From nobody Fri Dec 19 08:07:57 2025 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 3409DC4167B for ; Wed, 6 Dec 2023 09:11:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346806AbjLFJL0 (ORCPT ); Wed, 6 Dec 2023 04:11:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346770AbjLFJLM (ORCPT ); Wed, 6 Dec 2023 04:11:12 -0500 Received: from out30-98.freemail.mail.aliyun.com (out30-98.freemail.mail.aliyun.com [115.124.30.98]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4320D10C1 for ; Wed, 6 Dec 2023 01:11:18 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VxxSRQT_1701853874; Received: from e69b19392.et15sqa.tbsite.net(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VxxSRQT_1701853874) by smtp.aliyun-inc.com; Wed, 06 Dec 2023 17:11:15 +0800 From: Gao Xiang To: linux-erofs@lists.ozlabs.org Cc: LKML , dhavale@google.com, Gao Xiang Subject: [PATCH 4/5] erofs: refine z_erofs_transform_plain() for sub-page block support Date: Wed, 6 Dec 2023 17:10:56 +0800 Message-Id: <20231206091057.87027-5-hsiangkao@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231206091057.87027-1-hsiangkao@linux.alibaba.com> References: <20231206091057.87027-1-hsiangkao@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Sub-page block support is still unusable even with previous commits if interlaced PLAIN pclusters exist. Such pclusters can be found if the fragment feature is enabled. This commit tries to handle "the head part" of interlaced PLAIN pclusters first: it was once explained in commit fdffc091e6f9 ("erofs: support interlaced uncompressed data for compressed files"). It uses a unique way for both shifted and interlaced PLAIN pclusters. As an added bonus, PLAIN pclusters larger than the block size is also supported now for the upcoming large lclusters. Signed-off-by: Gao Xiang --- fs/erofs/decompressor.c | 81 ++++++++++++++++++++++++----------------- 1 file changed, 48 insertions(+), 33 deletions(-) diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 021be5feb1bc..5ec11f5024b7 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -319,43 +319,58 @@ static int z_erofs_lz4_decompress(struct z_erofs_deco= mpress_req *rq, static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq, struct page **pagepool) { - const unsigned int inpages =3D PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT; - const unsigned int outpages =3D + const unsigned int nrpages_in =3D + PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT; + const unsigned int nrpages_out =3D PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; - const unsigned int righthalf =3D min_t(unsigned int, rq->outputsize, - PAGE_SIZE - rq->pageofs_out); - const unsigned int lefthalf =3D rq->outputsize - righthalf; - const unsigned int interlaced_offset =3D - rq->alg =3D=3D Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out; - u8 *src; - - if (outpages > 2 && rq->alg =3D=3D Z_EROFS_COMPRESSION_SHIFTED) { - DBG_BUGON(1); - return -EFSCORRUPTED; - } - - if (rq->out[0] =3D=3D *rq->in) { - DBG_BUGON(rq->pageofs_out); - return 0; + const unsigned int bs =3D rq->sb->s_blocksize; + unsigned int cur =3D 0, ni =3D 0, no, pi, po, insz, cnt; + u8 *kin; + + DBG_BUGON(rq->outputsize > rq->inputsize); + if (rq->alg =3D=3D Z_EROFS_COMPRESSION_INTERLACED) { + cur =3D bs - (rq->pageofs_out & (bs - 1)); + pi =3D (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK; + cur =3D min(cur, rq->outputsize); + if (cur && rq->out[0]) { + kin =3D kmap_local_page(rq->in[nrpages_in - 1]); + if (rq->out[0] =3D=3D rq->in[nrpages_in - 1]) { + memmove(kin + rq->pageofs_out, kin + pi, cur); + flush_dcache_page(rq->out[0]); + } else { + memcpy_to_page(rq->out[0], rq->pageofs_out, + kin + pi, cur); + } + kunmap_local(kin); + } + rq->outputsize -=3D cur; } =20 - src =3D kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in; - if (rq->out[0]) - memcpy_to_page(rq->out[0], rq->pageofs_out, - src + interlaced_offset, righthalf); - - if (outpages > inpages) { - DBG_BUGON(!rq->out[outpages - 1]); - if (rq->out[outpages - 1] !=3D rq->in[inpages - 1]) { - memcpy_to_page(rq->out[outpages - 1], 0, src + - (interlaced_offset ? 0 : righthalf), - lefthalf); - } else if (!interlaced_offset) { - memmove(src, src + righthalf, lefthalf); - flush_dcache_page(rq->in[inpages - 1]); - } + for (; rq->outputsize; rq->pageofs_in =3D 0, cur +=3D PAGE_SIZE, ni++) { + insz =3D min(PAGE_SIZE - rq->pageofs_in, rq->outputsize); + rq->outputsize -=3D insz; + if (!rq->in[ni]) + continue; + kin =3D kmap_local_page(rq->in[ni]); + pi =3D 0; + do { + no =3D (rq->pageofs_out + cur + pi) >> PAGE_SHIFT; + po =3D (rq->pageofs_out + cur + pi) & ~PAGE_MASK; + DBG_BUGON(no >=3D nrpages_out); + cnt =3D min(insz - pi, PAGE_SIZE - po); + if (rq->out[no] =3D=3D rq->in[ni]) { + memmove(kin + po, + kin + rq->pageofs_in + pi, cnt); + flush_dcache_page(rq->out[no]); + } else if (rq->out[no]) { + memcpy_to_page(rq->out[no], po, + kin + rq->pageofs_in + pi, cnt); + } + pi +=3D cnt; + } while (pi < insz); + kunmap_local(kin); } - kunmap_local(src); + DBG_BUGON(ni > nrpages_in); return 0; } =20 --=20 2.39.3