Re: PROBLEM: IO lockup on reiserfs FS.

Re: PROBLEM: IO lockup on reiserfs FS.

[David Niklas]

I should add that in chasing down this bug I have tried all the IO
schedulers available (noop deadline and cfq). Cfq is the one I'm now
using to reproduce this.

Also, I don't know if it makes a difference, but when the system first
starts up it takes 20m to get from the login manager to having my web
browsers restart and get all their pages from online. It might be because
there is a lot of IO going on or it might be that there are several
stalls in the scheduling; just not bad enough to cause a hung task
problem like above.

Re: PROBLEM: IO lockup on reiserfs FS.

[Hgntkwis]

It's been over 1 week since I sent this into the reiserfs-devel mailing
list. I'm escalating this as the kernel docs recommend.
I'm still willing to help debug and test a fix for this problem.

"Given enough eyeballs, all bugs are shallow".
This bug is visible, could we please quash it?

Original message:
https://lkml.org/lkml/2020/7/28/1435
Filed bug:
https://bugzilla.kernel.org/show_bug.cgi?id=208719

Thanks,
David

Re: PROBLEM: IO lockup on reiserfs FS.

[Linus Torvalds]

On Wed, Aug 5, 2020 at 9:53 AM <Hgntkwis@vfemail.net> wrote:
>
> It's been over 1 week since I sent this into the reiserfs-devel mailing
> list. I'm escalating this as the kernel docs recommend.
> I'm still willing to help debug and test a fix for this problem.

The thing is, you're using an ancient 4.14 kernel, and a filesystem
that isn't really maintained any more. You'll find very few people
interested in trying to debug that combination.

You *might* have more luck with a more modern kernel, but even then
... reiserfs?

              Linus

Re: PROBLEM: IO lockup on reiserfs FS.

[Hgntkwis]

On Wed, 5 Aug 2020 12:51:41 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Wed, Aug 5, 2020 at 9:53 AM <Hgntkwis@vfemail.net> wrote:
> >
> > It's been over 1 week since I sent this into the reiserfs-devel
> > mailing list. I'm escalating this as the kernel docs recommend.
> > I'm still willing to help debug and test a fix for this problem.  
> 
> The thing is, you're using an ancient 4.14 kernel, 

Sorry, I didn't realize kernel development went that fast.
I did try to go to the 5.X series, but the AMDGPU drivers don't work on
my SI card anymore (I need to bisect which takes time and many re-boots
to find the problematic commit).
I'll try the Radeon-SI driver and see if I can reproduce this reliably.

> and a filesystem
> that isn't really maintained any more. You'll find very few people
> interested in trying to debug that combination.
> 
> You *might* have more luck with a more modern kernel, but even then
> ... reiserfs?
> 
>               Linus
> 

Why does no one (I've met others who share a similar sentiment), like
reiserfs? I'm not looking for fight, I'm incredulous. It's a great FS
that survives oops-es, power failures, and random crashes very very well.
It's the only FLOSS FS with tail packing.

Thanks,
David

Re: PROBLEM: IO lockup on reiserfs FS.

[Edward Shishkin]

On 08/06/2020 02:01 AM, Hgntkwis@vfemail.net wrote:
> On Wed, 5 Aug 2020 12:51:41 -0700
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
>> On Wed, Aug 5, 2020 at 9:53 AM <Hgntkwis@vfemail.net> wrote:
>>>
>>> It's been over 1 week since I sent this into the reiserfs-devel
>>> mailing list. I'm escalating this as the kernel docs recommend.
>>> I'm still willing to help debug and test a fix for this problem.
>>
>> The thing is, you're using an ancient 4.14 kernel,
> 
> Sorry, I didn't realize kernel development went that fast.
> I did try to go to the 5.X series, but the AMDGPU drivers don't work on
> my SI card anymore (I need to bisect which takes time and many re-boots
> to find the problematic commit).
> I'll try the Radeon-SI driver and see if I can reproduce this reliably.
> 
>> and a filesystem
>> that isn't really maintained any more. You'll find very few people
>> interested in trying to debug that combination.
>>
>> You *might* have more luck with a more modern kernel, but even then
>> ... reiserfs?
>>
>>                Linus
>>
> 
> Why does no one (I've met others who share a similar sentiment), like
> reiserfs? I'm not looking for fight, I'm incredulous. It's a great FS
> that survives oops-es, power failures, and random crashes very very well.
> It's the only FLOSS FS with tail packing.
> 
> Thanks,
> David
> 

Hi David,

The feature of "tail packing", that you need, is brought to perfection
in Reiser4 file system. Other file systems either don't provide tight
packing of records in the storage tree, or they are read-only. You just
need to manually patch (*) the kernel and install a pair of user-space
packages (**).

