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 20625eed55116555216cb594c49e4a0c36049675..a534eafa7a53c2816db41640115928d63d83a34a 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1107,6 +1107,22 @@ 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",
 };
@@ -1126,6 +1142,7 @@ 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 789cdea05893bb8e3420ede5d1aa65e7af408e1b..c7942acf1379d1b21f664e9b2ad82403432cc0c7 100644 (file)
--- 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)