From patchwork Fri May 19 07:40:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13247842 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC5C5C77B7A for ; Fri, 19 May 2023 07:45:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231409AbjESHpZ (ORCPT ); Fri, 19 May 2023 03:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231462AbjESHoz (ORCPT ); Fri, 19 May 2023 03:44:55 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AAFF19A for ; Fri, 19 May 2023 00:42:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684482146; 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=KIPsbdoO43iq3tUvemirM6xG5g+su+9PgNJxpKHBcQ0=; b=OeTLBJKu3ar0s3l5yedTUrqph075KAF3fdeIFuONOB0aGZMrele8yzDKc54ij+g03m07J2 UEXxWynpWQxs199z40PL4VoA1pOoRkEyNe/QT7zMQPOH2WZHjzoQ5GPX0ET1tQ57UwSeDh 8EgnhycgkQ+einsDvz6su9igEClyq44= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-581-aSvtV5ZQOk2ZrLbIVY_T4A-1; Fri, 19 May 2023 03:42:23 -0400 X-MC-Unique: aSvtV5ZQOk2ZrLbIVY_T4A-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 80C8380013A; Fri, 19 May 2023 07:42:22 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1CE32492B0A; Fri, 19 May 2023 07:42:20 +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 , Steve French , John Hubbard , linux-cifs@vger.kernel.org Subject: [PATCH v20 24/32] splice: Do splice read from a file without using ITER_PIPE Date: Fri, 19 May 2023 08:40:39 +0100 Message-Id: <20230519074047.1739879-25-dhowells@redhat.com> In-Reply-To: <20230519074047.1739879-1-dhowells@redhat.com> References: <20230519074047.1739879-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Make generic_file_splice_read() use filemap_splice_read() and direct_splice_read() rather than using an ITER_PIPE and call_read_iter(). With this, ITER_PIPE is no longer used. Signed-off-by: David Howells Reviewed-by: Christoph Hellwig cc: Jens Axboe cc: Steve French cc: Al Viro cc: David Hildenbrand cc: John Hubbard cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org --- Notes: ver #20) - Use s_maxbytes from the backing store (in->f_mapping), not the front inode (especially for a blockdev). ver #18) - Split out the change to cifs to make it use generic_file_splice_read(). - Split out the unexport of filemap_splice_read() (still needed by cifs). fs/splice.c | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 7b818b5b18d4..56d9802729d0 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -417,34 +417,17 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { - struct iov_iter to; - struct kiocb kiocb; - int ret; - + if (unlikely(*ppos >= in->f_mapping->host->i_sb->s_maxbytes)) + return 0; + if (unlikely(!len)) + return 0; #ifdef CONFIG_FS_DAX if (IS_DAX(in->f_mapping->host)) return direct_splice_read(in, ppos, pipe, len, flags); #endif - - iov_iter_pipe(&to, ITER_DEST, pipe, len); - init_sync_kiocb(&kiocb, in); - kiocb.ki_pos = *ppos; - ret = call_read_iter(in, &kiocb, &to); - if (ret > 0) { - *ppos = kiocb.ki_pos; - file_accessed(in); - } else if (ret < 0) { - /* free what was emitted */ - pipe_discard_from(pipe, to.start_head); - /* - * callers of ->splice_read() expect -EAGAIN on - * "can't put anything in there", rather than -EFAULT. - */ - if (ret == -EFAULT) - ret = -EAGAIN; - } - - return ret; + if ((in->f_flags & O_DIRECT)) + return direct_splice_read(in, ppos, pipe, len, flags); + return filemap_splice_read(in, ppos, pipe, len, flags); } EXPORT_SYMBOL(generic_file_splice_read);