mqueue: only set error codes if they are really necessary

... postponing assignments until they're needed. Doesn't change code size.
Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

ipc/mqueue.c

@@ -184,7 +184,7 @@ static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct inode *inode;
 	struct ipc_namespace *ns = data;
-	int error = 0;
+	int error;
 
 	sb->s_blocksize = PAGE_CACHE_SIZE;
 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
@@ -202,7 +202,9 @@ static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sb->s_root) {
 		iput(inode);
 		error = -ENOMEM;
+		goto out;
 	}
+	error = 0;
 
 out:
 	return error;
@@ -621,9 +623,10 @@ static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
 	int ret;
 
 	if (attr) {
-		ret = -EINVAL;
-		if (!mq_attr_ok(ipc_ns, attr))
+		if (!mq_attr_ok(ipc_ns, attr)) {
+			ret = -EINVAL;
 			goto out;
+		}
 		/* store for use during create */
 		dentry->d_fsdata = attr;
 	}
@@ -714,9 +717,10 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 	if (oflag & O_CREAT) {
 		if (dentry->d_inode) {	/* entry already exists */
 			audit_inode(name, dentry);
-			error = -EEXIST;
-			if (oflag & O_EXCL)
+			if (oflag & O_EXCL) {
+				error = -EEXIST;
 				goto out;
+			}
 			filp = do_open(ipc_ns, dentry, oflag);
 		} else {
 			filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
@@ -724,9 +728,10 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
 						u_attr ? &attr : NULL);
 		}
 	} else {
-		error = -ENOENT;
-		if (!dentry->d_inode)
+		if (!dentry->d_inode) {
+			error = -ENOENT;
 			goto out;
+		}
 		audit_inode(name, dentry);
 		filp = do_open(ipc_ns, dentry, oflag);
 	}
@@ -873,19 +878,24 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
 	audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
 	timeout = prepare_timeout(p);
 
-	ret = -EBADF;
 	filp = fget(mqdes);
-	if (unlikely(!filp))
+	if (unlikely(!filp)) {
+		ret = -EBADF;
 		goto out;
+	}
 
 	inode = filp->f_path.dentry->d_inode;
-	if (unlikely(filp->f_op != &mqueue_file_operations))
+	if (unlikely(filp->f_op != &mqueue_file_operations)) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 	info = MQUEUE_I(inode);
 	audit_inode(NULL, filp->f_path.dentry);
 
-	if (unlikely(!(filp->f_mode & FMODE_WRITE)))
+	if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 
 	if (unlikely(msg_len > info->attr.mq_msgsize)) {
 		ret = -EMSGSIZE;
@@ -962,19 +972,24 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
 	audit_mq_sendrecv(mqdes, msg_len, 0, p);
 	timeout = prepare_timeout(p);
 
-	ret = -EBADF;
 	filp = fget(mqdes);
-	if (unlikely(!filp))
+	if (unlikely(!filp)) {
+		ret = -EBADF;
 		goto out;
+	}
 
 	inode = filp->f_path.dentry->d_inode;
-	if (unlikely(filp->f_op != &mqueue_file_operations))
+	if (unlikely(filp->f_op != &mqueue_file_operations)) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 	info = MQUEUE_I(inode);
 	audit_inode(NULL, filp->f_path.dentry);
 
-	if (unlikely(!(filp->f_mode & FMODE_READ)))
+	if (unlikely(!(filp->f_mode & FMODE_READ))) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 
 	/* checks if buffer is big enough */
 	if (unlikely(msg_len < info->attr.mq_msgsize)) {
@@ -1064,13 +1079,14 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
 
 			/* create the notify skb */
 			nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
-			ret = -ENOMEM;
-			if (!nc)
+			if (!nc) {
+				ret = -ENOMEM;
 				goto out;
-			ret = -EFAULT;
+			}
 			if (copy_from_user(nc->data,
 					notification.sigev_value.sival_ptr,
 					NOTIFY_COOKIE_LEN)) {
+				ret = -EFAULT;
 				goto out;
 			}
 
@@ -1079,9 +1095,10 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
 			/* and attach it to the socket */
 retry:
 			filp = fget(notification.sigev_signo);
-			ret = -EBADF;
-			if (!filp)
+			if (!filp) {
+				ret = -EBADF;
 				goto out;
+			}
 			sock = netlink_getsockbyfilp(filp);
 			fput(filp);
 			if (IS_ERR(sock)) {
@@ -1093,7 +1110,7 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
 			timeo = MAX_SCHEDULE_TIMEOUT;
 			ret = netlink_attachskb(sock, nc, &timeo, NULL);
 			if (ret == 1)
-		       		goto retry;
+				goto retry;
 			if (ret) {
 				sock = NULL;
 				nc = NULL;
@@ -1102,14 +1119,17 @@ SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
 		}
 	}
 
-	ret = -EBADF;
 	filp = fget(mqdes);
-	if (!filp)
+	if (!filp) {
+		ret = -EBADF;
 		goto out;
+	}
 
 	inode = filp->f_path.dentry->d_inode;
-	if (unlikely(filp->f_op != &mqueue_file_operations))
+	if (unlikely(filp->f_op != &mqueue_file_operations)) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 	info = MQUEUE_I(inode);
 
 	ret = 0;
@@ -1172,14 +1192,17 @@ SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
 			return -EINVAL;
 	}
 
-	ret = -EBADF;
 	filp = fget(mqdes);
-	if (!filp)
+	if (!filp) {
+		ret = -EBADF;
 		goto out;
+	}
 
 	inode = filp->f_path.dentry->d_inode;
-	if (unlikely(filp->f_op != &mqueue_file_operations))
+	if (unlikely(filp->f_op != &mqueue_file_operations)) {
+		ret = -EBADF;
 		goto out_fput;
+	}
 	info = MQUEUE_I(inode);
 
 	spin_lock(&info->lock);