From patchwork Fri Mar 14 02:11:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 14016146 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 48AA617588 for ; Fri, 14 Mar 2025 02:12:07 +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=1741918329; cv=none; b=LoZgsqDHBDX1rpRhYtHH0AjO6I6tAwZIWGn4xFDg4+IEmv10tQzR72yGuaHgJal1bnIPaVA75iXo5YFHK28nMTOFOn4D+NC3NIerEJSjvEGFj0f11AEl4DBO9UwbopQglSTFlDqGIjrctDKwaVQz4px7ESsbSTchXfYZeu0o+1M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741918329; c=relaxed/simple; bh=XBrTJOi6RUf+zfX7H5Ssv7FsOXcGn3VYi6NQzhzSg8g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Yey6gQQ5N1GRjjIX9w//Fu92Ye6ZuuSQlUelJ7QeJo6qkxH1OiTe+DMkdRpuVJ0ulA3P5OWuVD66NPGTsjD6T/tgPZiEAflPb6j4NMHCXfAfW81Jy94Lji9UeD8EV3plJaUlpjjNXNbk5yo7oSmdtLX0UTTGG1xNuhgt8QcG1yE= 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=bFieyX45; 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="bFieyX45" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741918327; 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=ZJM7fhnzSVkAI0uB0b+VZz7idxBiXe+D5iz1Ay+75YE=; b=bFieyX45mPrqQC6Kz0U4VapoYlFFwCLQPhzZWEqvbcAVUaiHMWQp21c/GaaIHACrD0M5Hg 0IFgGm0rra9qyAq8LH8cbxDBmcy0NmwxsPaootQOL+DwI2PlepcPoW4HOReaqKBeQV+8Nh u6cj5wyk1xa2l26xd4mqTE23gwO9wh4= Received: from mx-prod-mc-08.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-685-_S5p_J8vPNq2zUOrYratmA-1; Thu, 13 Mar 2025 22:12:05 -0400 X-MC-Unique: _S5p_J8vPNq2zUOrYratmA-1 X-Mimecast-MFC-AGG-ID: _S5p_J8vPNq2zUOrYratmA_1741918324 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5BA86180AB1C; Fri, 14 Mar 2025 02:12:03 +0000 (UTC) Received: from localhost (unknown [10.72.120.27]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B1ACF1828A87; Fri, 14 Mar 2025 02:12:00 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Christoph Hellwig , Jooyung Han , Mike Snitzer , zkabelac@redhat.com, dm-devel@lists.linux.dev, Alasdair Kergon , Ming Lei Subject: [PATCH V2 1/5] loop: simplify do_req_filebacked() Date: Fri, 14 Mar 2025 10:11:41 +0800 Message-ID: <20250314021148.3081954-2-ming.lei@redhat.com> In-Reply-To: <20250314021148.3081954-1-ming.lei@redhat.com> References: <20250314021148.3081954-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: dm-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 lo_rw_aio() is only called for READ/WRITE operation, which can be figured out from request directly, so remove 'rw' parameter from lo_rw_aio(), meantime rename the local variable as 'dir' which makes the check more readable in lo_rw_aio(). Meantime add lo_rw_simple() so that do_req_filebacked() can be simplified in the following way: ``` if (cmd->use_aio) return lo_rw_aio(lo, cmd, pos); else return lo_rw_simple(lo, rq, pos); ``` Signed-off-by: Ming Lei Reviewed-by: Christoph Hellwig --- drivers/block/loop.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 657bf53decf3..554f6cefe8f6 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -285,6 +285,13 @@ static int lo_read_simple(struct loop_device *lo, struct request *rq, return 0; } +static int lo_rw_simple(struct loop_device *lo, struct request *rq, loff_t pos) +{ + if (req_op(rq) == REQ_OP_READ) + return lo_read_simple(lo, rq, pos); + return lo_write_simple(lo, rq, pos); +} + static void loop_clear_limits(struct loop_device *lo, int mode) { struct queue_limits lim = queue_limits_start_update(lo->lo_queue); @@ -400,13 +407,13 @@ 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, int rw) +static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, loff_t pos) { 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; @@ -448,7 +455,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, } atomic_set(&cmd->ref, 2); - iov_iter_bvec(&iter, rw, bvec, nr_bvec, blk_rq_bytes(rq)); + iov_iter_bvec(&iter, dir, bvec, nr_bvec, blk_rq_bytes(rq)); iter.iov_offset = offset; cmd->iocb.ki_pos = pos; @@ -457,7 +464,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, cmd->iocb.ki_flags = IOCB_DIRECT; cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); - if (rw == ITER_SOURCE) + if (dir == ITER_SOURCE) ret = file->f_op->write_iter(&cmd->iocb, &iter); else ret = file->f_op->read_iter(&cmd->iocb, &iter); @@ -498,15 +505,11 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq) case REQ_OP_DISCARD: return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE); case REQ_OP_WRITE: - if (cmd->use_aio) - return lo_rw_aio(lo, cmd, pos, ITER_SOURCE); - else - return lo_write_simple(lo, rq, pos); case REQ_OP_READ: if (cmd->use_aio) - return lo_rw_aio(lo, cmd, pos, ITER_DEST); + return lo_rw_aio(lo, cmd, pos); else - return lo_read_simple(lo, rq, pos); + return lo_rw_simple(lo, rq, pos); default: WARN_ON_ONCE(1); return -EIO;