[PATCH v3 04/21] Drivers: hv: fcopy: process deferred messages when we complete the transaction

From: Vitaly Kuznetsov
Date: Thu Apr 09 2015 - 04:45:27 EST


In theory, the host is not supposed to issue any requests before be reply to
the previous one. In KVP we, however, support the following scenarios:
1) A message was received before userspace daemon registered;
2) A message was received while the previous one is still being processed.
In FCOPY we support only the former. Add support for the later, use
hv_poll_channel() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
drivers/hv/hv_fcopy.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
index cd453e4..8bdf752 100644
--- a/drivers/hv/hv_fcopy.c
+++ b/drivers/hv/hv_fcopy.c
@@ -98,6 +98,8 @@ static void fcopy_work_func(struct work_struct *dummy)
if (down_trylock(&fcopy_transaction.read_sema))
;

+ hv_poll_channel(fcopy_transaction.fcopy_context,
+ hv_fcopy_onchannelcallback);
}

static int fcopy_handle_handshake(u32 version)
@@ -117,8 +119,8 @@ static int fcopy_handle_handshake(u32 version)
pr_info("FCP: user-mode registering done. Daemon version: %d\n",
version);
fcopy_transaction.active = false;
- if (fcopy_transaction.fcopy_context)
- hv_fcopy_onchannelcallback(fcopy_transaction.fcopy_context);
+ hv_poll_channel(fcopy_transaction.fcopy_context,
+ hv_fcopy_onchannelcallback);
in_hand_shake = false;
return 0;
}
@@ -226,6 +228,7 @@ void hv_fcopy_onchannelcallback(void *context)
fcopy_transaction.fcopy_context = context;
return;
}
+ fcopy_transaction.fcopy_context = NULL;

vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
&requestid);
@@ -333,8 +336,11 @@ static ssize_t fcopy_write(struct file *file, const char __user *buf,
* Complete the transaction by forwarding the result
* to the host. But first, cancel the timeout.
*/
- if (cancel_delayed_work_sync(&fcopy_work))
+ if (cancel_delayed_work_sync(&fcopy_work)) {
fcopy_respond_to_host(response);
+ hv_poll_channel(fcopy_transaction.fcopy_context,
+ hv_fcopy_onchannelcallback);
+ }

return sizeof(int);
}
--
1.9.3

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