From patchwork Thu Sep 16 18:22:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 12499917 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17AB6C433F5 for ; Thu, 16 Sep 2021 18:23:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00E4B611C4 for ; Thu, 16 Sep 2021 18:23:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240324AbhIPSY4 (ORCPT ); Thu, 16 Sep 2021 14:24:56 -0400 Received: from mx0b-00069f02.pphosted.com ([205.220.177.32]:55934 "EHLO mx0b-00069f02.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349529AbhIPSXr (ORCPT ); Thu, 16 Sep 2021 14:23:47 -0400 Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 18GIDHwN026756; Thu, 16 Sep 2021 18:22:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2021-07-09; bh=gUUL68PzT1tsHqbh2Eu96RtT1DlD2y4rsvPdvYDuQH0=; b=1FOEvpU1TFkPYNy+Mau8Z/a12f+P4pVi+GJ0qebkTCNZ8NeskOTWVMwLWUzr4CGgGAZI tCeEpAY6IE0Br/bzSH2T1q5qURd2RWcXV2EcP7pTOOVTyFENOcjfH3SAl6bf52vaKlPe 5RkAP1MC0q4j7mLB0Vh2+Z/D1/RGkWAi0t26mjN4qrWVfH900Wl+YQuPlGAlaH46GtU4 eBIRxoh3lOb4ts1SuEv9H2hqvphRr11IKUz5DNoXmcxGOfa0PRTON7x2yX1xixYdRbF+ G63dNgGo7gleRwyM/ZbJYNyulOKWvztVbCsuYHib3SKlaG5+wdTifG2FV6v7jCC8+gWl NQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=gUUL68PzT1tsHqbh2Eu96RtT1DlD2y4rsvPdvYDuQH0=; b=XVHeflLqxovsS4YdnOA5MTR+zFZnPi3/4TrPXFlsQaKQ3LW4FrZr8JDLGDs79qnFqmlK INCQpsx6UVUmWDlitVcfu65WSzlVlVtGnLyaMY6s0eHEM3NpO/4H/SOjCJ0nwyHbwmwA 78bEONJ1J7b9xGu5QSd3Z4u6daKxuUi9DdnUx0+MEgD7mmgxrVo9ejGn2n3d7d/n2vHt TlP9UsFJXr63SbeuDn+n/ZZZkARTdXrwZeJlN4TIvXKQTVEruWCWOTXT/+hEvl87eV9y 6c6l/M5WKEYZWRmWstfzZi/2XvHNPmLzxJ4qJ5ZYh37IsxZBLd+YLeVA/LGapro+apwa Gw== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by mx0b-00069f02.pphosted.com with ESMTP id 3b3jy7mqpe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Sep 2021 18:22:26 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 18GIAWhk149842; Thu, 16 Sep 2021 18:22:19 GMT Received: from pps.reinject (localhost [127.0.0.1]) by aserp3020.oracle.com with ESMTP id 3b0m99rpf9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Sep 2021 18:22:19 +0000 Received: from aserp3020.oracle.com (aserp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 18GIK46c182960; Thu, 16 Sep 2021 18:22:19 GMT Received: from aserp3030.oracle.com (ksplice-shell2.us.oracle.com [10.152.118.36]) by aserp3020.oracle.com with ESMTP id 3b0m99rpeg-2; Thu, 16 Sep 2021 18:22:19 +0000 From: Dai Ngo To: bfields@fieldses.org Cc: chuck.lever@oracle.com, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v3 1/3] fs/lock: add new callback, lm_expire_lock, to lock_manager_operations Date: Thu, 16 Sep 2021 14:22:10 -0400 Message-Id: <20210916182212.81608-2-dai.ngo@oracle.com> X-Mailer: git-send-email 2.20.1.1226.g1595ea5.dirty In-Reply-To: <20210916182212.81608-1-dai.ngo@oracle.com> References: <20210916182212.81608-1-dai.ngo@oracle.com> MIME-Version: 1.0 X-Proofpoint-GUID: plUQJPPn6Ln-iKjlWym-ja-LavCl6uLP X-Proofpoint-ORIG-GUID: plUQJPPn6Ln-iKjlWym-ja-LavCl6uLP Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add new callback, lm_expire_lock, to lock_manager_operations to allow the lock manager to take appropriate action to resolve the lock conflict if possible. The callback takes 2 arguments, file_lock of the blocker and a testonly flag: testonly = 1 check and return true if lock conflict can be resolved else return false. testonly = 0 resolve the conflict if possible, return true if conflict was resolved esle return false. Lock manager, such as NFSv4 courteous server, uses this callback to resolve conflict by destroying lock owner, or the NFSv4 courtesy client (client that has expired but allowed to maintains its states) that owns the lock. Signed-off-by: Dai Ngo --- fs/locks.c | 26 +++++++++++++++++++++++--- include/linux/fs.h | 1 + 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 3d6fb4ae847b..893b348a2d57 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -954,6 +954,7 @@ posix_test_lock(struct file *filp, struct file_lock *fl) struct file_lock *cfl; struct file_lock_context *ctx; struct inode *inode = locks_inode(filp); + bool ret; ctx = smp_load_acquire(&inode->i_flctx); if (!ctx || list_empty_careful(&ctx->flc_posix)) { @@ -962,11 +963,20 @@ posix_test_lock(struct file *filp, struct file_lock *fl) } spin_lock(&ctx->flc_lock); +retry: list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { - if (posix_locks_conflict(fl, cfl)) { - locks_copy_conflock(fl, cfl); - goto out; + if (!posix_locks_conflict(fl, cfl)) + continue; + if (cfl->fl_lmops && cfl->fl_lmops->lm_expire_lock && + cfl->fl_lmops->lm_expire_lock(cfl, 1)) { + spin_unlock(&ctx->flc_lock); + ret = cfl->fl_lmops->lm_expire_lock(cfl, 0); + spin_lock(&ctx->flc_lock); + if (ret) + goto retry; } + locks_copy_conflock(fl, cfl); + goto out; } fl->fl_type = F_UNLCK; out: @@ -1140,6 +1150,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, int error; bool added = false; LIST_HEAD(dispose); + bool ret; ctx = locks_get_lock_context(inode, request->fl_type); if (!ctx) @@ -1166,9 +1177,18 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, * blocker's list of waiters and the global blocked_hash. */ if (request->fl_type != F_UNLCK) { +retry: list_for_each_entry(fl, &ctx->flc_posix, fl_list) { if (!posix_locks_conflict(request, fl)) continue; + if (fl->fl_lmops && fl->fl_lmops->lm_expire_lock && + fl->fl_lmops->lm_expire_lock(fl, 1)) { + spin_unlock(&ctx->flc_lock); + ret = fl->fl_lmops->lm_expire_lock(fl, 0); + spin_lock(&ctx->flc_lock); + if (ret) + goto retry; + } if (conflock) locks_copy_conflock(conflock, fl); error = -EAGAIN; diff --git a/include/linux/fs.h b/include/linux/fs.h index e7a633353fd2..1a76b6451398 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1071,6 +1071,7 @@ struct lock_manager_operations { int (*lm_change)(struct file_lock *, int, struct list_head *); void (*lm_setup)(struct file_lock *, void **); bool (*lm_breaker_owns_lease)(struct file_lock *); + bool (*lm_expire_lock)(struct file_lock *fl, bool testonly); }; struct lock_manager {