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Message-Id: <20220627065050.274716-3-ebiggers@kernel.org> Date: Sun, 26 Jun 2022 23:50:50 -0700 From: Eric Biggers <ebiggers@...nel.org> To: linux-fscrypt@...r.kernel.org Cc: linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net, Matthew Wilcox <willy@...radead.org> Subject: [PATCH 2/2] fsverity: stop using PG_error to track error status From: Eric Biggers <ebiggers@...gle.com> 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 <ebiggers@...gle.com> --- fs/ext4/readpage.c | 8 ++---- fs/f2fs/compress.c | 61 +++++++++++++++++++++++----------------------- fs/f2fs/data.c | 49 ++++++++++++++++++++----------------- fs/verity/verify.c | 12 ++++----- 4 files changed, 64 insertions(+), 66 deletions(-) diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c index 5ce4706f68a7c..e604ea4e102b7 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 24824cd96f367..6d904a88d76b9 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1643,57 +1643,37 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic) f2fs_free_dic(dic); } -/* - * 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) +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); } -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); -} - /* * This is called when a compressed cluster has been decompressed * (or failed to be read and/or decompressed). */ void f2fs_decompress_end_io(struct decompress_io_ctx *dic, bool failed) { + int i; + if (!failed && dic->need_verity) { /* * Note that to avoid deadlocks, the verity work can't be done @@ -1703,9 +1683,28 @@ 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); + 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); } /* diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 47065f17d579c..19b2e0c1bf09c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -119,33 +119,39 @@ struct bio_post_read_ctx { block_t fs_blkaddr; }; -static void f2fs_finish_read_bio(struct bio *bio) +/* + * 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 fail_compressed) { 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); f2fs_put_page_dic(page); 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); } @@ -184,14 +190,16 @@ 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); + f2fs_finish_read_bio(bio, false); } /* @@ -211,7 +219,7 @@ static void f2fs_verify_and_finish_bio(struct bio *bio) INIT_WORK(&ctx->work, f2fs_verify_bio); fsverity_enqueue_verify_work(&ctx->work); } else { - f2fs_finish_read_bio(bio); + f2fs_finish_read_bio(bio, false); } } @@ -258,7 +266,7 @@ 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); + f2fs_finish_read_bio(bio, true); return; } @@ -282,7 +290,7 @@ static void f2fs_read_end_io(struct bio *bio) } if (bio->bi_status) { - f2fs_finish_read_bio(bio); + f2fs_finish_read_bio(bio, true); return; } @@ -1065,7 +1073,6 @@ 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); @@ -2109,7 +2116,6 @@ 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: @@ -2258,7 +2264,6 @@ 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; } @@ -2275,7 +2280,6 @@ 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]); } } @@ -2372,7 +2376,6 @@ 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 14e2fb49cff56..556dfbd4698de 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); -- 2.36.1
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