From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE98B36405A for ; Sat, 5 Sep 2026 21:43:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788644627; cv=none; b=mAYgcjKO389kaH9fovJzYK+GGmaBmTKTNfs/c367QfgAZxLWdjxHmh+JuhCWcXSfFzSmgIv2EzYuEVJddmjnMMOONnmU7loPDpmTBuPHuvhjGmrqpO3Q7hpMxWMlB9HAUPLE9sRfS7TIECN1tpwkUtpIJ6/SdkYxLvrqR1AKAWY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788644627; c=relaxed/simple; bh=+uwPW6+pLPi4UkTEhTfmHqJd3r/wyo4xCDSxcAeIjRo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CNJdnhct/AOegKQkwa8FgqtoT8bjQRdpTWNzqg1dxKGXER8iDjpF4O9JbMvNLL3n6vefo585w8UYztuYqwZUlxnpymCV2dbm9WcASz5t5X95jtvWLmhgSDvuoqJRu5Y+6FCp7YHyakNoor7VdbrTHrfV6PGHPDXa7xfPjF9E+EU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NwQxeMFa; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NwQxeMFa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2DA01F00A3A; Sat, 5 Sep 2026 21:43:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788644625; bh=u7ExC4I1uSkuIoOXuPz4n7riCsvqbXsYJyGIY9+rcSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NwQxeMFa3cY0lsAH/F+zSMAf+pu85n7sVbhOcPjGwj3qjaawZQy3YXWY+FrLHiDrD Ua2ojyPRhmUAcgx6eH1EMCD+lBxFIsqFQ8fZcTiwJiP3W3U77xKhmpZZxPBZjpQnkF s77U5moOwUVnJn8vV3CA30gnVkpMGczDnab29rIIntADHSmQd7exLiCV1uXKUw561v ZnpBG6OraqLWf2KhPXHWu1HHOJ1Ca/hmDmAv99zkl6u2fmBP6K6NfVjp8YUOm/EGj6 lTas+LhkDk1rFcUufIoGBCGhRpyqpif47q+O7+zXow/jxfh5FPukAEeHyQPHWUfHPq yUNjK1xYSsCYg== From: Sasha Levin To: stable@vger.kernel.org Cc: NeilBrown , Li Lingfeng , Jeff Layton , Chuck Lever , Sasha Levin Subject: [PATCH 5.10.y 1/3] nfsd: use workqueue enable/disable APIs for v4_end_grace sync Date: Sat, 5 Sep 2026 17:43:41 -0400 Message-ID: <20260905214343.701915-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090328-follicle-skinless-f045@gregkh> References: <2026090328-follicle-skinless-f045@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: NeilBrown [ Upstream commit 27e383ddeb3c88e20874c545285f2dce1a98f56a ] "nfsd: provide locking for v4_end_grace" introduced a client_tracking_active flag protected by nn->client_lock to prevent the laundromat from being scheduled before client tracking initialization or after shutdown begins. That commit is suitable for backporting to LTS kernels that predate commit 86898fa6b8cd ("workqueue: Implement disable/enable for (delayed) work items"). However, the workqueue subsystem in recent kernels provides enable_delayed_work() and disable_delayed_work_sync() for this purpose. Using this mechanism enable us to remove the client_tracking_active flag and associated spinlock operations while preserving the same synchronization guarantees, which is a cleaner long-term approach. Signed-off-by: NeilBrown Tested-by: Li Lingfeng Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Stable-dep-of: 9b57793863f6 ("nfsd: dedup nfs4_client_to_reclaim inserts") Signed-off-by: Sasha Levin --- fs/nfsd/netns.h | 1 - fs/nfsd/nfs4state.c | 22 +++++++++------------- 2 files changed, 9 insertions(+), 14 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index be0c8f1ce4e3e..139d9370f27f2 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -65,7 +65,6 @@ struct nfsd_net { struct lock_manager nfsd4_manager; bool grace_ended; bool grace_end_forced; - bool client_tracking_active; time64_t boot_time; struct dentry *nfsd_client_dir; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index c61e1a4ab620c..7095fa43fcf36 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -5928,14 +5928,14 @@ bool nfsd4_force_end_grace(struct nfsd_net *nn) { if (!nn->client_tracking_ops) return false; - spin_lock(&nn->client_lock); - if (nn->grace_ended || !nn->client_tracking_active) { - spin_unlock(&nn->client_lock); + if (READ_ONCE(nn->grace_ended)) return false; - } + /* laundromat_work must be initialised now, though it might be disabled */ WRITE_ONCE(nn->grace_end_forced, true); + /* mod_delayed_work() doesn't queue work after + * nfs4_state_shutdown_net() has called disable_delayed_work_sync() + */ mod_delayed_work(laundry_wq, &nn->laundromat_work, 0); - spin_unlock(&nn->client_lock); return true; } @@ -8187,7 +8187,6 @@ static int nfs4_state_create_net(struct net *net) nn->boot_time = ktime_get_real_seconds(); nn->grace_ended = false; nn->grace_end_forced = false; - nn->client_tracking_active = false; nn->nfsd4_manager.block_opens = true; INIT_LIST_HEAD(&nn->nfsd4_manager.list); INIT_LIST_HEAD(&nn->client_lru); @@ -8202,6 +8201,8 @@ static int nfs4_state_create_net(struct net *net) INIT_LIST_HEAD(&nn->blocked_locks_lru); INIT_DELAYED_WORK(&nn->laundromat_work, laundromat_main); + /* Make sure this cannot run until client tracking is initialised */ + disable_delayed_work(&nn->laundromat_work); INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker); get_net(net); @@ -8265,9 +8266,7 @@ nfs4_state_start_net(struct net *net) locks_start_grace(net, &nn->nfsd4_manager); nfsd4_client_tracking_init(net); /* safe for laundromat to run now */ - spin_lock(&nn->client_lock); - nn->client_tracking_active = true; - spin_unlock(&nn->client_lock); + enable_delayed_work(&nn->laundromat_work); if (nn->track_reclaim_completes && nn->reclaim_str_hashtbl_size == 0) goto skip_grace; printk(KERN_INFO "NFSD: starting %lld-second grace period (net %x)\n", @@ -8314,10 +8313,7 @@ nfs4_state_shutdown_net(struct net *net) unregister_shrinker(&nn->nfsd_client_shrinker); cancel_work_sync(&nn->nfsd_shrinker_work); - spin_lock(&nn->client_lock); - nn->client_tracking_active = false; - spin_unlock(&nn->client_lock); - cancel_delayed_work_sync(&nn->laundromat_work); + disable_delayed_work_sync(&nn->laundromat_work); locks_end_grace(&nn->nfsd4_manager); INIT_LIST_HEAD(&reaplist); -- 2.53.0