# When the USB device is attached, everything looks fine.

usb 2-1: new SuperSpeed USB device number 2 using xhci_hcd
usb-storage 2-1:1.0: USB Mass Storage device detected
scsi4 : usb-storage 2-1:1.0
scsi 4:0:0:0: Direct-Access     SSK      USB bridge            PQ: 0 ANSI: 0
sd 4:0:0:0: [sdb] 488397168 512-byte logical blocks: (250 GB/232 GiB)
sd 4:0:0:0: [sdb] Write Protect is off
sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
sd 4:0:0:0: [sdb] No Caching mode page found
sd 4:0:0:0: [sdb] Assuming drive cache: write through
sd 4:0:0:0: [sdb] No Caching mode page found
sd 4:0:0:0: [sdb] Assuming drive cache: write through
 sdb: sdb1
sd 4:0:0:0: [sdb] No Caching mode page found
sd 4:0:0:0: [sdb] Assuming drive cache: write through
sd 4:0:0:0: [sdb] Attached SCSI disk

# I use `cryptsetup luksOpen /dev/sdb1 foo` to open this device.
# Now I will write something (anything > 32 KiB) to /dev/mapper/foo
# Here we go ...

[  237.638334] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63
[  237.638336] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63
[  237.638338] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63
[  237.649031] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63

# ......
# There are more than seven million messages like this, taking up 1.9 GiB
# in systemd journal.
# ......

[  237.649035] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63
[  237.649037] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63
[  237.649040] xhci_hcd 0000:00:14.0: Too many fragments 64, max 63

# And finally I plugged out the USB device:

[  237.649079] usb 2-1: USB disconnect, device number 2
[  237.652307] scsi 3:0:0:0: rejecting I/O to offline device
[  237.652315] scsi 3:0:0:0: [sdb] killing request
[  237.652333] scsi 3:0:0:0: [sdb] Unhandled error code
[  237.652334] scsi 3:0:0:0: [sdb]  
[  237.652335] Result: hostbyte=0x01 driverbyte=0x00
[  237.652336] scsi 3:0:0:0: [sdb] CDB: 
[  237.652337] cdb[0]=0x2a: 2a 00 00 00 18 02 00 00 40 00
[  237.652342] end_request: I/O error, dev sdb, sector 6146
[  237.652351] Buffer I/O error on device dm-2, logical block 2
[  237.652352] lost page write due to I/O error on dm-2
[  237.652355] Buffer I/O error on device dm-2, logical block 3
[  237.652356] lost page write due to I/O error on dm-2
[  237.652358] Buffer I/O error on device dm-2, logical block 4
[  237.652359] lost page write due to I/O error on dm-2
[  237.652361] Buffer I/O error on device dm-2, logical block 5
[  237.652362] lost page write due to I/O error on dm-2
[  237.652366] Buffer I/O error on device dm-2, logical block 6
[  237.652366] lost page write due to I/O error on dm-2
[  237.652368] Buffer I/O error on device dm-2, logical block 7
[  237.652370] lost page write due to I/O error on dm-2
[  237.652377] Buffer I/O error on device dm-2, logical block 8
[  237.652377] lost page write due to I/O error on dm-2
[  237.652379] Buffer I/O error on device dm-2, logical block 9
[  237.652380] lost page write due to I/O error on dm-2
[  237.652383] Buffer I/O error on device dm-2, logical block 10
[  237.652384] lost page write due to I/O error on dm-2
[  237.652386] Buffer I/O error on device dm-2, logical block 11
[  237.652387] lost page write due to I/O error on dm-2