block: genhd: Add disk/partition specific uevent callbacks for partition info

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

Signed-off-by: Dima Zavin <dima@android.com>

diff --git a/block/genhd.c b/block/genhd.c
index bd30606..a60cfb2 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1109,6 +1109,22 @@ 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",
 };
@@ -1128,6 +1144,7 @@ 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 0d9e5f9..47284e7 100644 (file)
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -217,10 +217,21 @@ 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)