[RESEND][PATCH v2] block: partition: Add partition specific uevent callbacks for partition info

[RESEND][PATCH v2] block: partition: Add partition specific uevent callbacks for partition info

[John Stultz]

From: San Mehat <san@google.com>

This patch has been carried in the Android tree for quite some
time and is one of the few patches required to get a mainline
kernel up and running with an exsiting Android userspace. So I
wanted to submit it for review and consideration if it should
be merged.

For partitions, add new uevent parameters 'PARTN' which
specifies the partitions index in the table, and 'PARTNAME',
which specifies PARTNAME specifices the partition name of a
partition device.

Android's userspace uses this for creating device node links from the
partition name and number: ie:
	/dev/block/platform/soc/by-name/system
or
	/dev/block/platform/soc/by-num/p1

One can see its usage here:
https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355
and
https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rom Lemarchand <romlem@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: harald@redhat.com
Cc: kay@redhat.com
Signed-off-by: Dima Zavin <dima@android.com>
[Dropped NPARTS and reworded commit message for context]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
v2: Dropped NPARTS thanks to Jeff noticing it wasn't used.

 block/partition-generic.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/block/partition-generic.c b/block/partition-generic.c
index 3b03015..d12489e 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -216,10 +216,21 @@ static void part_release(struct device *dev)
 	kfree(p);
 }
 
+static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct hd_struct *part = dev_to_part(dev);
+
+	add_uevent_var(env, "PARTN=%u", part->partno);
+	if (part->info && part->info->volname[0])
+		add_uevent_var(env, "PARTNAME=%s", part->info->volname);
+	return 0;
+}
+
 struct device_type part_type = {
 	.name		= "partition",
 	.groups		= part_attr_groups,
 	.release	= part_release,
+	.uevent		= part_uevent,
 };
 
 static void delete_partition_rcu_cb(struct rcu_head *head)
-- 
1.9.1

Re: [RESEND][PATCH v2] block: partition: Add partition specific uevent callbacks for partition info

[John Stultz]

On Thu, Dec 10, 2015 at 12:00 PM, John Stultz <john.stultz@linaro.org> wrote:
> From: San Mehat <san@google.com>
>
> This patch has been carried in the Android tree for quite some
> time and is one of the few patches required to get a mainline
> kernel up and running with an exsiting Android userspace. So I
> wanted to submit it for review and consideration if it should
> be merged.
>
> For partitions, add new uevent parameters 'PARTN' which
> specifies the partitions index in the table, and 'PARTNAME',
> which specifies PARTNAME specifices the partition name of a
> partition device.
>
> Android's userspace uses this for creating device node links from the
> partition name and number: ie:
>         /dev/block/platform/soc/by-name/system
> or
>         /dev/block/platform/soc/by-num/p1
>
> One can see its usage here:
> https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355
> and
> https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494
>
> Cc: Jens Axboe <axboe@kernel.dk>
> Cc: Rom Lemarchand <romlem@google.com>
> Cc: Android Kernel Team <kernel-team@android.com>
> Cc: Jeff Moyer <jmoyer@redhat.com>
> Cc: harald@redhat.com
> Cc: kay@redhat.com
> Signed-off-by: Dima Zavin <dima@android.com>
> [Dropped NPARTS and reworded commit message for context]
> Signed-off-by: John Stultz <john.stultz@linaro.org>


Ping? Any thoughts on this? Am I missing someone on the CC list I
should be including?

thanks
-john

Re: [RESEND][PATCH v2] block: partition: Add partition specific uevent callbacks for partition info

[Kees Cook]

On Fri, Dec 18, 2015 at 8:07 PM, John Stultz <john.stultz@linaro.org> wrote:
> On Thu, Dec 10, 2015 at 12:00 PM, John Stultz <john.stultz@linaro.org> wrote:
>> From: San Mehat <san@google.com>
>>
>> This patch has been carried in the Android tree for quite some
>> time and is one of the few patches required to get a mainline
>> kernel up and running with an exsiting Android userspace. So I
>> wanted to submit it for review and consideration if it should
>> be merged.
>>
>> For partitions, add new uevent parameters 'PARTN' which
>> specifies the partitions index in the table, and 'PARTNAME',
>> which specifies PARTNAME specifices the partition name of a
>> partition device.
>>
>> Android's userspace uses this for creating device node links from the
>> partition name and number: ie:
>>         /dev/block/platform/soc/by-name/system
>> or
>>         /dev/block/platform/soc/by-num/p1
>>
>> One can see its usage here:
>> https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355
>> and
>> https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494
>>
>> Cc: Jens Axboe <axboe@kernel.dk>
>> Cc: Rom Lemarchand <romlem@google.com>
>> Cc: Android Kernel Team <kernel-team@android.com>
>> Cc: Jeff Moyer <jmoyer@redhat.com>
>> Cc: harald@redhat.com
>> Cc: kay@redhat.com
>> Signed-off-by: Dima Zavin <dima@android.com>
>> [Dropped NPARTS and reworded commit message for context]
>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>
>
> Ping? Any thoughts on this? Am I missing someone on the CC list I
> should be including?
>
> thanks
> -john
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Hi Jens,

Are you able to take this into your tree? Should akpm carry it instead?

Thanks!

-Kees

-- 
Kees Cook
Chrome OS & Brillo Security