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 66ED3C433F5 for ; Wed, 6 Apr 2022 12:13:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229972AbiDFMPd (ORCPT ); Wed, 6 Apr 2022 08:15:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231279AbiDFMOE (ORCPT ); Wed, 6 Apr 2022 08:14:04 -0400 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFC111B60E1; Wed, 6 Apr 2022 00:56:26 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R501e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=18;SR=0;TI=SMTPD_---0V9L0qp1_1649231779; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0V9L0qp1_1649231779) by smtp.aliyun-inc.com(127.0.0.1); Wed, 06 Apr 2022 15:56:20 +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 v8 04/20] cachefiles: notify user daemon when withdrawing cookie Date: Wed, 6 Apr 2022 15:55:56 +0800 Message-Id: <20220406075612.60298-5-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220406075612.60298-1-jefflexu@linux.alibaba.com> References: <20220406075612.60298-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Notify user daemon that cookie is going to be withdrawn, providing a hint that the associated anon_fd can be closed. The anon_fd attached in the CLOSE request shall be same with that in the previous OPEN request. Be noted that this is only a hint. User daemon can close the anon_fd when receiving the CLOSE request, then it will receive another anon_fd if the cookie gets looked up. Or it can also ignore the CLOSE request, and keep writing data into the anon_fd. However the next time cookie gets looked up, the user daemon will still receive another anon_fd. Signed-off-by: Jeffle Xu --- fs/cachefiles/interface.c | 2 ++ fs/cachefiles/internal.h | 5 +++++ fs/cachefiles/ondemand.c | 36 +++++++++++++++++++++++++++++++++ include/uapi/linux/cachefiles.h | 5 +++++ 4 files changed, 48 insertions(+) diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index ae93cee9d25d..a69073a1d3f0 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -362,6 +362,8 @@ static void cachefiles_withdraw_cookie(struct fscache_cookie *cookie) spin_unlock(&cache->object_list_lock); } + cachefiles_ondemand_clean_object(object); + if (object->file) { cachefiles_begin_secure(cache, &saved_cred); cachefiles_clean_up_object(object, cache); diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 7d5c7d391fdb..8a397d4da560 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -279,6 +279,7 @@ extern int cachefiles_ondemand_copen(struct cachefiles_cache *cache, char *args); extern int cachefiles_ondemand_init_object(struct cachefiles_object *object); +extern void cachefiles_ondemand_clean_object(struct cachefiles_object *object); #else static inline ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, @@ -291,6 +292,10 @@ static inline int cachefiles_ondemand_init_object(struct cachefiles_object *obje { return 0; } + +static inline void cachefiles_ondemand_clean_object(struct cachefiles_object *object) +{ +} #endif /* diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 75180d02af91..defd65124052 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -213,6 +213,12 @@ ssize_t cachefiles_ondemand_daemon_read(struct cachefiles_cache *cache, goto err_put_fd; } + /* CLOSE request has no reply */ + if (msg->opcode == CACHEFILES_OP_CLOSE) { + xa_erase(&cache->reqs, id); + complete(&req->done); + } + return n; err_put_fd: @@ -334,6 +340,28 @@ static int init_open_req(struct cachefiles_req *req, void *private) return 0; } +static int init_close_req(struct cachefiles_req *req, void *private) +{ + struct cachefiles_object *object = req->object; + struct cachefiles_close *load = (void *)req->msg.data; + int fd = object->fd; + + if (fd == -1) { + pr_info_once("CLOSE: anonymous fd closed prematurely.\n"); + return -EIO; + } + + /* + * It's possible if the cookie looking up phase failed before READ + * request has ever been sent. + */ + if (fd == 0) + return -ENOENT; + + load->fd = fd; + return 0; +} + int cachefiles_ondemand_init_object(struct cachefiles_object *object) { struct fscache_cookie *cookie = object->cookie; @@ -358,3 +386,11 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object) CACHEFILES_OP_OPEN, data_len, init_open_req, NULL); } + +void cachefiles_ondemand_clean_object(struct cachefiles_object *object) +{ + cachefiles_ondemand_send_req(object, + CACHEFILES_OP_CLOSE, + sizeof(struct cachefiles_close), + init_close_req, NULL); +} diff --git a/include/uapi/linux/cachefiles.h b/include/uapi/linux/cachefiles.h index 41492f2653c9..73397e142ab3 100644 --- a/include/uapi/linux/cachefiles.h +++ b/include/uapi/linux/cachefiles.h @@ -12,6 +12,7 @@ enum cachefiles_opcode { CACHEFILES_OP_OPEN, + CACHEFILES_OP_CLOSE, }; /* @@ -46,4 +47,8 @@ struct cachefiles_open { __u8 data[]; }; +struct cachefiles_close { + __u32 fd; +}; + #endif -- 2.27.0