From d27d7a9a7838587fcdcc6f2b042f5610eb4984a1 Mon Sep 17 00:00:00 2001
From: Thomas Stewart <thomas@stewarts.org.uk>
Date: Wed, 26 May 2010 14:42:33 -0700
Subject: [PATCH] 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>
---
fs/ufs/super.c | 2 ++
fs/ufs/ufs_fs.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 14743d935a93f..ad9bc1ebd3a65 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -918,6 +918,7 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
sbi->s_bytesex = BYTESEX_LE;
switch ((uspi->fs_magic = fs32_to_cpu(sb, usb3->fs_magic))) {
case UFS_MAGIC:
+ case UFS_MAGIC_BW:
case UFS2_MAGIC:
case UFS_MAGIC_LFN:
case UFS_MAGIC_FEA:
@@ -927,6 +928,7 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
sbi->s_bytesex = BYTESEX_BE;
switch ((uspi->fs_magic = fs32_to_cpu(sb, usb3->fs_magic))) {
case UFS_MAGIC:
+ case UFS_MAGIC_BW:
case UFS2_MAGIC:
case UFS_MAGIC_LFN:
case UFS_MAGIC_FEA:
diff --git a/fs/ufs/ufs_fs.h b/fs/ufs/ufs_fs.h
index 6943ec677c0be..8aba544f9fad8 100644
--- a/fs/ufs/ufs_fs.h
+++ b/fs/ufs/ufs_fs.h
@@ -48,6 +48,7 @@ typedef __u16 __bitwise __fs16;
#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 */
--
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