Re: [PATCH] virtio-blk: emit udev event when device is resized
From: Rusty Russell <hidden>
Date: 2013-02-25 21:30:27
Also in:
lkml
Milos Vyletel [off-list ref] writes:
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"This looks fine to me, but I like to check with Greg before adding udev callouts.... Greg? BTW, if this is good, it's good for stable IMHO. Cheers, Rusty.
quoted hunk
Signed-off-by: Milos Vyletel <redacted> --- drivers/block/virtio_blk.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 8ad21a2..5990382 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c@@ -539,6 +539,8 @@ 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 event[] = "RESIZE=1"; + char *envp[] = { event, NULL }; u64 capacity, size; mutex_lock(&vblk->config_lock);@@ -568,6 +570,7 @@ 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); }-- 1.7.1