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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 262DFECAAA1 for ; Tue, 6 Sep 2022 16:16:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232733AbiIFQQ1 (ORCPT ); Tue, 6 Sep 2022 12:16:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232538AbiIFQQK (ORCPT ); Tue, 6 Sep 2022 12:16:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67D26C22; Tue, 6 Sep 2022 08:43:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 03F9B6147A; Tue, 6 Sep 2022 15:43:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4025DC433D6; Tue, 6 Sep 2022 15:43:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662479032; bh=QSmG++p/09QybC7ELM/h7cbufKIxRZCTacsyXuZKpRg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=CaPHHFmzcnb25wT2OQrJepf2WrntVFZslP12RYLCAvNg+RSrL9nmHtbzEMqTnqKAc G5OZ0B/YUQUFv++BY9qYzR2KuDnf343TfKWKiBwzLLAHUGzAR4AfW9B9pHfeNHJYIK qiFQWTnj8g/3XQEx3DiUSpTthmcP6PeXl5k6GlAqA7xtahw2IMB1vJoPpzzn6g68q/ wnHi60DwBS4zBN9WxH51xahY/ZOYYr7auX10ytVpNy0Nitrkcs91wChHxu4FlXopAE GyvxaJSvyeEIU+GGT2EX5ul2KOQHKUIYRzsPrvOkHC+vWp1b80CXay7LQv99VUcCZV Pbl3ilhABe+mQ== Message-ID: <47a86f09-3e9b-f841-4191-d750feda6642@kernel.org> Date: Tue, 6 Sep 2022 23:43:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: [f2fs-dev] [PATCH v2 2/2] fsverity: stop using PG_error to track error status Content-Language: en-US To: Eric Biggers , linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net References: <20220815235052.86545-1-ebiggers@kernel.org> <20220815235052.86545-3-ebiggers@kernel.org> From: Chao Yu In-Reply-To: <20220815235052.86545-3-ebiggers@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On 2022/8/16 7:50, Eric Biggers wrote: > From: Eric Biggers > > As a step towards freeing the PG_error flag for other uses, change ext4 > and f2fs to stop using PG_error to track verity errors. Instead, if a > verity error occurs, just mark the whole bio as failed. The coarser > granularity isn't really a problem since it isn't any worse than what > the block layer provides, and errors from a multi-page readahead aren't > reported to applications unless a single-page read fails too. > > f2fs supports compression, which makes the f2fs changes a bit more > complicated than desired, but the basic premise still works. > > Signed-off-by: Eric Biggers > --- > fs/ext4/readpage.c | 8 ++---- > fs/f2fs/compress.c | 64 ++++++++++++++++++++++------------------------ > fs/f2fs/data.c | 52 ++++++++++++++++++++----------------- > fs/verity/verify.c | 12 ++++----- > 4 files changed, 68 insertions(+), 68 deletions(-) > > diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c > index 5ce4706f68a7c6..e604ea4e102b71 100644 > --- a/fs/ext4/readpage.c > +++ b/fs/ext4/readpage.c > @@ -75,14 +75,10 @@ static void __read_end_io(struct bio *bio) > bio_for_each_segment_all(bv, bio, iter_all) { > page = bv->bv_page; > > - /* PG_error was set if any post_read step failed */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > unlock_page(page); > } > if (bio->bi_private) > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > index 70e97075e535e5..f54fb3bb74197a 100644 > --- a/fs/f2fs/compress.c > +++ b/fs/f2fs/compress.c > @@ -1715,50 +1715,27 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task) > } > } > > -/* > - * Update and unlock the cluster's pagecache pages, and release the reference to > - * the decompress_io_ctx that was being held for I/O completion. > - */ > -static void __f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > - bool in_task) > +static void f2fs_verify_cluster(struct work_struct *work) > { > + struct decompress_io_ctx *dic = > + container_of(work, struct decompress_io_ctx, verity_work); > int i; > > + /* Verify, update, and unlock the decompressed pages. */ > for (i = 0; i < dic->cluster_size; i++) { > struct page *rpage = dic->rpages[i]; > > if (!rpage) > continue; > > - /* PG_error was set if verity failed. */ > - if (failed || PageError(rpage)) { > - ClearPageUptodate(rpage); > - /* will