On 5/4/18 10:14 AM, Tetsuo Handa wrote: > Jens Axboe wrote: >>> The loop module ignores sysfs_create_group() failure and pretends that >>> LOOP_SET_FD request succeeded. I guess that the author of commit >>> ee86273062cbb310 ("loop: add some basic read-only sysfs attributes") >>> assumed that it is not a fatal error enough to abort LOOP_SET_FD request. >>> >>> Do we want to abort LOOP_SET_FD request if sysfs_create_group() failed? >> >> Probably safer to retain that behavior. > > OK. > >> >>>> If that's not easily done, then my next suggestion would be to >>>> use a loop flag for it, LO_FLAGS_SYSFS_SETUP or something like that. >>> >>> Yes, that would be possible. >> >> Let's make that change. > > Since LO_FLAGS_* are defined in include/uapi/linux/loop.h as userspace visible > flags, I feel that using "struct loop_device"->lo_flags for recording whether > sysfs entry exists might be strange... Anyway, updated patch is shown below. Hmm yes, I forgot about that, I guess that makes the flags approach pretty much useless. Let's just go with your v1 in that case. -- Jens Axboe