IB/core: Avoid duplicate code

Move the check on the validity of the command to a common area.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/uverbs_main.c

@@ -689,6 +689,7 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 	struct ib_uverbs_file *file = filp->private_data;
 	struct ib_device *ib_dev;
 	struct ib_uverbs_cmd_hdr hdr;
+	__u32 command;
 	__u32 flags;
 	int srcu_key;
 	ssize_t ret;
@@ -707,12 +708,6 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 		goto out;
 	}
 
-	flags = (hdr.command &
-		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
-
-	if (!flags) {
-		__u32 command;
-
 	if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
 				   IB_USER_VERBS_CMD_COMMAND_MASK)) {
 		ret = -EINVAL;
@@ -721,6 +716,10 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 
 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
 
+	flags = (hdr.command &
+		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
+
+	if (!flags) {
 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
 		    !uverbs_cmd_table[command]) {
 			ret = -EINVAL;
@@ -749,21 +748,11 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 						 hdr.out_words * 4);
 
 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
-		__u32 command;
-
 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
 		struct ib_udata ucore;
 		struct ib_udata uhw;
 		size_t written_count = count;
 
-		if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
-					   IB_USER_VERBS_CMD_COMMAND_MASK)) {
-			ret = -EINVAL;
-			goto out;
-		}
-
-		command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
-
 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
 		    !uverbs_ex_cmd_table[command]) {
 			ret = -ENOSYS;