On Mon, Mar 18, 2024 at 11:29:17AM +0100, Christian Brauner wrote: > Don't forget: > > mknod /my/xfs/file/system b 8 0 > > which means you're not opening it via devtmpfs but via xfs. IOW, the > inode for that file is from xfs. Yes. file_inode() for block devices is always the "upper" fs, which can be any file system supporting device nodes. file->f_mapping->host will always be the bdevfs inode, and nothing in the I/O path should ever be using file_inode().
