kernel/3070: removable media does not detach correctly if it's currently mounted

From: <gumboot(at)clear.net.nz>
Date: Sat Jan 18 2003 - 18:07:41 EST

>Number: 3070
>Category: kernel
>Synopsis: removable media does not detach correctly if it's currently mounted
>Confidential: no
net
>Environment:
        

	System      : OpenBSD 3.2
	Architecture: OpenBSD.i386
	Machine     : i386

>Description:

Removing a USB storage device while it is mounted doesn't clear out all the device cruft that is added when it is attached. Consequential faults include applications (including umount) hanging when trying to access the mount point, and if you're really lucky you can get a kernel panic (I'm not reporting the panic, though).

The machine must be rebooted to access the device again.

>How-To-Repeat:

Remove a mounted USB storage device while it is mounted. Here's how I did it (my actions annotated with '**').

OpenBSD 3.2-stable (GENERIC.gumboot) #1: Thu Dec 19 18:48:19 NZDT 2002

    gumboot@cowpat.grottyflat.net:/usr/src/sys/arch/i386/compile/GENERIC.gumboot cpu0: AMD K6-2+/III+ ("AuthenticAMD" 586-class) 501 MHz cpu0: FPU,V86,DE,PSE,TSC,MSR,MCE,CX8,PGE,MMX real mem = 267956224 (261676K)
avail mem = 188190720 (183780K)
using 4278 buffers containing 67510272 bytes (65928K) of memory mainbus0 (root)
bios0 at mainbus0: AT/286+(ba) BIOS, date 10/03/00, BIOS32 rev. 0 @ 0xfb330 apm0 at bios0: Power Management spec V1.2 apm0: AC on, battery charge unknown
pcibios0 at bios0: rev. 2.1 @ 0xf0000/0xb7a8

pcibios0: PCI IRQ Routing Table rev. 1.0 @ 0xfdd50/128 (6 entries)
pcibios0: PCI Exclusive IRQs: 5 9 11
pcibios0: PCI Interrupt Router at 000:07:0 ("VIA VT82C586 PCI-ISA" rev 0x00)
pcibios0: PCI bus #2 is the last bus

bios0: ROM list: 0xc0000/0x8000 0xc8000/0x2600 pci0 at mainbus0 bus 0: configuration mode 1 (no bios) pchb0 at pci0 dev 0 function 0 "VIA VT82C597 Host-PCI" rev 0x04 ppb0 at pci0 dev 1 function 0 "VIA VT82C598 PCI-AGP" rev 0x00 pci1 at ppb0 bus 1
vga1 at pci1 dev 0 function 0 "Matrox MGA G400/G450 AGP" rev 0x05 wsdisplay0 at vga1: console (80x25, vt100 emulation) wsdisplay0: screen 1-5 added (80x25, vt100 emulation) pcib0 at pci0 dev 7 function 0 "VIA VT82C586 PCI-ISA" rev 0x47 pciide0 at pci0 dev 7 function 1 "VIA VT82C571 IDE" rev 0x06: ATA33, channel 0 configured to compatibility, channel 1 configured to compatibility atapiscsi0 at pciide0 channel 0 drive 1
scsibus0 at atapiscsi0: 2 targets
cd0 at scsibus0 targ 0 lun 0: [ASUS, CD-S500/A, 1.5D] SCSI0 5/cdrom removable cd0(pciide0:0:1): using PIO mode 4, Ultra-DMA mode 2 uhci0 at pci0 dev 7 function 2 "VIA VT83C572 USB" rev 0x02: irq 9 usb0 at uhci0: USB revision 1.0
uhub0 at usb0
uhub0: vendor 0x0000 UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered "VIA VT82C586 Power Mgmt" rev 0x10 at pci0 dev 7 function 3 not configured pciide1 at pci0 dev 8 function 0 "CMD Technology PCI0649" rev 0x02: DMA, channel 0 configured to native-PCI, channel 1 configured to native-PCI pciide1: using irq 5 for native-PCI interrupt wd0 at pciide1 channel 0 drive 0: [ST320011A] wd0: 16-sector PIO, LBA, 19092MB, 16383 cyl, 16 head, 63 sec, 39102336 sectors wd0(pciide1:0:0): using PIO mode 4, Ultra-DMA mode 5 wd1 at pciide1 channel 1 drive 0: [IC35L040AVER07-0] wd1: 16-sector PIO, LBA, 39266MB, 16383 cyl, 16 head, 63 sec, 80418240 sectors wd2 at pciide1 channel 1 drive 1: [ST380021A] wd2: 16-sector PIO, LBA, 76319MB, 16383 cyl, 16 head, 63 sec, 156301488 sectors wd1(pciide1:1:0): using PIO mode 4, Ultra-DMA mode 5 wd2(pciide1:1:1): using PIO mode 4, Ultra-DMA mode 5 bktr0 at pci0 dev 9 function 0 "Brooktree BT878" rev 0x02: irq 11 bktr0: Askey/Dynalink Magic TView, Philips PAL I tuner. "Brooktree BT878 Audio" rev 0x02 at pci0 dev 9 function 1 not configured cmpci0 at pci0 dev 10 function 0 "C-Media Electronics CMI8738/C3DX Audio" rev 0x10: "C-Media Electronics CMI8738/C3DX Audio" rev 0x10 (rev. 0x10) cmpci0: interrupting at irq 9
audio0 at cmpci0
opl at cmpci0 not configured
isa0 at pcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0 pmsi0 at pckbc0 (aux slot)
pckbc0: using irq 12 for aux slot
wsmouse0 at pmsi0 mux 0
we1 at isa0 port 0x300/32 iomem 0xcc000/16384 irq 10: WD8013EPC (16-bit) we1: address 00:00:c0:58:96:4a
pcppi0 at isa0 port 0x61
midi0 at pcppi0: [PC speaker]
sysbeep0 at pcppi0
lpt0 at isa0 port 0x378/4 irq 7
npx0 at isa0 port 0xf0/16: using exception 16 pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo pccom1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec biomask 4a60 netmask 4e60 ttymask 5ee2
pctr: user-level cycle counter enabled
mtrr: K6-family MTRR support (2 registers) dkcsum: wd0 matched BIOS disk 80
dkcsum: wd1 matched BIOS disk 81
wd2: no disk label
dkcsum: wd2 matched BIOS disk 82
root on wd0a
rootdev=0x0 rrootdev=0x300 rawdev=0x302

