In case of zero copy, ublk server needn't to pre-allocate IO buffer and provide it to driver more. Meantime not set the buffer in case of zero copy any more, and the userspace can use pread()/pwrite() to read from/write to the io request buffer, which is easier & simpler from userspace viewpoint. Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/block/ublk_drv.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 0ff70cda4b91..a744d3b5da91 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1410,25 +1410,30 @@ static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) goto out; /* FETCH_RQ has to provide IO buffer if NEED GET DATA is not enabled */ - if (!ub_cmd->addr && !ublk_need_get_data(ubq)) - goto out; + if (!ublk_support_zc(ubq)) { + if (!ub_cmd->addr && !ublk_need_get_data(ubq)) + goto out; + io->addr = ub_cmd->addr; + } io->cmd = cmd; io->flags |= UBLK_IO_FLAG_ACTIVE; - io->addr = ub_cmd->addr; - ublk_mark_io_ready(ub, ubq); break; case UBLK_IO_COMMIT_AND_FETCH_REQ: req = blk_mq_tag_to_rq(ub->tag_set.tags[ub_cmd->q_id], tag); + + if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) + goto out; /* * COMMIT_AND_FETCH_REQ has to provide IO buffer if NEED GET DATA is * not enabled or it is Read IO. */ - if (!ub_cmd->addr && (!ublk_need_get_data(ubq) || req_op(req) == REQ_OP_READ)) - goto out; - if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) - goto out; - io->addr = ub_cmd->addr; + if (!ublk_support_zc(ubq)) { + if (!ub_cmd->addr && (!ublk_need_get_data(ubq) || + req_op(req) == REQ_OP_READ)) + goto out; + io->addr = ub_cmd->addr; + } io->flags |= UBLK_IO_FLAG_ACTIVE; io->cmd = cmd; ublk_commit_completion(ub, ub_cmd); -- 2.39.2