From patchwork Sat Mar 22 01:26:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 14026127 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 A13C1259C for ; Sat, 22 Mar 2025 01:26:42 +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=1742606804; cv=none; b=jUSHsfxJWSrrCpJ0/q6oiYhUxIKuA1v4NbvghtF8m20D1+ztB/j7tFU1bvY5Dn1qn3GD83SSNjJ9qH6FFbsEVCbMF+uZX94LDaHSe5RxkFnURq/vfX7vfc7BkeRvMsYhFye69U6K5gvGY6+EC6osuCRwzQ82O6AFCbTim+mWHy0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742606804; c=relaxed/simple; bh=NcAuwn+i8L5oEuXthUIDxYma2alnjm5NSxoSC+LOAzg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FbtKutZIBnLMTOrd7v4VPNdgT6NPKc6jsoz3leL1TN/nifTtkIJAeMBd4H75/wJRp6vwRKwFB080hkrQ/xup+NNEOIPi8p053OG8mxJieQs/KUQoGObnReFAL+mXzdVMr48gDnV2Re/ETUoPCzksZTYZtVXKA0CfHTwJJFquRGs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=RMGMak0L; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="RMGMak0L" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742606801; 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=nUlqBDHfwWUJZK2tW62gTBJFE4Ef6WuSuhLHJpSvsEw=; b=RMGMak0LZB7/bF+NBIWnzDxBRZvQkgxYL6NiJuum3uqVvWChJYkVoyFd9WxV7dxeuDW7mB O+w1cNx/c7rY7b6BmqcgQKeXtFTwTrBsVAbngQv/HkD+BgQ59EIGOIqdNDDawnSSmIskVy yLOkyaHPP+ixdkzmjLpukb6badTiSl0= 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-131-yVCNuLI3NP275SQFsWYb3A-1; Fri, 21 Mar 2025 21:26:38 -0400 X-MC-Unique: yVCNuLI3NP275SQFsWYb3A-1 X-Mimecast-MFC-AGG-ID: yVCNuLI3NP275SQFsWYb3A_1742606797 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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 307311801A06; Sat, 22 Mar 2025 01:26:36 +0000 (UTC) Received: from localhost (unknown [10.72.120.2]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 6650219560AF; Sat, 22 Mar 2025 01:26:33 +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 , Mikulas Patocka , Ming Lei Subject: [PATCH V3 1/5] loop: simplify do_req_filebacked() Date: Sat, 22 Mar 2025 09:26:10 +0800 Message-ID: <20250322012617.354222-2-ming.lei@redhat.com> In-Reply-To: <20250322012617.354222-1-ming.lei@redhat.com> References: <20250322012617.354222-1-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 10.30.177.40 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); ``` Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei --- 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 674527d770dc..339b19671450 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -277,6 +277,13 @@ 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); @@ -392,13 +399,13 @@ 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; @@ -440,7 +447,7 @@ 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; @@ -449,7 +456,7 @@ 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); @@ -490,15 +497,11 @@ 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;