[PATCH] fs/proc/vmcore: a few cleanups for vmcore_add_device_dump

[Su Hui <suhui@nfschina.com>]

There are three cleanups for vmcore_add_device_dump(). Adjust data_size's
type from 'size_t' to 'unsigned int' for the consistency of data->size.
Return -ENOMEM directly rather than goto the label to simplify the code.
Using scoped_guard() to simplify the lock/unlock code.

Signed-off-by: Su Hui <suhui@nfschina.com>
---
 fs/proc/vmcore.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 10d01eb09c43..9ac2863c68d8 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -1477,7 +1477,7 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 {
 	struct vmcoredd_node *dump;
 	void *buf = NULL;
-	size_t data_size;
+	unsigned int data_size;
 	int ret;
 
 	if (vmcoredd_disabled) {
@@ -1490,10 +1490,8 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 		return -EINVAL;
 
 	dump = vzalloc(sizeof(*dump));
-	if (!dump) {
-		ret = -ENOMEM;
-		goto out_err;
-	}
+	if (!dump)
+		return -ENOMEM;
 
 	/* Keep size of the buffer page aligned so that it can be mmaped */
 	data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
@@ -1519,21 +1517,18 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 	dump->size = data_size;
 
 	/* Add the dump to driver sysfs list and update the elfcore hdr */
-	mutex_lock(&vmcore_mutex);
-	if (vmcore_opened)
-		pr_warn_once("Unexpected adding of device dump\n");
-	if (vmcore_open) {
-		ret = -EBUSY;
-		goto unlock;
-	}
-
-	list_add_tail(&dump->list, &vmcoredd_list);
-	vmcoredd_update_size(data_size);
-	mutex_unlock(&vmcore_mutex);
-	return 0;
+	scoped_guard(mutex, &vmcore_mutex) {
+		if (vmcore_opened)
+			pr_warn_once("Unexpected adding of device dump\n");
+		if (vmcore_open) {
+			ret = -EBUSY;
+			goto out_err;
+		}
 
-unlock:
-	mutex_unlock(&vmcore_mutex);
+		list_add_tail(&dump->list, &vmcoredd_list);
+		vmcoredd_update_size(data_size);
+		return 0;
+	}
 
 out_err:
 	vfree(buf);
-- 
2.30.2