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 7006EC433FE for ; Tue, 28 Dec 2021 05:46:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234887AbhL1FqU (ORCPT ); Tue, 28 Dec 2021 00:46:20 -0500 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:59614 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234859AbhL1FqQ (ORCPT ); Tue, 28 Dec 2021 00:46:16 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0V0240kf_1640670365; Received: from e18g06460.et15sqa.tbsite.net(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0V0240kf_1640670365) by smtp.aliyun-inc.com(127.0.0.1); Tue, 28 Dec 2021 13:46:14 +0800 From: Gao Xiang To: linux-erofs@lists.ozlabs.org, Chao Yu Cc: Yue Hu , LKML , Gao Xiang Subject: [PATCH v4 2/5] erofs: introduce z_erofs_fixup_insize Date: Tue, 28 Dec 2021 13:46:01 +0800 Message-Id: <20211228054604.114518-3-hsiangkao@linux.alibaba.com> X-Mailer: git-send-email 2.24.4 In-Reply-To: <20211228054604.114518-1-hsiangkao@linux.alibaba.com> References: <20211228054604.114518-1-hsiangkao@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To prepare for the upcoming ztailpacking feature, introduce z_erofs_fixup_insize() and pageofs_in to wrap up the process to get the exact compressed size via zero padding. Reviewed-by: Chao Yu Signed-off-by: Gao Xiang --- fs/erofs/compress.h | 4 +++- fs/erofs/decompressor.c | 34 +++++++++++++++++++++++++--------- fs/erofs/decompressor_lzma.c | 19 ++++++++----------- 3 files changed, 36 insertions(+), 21 deletions(-) diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h index 579406504919..19e6c56a9f47 100644 --- a/fs/erofs/compress.h +++ b/fs/erofs/compress.h @@ -12,7 +12,7 @@ struct z_erofs_decompress_req { struct super_block *sb; struct page **in, **out; - unsigned short pageofs_out; + unsigned short pageofs_in, pageofs_out; unsigned int inputsize, outputsize; /* indicate the algorithm will be used for decompression */ @@ -87,6 +87,8 @@ static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi, return page->mapping == MNGD_MAPPING(sbi); } +int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf, + unsigned int padbufsize); int z_erofs_decompress(struct z_erofs_decompress_req *rq, struct page **pagepool); diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 1d137fd42306..b8b2a3e34053 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -184,6 +184,24 @@ static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx, return src; } +/* + * Get the exact inputsize with zero_padding feature. + * - For LZ4, it should work if zero_padding feature is on (5.3+); + * - For MicroLZMA, it'd be enabled all the time. + */ +int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf, + unsigned int padbufsize) +{ + const char *padend; + + padend = memchr_inv(padbuf, 0, padbufsize); + if (!padend) + return -EFSCORRUPTED; + rq->inputsize -= padend - padbuf; + rq->pageofs_in += padend - padbuf; + return 0; +} + static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx, u8 *out) { @@ -198,21 +216,19 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx, inputmargin = 0; support_0padding = false; - /* decompression inplace is only safe when zero_padding is enabled */ + /* LZ4 decompression inplace is only safe if zero_padding is enabled */ if (erofs_sb_has_zero_padding(EROFS_SB(rq->sb))) { support_0padding = true; - - while (!headpage[inputmargin & ~PAGE_MASK]) - if (!(++inputmargin & ~PAGE_MASK)) - break; - - if (inputmargin >= rq->inputsize) { + ret = z_erofs_fixup_insize(rq, headpage + rq->pageofs_in, + min_t(unsigned int, rq->inputsize, + EROFS_BLKSIZ - rq->pageofs_in)); + if (ret) { kunmap_atomic(headpage); - return -EIO; + return ret; } } - rq->inputsize -= inputmargin; + inputmargin = rq->pageofs_in; src = z_erofs_lz4_handle_overlap(ctx, headpage, &inputmargin, &maptype, support_0padding); if (IS_ERR(src)) diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c index 50045510a1f4..05a3063cf2bc 100644 --- a/fs/erofs/decompressor_lzma.c +++ b/fs/erofs/decompressor_lzma.c @@ -156,7 +156,7 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT; const unsigned int nrpages_in = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT; - unsigned int inputmargin, inlen, outlen, pageofs; + unsigned int inlen, outlen, pageofs; struct z_erofs_lzma *strm; u8 *kin; bool bounced = false; @@ -164,16 +164,13 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, /* 1. get the exact LZMA compressed size */ kin = kmap(*rq->in); - inputmargin = 0; - while (!kin[inputmargin & ~PAGE_MASK]) - if (!(++inputmargin & ~PAGE_MASK)) - break; - - if (inputmargin >= PAGE_SIZE) { + err = z_erofs_fixup_insize(rq, kin + rq->pageofs_in, + min_t(unsigned int, rq->inputsize, + EROFS_BLKSIZ - rq->pageofs_in)); + if (err) { kunmap(*rq->in); - return -EFSCORRUPTED; + return err; } - rq->inputsize -= inputmargin; /* 2. get an available lzma context */ again: @@ -193,9 +190,9 @@ int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq, xz_dec_microlzma_reset(strm->state, inlen, outlen, !rq->partial_decoding); pageofs = rq->pageofs_out; - strm->buf.in = kin + inputmargin; + strm->buf.in = kin + rq->pageofs_in; strm->buf.in_pos = 0; - strm->buf.in_size = min_t(u32, inlen, PAGE_SIZE - inputmargin); + strm->buf.in_size = min_t(u32, inlen, PAGE_SIZE - rq->pageofs_in); inlen -= strm->buf.in_size; strm->buf.out = NULL; strm->buf.out_pos = 0; -- 2.24.4