ufs: permit mounting of BorderWare filesystems
I recently had to recover some files from an old broken machine that was
running BorderWare Document Gateway. It's basically a drop in web server
for sharing files. From the look of the init process and using strings on
of a few files it seems to be based on FreeBSD 3.3.
The process turned out to be more difficult than I imagined, but to cut a
long story short BorderWare in their wisdom use a nonstandard magic number
in their UFS (ufstype=44bsd) file systems. Thus Linux refuses to mount
the file systems in order to recover the data. After a bit of hunting I
was able to make a quick fix to fs/ufs/super.c in order to detect the new
magic number.
I assume that this number is the same for all installations. It's quite
easy to find out from ufs_fs.h. The superblock sits 8k into the block
device and the magic number its 1372 bytes into the superblock struct.
# dd if=/dev/sda5 skip=$(( 8192 + 1372 )) bs=1 count=4 2> /dev/null | hd
00000000 97 26 24 0f |.&$.|
#
Signed-off-by: Thomas Stewart <thomas@stewarts.org.uk>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ufs/ufs_fs.h b/fs/ufs/ufs_fs.h
index 6943ec6..8aba544 100644
--- a/fs/ufs/ufs_fs.h
+++ b/fs/ufs/ufs_fs.h
@@ -48,6 +48,7 @@
#define UFS_SECTOR_SIZE 512
#define UFS_SECTOR_BITS 9
#define UFS_MAGIC 0x00011954
+#define UFS_MAGIC_BW 0x0f242697
#define UFS2_MAGIC 0x19540119
#define UFS_CIGAM 0x54190100 /* byteswapped MAGIC */