Re: freezing on unmountin ext2fs USB device

On Tue, 25 Nov 2025 21:03:01 -0700
Warner Losh <imp@bsdimp.com> wrote:

> On Sun, Nov 23, 2025 at 7:15 AM A FreeBSD User <freebsd@walstatt-de.de>
> wrote:
> 
> > Hello,
> >
> > running FreeBSD 16.0-CURRENT #4 master-n282101-c8cf5a99f82b: Sun Nov 23
> > 13:56:23 CET
> > 2025 amd64 I'm running into a serious problem when mounting an ext2fs
> > formated USB Flash
> > device (512GB). The devince contains files written by a Linux system,
> > mounting the USB Flash
> > via extended4fs, the size of the written datafiles is > 128GB. Deleting
> > those files larger
> > than some 20GB results in an I/O error reported by FReeBSD (# sudo rm
> > /mnt/USB/filename).
> > Unmounting the ext2fs after deletion (sudo umount /mnt) results in a total
> > freeze of the box.
> > No crash, no core dump, nothing. I waited almost an hour hoping for
> > recover. I have to
> > physically switch off the box.
> >
> > I checked with other USB flash I have at hand, one Samsung 256 GB, ZFS -
> > no problem, another
> > 128GB, UFS, no problem and several much smaller (4 - 64GB) with FAT or UFS
> > filesystems, all no
> > problem.
> >
> > I can not figure out whether it is the USB flash drive itself, the size or
> > the ext2fs itself
> > causing the problem.
> >
> > Does anybody see similar problems or do have an tip to investigate without
> > risking my box'
> > health switching it on/off on failure?
> >  
> 
> I've not seen this on the smaller tests I've been able to run.
> 
> So can you share the error messages that you get when you say you get I/O
> errors? I'd like to see if this is due to an error in ext2fs or on the USB
> drive. It's kinda sounding a little like the particular USB is triggering
> some kind of issue that at the very least we should work around. Given that
> it's not happening on all ext2fs drives you try to access, I'm leaning
> towards the drive, but you never know.
> 
> Thanks

Plugging the USB flash gives the following hardware information on the console:

[...]
ugen1.5: <ASolid USB> at usbus1
umass0 on uhub6
umass0: <ASolid USB, class 0/0, rev 3.20/1.10, addr 4> on usbus1
(probe0:umass-sim0:0:0:0): REPORT LUNS. CDB: a0 00 00 00 00 00 00 00 00 10 00 00 
(probe0:umass-sim0:0:0:0): CAM status: SCSI Status Error
(probe0:umass-sim0:0:0:0): SCSI status: Check Condition
(probe0:umass-sim0:0:0:0): SCSI sense: ILLEGAL REQUEST asc:20,0 (Invalid command
operation code) (probe0:umass-sim0:0:0:0): Error 22, Unretryable error
da4 at umass-sim0 bus 0 scbus11 target 0 lun 0
da4: <ASolid USB > Removable Direct Access SPC-4 SCSI device
da4: Serial Number somer serial numbers
da4: 400.000MB/s transfers
da4: 475000MB (972800000 512 byte sectors)
da4: quirks=0x2<NO_6_BYTE>
[...]

Trying to mount via:  # mount -t ext2fs /dev/da4p1 /mnt/image

[...]
(da4:umass-sim0:0:0:0): got CAM status 0x444
(da4:umass-sim0:0:0:0): fatal error, failed to attach to device
da4 at umass-sim0 bus 0 scbus11 target 0 lun 0
da4: <ASolid USB >  s/n some serial numbers  detached
(da4:umass-sim0:0:0:0): Periph destroyed

mount: /dev/da4p1: Device not configured

[...]

[...]
# /compat/linux/sbin/fsck.ext4 /dev/da4p1
e2fsck 1.46.5 (30-Dec-2021)
SINA was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Error writing file system info: Invalid argument

XXXX: ***** FILE SYSTEM WAS MODIFIED *****

[...]

detaching and attaching to another USB slot on the same (external) HUB:

[...]
ugen1.5: <ASolid USB> at usbus1
umass0 on uhub6
umass0: <ASolid USB, class 0/0, rev 3.20/1.10, addr 6> on usbus1
(probe0:umass-sim0:0:0:0): REPORT LUNS. CDB: a0 00 00 00 00 00 00 00 00 10 00 00 
(probe0:umass-sim0:0:0:0): CAM status: SCSI Status Error
(probe0:umass-sim0:0:0:0): SCSI status: Check Condition
(probe0:umass-sim0:0:0:0): SCSI sense: ILLEGAL REQUEST asc:20,0 (Invalid command
operation code) (probe0:umass-sim0:0:0:0): Error 22, Unretryable error
da4 at umass-sim0 bus 0 scbus11 target 0 lun 0
da4: <ASolid USB > Removable Direct Access SPC-4 SCSI device
da4: Serial Number some serial numbers
da4: 400.000MB/s transfers
da4: 475000MB (972800000 512 byte sectors)
da4: quirks=0x2<NO_6_BYTE>
linux: jid 0 pid 5087 (fsck.ext4): linux_ioctl_fallback fd=3, cmd=0x127c ('\^R',124) is
not implemented linux: jid 0 pid 5087 (fsck.ext4): linux_ioctl_fallback fd=3, cmd=0x125e
('\^R',94) is not implemented (da4:umass-sim0:0:0:0): got CAM status 0x444
(da4:umass-sim0:0:0:0): fatal error, failed to attach to device
da4 at umass-sim0 bus 0 scbus11 target 0 lun 0
da4: <ASolid USB >  s/n some serial numbers detached
(da4:umass-sim0:0:0:0): Periph destroyed

[...]

I can not even mount the device on CURRENT (FreeBSD 16.0-CURRENT #1
master-n282217-34d66b0c96d5: Fri Nov 28 05:15:56 CET 2025 amd64).

Package used for linux operation: emulators/linux-rl9