22 October 2012 Karim Elatov

I was trying to share data between a Windows Machine and FreeBSD machine. They were not connected over the network so I decided to use my USB drive to transfer the data. I formatted the drive NTFS from the Windows side and then tried to transfer the data onto the disk from the FreeBSD machine. When I plugged in the drive into the FreeBSD machine I saw the following:

[email protected]:~>dmesg | tail -8
ugen2.2: <SanDisk> at usbus2
umass0: <SanDisk SanDisk USB, class 0/0, rev 2.00/1.26, addr 2> on usbus2
umass0: SCSI over Bulk-Only; quirks = 0x4100
umass0:2:0:-1: Attached to scbus2
da0 at umass-sim0 bus 0 scbus2 target 0 lun 0
da0: <SanDisk 1.26> Removable Direct Access SCSI-5 device
da0: 40.000MB/s transfers
da0: 7633MB (15633408 512 byte sectors: 255H 63S/T 973C)

Then checking the file system on the disk I saw the following:

[email protected]:~>sudo fdisk /dev/da0
*****\** Working on device /dev/da0 *******
parameters extracted from in-core disklabel are:
cylinders=973 heads=255 sectors/track=63 (16065 blks/cyl)

parameters to be used for BIOS calculations are:
cylinders=973 heads=255 sectors/track=63 (16065 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 7 (0x07),(NTFS, OS/2 HPFS, QNX-2 (16 bit) or Advanced UNIX)
start 2048, size 15631360 (7632 Meg), flag 0
beg: cyl 2/ head 31/ sector 12;
end: cyl 31/ head 0/ sector 21
The data for partition 2 is:
The data for partition 3 is:
The data for partition 4 is:

If you want a more concise view, you can use gpart:

[email protected]:~>gpart show /dev/da0
=> 63 15633345 da0 MBR (7.5G)
63 1985 - free - (992k)
2048 15631360 1 ntfs (7.5G)

So the first partition had NTFS on it. I then tried to mount the NTFS partition and I was actually successful:

[email protected]:~>sudo mount -t ntfs /dev/da0s1 /mnt/usb
[email protected]:~>df -h | grep usb
/dev/da0s1 7.5G 38M 7.4G 1% /mnt/usb
[email protected]:~>mount | grep da0
/dev/da0s1 on /mnt/usb (ntfs, local)

But when I tried to write files to it, I couldn’t. I then wanted to find any man pages regarding NTFS:

[email protected]:~>man -k ntfs
mount_ntfs(8) - mount an NTFS file system

Not much there :) Checking out the man page, I saw the following:

CAVEATS This utility is primarily used for read access to an NTFS volume. See the WRITING section for details about writing to an NTFS volume.

For a full read-write NTFS support consider sysutils/fusefs-ntfs port/package.

So it looks like I need to install another package to have write permission to an NTFS volume. So let’s get to it:

[email protected]:~>cd /usr/ports/sysutils/fusefs-ntfs
[email protected]:/usr/ports/sysutils/fusefs-ntfs>sudo make install clean

The install finished, and I wanted to mount it with the new package. First I un-mounted the drive:

[email protected]:~>sudo umount /mnt/usb
[email protected]:~>df -h | grep usb
[email protected]:~>

That looks good, next let’s figure out how to use this package to mount the NTFS partition. First update your man database and check out the man pages:

[email protected]:~>sudo makewhatis /usr/local/man
[email protected]:~>man -k ntfs
mount_ntfs(8) - mount an NTFS file system
mkntfs(8) - create an NTFS file system
ntfs-3g(8) - Third Generation Read/Write NTFS Driver
ntfs-3g.probe(8) - Probe an NTFS volume mountability
ntfs-3g.secaudit(8) - NTFS Security Data Auditing
ntfs-3g.usermap(8) - NTFS Building a User Mapping File
ntfscat(8) - print NTFS files and streams on the standard output
ntfsclone(8) - Efficiently clone, image, restore or rescue an NTFS
ntfscluster(8) - identify files in a specified region of an NTFS volume
ntfscmp(8) - compare two NTFS filesystems and tell the differences
ntfscp(8) - copy file to an NTFS volume
ntfsfix(8) - fix common errors and force Windows to check NTFS
ntfsinfo(8) - dump a file's attributes
ntfslabel(8) - display/change the label on an ntfs file system
ntfsls(8) - list directory contents on an NTFS filesystem
ntfsprogs(8) - tools for doing neat things with NTFS
ntfsresize(8) - resize an NTFS filesystem without data loss
ntfsundelete(8) - recover a deleted file from an NTFS volume

