Pasi,
I am attaching a patch that prints additional information when a vbd is
resized. Note that on the domu side, the generic block layer already prints
information on the device that is being resized.
Signed-off-by: K. Y. Srinivasan <ksrinivasan@xxxxxxxxxx>
>>> On 7/20/2010 at 3:06 PM, in message <20100720190656.GT17817@xxxxxxxxxxx>,
>>> Pasi
Kärkkäinen<pasik@xxxxxx> wrote:
> On Tue, Jul 20, 2010 at 09:00:39PM +0200, J. Roeleveld wrote:
>> > >
>> > > Hmm.. I don't seem to be able to find them.
>> > > Care to send them again?
>> > >
>> > > -- Pasi
>> >
>> > I will dig this up and send it out.
>> >
>> > Regards,
>> >
>> > K. Y
>> >
>>
>>
>> found this in my archives:
>>
>
> Thanks, but unfortunately this is not the patch that adds useful
> status/resize information printing..
>
> The patch you attached is already merged into Jeremy's xen.git kernel trees.
>
> -- Pasi
>
>>
>> The attached patch supports dynamic resizing of vbds. This patch fixes a bug
> in
>> the previous version of this patch that was sent out. With this patch you
> can
>> perform "online" resizing of file systems that support online resizing.
>>
>> Signed-off-by: K. Y. Srinivasan <ksrinivasan@xxxxxxxxxx>
>
>> Subject: Propagate changed size of VBDs
>> References: bnc#583677
>> Patch-mainline: n/a
>>
>> Support dynamic resizing of virtual block devices. This patch supports
>> both file backed block devices as well as physical devices that can be
>> dynamically resized on the host side.
>>
>> Signed-off-by: K. Y. Srinivasan <ksrinivasan@xxxxxxxxxx>
>>
>> Index: linux/drivers/xen/blkback/blkback.c
>> ===================================================================
>> --- linux.orig/drivers/xen/blkback/blkback.c 2010-03-18 14:17:28.000000000
>> -0600
>> +++ linux/drivers/xen/blkback/blkback.c 2010-03-18 14:17:33.000000000
>> -0600
>> @@ -209,6 +209,7 @@ static void print_stats(blkif_t *blkif)
>> int blkif_schedule(void *arg)
>> {
>> blkif_t *blkif = arg;
>> + struct vbd *vbd = &blkif->vbd;
>>
>> blkif_get(blkif);
>>
>> @@ -218,6 +219,8 @@ int blkif_schedule(void *arg)
>> while (!kthread_should_stop()) {
>> if (try_to_freeze())
>> continue;
>> + if (unlikely(vbd->size != vbd_size(vbd)))
>> + vbd_resize(blkif);
>>
>> wait_event_interruptible(
>> blkif->wq,
>> Index: linux/drivers/xen/blkback/vbd.c
>> ===================================================================
>> --- linux.orig/drivers/xen/blkback/vbd.c 2010-03-18 14:17:28.000000000
>> -0600
>> +++ linux/drivers/xen/blkback/vbd.c 2010-03-18 14:17:33.000000000 -0600
>> @@ -73,6 +73,7 @@ int vbd_create(blkif_t *blkif, blkif_vde
>> }
>>
>> vbd->bdev = bdev;
>> + vbd->size = vbd_size(vbd);
>>
>> if (vbd->bdev->bd_disk == NULL) {
>> DPRINTK("vbd_creat: device %08x doesn't exist.\n",
>> @@ -120,3 +121,45 @@ int vbd_translate(struct phys_req *req,
>> out:
>> return rc;
>> }
>> +
>> +void vbd_resize(blkif_t *blkif)
>> +{
>> + struct vbd *vbd = &blkif->vbd;
>> + struct xenbus_transaction xbt;
>> + int err;
>> + struct xenbus_device *dev = blkif->be->dev;
>> + unsigned long long new_size = vbd_size(vbd);
>> +
>> + printk(KERN_INFO "VBD Resize: new size %Lu\n", new_size);
>> + vbd->size = new_size;
>> +again:
>> + err = xenbus_transaction_start(&xbt);
>> + if (err) {
>> + printk(KERN_WARNING "Error starting transaction");
>> + return;
>> + }
>> + err = xenbus_printf(xbt, dev->nodename, "sectors", "%Lu",
>> + vbd_size(vbd));
>> + if (err) {
>> + printk(KERN_WARNING "Error writing new size");
>> + goto abort;
>> + }
>> + /*
>> + * Write the current state; we will use this to synchronize
>> + * the front-end. If the current state is "connected" the
>> + * front-end will get the new size information online.
>> + */
>> + err = xenbus_printf(xbt, dev->nodename, "state", "%d", dev->state);
>> + if (err) {
>> + printk(KERN_WARNING "Error writing the state");
>> + goto abort;
>> + }
>> +
>> + err = xenbus_transaction_end(xbt, 0);
>> + if (err == -EAGAIN)
>> + goto again;
>> + if (err)
>> + printk(KERN_WARNING "Error ending transaction");
>> +abort:
>> + xenbus_transaction_end(xbt, 1);
>> +}
>> Index: linux/drivers/xen/blkback/common.h
>> ===================================================================
>> --- linux.orig/drivers/xen/blkback/common.h 2010-03-18 14:17:28.000000000
>> -0600
>> +++ linux/drivers/xen/blkback/common.h 2010-03-18 14:17:33.000000000
>> -0600
>> @@ -56,6 +56,7 @@ struct vbd {
>> unsigned char type; /* VDISK_xxx */
>> u32 pdevice; /* phys device that this vbd maps to */
>> struct block_device *bdev;
>> + sector_t size; /* Cached size parameter */
>> };
>>
>> struct backend_info;
>> @@ -116,6 +117,7 @@ blkif_t *blkif_alloc(domid_t domid);
>> void blkif_disconnect(blkif_t *blkif);
>> void blkif_free(blkif_t *blkif);
>> int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int
> evtchn);
>> +void vbd_resize(blkif_t *blkif);
>>
>> #define blkif_get(_b) (atomic_inc(&(_b)->refcnt))
>> #define blkif_put(_b) \
>> Index: linux/drivers/xen/blkfront/blkfront.c
>> ===================================================================
>> --- linux.orig/drivers/xen/blkfront/blkfront.c 2010-03-18
>> 14:17:28.000000000 -0600
>> +++ linux/drivers/xen/blkfront/blkfront.c 2010-03-18 14:17:33.000000000
>> -0600
>> @@ -328,9 +328,25 @@ static void connect(struct blkfront_info
>> unsigned int binfo;
>> int err;
>>
>> - if ((info->connected == BLKIF_STATE_CONNECTED) ||
>> - (info->connected == BLKIF_STATE_SUSPENDED) )
>> + switch (info->connected) {
>> + case BLKIF_STATE_CONNECTED:
>> + /*
>> + * Potentially, the back-end may be signalling
>> + * a capacity change; update the capacity.
>> + */
>> + err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
>> + "sectors", "%Lu", §ors);
>> + if (XENBUS_EXIST_ERR(err))
>> + return;
>> + printk(KERN_INFO "Setting capacity to %Lu\n",
>> + sectors);
>> + set_capacity(info->gd, sectors);
>> + revalidate_disk(info->gd);
>> +
>> + /* fall through */
>> + case BLKIF_STATE_SUSPENDED:
>> return;
>> + }
>>
>> DPRINTK("blkfront.c:connect:%s.\n", info->xbdev->otherend);
>>
>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
online_resize_info.PATCH
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