From patchwork Sat Feb 12 18:12:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dai Ngo X-Patchwork-Id: 12744375 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 23922C4167B for ; Sat, 12 Feb 2022 18:13:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229502AbiBLSNL (ORCPT ); Sat, 12 Feb 2022 13:13:11 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:60998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229477AbiBLSNI (ORCPT ); Sat, 12 Feb 2022 13:13:08 -0500 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B086D50B28; Sat, 12 Feb 2022 10:13:02 -0800 (PST) Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 21C9Z6t6031164; Sat, 12 Feb 2022 18:13:00 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; s=corp-2021-07-09; bh=mdPzghmN+3g59Es/EjAsOg2joGfh0L0N1qdeZNAPrI0=; b=jCz9oD35KlZ+LBLoUcaHBJJoyoXYb9OoOomBemd9hU38aiqQdSMTsKw4JZndz2jZ2g0r BszFSCf/ZcNigxVxaI2Z6IsdIPiHvEP40X8epRVD4zee0EzQH6PbSweEJsD3V2IW0oYq lS5XP/cFUEO1Hd+Uvw9JNT01hRSfDtSjFEl1xq4E3jffoFEdv+eaVRYcig/iLkMyjy83 n/RMdAicLJWT1tF3XD5KRFLC9SsvscPH/UvJdnmGZd/r6uJdHkQIv5K/Yv0t5X+sBF7h gkgicqUKfwe4EQEiywWt5cCnZ/8fW1D7KViNa1B/X+JB7mxd/I6eEU/LZMsexLb5IX1A FQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by mx0b-00069f02.pphosted.com with ESMTP id 3e64sbrweu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 12 Feb 2022 18:12:59 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.1.2/8.16.1.2) with SMTP id 21CIBpn2120340; Sat, 12 Feb 2022 18:12:58 GMT Received: from pps.reinject (localhost [127.0.0.1]) by userp3020.oracle.com with ESMTP id 3e66bj2f5b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 12 Feb 2022 18:12:58 +0000 Received: from userp3020.oracle.com (userp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 21CICvrx121470; Sat, 12 Feb 2022 18:12:58 GMT Received: from ca-common-hq.us.oracle.com (ca-common-hq.us.oracle.com [10.211.9.209]) by userp3020.oracle.com with ESMTP id 3e66bj2f4u-3; Sat, 12 Feb 2022 18:12:58 +0000 From: Dai Ngo To: chuck.lever@oracle.com, bfields@fieldses.org Cc: jlayton@redhat.com, viro@zeniv.linux.org.uk, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH RFC v13 2/4] fs/lock: add new callback, lm_lock_expired, to lock_manager_operations Date: Sat, 12 Feb 2022 10:12:53 -0800 Message-Id: <1644689575-1235-3-git-send-email-dai.ngo@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1644689575-1235-1-git-send-email-dai.ngo@oracle.com> References: <1644689575-1235-1-git-send-email-dai.ngo@oracle.com> X-Proofpoint-GUID: twcGSNAeLh_n6XKGMVQYNZHb6LKNgvk0 X-Proofpoint-ORIG-GUID: twcGSNAeLh_n6XKGMVQYNZHb6LKNgvk0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Add new callback, lm_lock_expired, to lock_manager_operations to allow the lock manager to take appropriate action to resolve the lock conflict if possible. The callback takes 1 argument, the file_lock of the blocker and returns true if the conflict was resolved else returns false. Note that the lock manager has to be able to resolve the conflict while the spinlock flc_lock is held. 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 --- Documentation/filesystems/locking.rst | 2 ++ fs/locks.c | 14 ++++++++++---- include/linux/fs.h | 1 + 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index aaca0b601819..ebd73e76cb7e 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -434,6 +434,7 @@ prototypes:: void (*lm_break)(struct file_lock *); /* break_lease callback */ int (*lm_change)(struct file_lock **, int); bool (*lm_breaker_owns_lease)(struct file_lock *); + bool (*lm_lock_expired)(struct file_lock *); locking rules: @@ -445,6 +446,7 @@ lm_grant: no no no lm_break: yes no no lm_change yes no no lm_breaker_owns_lease: yes no no +lm_lock_expired yes no no ====================== ============= ================= ========= buffer_head diff --git a/fs/locks.c b/fs/locks.c index 8c6df10cd9ed..52ede42651df 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -883,10 +883,13 @@ posix_test_lock(struct file *filp, struct file_lock *fl) spin_lock(&ctx->flc_lock); 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_lock_expired && + cfl->fl_lmops->lm_lock_expired(cfl)) + continue; + locks_copy_conflock(fl, cfl); + goto out; } fl->fl_type = F_UNLCK; out: @@ -1089,6 +1092,9 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, 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_lock_expired && + fl->fl_lmops->lm_lock_expired(fl)) + continue; if (conflock) locks_copy_conflock(conflock, fl); error = -EAGAIN; diff --git a/include/linux/fs.h b/include/linux/fs.h index e2d892b201b0..831b20430d6e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1062,6 +1062,7 @@ 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_lock_expired)(struct file_lock *cfl); }; struct lock_manager {