Thanks Bart; I made the changes and sent them in as a v2, I'm sure you already saw. I have a quick, unrelated question if you have a moment. In testing the null_blk driver, I found that trim commands sent by fio were rejected due to lack of support. Tracking down Shaohua's commit 306eb6b4a ("nullb: support discard"), he mentions that "discard makes sense for memory backed disk". Just to see what would happen, I edited the source to make discard a configurable parameter at modprobe, and after the edit & build, the trim commands submitted fine. Does this sort of change make sense? I mean the ability to do discard to null_blk without it being memory backed; solely for testing/benchmarking purposes. I haven't found any good instructions on creating a memory backed or discard enabled null_blk device from the command line, so I assume a higher level driver would have to hook in and enable these features manually. Thanks for your time and any information. John On Fri, Jan 4, 2019 at 11:47 AM Bart Van Assche <bvanassche@xxxxxxx> wrote: > > On Fri, 2019-01-04 at 10:42 -0500, John Pittman wrote: > > static inline int null_zone_init(struct nullb_device *dev) > > { > > + pr_info("CONFIG_BLK_DEV_ZONED not enabled\n"); > > return -EINVAL; > > } > > Have you considered to use pr_err() instead of pr_info()? > > Thanks, > > Bart.