From patchwork Wed Dec 1 05:17:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 12649067 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 4C0E1C433FE for ; Wed, 1 Dec 2021 05:18:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346681AbhLAFVs (ORCPT ); Wed, 1 Dec 2021 00:21:48 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:55528 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346674AbhLAFVr (ORCPT ); Wed, 1 Dec 2021 00:21:47 -0500 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 DBB14212BA; Wed, 1 Dec 2021 05:18:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1638335905; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oIq5Wlg49F7ossiz/x4hZwHfw8NiGLRtkthYXsKRAUI=; b=RUutWjhmw4011/0N6rXEIxNQe8j28SAHrL7aUcI1EBbB+2YtZiz11gGi9fILZjdvW/a5h5 meEudKitdMeGsspJN+dCBtZDzRz/eWKG//uxEsxBIONm2GjbBlud3A45WzZJhnv3DjIqfe 7j1xY/+MZzH64c1tYX6bg96XZMuMhOA= 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 DEB8613425; Wed, 1 Dec 2021 05:18:24 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 0CDfKqAFp2EGbwAAMHmgww (envelope-from ); Wed, 01 Dec 2021 05:18:24 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: linux-block@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH 08/17] btrfs: make data buffered read path to handle split bio properly Date: Wed, 1 Dec 2021 13:17:47 +0800 Message-Id: <20211201051756.53742-9-wqu@suse.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211201051756.53742-1-wqu@suse.com> References: <20211201051756.53742-1-wqu@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org This involves the following modifications: - Use bio_for_each_segment() instead of bio_for_each_segment_all() bio_for_each_segment_all() will iterate all bvecs, even if they are not referred by current bi_iter. *_all() variant can only be used if the bio is never split. Change it to __bio_for_each_segment() call so we won't have endio called on the same range by both split and parent bios, and it can handle both split and unsplit bios. - Make check_data_csum() to take bbio->offset_to_original into consideration Since btrfs bio can be split now, split/original bio can all start with some offset to the original logical bytenr. Take btrfs_bio::offset_to_original into consideration to get correct checksum offset. - Remove the BIO_CLONED ASSERT() in submit_read_repair() Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 34 +++++++++++++++++++--------------- fs/btrfs/inode.c | 23 +++++++++++++++++++++-- fs/btrfs/volumes.h | 3 ++- 3 files changed, 42 insertions(+), 18 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 083700621b9f..e0e072c0e5c8 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2735,10 +2735,9 @@ static blk_status_t submit_read_repair(struct inode *inode, ASSERT(error_bitmap); /* - * We only get called on buffered IO, thus page must be mapped and bio - * must not be cloned. - */ - ASSERT(page->mapping && !bio_flagged(failed_bio, BIO_CLONED)); + * We only get called on buffered IO, thus page must be mapped + */ + ASSERT(page->mapping); /* Iterate through all the sectors in the range */ for (i = 0; i < nr_bits; i++) { @@ -2992,7 +2991,8 @@ static struct extent_buffer *find_extent_buffer_readpage( */ static void end_bio_extent_readpage(struct bio *bio) { - struct bio_vec *bvec; + struct bio_vec bvec; + struct bvec_iter iter; struct btrfs_bio *bbio = btrfs_bio(bio); struct extent_io_tree *tree, *failure_tree; struct processed_extent processed = { 0 }; @@ -3003,11 +3003,15 @@ static void end_bio_extent_readpage(struct bio *bio) u32 bio_offset = 0; int mirror; int ret; - struct bvec_iter_all iter_all; - bio_for_each_segment_all(bvec, bio, iter_all) { + /* + * We should have saved the orignal bi_iter, and then start iterating + * using that saved iter, as at endio time bi_iter is not reliable. + */ + ASSERT(bbio->iter.bi_size); + __bio_for_each_segment(bvec, bio, iter, bbio->iter) { bool uptodate = !bio->bi_status; - struct page *page = bvec->bv_page; + struct page *page = bvec.bv_page; struct inode *inode = page->mapping->host; struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); const u32 sectorsize = fs_info->sectorsize; @@ -3030,19 +3034,19 @@ static void end_bio_extent_readpage(struct bio *bio) * for unaligned offsets, and an error if they don't add up to * a full sector. */ - if (!IS_ALIGNED(bvec->bv_offset, sectorsize)) + if (!IS_ALIGNED(bvec.bv_offset, sectorsize)) btrfs_err(fs_info, "partial page read in btrfs with offset %u and length %u", - bvec->bv_offset, bvec->bv_len); - else if (!IS_ALIGNED(bvec->bv_offset + bvec->bv_len, + bvec.bv_offset, bvec.bv_len); + else if (!IS_ALIGNED(bvec.bv_offset + bvec.bv_len, sectorsize)) btrfs_info(fs_info, "incomplete page read with offset %u and length %u", - bvec->bv_offset, bvec->bv_len); + bvec.bv_offset, bvec.bv_len); - start = page_offset(page) + bvec->bv_offset; - end = start + bvec->bv_len - 1; - len = bvec->bv_len; + start = page_offset(page) + bvec.bv_offset; + end = start + bvec.bv_len - 1; + len = bvec.bv_len; mirror = bbio->mirror_num; if (likely(uptodate)) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1aa060de917c..186304c69900 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3225,6 +3225,24 @@ void btrfs_writepage_endio_finish_ordered(struct btrfs_inode *inode, finish_ordered_fn, uptodate); } +static u8 *bbio_get_real_csum(struct btrfs_fs_info *fs_info, + struct btrfs_bio *bbio) +{ + u8 *ret; + + /* Split bbio needs to grab csum from its parent */ + if (bbio->is_split_bio) + ret = btrfs_bio(bbio->parent)->csum; + else + ret = bbio->csum; + + if (ret == NULL) + return ret; + + return ret + (bbio->offset_to_original >> fs_info->sectorsize_bits) * + fs_info->csum_size; +} + /* * check_data_csum - verify checksum of one sector of uncompressed data * @inode: inode @@ -3252,7 +3270,8 @@ static int check_data_csum(struct inode *inode, struct btrfs_bio *bbio, ASSERT(pgoff + len <= PAGE_SIZE); offset_sectors = bio_offset >> fs_info->sectorsize_bits; - csum_expected = ((u8 *)bbio->csum) + offset_sectors * csum_size; + csum_expected = bbio_get_real_csum(fs_info, bbio) + + offset_sectors * csum_size; kaddr = kmap_atomic(page); shash->tfm = fs_info->csum_shash; @@ -3310,7 +3329,7 @@ unsigned int btrfs_verify_data_csum(struct btrfs_bio *bbio, * Normally this should be covered by above check for compressed read * or the next check for NODATASUM. Just do a quicker exit here. */ - if (bbio->csum == NULL) + if (bbio_get_real_csum(fs_info, bbio) == NULL) return 0; if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index bd789544268c..8825a17d0620 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -400,7 +400,8 @@ static inline struct btrfs_bio *btrfs_bio(struct bio *bio) static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio) { - if (bbio->csum != bbio->csum_inline) { + /* Only free the csum if we're not a split bio */ + if (!bbio->is_split_bio && bbio->csum != bbio->csum_inline) { kfree(bbio->csum); bbio->csum = NULL; }