| Message ID | 1445534852-7456-1-git-send-email-john.stultz@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Oct 22, 2015 at 10:27 AM, 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 disk devices, a new uevent parameter 'NPARTS' specifies the number > of partitions detected by the kernel. Partition devices get '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 > > Thoughts and feedback would be greatly appreciated! Ping? Any thoughts or objections to this? thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Mon, Nov 2, 2015 at 10:03 AM, Jeff Moyer <jmoyer@redhat.com> wrote: > Hi John, > > John Stultz <john.stultz@linaro.org> writes: > >> 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 disk devices, a new uevent parameter 'NPARTS' specifies the number >> of partitions detected by the kernel. Partition devices get '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 > > Those links don't appear to use the NPARTS uevent parameter, unless I > missed it. So good point! It looks like with Android Marshmallow they dropped using NPARTS. For context, here is where it was used with Lollipop: http://androidxref.com/5.1.1_r6/xref/system/vold/DirectVolume.cpp#192 Unless Rom or someone on the Android team objects, I'll remove that chunk from the patch and re-submit. Thanks for the review! -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/block/genhd.c b/block/genhd.c index 0c706f3..248139e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1115,6 +1115,22 @@ static void disk_release(struct device *dev) blk_put_queue(disk->queue); kfree(disk); } + +static int disk_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct gendisk *disk = dev_to_disk(dev); + struct disk_part_iter piter; + struct hd_struct *part; + int cnt = 0; + + disk_part_iter_init(&piter, disk, 0); + while ((part = disk_part_iter_next(&piter))) + cnt++; + disk_part_iter_exit(&piter); + add_uevent_var(env, "NPARTS=%u", cnt); + return 0; +} + struct class block_class = { .name = "block", }; @@ -1134,6 +1150,7 @@ static struct device_type disk_type = { .groups = disk_attr_groups, .release = disk_release, .devnode = block_devnode, + .uevent = disk_uevent, }; #ifdef CONFIG_PROC_FS diff --git a/block/partition-generic.c b/block/partition-generic.c index e771113..e5d91c9 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)