mei: mei_write: revamp error path handling

1. unify common amt and regular error path and use it early in the
  function
2. fix indentation
3. propagate error code directly from copy_from_user
4. print out errors using dev_err instead of dev_dbg

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 15de4b19caa5cc513d6936d55c2c0347931bf10b..8dcf59d43b0d21b6ef04d3e518a265d0b0f0a094 100644 (file)
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -621,10 +621,26 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
        mutex_lock(&dev->device_lock);
 
        if (dev->dev_state != MEI_DEV_ENABLED) {
-               mutex_unlock(&dev->device_lock);
-               return -ENODEV;
+               rets = -ENODEV;
+               goto unlock_dev;
        }
 
+       i = mei_me_cl_by_id(dev, cl->me_client_id);
+       if (i < 0) {
+               rets = -ENODEV;
+               goto unlock_dev;
+       }
+       if (length > dev->me_clients[i].props.max_msg_length || length <= 0) {
+               rets = -EMSGSIZE;
+               goto unlock_dev;
+       }
+
+       if (cl->state != MEI_FILE_CONNECTED) {
+               rets = -ENODEV;
+               dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
+                       cl->host_client_id, cl->me_client_id);
+               goto unlock_dev;
+       }
        if (cl == &dev->iamthif_cl) {
                write_cb = find_amthi_read_list_entry(dev, file);
 
@@ -633,11 +649,11 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
                                        msecs_to_jiffies(IAMTHIF_READ_TIMER);
 
                        if (time_after(jiffies, timeout) ||
-                                cl->reading_state == MEI_READ_COMPLETE) {
-                                       *offset = 0;
-                                       list_del(&write_cb->cb_list);
-                                       mei_free_cb_private(write_cb);
-                                       write_cb = NULL;
+                           cl->reading_state == MEI_READ_COMPLETE) {
+                               *offset = 0;
+                               list_del(&write_cb->cb_list);
+                               mei_free_cb_private(write_cb);
+                               write_cb = NULL;
                        }
                }
        }
@@ -670,8 +686,8 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 
        dev_dbg(&dev->pdev->dev, "cb request size = %zd\n", length);
 
-       rets = -EFAULT;
-       if (copy_from_user(write_cb->request_buffer.data, ubuf, length))
+       rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
+       if (rets)
                goto unlock_dev;
 
        cl->sm_state = 0;
@@ -685,29 +701,11 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
                cl->sm_state |= MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
 
        if (cl == &dev->iamthif_cl) {
-               if (dev->dev_state != MEI_DEV_ENABLED) {
-                       rets = -ENODEV;
-                       goto unlock_dev;
-               }
-               i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
-               if (i < 0) {
-                       rets = -ENODEV;
-                       goto unlock_dev;
-               }
-               if (length > dev->me_clients[i].props.max_msg_length ||
-                          length <= 0) {
-                       rets = -EMSGSIZE;
-                       goto unlock_dev;
-               }
                rets = mei_io_cb_alloc_resp_buf(write_cb, dev->iamthif_mtu);
                if (rets)
                        goto unlock_dev;
 
                write_cb->major_file_operations = MEI_IOCTL;
-               if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
-                       rets = -ENODEV;
-                       goto unlock_dev;
-               }
 
                if (!list_empty(&dev->amthi_cmd_list.mei_cb.cb_list) ||
                                dev->iamthif_state != MEI_IAMTHIF_IDLE) {
@@ -716,43 +714,24 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
                        dev_dbg(&dev->pdev->dev, "add amthi cb to amthi cmd waiting list\n");
                        list_add_tail(&write_cb->cb_list,
                                        &dev->amthi_cmd_list.mei_cb.cb_list);
-                       rets = length;
                } else {
                        dev_dbg(&dev->pdev->dev, "call amthi write\n");
                        rets = amthi_write(dev, write_cb);
 
                        if (rets) {
-                               dev_dbg(&dev->pdev->dev, "amthi write failed with status = %d\n",
+                               dev_err(&dev->pdev->dev, "amthi write failed with status = %d\n",
                                    rets);
                                goto unlock_dev;
                        }
-                       rets = length;
                }
                mutex_unlock(&dev->device_lock);
-               return rets;
+               return length;
        }
 
        write_cb->major_file_operations = MEI_WRITE;
 
        dev_dbg(&dev->pdev->dev, "host client = %d, ME client = %d\n",
            cl->host_client_id, cl->me_client_id);
-       if (cl->state != MEI_FILE_CONNECTED) {
-               rets = -ENODEV;
-               dev_dbg(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
-                   cl->host_client_id,
-                   cl->me_client_id);
-               goto unlock_dev;
-       }
-       i = mei_me_cl_by_id(dev, cl->me_client_id);
-       if (i < 0) {
-               rets = -ENODEV;
-               goto unlock_dev;
-       }
-       if (length > dev->me_clients[i].props.max_msg_length || length <= 0) {
-               rets = -EINVAL;
-               goto unlock_dev;
-       }
-
        rets = mei_flow_ctrl_creds(dev, cl);
        if (rets < 0)
                goto unlock_dev;