logfs unmount bug

[Jörn Engel]

On Wed, 31 August 2011 12:52:54 +0530, srimugunthan dhandapani wrote:
> On Wed, Aug 31, 2011 at 11:28 AM, Jörn Engel <joern at logfs.org> wrote:
> 
> > I can do.  Can you ensure you have my patch applied, rerun the rest
> > case and send me the kernel results?
> 
> I applied your patch1  and the bonnie output is the same(stuck at
> "Creating  files in sequential order ..."). The kernel is from your
> git directory(http://git.kernel.org/?p=linux/kernel/git/joern/logfs.git;a=summary)
> I am pretty sure i applied the patch. The git diff output is below[1]
> 
>  The kernel log is at
>  https://docs.google.com/leaf?id=0BycgLWCW61phNjY0ZDg4ZjUtYzAyMy00YTgwLWFlMmItNjlmZWIzMWFlNGUy&hl=en_US

600M.  And starting at line 34285 or about 0% in, the output mutates
to something like the below.  Not very useful. :(

Aug 31 12:28:06 mll kernel: [  991.561293] logfs_write_obj_alia 8,, 83,(3f(320(#2 #s #es sesaseiaslialilialilialialialialialialialialialialialialialilialialialilialialialililialialialilialialialilililialialialialialilialialiallialilialialialiaali_alj_abjo_ws_fsgfogflo lo] l4] 7581586156.561.591.9 9  [  >[7>[<7
Aug 31 12:28:06 mll kernel: <7
Aug 31 12:28:07 mll kernel: last message repeated 4 times
Aug 31 12:28:06 mll kernel: <
Aug 31 12:28:06 mll kernel: <7
Aug 31 12:28:06 mll kernel: <7
Aug 31 12:28:06 mll kernel: <
Aug 31 12:28:06 mll kernel: <
Aug 31 12:28:06 mll kernel: <7
Aug 31 12:28:06 mll kernel: <7
Aug 31 12:28:06 mll kernel: <

Can you set LOGFS_DEBUG to 0, both to cut down the noise and in the
hope that the log output doesn't get corrupted like this again?

> While i still have your attention, i would like to point out at max
> writepage size restriction in logfs. Currently logfs has a max
> writepage size as 4K. Currently, large page nand flashes and MLC nand
> come in  8K page sizes. As the usecase for logfs is large nand
> flashes(mostly with parallel and DMA write capabilities),  it may be
> essential to remove the 4K write page size restriction.
> I was only able to change the logfs-tools for >4K writepage size. If
> you send a patch, that makes logfs useable for writepagesize >4K, i
> can try on real hardware, instead of nandsim and give you the results
> :-)

That sure sounds useful.  I'll have a look...

Jörn

-- 
"Security vulnerabilities are here to stay."
-- Scott Culp, Manager of the Microsoft Security Response Center, 2001