Okay, I need to classify this bug report: "nested 9p filesystem with security_model=mapped-xattr". The possible categories are listed, and I have to choose one word from them. First, let's understand the bug. It mentions a nested 9P filesystem using the mapped-xattr security model. 9P is an older remote file access protocol used in QEMU for things like filesystems over networks or for virtual machines. The "security_model=mapped-xattr" part refers to how security attributes are handled, possibly mapping extended attributes (xattrs) to enforce certain security policies. Looking at the categories, I see options like 'file', 'permissions', etc. Since this is about a filesystem feature and specifically mentions security model, it might relate to permissions or file handling. However, 9P is more of an inter-process communication protocol for files, so maybe under 'files' category. Alternatively, since it's related to security attributes, perhaps 'permissions'. But wait, the bug is about nested 9P filesystems specifically using mapped-xattr. This could relate to how QEMU handles file operations and their associated permissions or security settings within nested virtualization environments. I'm a bit torn between 'files' and 'permissions'. The mention of 'security_model' suggests it's more about permissions, but the primary issue is with the 9P filesystem setup. So maybe 'files' is the broader category here. Alternatively, if the bug is about how security attributes are mapped, that could fall under 'permissions'. But I'm not certain. Let me think again: the report is about nested 9P with a specific security model, so it's likely related to how files are accessed and their permissions in this setup. Hmm, perhaps 'files' is more appropriate because it directly involves the filesystem structure and nesting, while the security part might be a subcategory under that. Or maybe it's under 'permissions' because it's about handling access control through xattrs. I'm leaning towards 'files' since the primary issue is with the 9P filesystem configuration and its nested setup. The security_model is an attribute of how files are handled within this structure, but the main bug is about the file system behavior. The bug report relates to a nested 9P filesystem using a specific security model, which falls under the handling of file systems and their attributes. files