RE: [PATCH 2/4] Drivers: hv: Support the newly introduced KVP messages in the driver

-----Original Message-----
From: Dan Carpenter [mailto:dan.carpenter@oracle.com]
Sent: Sunday, March 11, 2012 6:43 AM
To: KY Srinivasan
Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
devel@linuxdriverproject.org; virtualization@lists.osdl.org; ohering@suse.com;
Alan Stern
Subject: Re: [PATCH 2/4] Drivers: hv: Support the newly introduced KVP
messages in the driver

On Sat, Mar 10, 2012 at 03:32:09PM -0800, K. Y. Srinivasan wrote:

quoted

+		switch (message->kvp_hdr.operation) {
+		case KVP_OP_SET:
+			switch (in_msg->body.kvp_set.data.value_type) {
+			case REG_SZ:
+				/*
+				 * The value is a string - utf16 encoding.
+				 */
+				message->body.kvp_set.data.value_size =
+				utf16s_to_utf8s(
+				(wchar_t *)
+				in_msg->body.kvp_set.data.value,
+				in_msg->body.kvp_set.data.value_size,
+				UTF16_LITTLE_ENDIAN,
+				message->body.kvp_set.data.value,
+				HV_KVP_EXCHANGE_MAX_VALUE_SIZE) + 1;
+				break;
+

This block of unreadable text is so nasty.

You could return directly if the msg = kmalloc() fails and pull
everything in one indent level.  It's normally more readable to
handle errors as soon as possible anyway.

True.

Probably that's not enough to make a difference and we'd need to
introduce a new function.

Btw I don't know if utf16s_to_utf8s() counts the NUL char or not.
It feels like maybe we could end up with ->value_size equal to
HV_KVP_EXCHANGE_MAX_VALUE_SIZE + 1.

The MAX value is set to accommodate the maximum string that will ever
be handled including the string terminator. The function utf16s_to_utf8s()
returns the converted string length but the returned length does not 
include the string terminator (like strlen), hence the "+1".

Dan, I will see if there are other comments on these patches and will
accommodate your suggestion then. If there are no other comments,
would you mind if I addressed your comments here in a separate patch.  


Regards,

K. Y

regards,
dan carpenter