[PATCH RFC 10/23] scsi: core: let procfs copy in writes

@@ -678,39 +678,20 @@ static const struct seq_operations scsi_devinfo_seq_ops = {
  * To use, echo "vendor:model:flag" > /proc/scsi/device_info
  */
 static ssize_t proc_scsi_devinfo_write(struct file *file,
-				       const char __user *buf,
+				       char *buffer,
 				       size_t length, loff_t *ppos)
 {
-	char *buffer;
-	ssize_t err = length;
-
-	if (!buf || length>PAGE_SIZE)
+	if (length == PAGE_SIZE && buffer[PAGE_SIZE-1])
 		return -EINVAL;
-	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!buffer)
-		return -ENOMEM;
-	if (copy_from_user(buffer, buf, length)) {
-		err =-EFAULT;
-		goto out;
-	}
-
-	if (length < PAGE_SIZE)
-		buffer[length] = '\0';
-	else if (buffer[PAGE_SIZE-1]) {
-		err = -EINVAL;
-		goto out;
-	}
 
 	scsi_dev_info_list_add_str(buffer);
-
-out:
-	kfree(buffer);
-	return err;
+	return length;
 }
 
 static const struct proc_ops scsi_devinfo_proc_ops = {
 	.proc_seq_ops	= &scsi_devinfo_seq_ops,
-	.proc_write	= proc_scsi_devinfo_write,
+	.proc_write_buf	= proc_scsi_devinfo_write,
+	.proc_write_size = PAGE_SIZE,
 };
 #endif /* CONFIG_SCSI_PROC_FS */
 

@@ -62,30 +62,18 @@ struct scsi_proc_entry {
 	unsigned int		present;
 };
 
-static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
+static ssize_t proc_scsi_host_write(struct file *file, char *buf,
                            size_t count, loff_t *ppos)
 {
 	struct Scsi_Host *shost = pde_data(file_inode(file));
-	ssize_t ret = -ENOMEM;
-	char *page;
-    
+
 	if (count > PROC_BLOCK_SIZE)
 		return -EOVERFLOW;
 
 	if (!shost->hostt->write_info)
 		return -EINVAL;
 
-	page = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (page) {
-		ret = -EFAULT;
-		if (copy_from_user(page, buf, count))
-			goto out;
-		page[count] = '\0';
-		ret = shost->hostt->write_info(shost, page, count);
-	}
-out:
-	kfree(page);
-	return ret;
+	return shost->hostt->write_info(shost, buf, count);
 }
 
 static int proc_scsi_show(struct seq_file *m, void *v)

@@ -142,7 +130,7 @@ EXPORT_SYMBOL_GPL(scsi_template_proc_dir);
 static const struct proc_ops proc_scsi_ops = {
 	.proc_show	= proc_scsi_show,
 	.proc_open	= proc_scsi_host_open,
-	.proc_write	= proc_scsi_host_write
+	.proc_write_buf	= proc_scsi_host_write
 };
 
 /**

@@ -386,8 +374,8 @@ static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
 /**
  * proc_scsi_write - handle writes to /proc/scsi/scsi
  * @file: not used
- * @buf: buffer to write
- * @length: length of buf, at most PAGE_SIZE
+ * @buffer: buffer to write
+ * @length: length of buffer, at most PAGE_SIZE
  * @ppos: not used
  *
  * Description: this provides a legacy mechanism to add or remove devices by

@@ -402,32 +390,20 @@ static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
  */
 
 
-static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
+static ssize_t proc_scsi_write(struct file *file, char *buffer,
 			       size_t length, loff_t *ppos)
 {
 	int host, channel, id, lun;
-	char *buffer, *end, *p;
+	char *end, *p;
 	int err;
 
-	if (!buf || length > PAGE_SIZE)
-		return -EINVAL;
-
-	buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!buffer)
-		return -ENOMEM;
-
-	err = -EFAULT;
-	if (copy_from_user(buffer, buf, length))
-		goto out;
-
 	err = -EINVAL;
 	if (length < PAGE_SIZE) {
 		end = buffer + length;
-		*end = '\0';
 	} else {
 		end = buffer + PAGE_SIZE - 1;
 		if (*end)
-			goto out;
+			return err;
 	}
 
 	/*

@@ -466,8 +442,6 @@ static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
 	if (!err)
 		err = length;
 
- out:
-	kfree(buffer);
 	return err;
 }
 

@@ -521,7 +495,8 @@ static const struct seq_operations scsi_seq_ops = {
 
 static const struct proc_ops scsi_scsi_proc_ops = {
 	.proc_seq_ops	= &scsi_seq_ops,
-	.proc_write	= proc_scsi_write,
+	.proc_write_buf	= proc_scsi_write,
+	.proc_write_size = PAGE_SIZE,
 };
 
 /**