On Fri, Sep 11, 2020 at 03:17:19PM +0100, Christoph Hellwig wrote:
On Fri, Sep 11, 2020 at 09:32:39PM +0900, Naohiro Aota wrote:+ if (fs_info->max_zone_append_size && + bio_op(bio) == REQ_OP_WRITE && + bio->bi_iter.bi_size + size > fs_info->max_zone_append_size) + can_merge = false; + if (prev_bio_flags != bio_flags || !contig || !can_merge || force_bio_submit || bio_add_page(bio, page, page_size, pg_offset) < page_size) {For zoned devices you need to use bio_add_hw_page instead of so that all the hardware restrictions are applied. bio_add_hw_page asso gets the lenght limited passed as the last parameter so we won't need a separate check.
I think we can't use it here. This bio is built for btrfs's logical space, so the corresponding request queue is not available here. Technically, we can use fs_devices->lateste_bdev. But considering this bio can map to multiple bios to multiple devices, limiting the size of this bio under the minimum queue_max_zone_appends_sectors() among devices is feasible.
