On Tue, Jul 21, 2020 at 06:28:00PM +0200, Christoph Hellwig wrote: > Instead of passing a kernel pointer to vfs_stat by relying on the > implicit set_fs(KERNEL_DS) in md_setup_drive, just open code the > trivial getattr, and use the opportunity to move a little bit more > code from the caller into the new helper. Ugh... > +static void __init md_lookup_dev(const char *devname, dev_t *dev) > +{ > + struct kstat stat; > + struct path path; > + char filename[64]; > + > + if (strncmp(devname, "/dev/", 5) == 0) > + devname += 5; > + snprintf(filename, 63, "/dev/%s", devname); > + > + if (!kern_path(filename, LOOKUP_FOLLOW, &path) && > + !vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_NO_AUTOMOUNT) && > + S_ISBLK(stat.mode)) > + *dev = new_decode_dev(stat.rdev); > + path_put(&path); > +} How about fs/for_init.c and putting the damn helpers there? With calling conventions as close to syscalls as possible, and a fat comment regarding their intended use being _ONLY_ the setup in should-have-been-done-in-userland parts of init? I really want to keep the surface as small as possible - we had fun shite several releases ago when somebody tried that kind of crap (with open(), IIRC). Let's not go there again...