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 BAD9CC43334 for ; Tue, 19 Jul 2022 04:13:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236809AbiGSENu (ORCPT ); Tue, 19 Jul 2022 00:13:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234998AbiGSENs (ORCPT ); Tue, 19 Jul 2022 00:13:48 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76DB53E77F for ; Mon, 18 Jul 2022 21:13:44 -0700 (PDT) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 26J46s46027259 for ; Mon, 18 Jul 2022 21:13:44 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=Y+3UWzTV0pQ8LQ1QX73zMX49c9ImvBJAB6NmG1HM4x8=; b=QnoKtn1Waibj9CqOxGMAQZ3SqrQ28rRtwCei9MW/zPi+5Xe2hvfgeNAF4GAMRf1zELIW vFAQ3jcX0yv8cq1XXQZfU3GtRXjZqyHtJA2nUvgEeTMTmIIy1k3Z99TNphUAhnAlftyD 5RrFTaSBdZ025OFhmfNG07WfkOjKso3vBNI= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3hd9744k5v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 18 Jul 2022 21:13:43 -0700 Received: from twshared25478.08.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Mon, 18 Jul 2022 21:13:42 -0700 Received: by devvm7778.ftw0.facebook.com (Postfix, from userid 558217) id 083D624A8C9C; Mon, 18 Jul 2022 21:13:35 -0700 (PDT) From: Ioannis Angelakopoulos To: , Subject: [PATCH v2 2/5] btrfs: Add a lockdep model for the num_extwriters wait event Date: Mon, 18 Jul 2022 21:09:54 -0700 Message-ID: <20220719040954.3964407-3-iangelak@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220719040954.3964407-1-iangelak@fb.com> References: <20220719040954.3964407-1-iangelak@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: 9zohAz4CshzDtyDUd40GnBO4Nirvfpm4 X-Proofpoint-GUID: 9zohAz4CshzDtyDUd40GnBO4Nirvfpm4 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-07-18_22,2022-07-18_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Similarly to the num_writers wait event in fs/btrfs/transaction.c add a lockdep annotation for the num_extwriters wait event. Use a read/write lockdep map for the annotation. A thread starting/joinin= g the transaction acquires the map as a reader when it increments cur_trans->num_writers and it acquires the map as a writer before it blocks on the wait event. Signed-off-by: Ioannis Angelakopoulos --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 4 ++++ fs/btrfs/transaction.c | 13 +++++++++++++ 3 files changed, 18 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 999868734be7..586756f831e5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1096,6 +1096,7 @@ struct btrfs_fs_info { struct btrfs_commit_stats commit_stats; =20 struct lockdep_map btrfs_trans_num_writers_map; + struct lockdep_map btrfs_trans_num_extwriters_map; =20 #ifdef CONFIG_BTRFS_FS_REF_VERIFY spinlock_t ref_verify_lock; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 01a5a49a3a11..b1193584ba49 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3047,6 +3047,7 @@ static int __cold init_tree_roots(struct btrfs_fs_i= nfo *fs_info) void btrfs_init_fs_info(struct btrfs_fs_info *fs_info) { static struct lock_class_key btrfs_trans_num_writers_key; + static struct lock_class_key btrfs_trans_num_extwriters_key; =20 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC); INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC); @@ -3079,6 +3080,9 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_in= fo) lockdep_init_map(&fs_info->btrfs_trans_num_writers_map, "btrfs_trans_num_writers", &btrfs_trans_num_writers_key, 0); + lockdep_init_map(&fs_info->btrfs_trans_num_extwriters_map, + "btrfs_trans_num_extwriters", + &btrfs_trans_num_extwriters_key, 0); =20 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots); INIT_LIST_HEAD(&fs_info->space_info); diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index d8287ec890bc..c9751a05c029 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -314,6 +314,7 @@ static noinline int join_transaction(struct btrfs_fs_= info *fs_info, extwriter_counter_inc(cur_trans, type); spin_unlock(&fs_info->trans_lock); btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers); + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters); return 0; } spin_unlock(&fs_info->trans_lock); @@ -336,6 +337,7 @@ static noinline int join_transaction(struct btrfs_fs_= info *fs_info, return -ENOMEM; =20 btrfs_lockdep_acquire(fs_info, btrfs_trans_num_writers); + btrfs_lockdep_acquire(fs_info, btrfs_trans_num_extwriters); =20 spin_lock(&fs_info->trans_lock); if (fs_info->running_transaction) { @@ -343,11 +345,13 @@ static noinline int join_transaction(struct btrfs_f= s_info *fs_info, * someone started a transaction after we unlocked. Make sure * to redo the checks above */ + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); kfree(cur_trans); goto loop; } else if (BTRFS_FS_ERROR(fs_info)) { spin_unlock(&fs_info->trans_lock); + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); kfree(cur_trans); return -EROFS; @@ -1028,6 +1032,7 @@ static int __btrfs_end_transaction(struct btrfs_tra= ns_handle *trans, =20 cond_wake_up(&cur_trans->writer_wait); =20 + btrfs_lockdep_release(info, btrfs_trans_num_extwriters); btrfs_lockdep_release(info, btrfs_trans_num_writers); =20 btrfs_put_transaction(cur_trans); @@ -2270,6 +2275,13 @@ int btrfs_commit_transaction(struct btrfs_trans_ha= ndle *trans) if (ret) goto lockdep_release; =20 + /* + * The thread has started/joined the transaction thus it holds the lock= dep + * map as a reader. It has to release it before acquiring the lockdep m= ap + * as a writer. + */ + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); + btrfs_might_wait_for_event(fs_info, btrfs_trans_num_extwriters); wait_event(cur_trans->writer_wait, extwriter_counter_read(cur_trans) =3D=3D 0); =20 @@ -2540,6 +2552,7 @@ int btrfs_commit_transaction(struct btrfs_trans_han= dle *trans) =20 return ret; lockdep_release: + btrfs_lockdep_release(fs_info, btrfs_trans_num_extwriters); btrfs_lockdep_release(fs_info, btrfs_trans_num_writers); goto cleanup_transaction; } --=20 2.30.2