2.0.22 Oops: VFS: brelse: Trying to free free buffer

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Sun, 3 Nov 1996 02:16:10 +0100 (MET)

I get the Oops below on both x86 and AXP for 2.0.22 (can't test .23 or .24
right now, sorry). it's very easy to reproduce this: just read the
swap partition e.g. with dd, even when swapoff'ed before.
e.g. (/dev/sdb6 is a 16MB partition, having 32MB ram on x86; same problem
with an alpha UDB166 iwht 64MB ram and 80MB swap partition...):

# swapon /dev/sdb6
Adding Swap: 16376k swap-space
# swapoff /dev/sdb6 # doesn't matter
# dd if=/dev/sdb6 of=/dev/null bs=64k

==> Oops (see below)

after that the swap parition /dev/sdb6 is "busy" and can't be swapon'ed
anymore:

# swapon /dev/sdb6
swapon: /dev/sdb6: Device or resource busy

Harald
-------------------------------------------------------------------------------
VFS: brelse: Trying to free free buffer
Unable to handle kernel paging request at virtual address c32e5be0
current->tss.cr3 = 010d1000, %cr3 = 010d1000
*pde = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<0012f772>]
EFLAGS: 00010216
eax: 000ef6ff ebx: 00000002 ecx: 00243000 edx: 00c28af3
esi: 01f93c00 edi: 40013c10 ebp: 0186aeb8 esp: 0186accc
ds: 0018 es: 0018 fs: 002b gs: 002b ss: 0018
Process buffer (pid: 30936, process nr: 21, stackpage=0186a000)
Stack: 00000002 01f93c00 40013c10 0186aeb8 0153f6a4 01f93c00 40013c10 0012fc22
00000002 00000002 00000000 00000c00 0013503d 00000002 01124580 00000000
00010000 00076e88 0186af74 00001000 00000000 00000001 00000c00 00000000
Call Trace: [<0012fc22>] [<0013503d>] [<00114adc>] [<00114b14>] [<0011f58e>] [<0010b73b>] [<0014269e>]
[<00143ed4>] [<001219b3>] [<00145c39>] [<00122cdc>] [<00122d46>] [<00125828>] [<0012c5c4>] [<0010b7b2>]
Code: 83 7c 91 14 01 7f 06 f6 43 14 40 74 11 be 05 00 00 00 eb 31
Using `System.map' to map addresses to symbols.

>>EIP: 12f772 <_refile_buffer+52/4e0>
Trace: 12fc22 <___brelse+22/40>
Trace: 13503d <_block_read+681/6d0>
Trace: 114adc <_timer_bh+e4/180>
Trace: 114b14 <_timer_bh+11c/180>
Trace: 11f58e <_do_bottom_half+3a/94>
Trace: 10b73b <handle_bottom_half+b/20>
Trace: 14269e <_update_queue+76/90>
Trace: 143ed4 <_sys_semop+32c/470>
Trace: 1219b3 <_copy_page_range+18b/410>
Trace: 145c39 <_shm_map+81/1d0>
Trace: 122cdc <_do_no_page+124/310>
Trace: 122d46 <_do_no_page+18e/310>
Trace: 125828 <_filemap_nopage>
Trace: 12c5c4 <_sys_read+8c/c0>
Trace: 10b7b2 <_system_call+52/80>

Code: 12f772 <_refile_buffer+52/4e0> cmpl $0x1,0x14(%ecx,%edx,4)
Code: 12f777 <_refile_buffer+57/4e0> jg 12f77f <_refile_buffer+5f/4e0>
Code: 12f779 <_refile_buffer+59/4e0> testb $0x40,0x14(%ebx)
Code: 12f77d <_refile_buffer+5d/4e0> je 12f790 <_refile_buffer+70/4e0>
Code: 12f77f <_refile_buffer+5f/4e0> movl $0x5,%esi
Code: 12f784 <_refile_buffer+64/4e0> jmp 12f7b7 <_refile_buffer+97/4e0>

--
All SCSI disks will from now on                     ___       _____
be required to send an email notice                0--,|    /OOOOOOO\
24 hours prior to complete hardware failure!      <_/  /  /OOOOOOOOOOO\
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                                                      \ OOOOOOOOOOOOOOOOO|//
Harald Koenig,                                         \/\/\/\/\/\/\/\/\/
Inst.f.Theoret.Astrophysik                              //  /     \\  \
koenig@tat.physik.uni-tuebingen.de                     ^^^^^       ^^^^^