• connect camera umass0 at uhub0 port 2 configuration 1 interface 0 umass0: vendor 0x0595 Concord EyeQ Duo Digital Camera, rev 1.00/1.00, addr 2 umass0: using SFF8070i over CBI-I scsibus1 at umass0: 2 targets sd0 at scsibus1 targ 1 lun 0: [CONCORD, DIGITAL CAMERA, 1.00] SCSI0 0/direct removable sd0: 7MB, 33000 cyl, 48 head, 26 sec, 512 bytes/sec, 14528 sec total
• disconnect camera umass0: at uhub0 port 2 (addr 2) disconnected sd0 detached scsibus1 detached umass0 detached
• connect camera umass0 at uhub0 port 2 configuration 1 interface 0 umass0: vendor 0x0595 Concord EyeQ Duo Digital Camera, rev 1.00/1.00, addr 2 umass0: using SFF8070i over CBI-I scsibus1 at umass0: 2 targets sd0 at scsibus1 targ 1 lun 0: [CONCORD, DIGITAL CAMERA, 1.00] SCSI0 0/direct removable sd0: 7MB, 174 cyl, 16 head, 0 sec, 512 bytes/sec, 14528 sec total
• mount /dev/sd0i on /home/camera type msdos (local, noatime, nodev, noexec, nosuid, read-only)
• umount
• disconnect camera umass0: at uhub0 port 2 (addr 2) disconnected sd0 detached scsibus1 detached umass0 detached
• connect camera umass0 at uhub0 port 2 configuration 1 interface 0 umass0: vendor 0x0595 Concord EyeQ Duo Digital Camera, rev 1.00/1.00, addr 2 umass0: using SFF8070i over CBI-I scsibus1 at umass0: 2 targets sd0 at scsibus1 targ 1 lun 0: [CONCORD, DIGITAL CAMERA, 1.00] SCSI0 0/direct removable sd0: 7MB, 49384 cyl, 48 head, 160 sec, 512 bytes/sec, 14528 sec total
• mount
• disconnect camera umass0: at uhub0 port 2 (addr 2) disconnected

No further cleanup is performed, and when the device is reattached no new messages appear.

Only the final stages are necessary, but I include the others to demonstrate how it normally works.

>Fix:

        unknown

>Release-Note:
Received on Sat Jan 18 19:39:29 2003