On 05/15/2015 07:14 PM, Roger Pau Monné wrote:
> El 15/05/15 a les 13.03, Bob Liu ha escrit:
>>
>> On 05/15/2015 06:01 PM, Roger Pau Monné wrote:
>>> El 12/05/15 a les 13.01, Bob Liu ha escrit:
>>>> The right place for talk_to_blkback() to query backend features and
>>>> transport
>>>> parameters is after backend entered XenbusStateInitWait. There is no
>>>> problem
>>>
>>> talk_to_blkback doesn't gather any backend features, it just publishes
>>> the features supported by the frontend, which AFAICT can be done at any
>>
>> 1) But talk_tlkback will also allocate and initialize the request ring which
>> should be done after backend entered XenbusStateInitWait.
>
> Maybe setup_blkring should be moved to a more suitable location instead
> of moving the whole function?
>
Most of other parts in talk_to_blkback() depends on setup_blkring() like write
out ring-ref and event-channel.
Only notify 'feature-persistent' and 'protocol:XEN_IO_PROTO_ABI_NATIVE' can be
left in front probe().
Then the patch would like this:
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2c61cf8..6b918e0 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1318,17 +1318,6 @@ again:
message = "writing event-channel";
goto abort_transaction;
}
- err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
- XEN_IO_PROTO_ABI_NATIVE);
- if (err) {
- message = "writing protocol";
- goto abort_transaction;
- }
- err = xenbus_printf(xbt, dev->nodename,
- "feature-persistent", "%u", 1);
- if (err)
- dev_warn(&dev->dev,
- "writing persistent grants feature to xenbus");
err = xenbus_transaction_end(xbt, 0);
if (err) {
@@ -1430,13 +1419,17 @@ static int blkfront_probe(struct xenbus_device *dev,
info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
dev_set_drvdata(&dev->dev, info);
- err = talk_to_blkback(dev, info);
+ err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
+ XEN_IO_PROTO_ABI_NATIVE);
if (err) {
- kfree(info);
- dev_set_drvdata(&dev->dev, NULL);
- return err;
+ message = "writing protocol";
+ goto abort_transaction;
}
-
+ err = xenbus_printf(xbt, dev->nodename,
+ "feature-persistent", "%u", 1);
+ if (err)
+ dev_warn(&dev->dev,
+ "writing persistent grants feature to xenbus");
return 0;
}
@@ -1906,8 +1899,13 @@ static void blkback_changed(struct xenbus_device *dev,
dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n",
backend_state);
switch (backend_state) {
- case XenbusStateInitialising:
case XenbusStateInitWait:
+ if (talk_to_blkback(dev, info)) {
+ kfree(info);
+ dev_set_drvdata(&dev->dev, NULL);
+ break;
+ }
+ case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateReconfiguring:
case XenbusStateReconfigured:
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
