Patchwork [09/12] initscripts: inherit volatiles to support read-only rootfs

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Submitter Qi.Chen@windriver.com
Date Jan. 24, 2013, 8:16 a.m.
Message ID <680bfa5f6dd8d3a3e77a18240caab373f03b8006.1359014474.git.Qi.Chen@windriver.com>
Download mbox | patch
Permalink /patch/43257/
State New
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Comments

Qi.Chen@windriver.com - Jan. 24, 2013, 8:16 a.m.
From: Chen Qi <Qi.Chen@windriver.com>

Inherit volatiles.bbclass to support read-only rootfs.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/recipes-core/initscripts/initscripts_1.0.bb |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
Ross Burton - Jan. 25, 2013, 1:11 p.m.
On 24 January 2013 08:16,  <Qi.Chen@windriver.com> wrote:
> +VOLATILE_DIR = "/var/volatile/lib/urandom"
> +VOLATILE_LINK = "/var/lib/urandom"

A better solution would be to not attempt to save and restore a seed
value that is intended to persist across reboots when it's on a tmpfs.
 Putting the urandom seed into tmpfs is just a waste of time.

Ross
Richard Purdie - Jan. 25, 2013, 2:14 p.m.
On Fri, 2013-01-25 at 13:11 +0000, Burton, Ross wrote:
> On 24 January 2013 08:16,  <Qi.Chen@windriver.com> wrote:
> > +VOLATILE_DIR = "/var/volatile/lib/urandom"
> > +VOLATILE_LINK = "/var/lib/urandom"
> 
> A better solution would be to not attempt to save and restore a seed
> value that is intended to persist across reboots when it's on a tmpfs.
>  Putting the urandom seed into tmpfs is just a waste of time.

I have to wonder why we don't put a union mount tmpfs over /var/lib to
be honest...

or if we don't want to depend on unionfs, a tmpfs over /var/lib...

Cheers,

Richard
Qi.Chen@windriver.com - Jan. 28, 2013, 1:45 a.m.
On 01/25/2013 09:11 PM, Burton, Ross wrote:
> On 24 January 2013 08:16,  <Qi.Chen@windriver.com> wrote:
>> +VOLATILE_DIR = "/var/volatile/lib/urandom"
>> +VOLATILE_LINK = "/var/lib/urandom"
> A better solution would be to not attempt to save and restore a seed
> value that is intended to persist across reboots when it's on a tmpfs.
>   Putting the urandom seed into tmpfs is just a waste of time.
>
> Ross
>
>
I agree.

I'll just remove this patch.

Thanks,
Chen Qi
Qi.Chen@windriver.com - Jan. 28, 2013, 2:11 a.m.
On 01/25/2013 10:14 PM, Richard Purdie wrote:
> On Fri, 2013-01-25 at 13:11 +0000, Burton, Ross wrote:
>> On 24 January 2013 08:16,  <Qi.Chen@windriver.com> wrote:
>>> +VOLATILE_DIR = "/var/volatile/lib/urandom"
>>> +VOLATILE_LINK = "/var/lib/urandom"
>> A better solution would be to not attempt to save and restore a seed
>> value that is intended to persist across reboots when it's on a tmpfs.
>>   Putting the urandom seed into tmpfs is just a waste of time.
> I have to wonder why we don't put a union mount tmpfs over /var/lib to
> be honest...
>
> or if we don't want to depend on unionfs, a tmpfs over /var/lib...
>
> Cheers,
>
> Richard
>
>
>
A union mount tmpfs over /var/lib (and maybe /etc) was the first 
solution that came into my mind. Then I saw a bug related to unionfs 
about getcwd() call, and I saw the unionfs was still disabled for live 
images. So I thought "maybe I should not use unionfs".

A tmpfs over /var/lib.
Hmm... I thought about that too. The reason that I didn't use this 
method was that I thought that some directories under /etc might also 
need to be written to.
It turns out that this concern seems unnecessary.

Anyway, I'll try out the tmpfs-over-var-lib method and let you know the 
result.

Thanks,
Chen Qi

Patch

diff --git a/meta/recipes-core/initscripts/initscripts_1.0.bb b/meta/recipes-core/initscripts/initscripts_1.0.bb
index 6e15f88..a33c0f6 100644
--- a/meta/recipes-core/initscripts/initscripts_1.0.bb
+++ b/meta/recipes-core/initscripts/initscripts_1.0.bb
@@ -3,7 +3,7 @@  DESCRIPTION = "Initscripts provide the basic system startup initialization scrip
 SECTION = "base"
 LICENSE = "GPLv2"
 LIC_FILES_CHKSUM = "file://COPYING;md5=751419260aa954499f7abaabaa882bbe"
-PR = "r139"
+PR = "r140"
 
 INHIBIT_DEFAULT_DEPS = "1"
 
@@ -42,6 +42,10 @@  ALTERNATIVE_PRIORITY = "90"
 ALTERNATIVE_${PN} = "functions"
 ALTERNATIVE_LINK_NAME[functions] = "${sysconfdir}/init.d/functions"
 
+inherit volatiles
+VOLATILE_DIR = "/var/volatile/lib/urandom"
+VOLATILE_LINK = "/var/lib/urandom"
+
 HALTARGS ?= "-d -f"
 
 do_configure() {