From patchwork Sat Mar 8 16:14:55 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 14007580 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DD4C383A2 for ; Sat, 8 Mar 2025 16:15:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741450548; cv=none; b=e+2DGDGfJL+qWNfd/rx8OxjyGdVzVxuYXxx2BV8D5HFopRwWTXENRnW08qfFNy8FDxwgxrpWjK0hQRS+7AidOGum7kQJC5PxNE0ODcWZ7DZu7ME+bZN8za3QatWx89i7tUR6ThPoAPEy9rpVoNqq7l6lr28srgBo+REWtEkoIj0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741450548; c=relaxed/simple; bh=KBgRzZAbBGIQ69PfZ+7dGozNCyjO2VGPL3YMzUSFfpQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f8iFmsjBRZkicA1IA9s8vhVjb1XRA6zgI7v6N0qNK6UwlKSB8Gr9MZSQRKq2ogCjNduf4nT/jx3bCvEKDbPRniQGveOgpwxQcjaBBeFjUlvwveqRjJuw+aBj/HdrgVM8dYfbWIw6htGMixfuGJUOfGIQh3tUfVA37USnqBdYlcU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=H5A6iEi1; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H5A6iEi1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741450545; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=exaflMSl1un4CsRdVEleWfiozXNaKVaxajlaSlzzCVU=; b=H5A6iEi1kV/4aa2XGwcdyNOLwZBnkZfFxRaPdIxrPcnoBhT8JrXwh7Fc0PfTfzetRe7LE0 GqQyhicexTu+dcXvlNqEFJI+K1bZBDMIfBz/4XRClOD2f/brH+fm5PjRgnTx4ITrgIz8Df CwJ0mPHkG5NRgQ1xysaFf38Pgz15fbM= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-83-1T0K3prCMUO-zsFvyUyb-A-1; Sat, 08 Mar 2025 11:15:42 -0500 X-MC-Unique: 1T0K3prCMUO-zsFvyUyb-A-1 X-Mimecast-MFC-AGG-ID: 1T0K3prCMUO-zsFvyUyb-A_1741450541 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 11F59180049D; Sat, 8 Mar 2025 16:15:41 +0000 (UTC) Received: from localhost (unknown [10.72.120.5]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id F16AD1956095; Sat, 8 Mar 2025 16:15:39 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Ming Lei Subject: [PATCH 2/5] loop: cleanup lo_rw_aio() Date: Sun, 9 Mar 2025 00:14:55 +0800 Message-ID: <20250308161504.1639157-6-ming.lei@redhat.com> In-Reply-To: <20250308161504.1639157-1-ming.lei@redhat.com> References: <20250308161504.1639157-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Cleanup lo_rw_aio() a bit by refactoring it into three parts: - lo_cmd_nr_bvec(), for calculating how many bvecs in this request - lo_rw_aio_prep(), for preparing loop command, which need to be called once - lo_submit_rw_aio(), for submitting this lo command, which can be called multiple times Prepare for trying to handle loop command by NOWAIT read/write IO first. Signed-off-by: Ming Lei --- drivers/block/loop.c | 83 +++++++++++++++++++++++++++++--------------- 1 file changed, 55 insertions(+), 28 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 6bbbaa4aaf2c..eae38cd38b7b 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -394,24 +394,63 @@ static void lo_rw_aio_complete(struct kiocb *iocb, long ret) lo_rw_aio_do_completion(cmd); } -static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, loff_t pos) +static int lo_submit_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, + loff_t pos, int nr_bvec) { - struct iov_iter iter; - struct req_iterator rq_iter; - struct bio_vec *bvec; struct request *rq = blk_mq_rq_from_pdu(cmd); int dir = (req_op(rq) == REQ_OP_READ) ? ITER_DEST : ITER_SOURCE; - struct bio *bio = rq->bio; struct file *file = lo->lo_backing_file; - struct bio_vec tmp; + struct iov_iter iter; + struct bio_vec *bvec; unsigned int offset; - int nr_bvec = 0; int ret; + if (rq->bio != rq->biotail) { + bvec = cmd->bvec; + offset = 0; + } else { + struct bio *bio = rq->bio; + + offset = bio->bi_iter.bi_bvec_done; + bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); + } + iov_iter_bvec(&iter, dir, bvec, nr_bvec, blk_rq_bytes(rq)); + iter.iov_offset = offset; + cmd->iocb.ki_pos = pos; + + atomic_set(&cmd->ref, 2); + if (dir == ITER_SOURCE) + ret = file->f_op->write_iter(&cmd->iocb, &iter); + else + ret = file->f_op->read_iter(&cmd->iocb, &iter); + lo_rw_aio_do_completion(cmd); + + return ret; +} + +static inline unsigned lo_cmd_nr_bvec(struct loop_cmd *cmd) +{ + struct req_iterator rq_iter; + struct request *rq = blk_mq_rq_from_pdu(cmd); + struct bio_vec tmp; + int nr_bvec = 0; + rq_for_each_bvec(tmp, rq, rq_iter) nr_bvec++; + return nr_bvec; +} + +static int lo_rw_aio_prep(struct loop_device *lo, struct loop_cmd *cmd, + unsigned nr_bvec) +{ + struct request *rq = blk_mq_rq_from_pdu(cmd); + struct file *file = lo->lo_backing_file; + if (rq->bio != rq->biotail) { + struct req_iterator rq_iter; + struct bio_vec *bvec; + struct bio_vec tmp; bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), GFP_NOIO); @@ -429,35 +468,23 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, loff_t pos) *bvec = tmp; bvec++; } - bvec = cmd->bvec; - offset = 0; - } else { - /* - * Same here, this bio may be started from the middle of the - * 'bvec' because of bio splitting, so offset from the bvec - * must be passed to iov iterator - */ - offset = bio->bi_iter.bi_bvec_done; - bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); } - atomic_set(&cmd->ref, 2); - - iov_iter_bvec(&iter, dir, bvec, nr_bvec, blk_rq_bytes(rq)); - iter.iov_offset = offset; - - cmd->iocb.ki_pos = pos; cmd->iocb.ki_filp = file; cmd->iocb.ki_complete = lo_rw_aio_complete; cmd->iocb.ki_flags = IOCB_DIRECT; cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); - if (dir == ITER_SOURCE) - ret = file->f_op->write_iter(&cmd->iocb, &iter); - else - ret = file->f_op->read_iter(&cmd->iocb, &iter); + return 0; +} - lo_rw_aio_do_completion(cmd); +static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, loff_t pos) +{ + unsigned int nr_bvec = lo_cmd_nr_bvec(cmd); + int ret = lo_rw_aio_prep(lo, cmd, nr_bvec); + if (ret < 0) + return ret; + ret = lo_submit_rw_aio(lo, cmd, pos, nr_bvec); if (ret != -EIOCBQUEUED) lo_rw_aio_complete(&cmd->iocb, ret); return 0;