Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb

Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb

[Jan Kara]

  Hello,

  can you please consider commit 7d7345322d60edb0fa49a64a89b31360f01d09cb "ext4: fix warning in
ext4_da_update_reserve_space()" for -stable kernels (3.10 & 3.11 would make
sense). Although the problem mostly results only in a warning, it can cause
fs corruption in the rare case of hitting ENOSPC at the wrong moment.

								Honza

-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

Re: Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb

[Lukáš Czerner]

On Wed, 23 Oct 2013, Jan Kara wrote:

> Date: Wed, 23 Oct 2013 12:38:55 +0200
> From: Jan Kara <jack@suse.cz>
> To: stable@vger.kernel.org
> Cc: Ted Tso <tytso@mit.edu>, linux-ext4@vger.kernel.org
> Subject: Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb
> 
>   Hello,
> 
>   can you please consider commit 7d7345322d60edb0fa49a64a89b31360f01d09cb "ext4: fix warning in
> ext4_da_update_reserve_space()" for -stable kernels (3.10 & 3.11 would make
> sense). Although the problem mostly results only in a warning, it can cause
> fs corruption in the rare case of hitting ENOSPC at the wrong moment.

I am not sure about that. First of all we would have to consider
commit 1c8924eb106c1ac755d5d35ce9b3ff42e89e2511 as well since you
make a use of the function introduced in that commit.

Also it's quite big change to be pushed to stable. However I think
that the warning is actually mostly harmless since we have

27dd43854227bb0e6ab70129bd21b60d396db2e7 ext4: introduce reserved
space


so If I am not missing something, then chances that we'll end up with
no space to allocate metadata blocks from are very very low.

Thanks!
-Lukas

> 
> 								Honza
> 
> 

Re: Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb

[Jan Kara]

On Wed 23-10-13 14:11:50, Lukáš Czerner wrote:
> On Wed, 23 Oct 2013, Jan Kara wrote:
> 
> > Date: Wed, 23 Oct 2013 12:38:55 +0200
> > From: Jan Kara <jack@suse.cz>
> > To: stable@vger.kernel.org
> > Cc: Ted Tso <tytso@mit.edu>, linux-ext4@vger.kernel.org
> > Subject: Commit 7d7345322d60edb0fa49a64a89b31360f01d09cb
> > 
> >   Hello,
> > 
> >   can you please consider commit 7d7345322d60edb0fa49a64a89b31360f01d09cb "ext4: fix warning in
> > ext4_da_update_reserve_space()" for -stable kernels (3.10 & 3.11 would make
> > sense). Although the problem mostly results only in a warning, it can cause
> > fs corruption in the rare case of hitting ENOSPC at the wrong moment.
> 
> I am not sure about that. First of all we would have to consider
> commit 1c8924eb106c1ac755d5d35ce9b3ff42e89e2511 as well since you
> make a use of the function introduced in that commit.
  Right, I forgot about that.

> Also it's quite big change to be pushed to stable. However I think
> that the warning is actually mostly harmless since we have
> 
> 27dd43854227bb0e6ab70129bd21b60d396db2e7 ext4: introduce reserved
> space
> 
> 
> so If I am not missing something, then chances that we'll end up with
> no space to allocate metadata blocks from are very very low.
  OK, right. The reserved metadata blocks patch is going to make the real
failure even more unlikely. So you are right we probably don't need the
patch in stable after all. I'm withdrawing my request. Thanks for having a
look.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR