+ mutex_unlock(&attr->mutex);
+ return ret;
+}
+
+/**
+ * generic_fh_to_dentry - generic helper for the fh_to_dentry export operation
+ * @sb: filesystem to do the file handle conversion on
+ * @fid: file handle to convert
+ * @fh_len: length of the file handle in bytes
+ * @fh_type: type of file handle
+ * @get_inode: filesystem callback to retrieve inode
+ *
+ * This function decodes @fid as long as it has one of the well-known
+ * Linux filehandle types and calls @get_inode on it to retrieve the
+ * inode for the object specified in the file handle.
+ */
+struct dentry *generic_fh_to_dentry(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type, struct inode *(*get_inode)
+ (struct super_block *sb, u64 ino, u32 gen))
+{
+ struct inode *inode = NULL;
+
+ if (fh_len < 2)
+ return NULL;
+
+ switch (fh_type) {
+ case FILEID_INO32_GEN:
+ case FILEID_INO32_GEN_PARENT:
+ inode = get_inode(sb, fid->i32.ino, fid->i32.gen);
+ break;
+ }
+
+ return d_obtain_alias(inode);
+}
+EXPORT_SYMBOL_GPL(generic_fh_to_dentry);
+
+/**
+ * generic_fh_to_dentry - generic helper for the fh_to_parent export operation
+ * @sb: filesystem to do the file handle conversion on
+ * @fid: file handle to convert
+ * @fh_len: length of the file handle in bytes
+ * @fh_type: type of file handle
+ * @get_inode: filesystem callback to retrieve inode
+ *
+ * This function decodes @fid as long as it has one of the well-known
+ * Linux filehandle types and calls @get_inode on it to retrieve the
+ * inode for the _parent_ object specified in the file handle if it
+ * is specified in the file handle, or NULL otherwise.
+ */
+struct dentry *generic_fh_to_parent(struct super_block *sb, struct fid *fid,
+ int fh_len, int fh_type, struct inode *(*get_inode)
+ (struct super_block *sb, u64 ino, u32 gen))
+{
+ struct inode *inode = NULL;
+
+ if (fh_len <= 2)
+ return NULL;
+
+ switch (fh_type) {
+ case FILEID_INO32_GEN_PARENT:
+ inode = get_inode(sb, fid->i32.parent_ino,
+ (fh_len > 3 ? fid->i32.parent_gen : 0));
+ break;
+ }
+
+ return d_obtain_alias(inode);
+}
+EXPORT_SYMBOL_GPL(generic_fh_to_parent);
+
+int simple_fsync(struct file *file, struct dentry *dentry, int datasync)
+{
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 0, /* metadata-only; caller takes care of data */
+ };
+ struct inode *inode = dentry->d_inode;
+ int err;
+ int ret;
+
+ ret = sync_mapping_buffers(inode->i_mapping);
+ if (!(inode->i_state & I_DIRTY))
+ return ret;
+ if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
+ return ret;
+
+ err = sync_inode(inode, &wbc);
+ if (ret == 0)
+ ret = err;