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[2620:137:e000::1:20]) by mx.google.com with ESMTP id a10-20020a655c8a000000b004cc67cfc92bsi3384337pgt.97.2023.03.14.15.35.38; Tue, 14 Mar 2023 15:35:51 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=GiNbBaSg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231247AbjCNWJR (ORCPT + 99 others); Tue, 14 Mar 2023 18:09:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229674AbjCNWJE (ORCPT ); Tue, 14 Mar 2023 18:09:04 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF4BF2FCD0 for ; Tue, 14 Mar 2023 15:08:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678831693; 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=fEHZtUBR4B7sSEpj4V24Co6bhAobBEWGUt1eQB77Iqg=; b=GiNbBaSghhcxzvdmL6iS8IcJZavYOXc/NxCR8hc7CocyipG82TM/pAbORFaQ/vpBu5+Nne yp07J2E1QydctJL83U5l5xuE3aUpPCKZKSFTi5CnA5/qcqEyfeTcOMw9P7/ywS9Yiwf8Rj 67MkCWP/+sIOKn8HdSar9DsWOIAUZ9g= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-412-DdUmrbONMJOLxGdg1BeEdA-1; Tue, 14 Mar 2023 18:08:10 -0400 X-MC-Unique: DdUmrbONMJOLxGdg1BeEdA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D1B623806702; Tue, 14 Mar 2023 22:08:09 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id B6B8840C6E67; Tue, 14 Mar 2023 22:08:07 +0000 (UTC) From: David Howells To: Jens Axboe , Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard Subject: [PATCH v18 01/15] splice: Clean up direct_splice_read() a bit Date: Tue, 14 Mar 2023 22:07:43 +0000 Message-Id: <20230314220757.3827941-2-dhowells@redhat.com> In-Reply-To: <20230314220757.3827941-1-dhowells@redhat.com> References: <20230314220757.3827941-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1760384360298758507?= X-GMAIL-MSGID: =?utf-8?q?1760384360298758507?= Do a couple of cleanups to direct_splice_read(): (1) Cast to struct page **, not void *. (2) Simplify the calculation of the number of pages to keep/reclaim in direct_splice_read(). Suggested-by: Christoph Hellwig Signed-off-by: David Howells Reviewed-by: Christoph Hellwig cc: Jens Axboe cc: Al Viro cc: David Hildenbrand cc: John Hubbard cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org --- fs/splice.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 2e76dbb81a8f..abd21a455a2b 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -295,7 +295,7 @@ ssize_t direct_splice_read(struct file *in, loff_t *ppos, struct kiocb kiocb; struct page **pages; ssize_t ret; - size_t used, npages, chunk, remain, reclaim; + size_t used, npages, chunk, remain, keep = 0; int i; /* Work out how much data we can actually add into the pipe */ @@ -309,7 +309,7 @@ ssize_t direct_splice_read(struct file *in, loff_t *ppos, if (!bv) return -ENOMEM; - pages = (void *)(bv + npages); + pages = (struct page **)(bv + npages); npages = alloc_pages_bulk_array(GFP_USER, npages, pages); if (!npages) { kfree(bv); @@ -332,11 +332,8 @@ ssize_t direct_splice_read(struct file *in, loff_t *ppos, kiocb.ki_pos = *ppos; ret = call_read_iter(in, &kiocb, &to); - reclaim = npages * PAGE_SIZE; - remain = 0; if (ret > 0) { - reclaim -= ret; - remain = ret; + keep = DIV_ROUND_UP(ret, PAGE_SIZE); *ppos = kiocb.ki_pos; file_accessed(in); } else if (ret < 0) { @@ -349,14 +346,12 @@ ssize_t direct_splice_read(struct file *in, loff_t *ppos, } /* Free any pages that didn't get touched at all. */ - reclaim /= PAGE_SIZE; - if (reclaim) { - npages -= reclaim; - release_pages(pages + npages, reclaim); - } + if (keep < npages) + release_pages(pages + keep, npages - keep); /* Push the remaining pages into the pipe. */ - for (i = 0; i < npages; i++) { + remain = ret; + for (i = 0; i < keep; i++) { struct pipe_buffer *buf = pipe_head_buf(pipe); chunk = min_t(size_t, remain, PAGE_SIZE);