Page fault in umount

Page fault in umount

[Pierre Ossman]

When I yank out my MP3 player, the programs trying to umount the disk 
cause the following page fault:

usb 1-5: USB disconnect, address 2
scsi0 (0:0): rejecting I/O to dead device
FAT bread failed in fat_clusters_flush
Unable to handle kernel paging request at virtual address 6b6b6b6b
  printing eip:
e0a0ecaf
*pde = 00000000
Oops: 0000 [#1]
PREEMPT
Modules linked in: radeon pcspkr iptable_filter tun parport_pc lp 
parport irport irnet ppp_generic slhc ircomm_tty ircomm irda crc_ccitt 
sd_mod autofs4 hidp rfcomm l2cap bluetooth pcmcia sunrpc ipt_MASQUERADE 
iptable_nat usb_storage scsi_mod ip_conntrack ip_tables microcode 
binfmt_misc nls_iso8859_1 nls_cp437 vfat fat ext3 jbd video button 
battery ac ohci1394 ieee1394 yenta_socket pcmcia_core uhci_hcd ehci_hcd 
i2c_i801 i2c_core snd_intel8x0m snd_intel8x0 snd_ac97_codec snd_pcm_oss 
snd_mixer_oss snd_pcm snd_timer snd soundcore snd_page_alloc 8139cp mii
CPU:    0
EIP:    0060:[<e0a0ecaf>]    Not tainted VLI
EFLAGS: 00010296   (2.6.10)
EIP is at scsi_device_put+0xf/0x70 [scsi_mod]
eax: 6b6b6b6b   ebx: d8994150   ecx: 00000000   edx: 00000000
esi: 6b6b6b6b   edi: dfcae46c   ebp: 00000000   esp: ce6b3ee4
ds: 007b   es: 007b   ss: 0068
Process umount (pid: 7190, threadinfo=ce6b2000 task=cbe5c000)
Stack: d883b9f4 d8994150 d883b9f4 e0b38103 6b6b6b6b e0b3a190 d8994150 
e0b386f7
        d8994150 00000000 dc6a1764 dc6a17f8 c0195e56 dc6a17f8 00000000 
dc6a19b8
        c0472680 00000000 00000000 c0195ed0 dc6a1764 c0193acd d89645f8 
e09f6ec0
Call Trace:
  [<e0b38103>] scsi_disk_put+0x33/0x50 [sd_mod]
  [<e0b3a190>] scsi_disk_release+0x0/0x1b0 [sd_mod]
  [<e0b386f7>] sd_release+0x47/0x90 [sd_mod]
  [<c0195e56>] blkdev_put+0xc6/0x170
  [<c0195ed0>] blkdev_put+0x140/0x170
  [<c0193acd>] kill_block_super+0x3d/0x60
  [<c019144c>] deactivate_super+0xac/0x120
  [<c01b4f95>] __mntput+0x25/0x40
  [<c01b5c9f>] sys_umount+0x3f/0xa0
  [<c01746a4>] sys_munmap+0x44/0x70
  [<c0103c59>] sysenter_past_esp+0x52/0x75
Code: 34 24 e8 05 ba 90 df ba fa ff ff ff eb e0 8d b4 26 00 00 00 00 8d 
bc 27 00 00 00 00 83 ec 0c 89 74 24 08 8b 74 24 10 89 5c 24 04 <8b> 06 
8b 80 b4 00 00 00 8b 00 85 c0 74 1f bb 00 e0 ff ff 21 e3

The device is mounted in sync so shouldn't this be safe as long as the 
device isn't busy? This works on other USB devices I have.
A page fault seems severe either way.

Rgds
Pierre

Re: Page fault in umount

[Andrew Morton]

Pierre Ossman <drzeus-list@drzeus.cx> wrote:
>
> When I yank out my MP3 player, the programs trying to umount the disk 
> cause the following page fault:
> 
> ...
> EIP is at scsi_device_put+0xf/0x70 [scsi_mod]

This should be fixed in 2.6.11-rc2-mm1, via bk-scsi-rc-fixes.patch.  Could you
retest with either

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11-rc2/2.6.11-rc2-mm1/2.6.11-rc2-mm1.bz2

or

ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11-rc2/2.6.11-rc2-mm1/broken-out/bk-scsi-rc-fixes.patch

applied?

Re: Page fault in umount

[Pierre Ossman]

Andrew Morton wrote:

>Pierre Ossman <drzeus-list@drzeus.cx> wrote:
>  
>
>>When I yank out my MP3 player, the programs trying to umount the disk 
>>cause the following page fault:
>>
>>...
>>EIP is at scsi_device_put+0xf/0x70 [scsi_mod]
>>    
>>
>
>This should be fixed in 2.6.11-rc2-mm1, via bk-scsi-rc-fixes.patch.  Could you
>retest with either
>
>ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11-rc2/2.6.11-rc2-mm1/2.6.11-rc2-mm1.bz2
>
>or
>
>ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.11-rc2/2.6.11-rc2-mm1/broken-out/bk-scsi-rc-fixes.patch
>
>applied?
>  
>
The patch seems to solve the problem. Thanks.

Rgds
Pierre