Latest working kernel version: N/A

Earliest failing kernel version: 2.6.25-rc6

Distribution: Debian/Suse

Hardware Environment: Dell XPS M1210 Laptop
Dual Core CPU 2.0 Ghz
RAM - 2GB
HDD - SATA 60 GB + USB 120 GB Self-Powered

Software Environment: DM + DM-Crypt + LVM2

Problem Description:
> On my laptop, doing heavy C++ compilations in parallel with -j3 (this
> is a dual core) often generates the following trace:
> 
> INFO: task g++:25119 blocked for more than 120 seconds.
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
> message.
> g++           D c03916c0     0 25119  25118
>        ecfef200 00200086 c038ef18 c03916c0 c03916c0 f77b2230 f77b2378
> c17fa6c0 
>        00000000 f89817bc f7486280 000000ff f7a1eb20 00000000 00000000
> 00000000 
>        c17fa6c0 00000000 d1401e9c c17f0408 c02a2aa1 d1401e94 c0147100
> c02a2c93 
> Call Trace:
>  [<f89817bc>] dm_table_unplug_all+0x1e/0x2e [dm_mod]
>  [<c02a2aa1>] io_schedule+0x1b/0x24
>  [<c0147100>] sync_page+0x33/0x36
>  [<c02a2c93>] __wait_on_bit+0x33/0x58
>  [<c01470cd>] sync_page+0x0/0x36
>  [<c01472fd>] wait_on_page_bit+0x59/0x60
>  [<c012cf7b>] wake_bit_function+0x0/0x3c
>  [<c014e20d>] truncate_inode_pages_range+0x238/0x29f
>  [<c014e27d>] truncate_inode_pages+0x9/0xc
>  [<f8c67187>] ext2_delete_inode+0x12/0x6e [ext2]
>  [<f8c67175>] ext2_delete_inode+0x0/0x6e [ext2]
>  [<c0170ea5>] generic_delete_inode+0x8f/0xf3
>  [<c0170819>] iput+0x60/0x62
>  [<c0169aa5>] do_unlinkat+0xb7/0xf9
>  [<c0113a3e>] do_page_fault+0x1fa/0x4dc
>  [<c0104822>] sysenter_past_esp+0x5f/0x85
>  =======================
> 
> This is with 2.6.25-rc6 (SMP) and has been present, as far as I can
> remember, since the beginning of the 2.6.25-rc series. It is not
> always reproducible, but the trace is always the same.
> 
> My filesystem is stored on a ext3 (rw,noatime) dm_crypt'd partition
> leaving in a LVM volume.
> 
> % lsmod | grep dm | grep -v ' 0 *$'
> dm_crypt               14340  1 
> crypto_blkcipher       18308  6 ecb,cbc,dm_crypt
> dm_mod                 53008  26 dm_crypt,dm_mirror,dm_snapshot
> 
> Here is the code I have in dm-table.o:
> 
> 00001042 <dm_table_unplug_all>:
>     1042:       56                      push   %esi
>     1043:       53                      push   %ebx
>     1044:       8b 98 a0 00 00 00       mov    0xa0(%eax),%ebx
>     104a:       8d b0 a0 00 00 00       lea    0xa0(%eax),%esi
>     1050:       eb 10                   jmp    1062
> <dm_table_unplug_all+0x20>
>     1052:       8b 43 10                mov    0x10(%ebx),%eax
>     1055:       8b 40 5c                mov    0x5c(%eax),%eax
>     1058:       8b 40 34                mov    0x34(%eax),%eax
>     105b:       e8 fc ff ff ff          call   105c
> <dm_table_unplug_all+0x1a>
>     1060:       8b 1b                   mov    (%ebx),%ebx
>     1062:       8b 03                   mov    (%ebx),%eax
>     1064:       0f 1f 40 00             nopl   0x0(%eax)
>     1068:       39 f3                   cmp    %esi,%ebx
>     106a:       75 e6                   jne    1052
> <dm_table_unplug_all+0x10>
>     106c:       5b                      pop    %ebx
>     106d:       5e                      pop    %esi
>     106e:       c3                      ret    
> 
> The symbol in 105b call is, after relocation, blk_unplug.
> 
> It there anything else I can do to help debugging this?
> 
>  Sam

Steps to reproduce:
Steps to reproduce is not consistent. The last time I reported, I wasn't able to reproduce the bug on a different setup (An IBM xSeries server).
One point to notice is that, for both us users, it has been reproducible on the laptops.

I'm filing this bugzilla report because now the user count is 2. And the report is identical.

This was earlier discussed here in this thread:
https://www.redhat.com/archives/dm-devel/2008-March/msg00014.html