Okay, I need to classify this bug report as either user-mode or system-mode related. Let me think through it step by step. The problem occurs when using `qemu-img` commands like commit or bitmap merge. The user provided a script that creates two images and demonstrates the issue when merging them. The error messages mention "No space left on device" during operations, specifically in functions like qcow2_free_clusters and while writing bitmaps. I remember that `qemu-img` runs as a user-space application. It doesn't require special privileges unless it's accessing raw devices, but even then, it's typically handled by the user or system through permissions. Looking at the error context: The failure is when trying to write bitmaps into an image file. Since the images are stored on logical volumes (LVs) which are block devices, but `qemu-img` interacts with them as files in this case. When it tries to modify these files, it's within user space operations. The issue arises because the LV size doesn't account for the stale bitmaps, leading to a situation where there's no space left on the device during writes. This is an issue with how `qemu-img` handles the file operations and bitmap merging, not something related to hardware or kernel-level processes. System-mode issues would involve lower-level components like drivers, hardware interactions, or kernel processes. Since this problem is about application behavior when interacting with files (even if they're block devices), it's more of a user-mode concern. Therefore, this bug report falls under the 'user' category. The issue involves `qemu-img` handling file operations and bitmap merging, which are user-space tasks, not involving kernel or hardware-level interactions. user