Another trace, this time a bit deeper:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c1079e7b>] end_buffer_async_read+0x59/0xc5
*pde = 00000000
Oops: 0000 [#1] PREEMPT
last sysfs file:
Modules linked in: netconsole atl1c rtc
Pid: 1300, comm: gzip Not tainted (2.6.31.6 #5) G31M-ES2L
EIP: 0060:[<c1079e7b>] EFLAGS: 00010013 CPU: 0
EIP is at end_buffer_async_read+0x59/0xc5
EAX: 00000000 EBX: c1ae7b38 ECX: 00000000 EDX: c1079e22
ESI: 00000202 EDI: c17b5040 EBP: 00000000 ESP: df1dde80
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process gzip (pid: 1300, ti=df1dc000 task=df866420 task.ti=df1dc000)
Stack:
ce632840 ce632840 df91de78 df1dded0 c107ccb9 c107cc89 c107e551 00000200
<0> c11587c4 00000000 00000001 df430298 00000000 00000000 0000be00 00004200
<0> 00000000 df91de78 00000000 df91de78 df8ef168 c115893e df8a6c80 00000000
Call Trace:
[<c107ccb9>] ? end_bio_bh_io_sync+0x30/0x38
[<c107cc89>] ? end_bio_bh_io_sync+0x0/0x38
[<c107e551>] ? bio_endio+0x24/0x26
[<c11587c4>] ? blk_update_request+0xdf/0x24e
[<c115893e>] ? blk_update_bidi_request+0xb/0x41
[<c11589f5>] ? blk_end_bidi_request+0x10/0x4f
[<c1158a64>] ? blk_end_request+0x7/0xc
[<c11abcb2>] ? scsi_end_request+0x17/0x69
[<c11abfc3>] ? scsi_io_completion+0x173/0x335
[<c11a8330>] ? scsi_finish_command+0x70/0x86
[<c11ac6a6>] ? scsi_softirq_done+0xd7/0xdc
[<c115b3f9>] ? blk_done_softirq+0x51/0x5d
[<c101bde0>] ? __do_softirq+0x5f/0xc8
[<c101be6b>] ? do_softirq+0x22/0x26
[<c101becd>] ? irq_exit+0x29/0x34
[<c1004097>] ? do_IRQ+0x53/0x63
[<c1002ea9>] ? common_interrupt+0x29/0x30
Code: e8 d2 fd ff ff 80 0f 02 f6 47 01 08 75 04 0f 0b eb fe 9c 5e fa
89 e0 25 00 e0 ff ff ff 40 14 80 23 7f 89 d8 e8 58 fd ff ff 89 d9<8b>
11 b8 00 00 00 00 f6 c2 01 0f 44 e8 f6 c2 80 74 09 80 e2 04
EIP: [<c1079e7b>] end_buffer_async_read+0x59/0xc5 SS:ESP 0068:df1dde80
CR2: 0000000000000000
---[ end trace 2e93648aef49fa0e ]---
It looks like buffer_tmp was NULL during end_buffer_async_read's
buffer_uptodate(tmp).
This one just happened when I interrupted the dd:
BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: [<c107ae05>] block_invalidatepage+0x22/0x54
*pde = 00000000
Oops: 0000 [#1] PREEMPT
last sysfs file:
Modules linked in: netconsole atl1c rtc
Pid: 1296, comm: dd Not tainted (2.6.31.6 #6) G31M-ES2L
EIP: 0060:[<c107ae05>] EFLAGS: 00010217 CPU: 0
EIP is at block_invalidatepage+0x22/0x54
EAX: 00000000 EBX: c14f1540 ECX: 00000002 EDX: 00001000
ESI: 00000000 EDI: 00001000 EBP: c8d4fc88 ESP: df1d7ed0
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process dd (pid: 1296, ti=df1d6000 task=df87bc00 task.ti=df1d6000)
Stack:
00000000 c14f1540 00000000 c14f1540 00064156 c1048c29 c14f1540 c1048cab
<0> 00000001 c1048def ffffffff 00000000 df4cff54 0000000e 00000000 c13f0440
<0> c14f1540 c14f2ae0 c13f7a40 c13f7e80 c13fd220 c13efd40 c13efd60 c13f01c0
Call Trace:
[<c1048c29>] ? do_invalidatepage+0x1d/0x1f
[<c1048cab>] ? truncate_complete_page+0x19/0x4b
[<c1048def>] ? truncate_inode_pages_range+0xd1/0x2af
[<c1048fd6>] ? truncate_inode_pages+0x9/0xc
[<c107fb83>] ? __blkdev_put+0x47/0xec
[<c1060fe7>] ? __fput+0xc4/0x177
[<c105fa8a>] ? filp_close+0x4c/0x52
[<c105faee>] ? sys_close+0x5e/0x99
[<c10027f0>] ? sysenter_do_call+0x12/0x22
Code: bf 89 d8 5b e9 ee ed ff ff 55 57 56 53 89 c3 56 89 14 24 31 d2
8b 00 a8 01 75 04 0f 0b eb fe f6 c4 08 74 33 8b 6b 0c 89 e8 89 d7<8b>
70 04 03 78 14 39 14 24 77 05 e8 97 ff ff ff 39 ee 89 fa 89
EIP: [<c107ae05>] block_invalidatepage+0x22/0x54 SS:ESP 0068:df1d7ed0
CR2: 0000000000000004
---[ end trace 64b0df80bcbb02ce ]---
Here, it looks like bh is NULL in block_invalidatepage's loop, dying
at bh->b_size.
I'm not sure where to go from here.