Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()

vmbus_recvpacket() and vmbus_recvpacket_raw() are almost identical but
there are two discrepancies:
1) vmbus_recvpacket() doesn't propagate errors from hv_ringbuffer_read()
   which looks like it is not desired.
2) There is an error message printed in packetlen > bufferlen case in
   vmbus_recvpacket(). I'm removing it as it is usless for users to see
   such messages and /vmbus_recvpacket_raw() doesn't have it.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 22 insertions, 43 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 2889d97c03b1..dd6de7fc442f 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -922,8 +922,10 @@ EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
  *
  * Mainly used by Hyper-V drivers.
  */
-int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
-                        u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
+static inline int
+__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
+                   u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
+                   bool raw)
 {
         struct vmpacket_descriptor desc;
         u32 packetlen;
@@ -941,27 +943,34 @@ int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
                 return 0;
 
         packetlen = desc.len8 << 3;
-        userlen = packetlen - (desc.offset8 << 3);
+        if (!raw)
+                userlen = packetlen - (desc.offset8 << 3);
+        else
+                userlen = packetlen;
 
         *buffer_actual_len = userlen;
 
-        if (userlen > bufferlen) {
-
-                pr_err("Buffer too small - got %d needs %d\n",
-                           bufferlen, userlen);
-                return -ETOOSMALL;
-        }
+        if (userlen > bufferlen)
+                return -ENOBUFS;
 
         *requestid = desc.trans_id;
 
         /* Copy over the packet to the user buffer */
         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
-                             (desc.offset8 << 3), &signal);
+                                 raw ? 0 : desc.offset8 << 3, &signal);
 
         if (signal)
                 vmbus_setevent(channel);
 
-        return 0;
+        return ret;
+}
+
+int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
+                     u32 bufferlen, u32 *buffer_actual_len,
+                     u64 *requestid)
+{
+        return __vmbus_recvpacket(channel, buffer, bufferlen,
+                                  buffer_actual_len, requestid, false);
 }
 EXPORT_SYMBOL(vmbus_recvpacket);
 
@@ -972,37 +981,7 @@ int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
                               u32 bufferlen, u32 *buffer_actual_len,
                               u64 *requestid)
 {
-        struct vmpacket_descriptor desc;
-        u32 packetlen;
-        int ret;
-        bool signal = false;
-
-        *buffer_actual_len = 0;
-        *requestid = 0;
-
-
-        ret = hv_ringbuffer_peek(&channel->inbound, &desc,
-                             sizeof(struct vmpacket_descriptor));
-        if (ret != 0)
-                return 0;
-
-
-        packetlen = desc.len8 << 3;
-
-        *buffer_actual_len = packetlen;
-
-        if (packetlen > bufferlen)
-                return -ENOBUFS;
-
-        *requestid = desc.trans_id;
-
-        /* Copy over the entire packet to the user buffer */
-        ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
-                                 &signal);
-
-        if (signal)
-                vmbus_setevent(channel);
-
-        return ret;
+        return __vmbus_recvpacket(channel, buffer, bufferlen,
+                                  buffer_actual_len, requestid, true);
 }
 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);