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 9A8EBC433EF for ; Mon, 25 Apr 2022 12:23:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241839AbiDYM0O (ORCPT ); Mon, 25 Apr 2022 08:26:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241748AbiDYMZS (ORCPT ); Mon, 25 Apr 2022 08:25:18 -0400 Received: from out30-54.freemail.mail.aliyun.com (out30-54.freemail.mail.aliyun.com [115.124.30.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7FDF62A26; Mon, 25 Apr 2022 05:22:11 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R511e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0VBE4bIb_1650889326; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VBE4bIb_1650889326) by smtp.aliyun-inc.com(127.0.0.1); Mon, 25 Apr 2022 20:22:07 +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, zhangjiachen.jaycee@bytedance.com, zhujia.zj@bytedance.com Subject: [PATCH v10 14/21] erofs: add erofs_fscache_read_folios() helper Date: Mon, 25 Apr 2022 20:21:36 +0800 Message-Id: <20220425122143.56815-15-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220425122143.56815-1-jefflexu@linux.alibaba.com> References: <20220425122143.56815-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add erofs_fscache_read_folios() helper reading from fscache. It supports on-demand read semantics. That is, it will make the backend prepare for the data when cache miss. Once data ready, it will read from the cache. This helper can then be used to implement .readpage()/.readahead() of on-demand read semantics. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang --- fs/erofs/fscache.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 26f038d9c4e1..ac02af8cce3e 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -5,6 +5,60 @@ #include #include "internal.h" +/* + * Read data from fscache and fill the read data into page cache described by + * @start/len, which shall be both aligned with PAGE_SIZE. @pstart describes + * the start physical address in the cache file. + */ +static int erofs_fscache_read_folios(struct fscache_cookie *cookie, + struct address_space *mapping, + loff_t start, size_t len, + loff_t pstart) +{ + enum netfs_io_source source; + struct netfs_io_request rreq = {}; + struct netfs_io_subrequest subreq = { .rreq = &rreq, }; + struct netfs_cache_resources *cres = &rreq.cache_resources; + struct super_block *sb = mapping->host->i_sb; + struct iov_iter iter; + size_t done = 0; + int ret; + + ret = fscache_begin_read_operation(cres, cookie); + if (ret) + return ret; + + while (done < len) { + subreq.start = pstart + done; + subreq.len = len - done; + subreq.flags = 1 << NETFS_SREQ_ONDEMAND; + + source = cres->ops->prepare_read(&subreq, LLONG_MAX); + if (WARN_ON(subreq.len == 0)) + source = NETFS_INVALID_READ; + if (source != NETFS_READ_FROM_CACHE) { + erofs_err(sb, "failed to fscache prepare_read (source %d)", + source); + ret = -EIO; + goto out; + } + + iov_iter_xarray(&iter, READ, &mapping->i_pages, + start + done, subreq.len); + ret = fscache_read(cres, subreq.start, &iter, + NETFS_READ_HOLE_FAIL, NULL, NULL); + if (ret) { + erofs_err(sb, "failed to fscache_read (ret %d)", ret); + goto out; + } + + done += subreq.len; + } +out: + fscache_end_operation(cres); + return ret; +} + static const struct address_space_operations erofs_fscache_meta_aops = { }; -- 2.27.0 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 14D8DC4321E for ; Mon, 25 Apr 2022 12:22:28 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Kn4024wN0z3brS for ; Mon, 25 Apr 2022 22:22:26 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.133; helo=out30-133.freemail.mail.aliyun.com; envelope-from=jefflexu@linux.alibaba.com; receiver=) Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Kn3zq5Nn2z3bfC for ; Mon, 25 Apr 2022 22:22:14 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R511e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04400; MF=jefflexu@linux.alibaba.com; NM=1; PH=DS; RN=20; SR=0; TI=SMTPD_---0VBE4bIb_1650889326; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VBE4bIb_1650889326) by smtp.aliyun-inc.com(127.0.0.1); Mon, 25 Apr 2022 20:22:07 +0800 From: Jeffle Xu To: dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org Subject: [PATCH v10 14/21] erofs: add erofs_fscache_read_folios() helper Date: Mon, 25 Apr 2022 20:21:36 +0800 Message-Id: <20220425122143.56815-15-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220425122143.56815-1-jefflexu@linux.alibaba.com> References: <20220425122143.56815-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gregkh@linuxfoundation.org, fannaihao@baidu.com, willy@infradead.org, linux-kernel@vger.kernel.org, tianzichen@kuaishou.com, joseph.qi@linux.alibaba.com, zhangjiachen.jaycee@bytedance.com, linux-fsdevel@vger.kernel.org, luodaowen.backend@bytedance.com, gerry@linux.alibaba.com, torvalds@linux-foundation.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" Add erofs_fscache_read_folios() helper reading from fscache. It supports on-demand read semantics. That is, it will make the backend prepare for the data when cache miss. Once data ready, it will read from the cache. This helper can then be used to implement .readpage()/.readahead() of on-demand read semantics. Signed-off-by: Jeffle Xu Reviewed-by: Gao Xiang --- fs/erofs/fscache.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 26f038d9c4e1..ac02af8cce3e 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -5,6 +5,60 @@ #include #include "internal.h" +/* + * Read data from fscache and fill the read data into page cache described by + * @start/len, which shall be both aligned with PAGE_SIZE. @pstart describes + * the start physical address in the cache file. + */ +static int erofs_fscache_read_folios(struct fscache_cookie *cookie, + struct address_space *mapping, + loff_t start, size_t len, + loff_t pstart) +{ + enum netfs_io_source source; + struct netfs_io_request rreq = {}; + struct netfs_io_subrequest subreq = { .rreq = &rreq, }; + struct netfs_cache_resources *cres = &rreq.cache_resources; + struct super_block *sb = mapping->host->i_sb; + struct iov_iter iter; + size_t done = 0; + int ret; + + ret = fscache_begin_read_operation(cres, cookie); + if (ret) + return ret; + + while (done < len) { + subreq.start = pstart + done; + subreq.len = len - done; + subreq.flags = 1 << NETFS_SREQ_ONDEMAND; + + source = cres->ops->prepare_read(&subreq, LLONG_MAX); + if (WARN_ON(subreq.len == 0)) + source = NETFS_INVALID_READ; + if (source != NETFS_READ_FROM_CACHE) { + erofs_err(sb, "failed to fscache prepare_read (source %d)", + source); + ret = -EIO; + goto out; + } + + iov_iter_xarray(&iter, READ, &mapping->i_pages, + start + done, subreq.len); + ret = fscache_read(cres, subreq.start, &iter, + NETFS_READ_HOLE_FAIL, NULL, NULL); + if (ret) { + erofs_err(sb, "failed to fscache_read (ret %d)", ret); + goto out; + } + + done += subreq.len; + } +out: + fscache_end_operation(cres); + return ret; +} + static const struct address_space_operations erofs_fscache_meta_aops = { }; -- 2.27.0