The ext2 (and ext3, ext4) filesystems write the number of free inodes to
location 0x410.
On a MINIX filesystem, that same location is used for the MINIX superblock
magic number.
If the number of free inodes on an ext2 filesystem is equal to any
of the four MINIX superblock magic values plus any multiple of 65536,
GRUB's MINIX filesystem code will probe it as a MINIX filesystem.
In the case of an OS using ext2 as the root filesystem, since there will
ordinarily be some amount of file creation and deletion on every bootup,
it effectively means that this situation has a 1:16384 chance of being hit
on every reboot.
This will cause GRUB's filesystem probing code to mistakenly identify an
ext2 filesystem as MINIX. This can be seen by e.g. "search --label"
incorrectly indicating that no such ext2 partition with matching label
exists, whereas in fact it does.
After spotting the rough cause of the issue I was facing here, I borrowed
much of the diagnosis/explanation from meierfra who found and investigated
the same issue in util-linux in 2010:
https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/518582
This was fixed in util-linux by having the MINIX code check for the
ext2 magic. Do the same here.
Signed-off-by: Daniel Drake <drake@endlessm.com>
Reviewed-by: Derek Foreman <derek@endlessos.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
* grub-core/fs/minix.c (GRUB_MINIX_ZONESZ): Use block_size.
(grub_minix_data): Replace log_block_size with block_size.
(grub_minix_read_file): Use block_size but avoid 64-bit division.
(grub_minix_mount): Fill block_size.
* grub-core/fs/minix.c (GRUB_MINIX_ZONESZ): Use log_block_size.
(GRUB_MINIX_ZONE2SECT): Likewise.
(grub_minix_data): Replace block_size with log_block_size.
(grub_minix_read_file): Use shifts.
(grub_minix_mount): Check block size and take a logarithm.
* grub-core/kern/misc.c (grub_divmod64_full): Renamed to ...
(grub_divmod64): ... this.
* include/grub/misc.h (grub_divmod64): Removed. All users switch to full
version.
* grub-core/fs/affs.c (grub_affs_time): New struct.
(grub_affs_file): New field mtime.
(grub_fshelp_node): Changed 'block' and 'parent' to more appropriate
type. Removed 'size'. New field 'di'. All users updated.
(grub_affs_mount): Simplify checsum checking.
(grub_affs_iterate_dir): New helper grub_affs_create_node.
(grub_affs_dir): Handle mtime.
* grub-core/fs/cpio.c (grub_cpio_find_file): Handle mtime.
(grub_cpio_dir): Likewise.
* grub-core/fs/hfs.c (grub_hfs_dirrec): New fields 'ctime' and 'mtime'.
(grub_hfs_filerec): New field mtime.
(grub_hfs_dir): Handle mtime.
(grub_hfs_mtime): New function.
(grub_hfs_fs): Register grub_hfs_mtime.
* grub-core/fs/iso9660.c (grub_iso9660_date2): New struct.
(grub_iso9660_dir): New field mtime.
(grub_fshelp_node): New field dirent.
(iso9660_to_unixtime): New function.
(iso9660_to_unixtime2): Likewise.
(grub_iso9660_read_symlink): Use node->dirent.
(grub_iso9660_iterate_dir): Likewise.
(grub_iso9660_dir): Set mtime.
(grub_iso9660_mtime): New function.
(grub_iso9660_fs): Register grub_iso9660_mtime.
* grub-core/fs/jfs.c (grub_jfs_time): New struct.
(grub_jfs_inode): New fields atime, ctime and mtime.
(grub_jfs_dir): Set mtime.
* grub-core/fs/minix.c (grub_minix_dir): Likewise.
* grub-core/fs/ntfs.c (list_file): Set mtime.
(grub_ntfs_dir): Likewise.
* grub-core/fs/reiserfs.c (grub_fshelp_node): New field 'mtime'.
(grub_reiserfs_iterate_dir): Set mtime.
(grub_reiserfs_dir): Likewise.
* grub-core/fs/sfs.c (grub_sfs_obj): New field mtime.
(grub_fshelp_node): Likewise.
(grub_sfs_iterate_dir): Set mtime.
(grub_sfs_dir): Likewise.
* grub-core/fs/udf.c (grub_udf_dir): Set mtime.
* grub-core/fs/xfs.c (grub_xfs_time): New struct.
(grub_xfs_inode): New fields atime, mtime, ctime.
(grub_xfs_dir): Set mtime.
* include/grub/datetime.h (grub_datetime2unixtime): New function.
* include/grub/hfs.h (grub_hfs_sblock): New fields ctime and mtime.
* include/grub/ntfs.h (grub_fshelp_node): New field mtime.
Support UDF symlinks.
* grub-core/fs/udf.c (grub_udf_iterate_dir): Handle symlinks.
(grub_ufs_read_symlink): New function. All users updated.
Check amiga partmap checksum.
* grub-core/partmap/amiga.c (grub_amiga_rdsk): Pad to 128 bytes.
(grub_amiga_partition): Likewise.
(amiga_partition_map_checksum): New function.
(amiga_partition_map_iterate): Check checksum.
* grub-core/Makefile.core.def (minix3): New module.
* grub-core/fs/minix.c (GRUB_MINIX_MAGIC) [MODE_MINIX3]: New value.
(GRUB_MINIX_BSIZE): Removed.
(GRUB_MINIX_INODE_DIR_BLOCKS): New definition. All users updated.
(grub_minix_ino_t): New type.
(grub_minix_le_to_cpu_ino): New macro.
(GRUB_MINIX_ZONE2SECT): New definition. All users updated.
(grub_minix_sblock) [MODE_MINIX3]: Change for minix3.
(grub_minix_data): New field block_size.
(grub_minix_read_file): Handle 64-bit correctly.
* grub-core/fs/minix3.c: New file.
Also-By: Vladimir Serbinenko <phcoder@gmail.com>
* Makefile.util.def (libgrub.a): Add grub-core/fs/minix2.c.
* grub-core/Makefile.core.def (minix2): New module.
* grub-core/fs/minix.c: Use definitions instead of runtime version
checking.
* grub-core/fs/minix2.c: New file.
