From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63C98C4BA07 for ; Tue, 25 Feb 2020 21:49:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1063424653 for ; Tue, 25 Feb 2020 21:49:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="BexBWYcV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1063424653 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7910C6B0074; Tue, 25 Feb 2020 16:48:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 655A16B006E; Tue, 25 Feb 2020 16:48:46 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DCFA86B000A; Tue, 25 Feb 2020 16:48:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id 40CB86B000A for ; Tue, 25 Feb 2020 16:48:45 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DC018248C for ; Tue, 25 Feb 2020 21:48:44 +0000 (UTC) X-FDA: 76529989368.09.hands68_2f36a53b44b0b X-HE-Tag: hands68_2f36a53b44b0b X-Filterd-Recvd-Size: 8093 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Tue, 25 Feb 2020 21:48:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=yBa1NPGpwbmn0gnLMSJ5yytmmVWZFSa0V+TVtsWzB8o=; b=BexBWYcVXzH1yGphVd7A/Z2aWJ mVAzBuwaIsfZbT4rukJouhqlyekyujIJREvGdlBXc5oGNyAn6reZ3ApNP3Ua9ico9S4PgJJ74xw5g 1YeHAEaBWokE9B9mvSFClhn0JDQmjsg0/XmdFlzKRmUtQbKAxYogfb41+nIQlpYNmzwLZ2dZpGovT jbZwYx7luRNLehR17QKjgThogCPItoSr8wEkdwTVwlureko3vj/vYmhbvnthCcXTMpowFZGsSr3a7 a0Z0Y2guLdrKmQO0xOVOtW77BoP0qqfrftj5Ttg7jtEcddsOGfHqd6iRjf8NqBYrFkdq0ObzS0GGE aKRmUUug==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6i4G-0007pL-Va; Tue, 25 Feb 2020 21:48:40 +0000 From: Matthew Wilcox To: linux-fsdevel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, ocfs2-devel@oss.oracle.com, linux-xfs@vger.kernel.org, Dave Chinner , John Hubbard , Christoph Hellwig Subject: [PATCH v8 02/25] mm: Return void from various readahead functions Date: Tue, 25 Feb 2020 13:48:15 -0800 Message-Id: <20200225214838.30017-3-willy@infradead.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200225214838.30017-1-willy@infradead.org> References: <20200225214838.30017-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: "Matthew Wilcox (Oracle)" ondemand_readahead has two callers, neither of which use the return value= . That means that both ra_submit and __do_page_cache_readahead() can return void, and we don't need to worry that a present page in the readahead window causes us to return a smaller nr_pages than we ought to have. Similarly, no caller uses the return value from force_page_cache_readahea= d(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Dave Chinner Reviewed-by: John Hubbard Reviewed-by: Christoph Hellwig --- mm/fadvise.c | 4 ---- mm/internal.h | 12 ++++++------ mm/readahead.c | 31 +++++++++++++------------------ 3 files changed, 19 insertions(+), 28 deletions(-) diff --git a/mm/fadvise.c b/mm/fadvise.c index 3efebfb9952c..0e66f2aaeea3 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -104,10 +104,6 @@ int generic_fadvise(struct file *file, loff_t offset= , loff_t len, int advice) if (!nrpages) nrpages =3D ~0UL; =20 - /* - * Ignore return value because fadvise() shall return - * success even if filesystem can't retrieve a hint, - */ force_page_cache_readahead(mapping, file, start_index, nrpages); break; case POSIX_FADV_NOREUSE: diff --git a/mm/internal.h b/mm/internal.h index 83f353e74654..15aaebebd768 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -49,20 +49,20 @@ void unmap_page_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end, struct zap_details *details); =20 -int force_page_cache_readahead(struct address_space *, struct file *, +void force_page_cache_readahead(struct address_space *, struct file *, pgoff_t index, unsigned long nr_to_read); -extern unsigned int __do_page_cache_readahead(struct address_space *mapp= ing, - struct file *filp, pgoff_t offset, unsigned long nr_to_read, +void __do_page_cache_readahead(struct address_space *, struct file *, + pgoff_t index, unsigned long nr_to_read, unsigned long lookahead_size); =20 /* * Submit IO for the read-ahead request in file_ra_state. */ -static inline unsigned long ra_submit(struct file_ra_state *ra, +static inline void ra_submit(struct file_ra_state *ra, struct address_space *mapping, struct file *filp) { - return __do_page_cache_readahead(mapping, filp, - ra->start, ra->size, ra->async_size); + __do_page_cache_readahead(mapping, filp, + ra->start, ra->size, ra->async_size); } =20 /* diff --git a/mm/readahead.c b/mm/readahead.c index 2fe72cd29b47..41a592886da7 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -149,10 +149,8 @@ static int read_pages(struct address_space *mapping,= struct file *filp, * the pages first, then submits them for I/O. This avoids the very bad * behaviour which would occur if page allocations are causing VM writeb= ack. * We really don't want to intermingle reads and writes like that. - * - * Returns the number of pages requested, or the maximum amount of I/O a= llowed. */ -unsigned int __do_page_cache_readahead(struct address_space *mapping, +void __do_page_cache_readahead(struct address_space *mapping, struct file *filp, pgoff_t offset, unsigned long nr_to_read, unsigned long lookahead_size) { @@ -166,7 +164,7 @@ unsigned int __do_page_cache_readahead(struct address= _space *mapping, gfp_t gfp_mask =3D readahead_gfp_mask(mapping); =20 if (isize =3D=3D 0) - goto out; + return; =20 end_index =3D ((isize - 1) >> PAGE_SHIFT); =20 @@ -211,23 +209,21 @@ unsigned int __do_page_cache_readahead(struct addre= ss_space *mapping, if (nr_pages) read_pages(mapping, filp, &page_pool, nr_pages, gfp_mask); BUG_ON(!list_empty(&page_pool)); -out: - return nr_pages; } =20 /* * Chunk the readahead into 2 megabyte units, so that we don't pin too m= uch * memory at once. */ -int force_page_cache_readahead(struct address_space *mapping, struct fil= e *filp, - pgoff_t offset, unsigned long nr_to_read) +void force_page_cache_readahead(struct address_space *mapping, + struct file *filp, pgoff_t offset, unsigned long nr_to_read) { struct backing_dev_info *bdi =3D inode_to_bdi(mapping->host); struct file_ra_state *ra =3D &filp->f_ra; unsigned long max_pages; =20 if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages)) - return -EINVAL; + return; =20 /* * If the request exceeds the readahead window, allow the read to @@ -245,7 +241,6 @@ int force_page_cache_readahead(struct address_space *= mapping, struct file *filp, offset +=3D this_chunk; nr_to_read -=3D this_chunk; } - return 0; } =20 /* @@ -378,11 +373,10 @@ static int try_context_readahead(struct address_spa= ce *mapping, /* * A minimal readahead algorithm for trivial sequential/random reads. */ -static unsigned long -ondemand_readahead(struct address_space *mapping, - struct file_ra_state *ra, struct file *filp, - bool hit_readahead_marker, pgoff_t offset, - unsigned long req_size) +static void ondemand_readahead(struct address_space *mapping, + struct file_ra_state *ra, struct file *filp, + bool hit_readahead_marker, pgoff_t offset, + unsigned long req_size) { struct backing_dev_info *bdi =3D inode_to_bdi(mapping->host); unsigned long max_pages =3D ra->ra_pages; @@ -428,7 +422,7 @@ ondemand_readahead(struct address_space *mapping, rcu_read_unlock(); =20 if (!start || start - offset > max_pages) - return 0; + return; =20 ra->start =3D start; ra->size =3D start - offset; /* old async_size */ @@ -464,7 +458,8 @@ ondemand_readahead(struct address_space *mapping, * standalone, small random read * Read as is, and do not pollute the readahead state. */ - return __do_page_cache_readahead(mapping, filp, offset, req_size, 0); + __do_page_cache_readahead(mapping, filp, offset, req_size, 0); + return; =20 initial_readahead: ra->start =3D offset; @@ -489,7 +484,7 @@ ondemand_readahead(struct address_space *mapping, } } =20 - return ra_submit(ra, mapping, filp); + ra_submit(ra, mapping, filp); } =20 /** --=20 2.25.0