From the man page:

EXAMPLE Test if /dev/sda1 can be mounted read-write:

ntfs-3g.probe -readwrite /dev/sda1

EXIT CODES The exit codes are as follows:

0 Volume is mountable. 11 Syntax error, command line parsing failed.

Let’s see if we are okay:

[email protected]:~>sudo ntfs-3g.probe --readwrite /dev/da0s1
[email protected]:~>echo $?

That means we can mount it read/write. Now let’s actually mount it. From the man page here are some examples:

EXAMPLES Mount /dev/sda1 to /mnt/windows:

ntfs-3g /dev/sda1 /mnt/windows or mount -t ntfs-3g /dev/sda1 /mnt/windows

Mount the ntfs data partition /dev/sda3 to /mnt/data with standard Linux permissions applied :

ntfs-3g -o permissions /dev/sda3 /mnt/data or mount -t ntfs-3g -o permissions /dev/sda3 /mnt/data

Read-only mount /dev/sda5 to /home/user/mnt and make user with uid 1000 to be the owner of all files:

ntfs-3g /dev/sda5 /home/user/mnt -o ro,uid=1000

Here is what I did to try to mount my NTFS Partition:

[email protected]:~>sudo ntfs-3g /dev/da0s1 /mnt/usb -o uid=500
fuse: failed to open fuse device: No such file or directory

I didn’t remember the “Install Notice” for the packages, so I decided to refresh my memory:

[email protected]:~>pkg_info -D -x fusefs-ntfs-2012.1.15
Information for fusefs-ntfs-2012.1.15:

Install notice:

NTFS-3G has been installed, for information, known issues and how to report
bugs see the FreeBSD README:


Also see the official README (but has some Linux specific parts).


Checking out the package and it’s files I saw this:

[email protected]:~>pkg_info | grep ntfs
fusefs-ntfs-2012.1.15 Mount NTFS partitions (read/write) and disk images
[email protected]:~>pkg_info -L fusefs-ntfs-2012.1.15 | grep -i read

From the README, I saw the following:

To mount at startup you need to have the following line in /etc/rc.conf:


so I added that to my rc.conf and then started the service:

[email protected]:~>sudo /usr/local/etc/rc.d/fusefs start
Starting fusefs.

You will also see the fuse module loaded now:

[email protected]:~>kldstat | grep fuse
2 1 0xc6467000 e000 fuse.ko

Now trying to mount the NTFS volume:

[email protected]:~>sudo ntfs-3g /dev/da0s1 /mnt/usb -o uid=500
[email protected]:~>df -h | grep usb
/dev/fuse0 7.5G 38M 7.4G 1% /mnt/usb
[email protected]:~>mount | grep usb
/dev/fuse0 on /mnt/usb (fusefs, local, synchronous)

That looked good, and I was able to write to the usb disk:

[email protected]:~>cd /mnt/usb/
[email protected]:/mnt/usb>ls
[email protected]:/mnt/usb>touch test
[email protected]:/mnt/usb>ls -l
total 0
-rwxrwxrwx 1 elatov wheel 0 Oct 13 13:58 test

That was it. However when I tried to copy files to the NTFS volume, I would get a kernel panic. Here is a screenshot:


Another person had the issue as well, here a link to his kernel panic. No one actually answered the previous post, here is a copy of his back trace:

Fatal trap 12: page fault while in kernel mode fault virtual address = 0x0 fault code = supervisor read, page not present instruction pointer = 0x20:0x0 stack pointer = 0x28:0xeae1ec48 frame pointer = 0x28:0xeae1ec70 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, def32 1, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 2390 (mv) trap number = 12

Later I found this post. It’s in Japanese but you can always translate it. In this post there is actually a patch to the fusefs-kmod package to fix the issue, since there are issues with chown and chmod when it tries to copy files to an NTFS volume. So let’s patch the source and see if it helps out. First download the source if you don’t have it:

