From nobody Tue Nov 5 11:30:11 2024 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 33815C636D4 for ; Fri, 3 Feb 2023 03:02:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232369AbjBCDCW (ORCPT ); Thu, 2 Feb 2023 22:02:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232253AbjBCDBw (ORCPT ); Thu, 2 Feb 2023 22:01:52 -0500 Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CEE8819F32; Thu, 2 Feb 2023 19:01:51 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R441e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VamyBZQ_1675393309; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0VamyBZQ_1675393309) by smtp.aliyun-inc.com; Fri, 03 Feb 2023 11:01:49 +0800 From: Jingbo Xu To: xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org Cc: huyue2@coolpad.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 6/9] erofs: implement .read_iter for page cache sharing Date: Fri, 3 Feb 2023 11:01:40 +0800 Message-Id: <20230203030143.73105-7-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20230203030143.73105-1-jefflexu@linux.alibaba.com> References: <20230203030143.73105-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When page cache sharing enabled, page caches are managed in the address space of blobs rather than erofs inodes. All erofs inodes sharing one chunk will refer to and share the page cache in the blob's address space. Signed-off-by: Jingbo Xu --- fs/erofs/fscache.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c index 4fe7f23b022e..bdeb048b78b5 100644 --- a/fs/erofs/fscache.c +++ b/fs/erofs/fscache.c @@ -410,8 +410,31 @@ static int erofs_fscache_share_file_open(struct inode = *inode, struct file *filp) return 0; } =20 +static ssize_t erofs_fscache_share_file_read_iter(struct kiocb *iocb, + struct iov_iter *iter) +{ + struct file *realfile =3D iocb->ki_filp->private_data; + struct erofs_fscache_finfo *finfo =3D realfile->private_data; + ssize_t res; + + if (!iov_iter_count(iter)) + return 0; + + if (!is_sync_kiocb(iocb)) + return filemap_read(iocb, iter, 0); + + iov_iter_truncate(iter, file_inode(iocb->ki_filp)->i_size - iocb->ki_pos); + iocb->ki_filp =3D realfile; + iocb->ki_pos +=3D finfo->pa; + + res =3D filemap_read(iocb, iter, 0); + iocb->ki_pos -=3D finfo->pa; + return res; +} + const struct file_operations erofs_fscache_share_file_fops =3D { .llseek =3D generic_file_llseek, + .read_iter =3D erofs_fscache_share_file_read_iter, .open =3D erofs_fscache_share_file_open, .release =3D erofs_fscache_share_file_release, }; --=20 2.19.1.6.gb485710b