On Tue, May 20, 2025 at 06:29:48AM +0000, Xu, Lizhi wrote: > I figured out your steps to reproduce, and yes, this problem will occur if you do losetup with a file in a filesystem that does not support read_iter, which is what this patch does. isofs does support read_iter, without that it would not have worked before either. That is not the problem. It must be related to the FMODE_WRITE check - i.e. we have a writable FD here, but a file system that does not actually supports writes. Which honestly feels weird, but we'll have to figure it out to unbreak these setups.
