On Wed, Mar 17, 2021 at 05:57:31PM +0900, Johannes Thumshirn wrote: > In btrfs_submit_direct() there's a WAN_ON_ONCE() that will trigger if > we're submitting a DIO write on a zoned filesystem but are not using > REQ_OP_ZONE_APPEND to submit the IO to the block device. > > This is a left over from a previous version where btrfs_dio_iomap_begin() > didn't use btrfs_use_zone_append() to check for sequential write only > zones.
I can't identify the patch where this got changed. I've landed on 544d24f9de73 ("btrfs: zoned: enable zone append writing for direct IO") but that adds the btrfs_use_zone_append, the append flag and also the warning.