The next filesystem. */
struct grub_fs *next;
};
=== modified file 'util/i386/pc/grub-setup.c'
--- util/i386/pc/grub-setup.c 2009-08-25 08:28:13 +0000
+++ util/i386/pc/grub-setup.c 2009-10-24 23:57:58 +0000
@@ -86,7 +86,7 @@
static void
setup (const char *dir,
const char *boot_file, const char *core_file,
- const char *root, const char *dest, int must_embed, int force)
+ const char *root, const char *dest, int must_embed, int force, int fs_probe)
{
char *boot_path, *core_path, *core_path_dev;
char *boot_img, *core_img;
@@ -251,6 +251,21 @@
if (grub_disk_read (dest_dev->disk, 0, 0, GRUB_DISK_SECTOR_SIZE, tmp_img))
grub_util_error ("%s", grub_errmsg);
+ if (dest_dev->disk->partition && fs_probe)
+ {
+ grub_fs_t fs;
+ fs = grub_fs_probe (dest_dev);
+ if (! fs)
+ grub_util_error ("Unable to identify a filesystem in %s; safety check can't be performed.");
+
+ if (! fs->reserved_first_sector)
+ grub_util_error ("%s appears to contain a %s filesystem which isn't known to "
+ "reserve space for DOS-style boot. Installing GRUB there could "
+ "result in FILESYSTEM DESTRUCTION if valuable data is overwritten "
+ "by grub-setup (--skip-fs-probe disables this "
+ "check, use at your own risk).", dest_dev->disk->name, fs->name);
+ }
+
/* Copy the possible DOS BPB. */
memcpy (boot_img + GRUB_BOOT_MACHINE_BPB_START,
tmp_img + GRUB_BOOT_MACHINE_BPB_START,
@@ -556,6 +571,7 @@
{"device-map", required_argument, 0, 'm'},
{"root-device", required_argument, 0, 'r'},
{"force", no_argument, 0, 'f'},
+ {"skip-fs-probe", no_argument, 0, 's'},
{"help", no_argument, 0, 'h'},
{"version", no_argument, 0, 'V'},
{"verbose", no_argument, 0, 'v'},
@@ -580,6 +596,7 @@
-m, --device-map=FILE use FILE as the device map [default=%s]\n\
-r, --root-device=DEV use DEV as the root device [default=guessed]\n\
-f, --force install even if problems are detected\n\
+ -s, --skip-fs-probe do not probe for filesystems in DEVICE\n\
-h, --help display this message and exit\n\
-V, --version print version information and exit\n\
-v, --verbose print verbose messages\n\
@@ -613,7 +630,7 @@
char *dev_map = 0;
char *root_dev = 0;
char *dest_dev;
- int must_embed = 0, force = 0;
+ int must_embed = 0, force = 0, fs_probe = 1;
progname = "grub-setup";
@@ -666,6 +683,10 @@
force = 1;
break;
+ case 's':
+ fs_probe = 0;
+ break;
+
case 'h':
usage (0);
break;
@@ -767,7 +788,7 @@
setup (dir ? : DEFAULT_DIRECTORY,
boot_file ? : DEFAULT_BOOT_FILE,
core_file ? : DEFAULT_CORE_FILE,
- root_dev, grub_util_get_grub_dev (devicelist[i]), 1, force);
+ root_dev, grub_util_get_grub_dev (devicelist[i]), 1, force, fs_probe);
}
}
else
@@ -776,7 +797,7 @@
setup (dir ? : DEFAULT_DIRECTORY,
boot_file ? : DEFAULT_BOOT_FILE,
core_file ? : DEFAULT_CORE_FILE,
- root_dev, dest_dev, must_embed, force);
+ root_dev, dest_dev, must_embed, force, fs_probe);
/* Free resources. */
grub_fini_all ();
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