From patchwork Fri Mar 25 12:22:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 12791551 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 D0FF9C433F5 for ; Fri, 25 Mar 2022 12:23:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354835AbiCYMZL (ORCPT ); Fri, 25 Mar 2022 08:25:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359097AbiCYMYu (ORCPT ); Fri, 25 Mar 2022 08:24:50 -0400 Received: from out30-44.freemail.mail.aliyun.com (out30-44.freemail.mail.aliyun.com [115.124.30.44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAA06BE6; Fri, 25 Mar 2022 05:23:01 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R311e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0V89zY52_1648210976; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0V89zY52_1648210976) by smtp.aliyun-inc.com(127.0.0.1); Fri, 25 Mar 2022 20:22:57 +0800 From: Jeffle Xu To: dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org Cc: torvalds@linux-foundation.org, gregkh@linuxfoundation.org, willy@infradead.org, linux-fsdevel@vger.kernel.org, joseph.qi@linux.alibaba.com, bo.liu@linux.alibaba.com, tao.peng@linux.alibaba.com, gerry@linux.alibaba.com, eguan@linux.alibaba.com, linux-kernel@vger.kernel.org, luodaowen.backend@bytedance.com, tianzichen@kuaishou.com, fannaihao@baidu.com Subject: [PATCH v6 21/22] erofs: implement fscache-based data readahead Date: Fri, 25 Mar 2022 20:22:22 +0800 Message-Id: <20220325122223.102958-22-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220325122223.102958-1-jefflexu@linux.alibaba.com> References: <20220325122223.102958-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Implements fscache-based data readahead. Also registers an individual bdi for each erofs instance to enable readahead. Signed-off-by: Jeffle Xu --- fs/erofs/fscache.c | 114 +++++++++++++++++++++++++++++++++++++++++++++ fs/erofs/super.c | 4 ++ 2 files changed, 118 insertions(+) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index cbb39657615e..589d1e7c2b1b 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -191,12 +191,126 @@ static int erofs_fscache_readpage(struct file *file, struct page *page) return ret; } +static inline size_t erofs_fscache_calc_len(struct erofs_map_blocks *map, + size_t len, size_t done) +{ + /* + * 1) For CHUNK_BASED layout, the output m_la is rounded down to the + * nearest chunk boundary, and the output m_llen actually starts from + * the start of the containing chunk. + * 2) For other cases, the output m_la is equal to o_la. + */ + size_t length = map->m_llen - (map->o_la - map->m_la); + + return min_t(size_t, length, len - done); +} + +static inline void erofs_fscache_unlock_folios(struct readahead_control *rac, + size_t len) +{ + while (len) { + struct folio *folio = readahead_folio(rac); + + len -= folio_size(folio); + folio_mark_uptodate(folio); + folio_unlock(folio); + } +} + +static void erofs_fscache_readahead(struct readahead_control *rac) +{ + struct inode *inode = rac->mapping->host; + struct erofs_inode *vi = EROFS_I(inode); + struct super_block *sb = inode->i_sb; + size_t len, done = 0; + loff_t start; + int ret; + + if (erofs_inode_is_data_compressed(vi->datalayout)) { + erofs_info(sb, "compressed layout not supported yet"); + return; + } + + if (!readahead_count(rac)) + return; + + start = readahead_pos(rac); + len = readahead_length(rac); + + do { + struct erofs_map_blocks map; + + map.m_la = map.o_la = start + done; + + ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW); + if (ret) + return; + + /* Read-ahead Hole + * Two cases will hit this: + * 1) EOF. Imposibble in readahead routine; + * 2) hole. Only CHUNK_BASED layout supports hole. + */ + if (!(map.m_flags & EROFS_MAP_MAPPED)) { + struct iov_iter iter; + loff_t offset = start + done; + size_t count = erofs_fscache_calc_len(&map, len, done); + + iov_iter_xarray(&iter, READ, &rac->mapping->i_pages, offset, count); + iov_iter_zero(count, &iter); + + erofs_fscache_unlock_folios(rac, count); + ret = count; + continue; + } + + ret = erofs_fscache_get_map(&map, sb); + if (ret) + return; + + /* Read-ahead Inline */ + if (map.m_flags & EROFS_MAP_META) { + struct folio *folio = readahead_folio(rac); + + ret = erofs_fscache_readpage_inline(folio, &map); + if (!ret) { + folio_mark_uptodate(folio); + ret = folio_size(folio); + } + + folio_unlock(folio); + continue; + } + + /* Read-ahead No-inline */ + if (vi->datalayout == EROFS_INODE_FLAT_PLAIN || + vi->datalayout == EROFS_INODE_FLAT_INLINE || + vi->datalayout == EROFS_INODE_CHUNK_BASED) { + struct fscache_cookie *cookie = map.m_fscache->cookie; + loff_t offset = start + done; + size_t count = erofs_fscache_calc_len(&map, len, done); + loff_t pstart = map.m_pa + (map.o_la - map.m_la); + + ret = erofs_fscache_read_folios(cookie, rac->mapping, + offset, count, pstart); + if (!ret) { + erofs_fscache_unlock_folios(rac, count); + ret = count; + } + } else { + DBG_BUGON(1); + return; + } + } while (ret > 0 && ((done += ret) < len)); +} + static const struct address_space_operations erofs_fscache_blob_aops = { .readpage = erofs_fscache_readpage_blob, }; const struct address_space_operations erofs_fscache_access_aops = { .readpage = erofs_fscache_readpage, + .readahead = erofs_fscache_readahead, }; /* diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 9a6f35e0c22b..8ac400581784 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -619,6 +619,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) return PTR_ERR(bootstrap); sbi->bootstrap = bootstrap; + + err = super_setup_bdi(sb); + if (err) + return err; } err = erofs_read_superblock(sb);