lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 24 Sep 2015 16:48:06 -0400
From:	Tejun Heo <>
To:	Artem Bityutskiy <>
Cc:	Theodore Ts'o <>,,,,,,,,,, Dexuan Cui <>
Subject: Re: [PATCH cgroup/for-4.3-fixes] cgroup, writeback: don't enable
 cgroup writeback on traditional hierarchies

On Wed, Sep 23, 2015 at 05:07:29PM -0400, Tejun Heo wrote:
> inode_cgwb_enabled() gates cgroup writeback support.  If it returns
> true, each inode is attached to the corresponding memory domain which
> gets mapped to io domain.  It currently only tests whether the
> filesystem and bdi support cgroup writeback; however, cgroup writeback
> support doesn't work on traditional hierarchies and thus it should
> also test whether memcg and iocg are on the default hierarchy.
> This caused traditional hierarchy setups to hit the cgroup writeback
> path inadvertently and ended up creating separate writeback domains
> for each memcg and mapping them all to the root iocg uncovering a
> couple issues in the cgroup writeback path.
> cgroup writeback was never meant to be enabled on traditional
> hierarchies.  Make inode_cgwb_enabled() test whether both memcg and
> iocg are on the default hierarchy.
> Signed-off-by: Tejun Heo <>
> Reported-by: Artem Bityutskiy <>
> Reported-by: Dexuan Cui <>
> Link:
> Link:

Applying to cgroup/for-4.3-fixes.


To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists