From patchwork Fri Apr 29 00:43:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12831359 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 DCC5BC433EF for ; Fri, 29 Apr 2022 00:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350820AbiD2AsD (ORCPT ); Thu, 28 Apr 2022 20:48:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237629AbiD2AsC (ORCPT ); Thu, 28 Apr 2022 20:48:02 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3350FBB902; Thu, 28 Apr 2022 17:44:46 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BCA8121872; Fri, 29 Apr 2022 00:44:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1651193084; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JrU/wsC8sdfT/R0JtZvwzkc1EUgEvszFC5tR6hfJPHE=; b=HcAEspUL3B+9CGfESTkkWyVHLwjkJyuXcPrNSc2itnNpsG4afpKgD2fceNteEvGeIDzDkF vam2Q7ZjD4Gu5lf4cLuh8wj+2UI/XuhK0NK7Izl6oYOI2DyEklQM6ZBCinCG9RVEBqv6mY w/P+5PydmAsMkqnfWIlJG5nPcjgdwrc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1651193084; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JrU/wsC8sdfT/R0JtZvwzkc1EUgEvszFC5tR6hfJPHE=; b=pAN5MwCEnPu7JYa0cLy1RgMWnMu44JE2gGqZNmMinRWucAubigJnhLMMABEnAgm3z3Cafp P+EvQ9EmCJq+XnAQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id A593513491; Fri, 29 Apr 2022 00:44:42 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ljwOGfo0a2IrSgAAMHmgww (envelope-from ); Fri, 29 Apr 2022 00:44:42 +0000 Subject: [PATCH 1/2] MM: handle THP in swap_*page_fs() From: NeilBrown To: Andrew Morton Cc: Geert Uytterhoeven , Christoph Hellwig , Miaohe Lin , linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Fri, 29 Apr 2022 10:43:34 +1000 Message-ID: <165119301488.15698.9457662928942765453.stgit@noble.brown> In-Reply-To: <165119280115.15698.2629172320052218921.stgit@noble.brown> References: <165119280115.15698.2629172320052218921.stgit@noble.brown> User-Agent: StGit/1.5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Pages passed to swap_readpage()/swap_writepage() are not necessarily all the same size - there may be transparent-huge-pages involves. The BIO paths of swap_*page() handle this correctly, but the SWP_FS_OPS path does not. So we need to use thp_size() to find the size, not just assume PAGE_SIZE, and we need to track the total length of the request, not just assume it is "page * PAGE_SIZE". Reported-by: Miaohe Lin Signed-off-by: NeilBrown --- mm/page_io.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index c132511f521c..d636a3531cad 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -239,6 +239,7 @@ struct swap_iocb { struct kiocb iocb; struct bio_vec bvec[SWAP_CLUSTER_MAX]; int pages; + int len; }; static mempool_t *sio_pool; @@ -261,7 +262,7 @@ static void sio_write_complete(struct kiocb *iocb, long ret) struct page *page = sio->bvec[0].bv_page; int p; - if (ret != PAGE_SIZE * sio->pages) { + if (ret != sio->len) { /* * In the case of swap-over-nfs, this can be a * temporary failure if the system has limited @@ -301,7 +302,7 @@ static int swap_writepage_fs(struct page *page, struct writeback_control *wbc) sio = *wbc->swap_plug; if (sio) { if (sio->iocb.ki_filp != swap_file || - sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { + sio->iocb.ki_pos + sio->len != pos) { swap_write_unplug(sio); sio = NULL; } @@ -312,10 +313,12 @@ static int swap_writepage_fs(struct page *page, struct writeback_control *wbc) sio->iocb.ki_complete = sio_write_complete; sio->iocb.ki_pos = pos; sio->pages = 0; + sio->len = 0; } sio->bvec[sio->pages].bv_page = page; - sio->bvec[sio->pages].bv_len = PAGE_SIZE; + sio->bvec[sio->pages].bv_len = thp_size(page); sio->bvec[sio->pages].bv_offset = 0; + sio->len += thp_size(page); sio->pages += 1; if (sio->pages == ARRAY_SIZE(sio->bvec) || !wbc->swap_plug) { swap_write_unplug(sio); @@ -371,8 +374,7 @@ void swap_write_unplug(struct swap_iocb *sio) struct address_space *mapping = sio->iocb.ki_filp->f_mapping; int ret; - iov_iter_bvec(&from, WRITE, sio->bvec, sio->pages, - PAGE_SIZE * sio->pages); + iov_iter_bvec(&from, WRITE, sio->bvec, sio->pages, sio->len); ret = mapping->a_ops->swap_rw(&sio->iocb, &from); if (ret != -EIOCBQUEUED) sio_write_complete(&sio->iocb, ret); @@ -383,7 +385,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret) struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb); int p; - if (ret == PAGE_SIZE * sio->pages) { + if (ret == sio->len) { for (p = 0; p < sio->pages; p++) { struct page *page = sio->bvec[p].bv_page; @@ -415,7 +417,7 @@ static void swap_readpage_fs(struct page *page, sio = *plug; if (sio) { if (sio->iocb.ki_filp != sis->swap_file || - sio->iocb.ki_pos + sio->pages * PAGE_SIZE != pos) { + sio->iocb.ki_pos + sio->len != pos) { swap_read_unplug(sio); sio = NULL; } @@ -426,10 +428,12 @@ static void swap_readpage_fs(struct page *page, sio->iocb.ki_pos = pos; sio->iocb.ki_complete = sio_read_complete; sio->pages = 0; + sio->len = 0; } sio->bvec[sio->pages].bv_page = page; - sio->bvec[sio->pages].bv_len = PAGE_SIZE; + sio->bvec[sio->pages].bv_len = thp_size(page); sio->bvec[sio->pages].bv_offset = 0; + sio->len += thp_size(page); sio->pages += 1; if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) { swap_read_unplug(sio); @@ -521,8 +525,7 @@ void __swap_read_unplug(struct swap_iocb *sio) struct address_space *mapping = sio->iocb.ki_filp->f_mapping; int ret; - iov_iter_bvec(&from, READ, sio->bvec, sio->pages, - PAGE_SIZE * sio->pages); + iov_iter_bvec(&from, READ, sio->bvec, sio->pages, sio->len); ret = mapping->a_ops->swap_rw(&sio->iocb, &from); if (ret != -EIOCBQUEUED) sio_read_complete(&sio->iocb, ret);