[email protected]:/usr/ports/sysutils/fusefs-kmod>sudo make fetch
===> Found saved configuration for fusefs-kmod-0.3.9.p1.20080208_11
=> 498acaef33b0.tar.gz doesn't seem to exist in /usr/ports/distfiles/fuse4bsd.
=> Attempting to fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/distfiles/fuse4bsd/498acaef33b0.tar.gz
498acaef33b0.tar.gz 100% of 113 kB 171 kBps

Then extract the source:

[email protected]:/usr/ports/sysutils/fusefs-kmod>sudo make extract
===> Found saved configuration for fusefs-kmod-0.3.9.p1.20080208_11
===> Extracting for fusefs-kmod-0.3.9.p1.20080208_11
=> SHA256 Checksum OK for fuse4bsd/498acaef33b0.tar.gz.
[email protected]:/usr/ports/sysutils/fusefs-kmod>ls -lrt
total 24
-rw-r--r-- 1 root wheel 75 Feb 10 2006 pkg-descr
-rw-r--r-- 1 root wheel 150 Mar 19 2011 distinfo
-rw-r--r-- 1 root wheel 1035 Nov 29 2011 pkg-plist
-rw-r--r-- 1 root wheel 3092 Sep 20 17:52 Makefile
drwxr-xr-x 2 root wheel 512 Sep 29 08:30 files
drwxr-xr-x 3 root wheel 512 Oct 14 08:02 work

After you extract the source you will see a ‘work’ directory. The patch process is described here. From the FreeBSD page:

Each patch you wish to apply should be saved into a file named patch-* where * indicates the pathname of the file that is patched, such as patch-Imakefile or patch-src-config.h. These files should be stored in PATCHDIR (usually files/, from where they will be automatically applied. All patches must be relative to WRKSRC (generally the directory your port’s tarball unpacks itself into, that being where the build is done). .. .. Note that if the path of a patched file contains an underscore (_) character, the patch needs to have two underscores instead in its name. For example, to patch a file named src/freeglut_joystick.c, the corresponding patch should be named patch-src-freeglut__joystick.c.

So we were patching the “fuse_vnops.c” file. First let’s find it’s location in the source:

[email protected]:/usr/ports/sysutils/fusefs-kmod>find . -name 'fuse_vnops.c'

Now checking out the distfile directory, I actually saw a patch for that file:

[email protected]:/usr/ports/sysutils/fusefs-kmod>ls -l files/ | grep vn
-rw-r--r-- 1 root wheel 443 Sep 21 2011 extra-patch-fuse_module__fuse_vnops.c
-rw-r--r-- 1 root wheel 269 May 11 01:08 extrapatch-fuse_module__fuse_vnops.c
-rw-r--r-- 1 root wheel 2221 Sep 20 17:52 patch-fuse_module__fuse_vnops.c

so I went ahead and edited the ‘patch-fuse_module__fuse_vnops.c’ file and added the changes described in the above page. Here is my final patch file. I then removed both packages:

[email protected]:> sudo /usr/local/etc/rc.d/fusefs stop
[email protected]:>cd /usr/ports/sysutils/fusefs-kmod
[email protected]:/usr/ports/sysutils/fusefs-kmod>sudo make deinstall
[email protected]:/usr/ports/sysutils/fusefs-kmod>cd ../fusefs-ntfs
[email protected]:/usr/ports/sysutils/fusefs-nfts>sudo make deinstall

I then applied my new patch file:

[email protected]:~>fetch http://assets.virtuallyhyper.com/2012-10-patch-fuse_module__fuse_vnops.c
[email protected]:~>sudo cp patch-fuse_module\__fuse_vnops.c /usr/ports/sysutils/fusefs-kmod/files/patch-fuse_module__fuse_vnops.c

And then re-installed both:

[email protected]:>cd /usr/ports/sysutils/fusefs-kmod
[email protected]:/usr/ports/sysutils/fusefs-kmod> sudo make install clean
[email protected]:/usr/ports/sysutils/fusefs-kmod> cd ../fusefs-ntfs
[email protected]:/usr/ports/sysutils/fusefs-ntfs> sudo make install clean
[email protected]:> sudo /usr/local/etc/rc.d/fusefs start

After that I was able to copy files just fine :)

[email protected]:~>touch test
[email protected]:~>cp test /mnt/usb/.
[email protected]:~>ls -l /mnt/usb/
total 0
-rwxrwxrwx 1 elatov wheel 0 Oct 14 17:15 test

And no kernel panic occurred.

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