re-read again later */ > - ClearPageError(rpage); > - } else { > + if (fsverity_verify_page(rpage)) > SetPageUptodate(rpage); > - } > + else > + ClearPageUptodate(rpage); > unlock_page(rpage); > } > > - f2fs_put_dic(dic, in_task); > -} > - > -static void f2fs_verify_cluster(struct work_struct *work) > -{ > - struct decompress_io_ctx *dic = > - container_of(work, struct decompress_io_ctx, verity_work); > - int i; > - > - /* Verify the cluster's decompressed pages with fs-verity. */ > - for (i = 0; i < dic->cluster_size; i++) { > - struct page *rpage = dic->rpages[i]; > - > - if (rpage && !fsverity_verify_page(rpage)) > - SetPageError(rpage); > - } > - > - __f2fs_decompress_end_io(dic, false, true); > + f2fs_put_dic(dic, true); > } > > /* > @@ -1768,6 +1745,8 @@ static void f2fs_verify_cluster(struct work_struct *work) > void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > bool in_task) > { > + int i; > + > if (!failed && dic->need_verity) { > /* > * Note that to avoid deadlocks, the verity work can't be done > @@ -1777,9 +1756,28 @@ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed, > */ > INIT_WORK(&dic->verity_work, f2fs_verify_cluster); > fsverity_enqueue_verify_work(&dic->verity_work); > - } else { > - __f2fs_decompress_end_io(dic, failed, in_task); Will it be possible to clean up __f2fs_decompress_end_io() and f2fs_verify_cluster(), they looks almost similar... > + return; > + } > + > + /* Update and unlock the cluster's pagecache pages. */ > + for (i = 0; i < dic->cluster_size; i++) { > + struct page *rpage = dic->rpages[i]; > + > + if (!rpage) > + continue; > + > + if (failed) > + ClearPageUptodate(rpage); > + else > + SetPageUptodate(rpage); > + unlock_page(rpage); > } > + > + /* > + * Release the reference to the decompress_io_ctx that was being held > + * for I/O completion. > + */ > + f2fs_put_dic(dic, in_task); > } > > /* > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 93cc2ec51c2aeb..34af260975a2e6 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -119,34 +119,41 @@ struct bio_post_read_ctx { > block_t fs_blkaddr; > }; > > -static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > +/* > + * Update and unlock a bio's pages, and free the bio. > + * > + * This marks pages up-to-date only if there was no error in the bio (I/O error, > + * decryption error, or verity error), as indicated by bio->bi_status. > + * > + * "Compressed pages" (pagecache pages backed by a compressed cluster on-disk) > + * aren't marked up-to-date here, as decompression is done on a per-compression- > + * cluster basis rather than a per-bio basis. Instead, we only must do two > + * things for each compressed page here: call f2fs_end_read_compressed_page() > + * with failed=true if an error occurred before it would have normally gotten > + * called (i.e., I/O error or decryption error, but *not* verity error), and > + * release the bio's reference to the decompress_io_ctx of the page's cluster. > + */ > +static void f2fs_finish_read_bio(struct bio *bio, bool in_task, > + bool fail_compressed) Not sure, fail_decompress or fail_decompression may looks more readable? Thanks, > { > struct bio_vec *bv; > struct bvec_iter_all iter_all; > > - /* > - * Update and unlock the bio's pagecache pages, and put the > - * decompression context for any compressed pages. > - */ > bio_for_each_segment_all(bv, bio, iter_all) { > struct page *page = bv->bv_page; > > if (f2fs_is_compressed_page(page)) { > - if (bio->bi_status) > + if (fail_compressed) > f2fs_end_read_compressed_page(page, true, 0, > in_task); > f2fs_put_page_dic(page, in_task); > continue; > } > > - /* PG_error was set if verity failed. */ > - if (bio->bi_status || PageError(page)) { > + if (bio->bi_status) > ClearPageUptodate(page); > - /* will re-read again later */ > - ClearPageError(page); > - } else { > + else > SetPageUptodate(page); > - } > dec_page_count(F2FS_P_SB(page), __read_io_type(page)); > unlock_page(page); > } > @@ -185,14 +192,17 @@ static void f2fs_verify_bio(struct work_struct *work) > struct page *page = bv->bv_page; > > if (!f2fs_is_compressed_page(page) && > - !fsverity_verify_page(page)) > - SetPageError(page); > + !fsverity_verify_page(page)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > } else { > fsverity_verify_bio(bio); > } > > - f2fs_finish_read_bio(bio, true); > + f2fs_finish_read_bio(bio, true /* in_task */, > + false /* fail_compressed */); > } > > /* > @@ -212,7 +222,7 @@ static void f2fs_verify_and_finish_bio(struct bio *bio, bool in_task) > INIT_WORK(&ctx->work, f2fs_verify_bio); > fsverity_enqueue_verify_work(&ctx->work); > } else { > - f2fs_finish_read_bio(bio, in_task); > + f2fs_finish_read_bio(bio, in_task, false /* fail_compressed */); > } > } > > @@ -261,7 +271,8 @@ static void f2fs_post_read_work(struct work_struct *work) > struct bio *bio = ctx->bio; > > if ((ctx->enabled_steps & STEP_DECRYPT) && !fscrypt_decrypt_bio(bio)) { > - f2fs_finish_read_bio(bio, true); > + f2fs_finish_read_bio(bio, true /* in_task */, > + true /* fail_compressed */); > return; > } > > @@ -286,7 +297,7 @@ static void f2fs_read_end_io(struct bio *bio) > } > > if (bio->bi_status) { > - f2fs_finish_read_bio(bio, intask); > + f2fs_finish_read_bio(bio, intask, true /* fail_compressed */); > return; > } > > @@ -1083,7 +1094,6 @@ static int f2fs_submit_page_read(struct inode *inode, struct page *page, > bio_put(bio); > return -EFAULT; > } > - ClearPageError(page); > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE); > __submit_bio(sbi, bio, DATA); > @@ -2125,7 +2135,6 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page, > > inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); > f2fs_update_iostat(F2FS_I_SB(inode), FS_DATA_READ_IO, F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = block_nr; > goto out; > out: > @@ -2274,7 +2283,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > inc_page_count(sbi, F2FS_RD_DATA); > f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE); > f2fs_update_iostat(sbi, FS_CDATA_READ_IO, F2FS_BLKSIZE); > - ClearPageError(page); > *last_block_in_bio = blkaddr; > } > > @@ -2291,7 +2299,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, > for (i = 0; i < cc->cluster_size; i++) { > if (cc->rpages[i]) { > ClearPageUptodate(cc->rpages[i]); > - ClearPageError(cc->rpages[i]); > unlock_page(cc->rpages[i]); > } > } > @@ -2388,7 +2395,6 @@ static int f2fs_mpage_readpages(struct inode *inode, > #ifdef CONFIG_F2FS_FS_COMPRESSION > set_error_page: > #endif > - SetPageError(page); > zero_user_segment(page, 0, PAGE_SIZE); > unlock_page(page); > } > diff --git a/fs/verity/verify.c b/fs/verity/verify.c > index 14e2fb49cff561..556dfbd4698dea 100644 > --- a/fs/verity/verify.c > +++ b/fs/verity/verify.c > @@ -210,9 +210,8 @@ EXPORT_SYMBOL_GPL(fsverity_verify_page); > * @bio: the bio to verify > * > * Verify a set of pages that have just been read from a verity file. The pages > - * must be pagecache pages that are still locked and not yet uptodate. Pages > - * that fail verification are set to the Error state. Verification is skipped > - * for pages already in the Error state, e.g. due to fscrypt decryption failure. > + * must be pagecache pages that are still locked and not yet uptodate. If a > + * page fails verification, then bio->bi_status is set to an error status. > * > * This is a helper function for use by the ->readahead() method of filesystems > * that issue bios to read data directly into the page cache. Filesystems that > @@ -254,9 +253,10 @@ void fsverity_verify_bio(struct bio *bio) > unsigned long level0_ra_pages = > min(max_ra_pages, params->level0_blocks - level0_index); > > - if (!PageError(page) && > - !verify_page(inode, vi, req, page, level0_ra_pages)) > - SetPageError(page); > + if (!verify_page(inode, vi, req, page, level0_ra_pages)) { > + bio->bi_status = BLK_STS_IOERR; > + break; > + } > } > > fsverity_free_hash_request(params->hash_alg, req);