From 9d9598b81c5c05495009e81ac0508ec8d1558015 Mon Sep 17 00:00:00 2001 From: Milos Vyletel Date: Tue, 12 Mar 2013 15:34:40 +1030 Subject: [PATCH] virtio-blk: emit udev event when device is resized When virtio-blk device is resized from host (using block_resize from QEMU) emit KOBJ_CHANGE uevent to notify guest about such change. This allows user to have custom udev rules which would take whatever action if such event occurs. As a proof of concept I've created simple udev rule that automatically resize filesystem on virtio-blk device. ACTION=="change", KERNEL=="vd*", \ ENV{RESIZE}=="1", \ ENV{ID_FS_TYPE}=="ext[3-4]", \ RUN+="/sbin/resize2fs /dev/%k" ACTION=="change", KERNEL=="vd*", \ ENV{RESIZE}=="1", \ ENV{ID_FS_TYPE}=="LVM2_member", \ RUN+="/sbin/pvresize /dev/%k" Signed-off-by: Milos Vyletel Tested-by: Asias He Signed-off-by: Rusty Russell (minor simplification) --- drivers/block/virtio_blk.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 8ad21a2..922bcb9 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -539,6 +539,7 @@ static void virtblk_config_changed_work(struct work_struct *work) struct virtio_device *vdev = vblk->vdev; struct request_queue *q = vblk->disk->queue; char cap_str_2[10], cap_str_10[10]; + char *envp[] = { "RESIZE=1", NULL }; u64 capacity, size; mutex_lock(&vblk->config_lock); @@ -568,6 +569,7 @@ static void virtblk_config_changed_work(struct work_struct *work) set_capacity(vblk->disk, capacity); revalidate_disk(vblk->disk); + kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp); done: mutex_unlock(&vblk->config_lock); } -- 2.7.4