The latest stuff (against Linux-5.7) is stable. For older kernels you
will need a backport for some fixups (***). We can prepare it for you.

Reiser4 is fully supported. If any problems (including partition
check/repair) - send a message to reiserfs-devel mailing list.

(*)   https://reiser4.wiki.kernel.org/index.php/Reiser4_Howto
       https://sourceforge.net/projects/reiser4/files/
(**)  https://sourceforge.net/projects/reiser4/files/reiser4-utils/
(***) https://marc.info/?l=reiserfs-devel&m=158086248927420&w=2

Thanks,
Edward.

Re: PROBLEM: IO lockup on reiserfs FS.

[David Niklas]

On Wed, 5 Aug 2020 12:51:41 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Wed, Aug 5, 2020 at 9:53 AM <Hgntkwis@vfemail.net> wrote:
> >
> > It's been over 1 week since I sent this into the reiserfs-devel
> > mailing list. I'm escalating this as the kernel docs recommend.
> > I'm still willing to help debug and test a fix for this problem.  
> 
> The thing is, you're using an ancient 4.14 kernel, and a filesystem
> that isn't really maintained any more. You'll find very few people
> interested in trying to debug that combination.
> 
> You *might* have more luck with a more modern kernel, but even then
> ... reiserfs?
> 
>               Linus
> 

This bug appears to have been fixed some where between 4.14.X and the
5.17.X series. I don't know why the fix wasn't backported, but it doesn't
really matter to me as I can run the newer kernel.

Thanks everyone for your help.
David

PATCH reiser4 support for Linux 5.8.10

[David Niklas]

I'm a kernel dev newbie. Please double check my work if in doubt.

The patch for reiser4 support for Linux 5.8.1 didn't apply to 5.8.10. It
needed only a one line change, but because of all the fuzzy matching and
offset matching I thought I'd make a new one.
The file that failed to patch is fs/fs-writeback.c. A struct got one of
it's members removed. As the entire struct was removed by the patch I
thought it good to ignore the missing member instead of trying to dig up
what it was used for and why it was removed.

Thanks,
David

Re: PATCH reiser4 support for Linux 5.8.10

[Edward Shishkin]

On 09/24/2020 07:21 PM, David Niklas wrote:
> I'm a kernel dev newbie. Please double check my work if in doubt.
> 
> The patch for reiser4 support for Linux 5.8.1 didn't apply to 5.8.10. It
> needed only a one line change, but because of all the fuzzy matching and
> offset matching I thought I'd make a new one.
> The file that failed to patch is fs/fs-writeback.c. A struct got one of
> it's members removed. As the entire struct was removed by the patch

Hi David,

Precisely speaking, it is not removed, but moved to a header file.

Anyway, I guess that the missing member wasn't used by reiser4, so feel
free to ignore it.

Thanks,
Edward.


  I
> thought it good to ignore the missing member instead of trying to dig up
> what it was used for and why it was removed.
> 
> Thanks,
> David
> 

Re: PATCH reiser4 support for Linux 5.8.10

[David Niklas]

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On Thu, 24 Sep 2020 20:34:19 +0200
edward.shishkin@gmail.com wrote:
> On 09/24/2020 07:21 PM, David Niklas wrote:
> > I'm a kernel dev newbie. Please double check my work if in doubt.
> > 
> > The patch for reiser4 support for Linux 5.8.1 didn't apply to 5.8.10.
> > It needed only a one line change, but because of all the fuzzy
> > matching and offset matching I thought I'd make a new one.
> > The file that failed to patch is fs/fs-writeback.c. A struct got one
> > of it's members removed. As the entire struct was removed by the patch
> 
> Hi David,
> 
> Precisely speaking, it is not removed, but moved to a header file.
> 
> Anyway, I guess that the missing member wasn't used by reiser4, so feel
> free to ignore it.
> 
> Thanks,
> Edward.
> 
> 
>   I
> > thought it good to ignore the missing member instead of trying to dig
> > up what it was used for and why it was removed.
> > 
> > Thanks,
> > David
> > 
> 

Duh! I wanted to send you guys the patch so you could place it on
sourceforge.
Here it is.

Thanks for clarifying,
David

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