1 files changed, 48 insertions, 2 deletions

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index d575452cd9f7..66a505422e5c 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -39,7 +39,7 @@ static int default_open(struct inode *inode, struct file *file)
         return 0;
 }
 
-struct file_operations debugfs_file_operations = {
+const struct file_operations debugfs_file_operations = {
         .read =         default_read_file,
         .write =        default_write_file,
         .open =         default_open,
@@ -213,7 +213,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
         return count;
 }
 
-static struct file_operations fops_bool = {
+static const struct file_operations fops_bool = {
         .read =         read_file_bool,
         .write =        write_file_bool,
         .open =         default_open,
@@ -251,3 +251,49 @@ struct dentry *debugfs_create_bool(const char *name, mode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_bool);
 
+static ssize_t read_file_blob(struct file *file, char __user *user_buf,
+                              size_t count, loff_t *ppos)
+{
+        struct debugfs_blob_wrapper *blob = file->private_data;
+        return simple_read_from_buffer(user_buf, count, ppos, blob->data,
+                        blob->size);
+}
+
+static struct file_operations fops_blob = {
+        .read =         read_file_blob,
+        .open =         default_open,
+};
+
+/**
+ * debugfs_create_blob - create a file in the debugfs filesystem that is
+ * used to read and write a binary blob.
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this paramater is NULL, then the
+ *          file will be created in the root of the debugfs filesystem.
+ * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
+ *        to the blob data and the size of the data.
+ *
+ * This function creates a file in debugfs with the given name that exports
+ * @blob->data as a binary blob. If the @mode variable is so set it can be
+ * read from. Writing is not supported.
+ *
+ * This function will return a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the debugfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.)  If an error occurs, NULL will be returned.
+ *
+ * If debugfs is not enabled in the kernel, the value -ENODEV will be
+ * returned.  It is not wise to check for this value, but rather, check for
+ * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * code.
+ */
+struct dentry *debugfs_create_blob(const char *name, mode_t mode,
+                                   struct dentry *parent,
+                                   struct debugfs_blob_wrapper *blob)
+{
+        return debugfs_create_file(name, mode, parent, blob, &fops_blob);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_blob);