From patchwork Thu Nov 9 15:40:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13451254 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 7E58632C82 for ; Thu, 9 Nov 2023 15:41:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fKzen+VH" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0DD03AB7 for ; Thu, 9 Nov 2023 07:41:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1699544476; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xQ1ztg8XqgkGPytJCAaxTcEbNYz7HP0Vo6mf7bCyHww=; b=fKzen+VHckyw9Ca52ZlLlnpPtU1KUlaoKBemis09lGc5x/AsWa5y6nFWUYGx+eJvp9Bmdd x9VV5i/EexQEw351ILApmBKEv7/3HKlQjS2rcb5GC+0Q86M43Iq/l5+TXiu4fE9nDcc72j igePG1epzo2et3yExaEqxM8Ek59DdVM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-447-yPfoRaPzNsW7_PhfTB5g3g-1; Thu, 09 Nov 2023 10:41:13 -0500 X-MC-Unique: yPfoRaPzNsW7_PhfTB5g3g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 172B7811E7D; Thu, 9 Nov 2023 15:41:13 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.13]) by smtp.corp.redhat.com (Postfix) with ESMTP id 35A5A25C1; Thu, 9 Nov 2023 15:41:12 +0000 (UTC) From: David Howells To: Marc Dionne Cc: David Howells , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 37/41] afs: Apply server breaks to mmap'd files in the call processor Date: Thu, 9 Nov 2023 15:40:00 +0000 Message-ID: <20231109154004.3317227-38-dhowells@redhat.com> In-Reply-To: <20231109154004.3317227-1-dhowells@redhat.com> References: <20231109154004.3317227-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Apply server breaks to mmap'd files that are being used from that server from the call processor work function rather than punting it off to a workqueue. The work item, afs_server_init_callback(), then bumps each individual inode off to its own work item introducing a potentially lengthy delay. This reduces that delay at the cost of extending the amount of time we delay replying to the CB.InitCallBack3 notification RPC from the server. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- fs/afs/callback.c | 33 +++++++++++++++++++-------------- fs/afs/cell.c | 2 +- fs/afs/internal.h | 6 +++--- fs/afs/server.c | 2 -- fs/afs/server_list.c | 22 +++++++++++----------- fs/afs/volume.c | 15 +++++++++++++++ include/trace/events/afs.h | 2 ++ 7 files changed, 51 insertions(+), 31 deletions(-) diff --git a/fs/afs/callback.c b/fs/afs/callback.c index a484fa642808..535477f88a4f 100644 --- a/fs/afs/callback.c +++ b/fs/afs/callback.c @@ -33,9 +33,8 @@ void afs_invalidate_mmap_work(struct work_struct *work) unmap_mapping_pages(vnode->netfs.inode.i_mapping, 0, 0, false); } -void afs_server_init_callback_work(struct work_struct *work) +static void afs_server_init_callback(struct afs_server *server) { - struct afs_server *server = container_of(work, struct afs_server, initcb_work); struct afs_vnode *vnode; struct afs_cell *cell = server->cell; @@ -57,15 +56,19 @@ void afs_server_init_callback_work(struct work_struct *work) */ void afs_init_callback_state(struct afs_server *server) { - rcu_read_lock(); + struct afs_cell *cell = server->cell; + + down_read(&cell->vs_lock); + do { server->cb_s_break++; atomic_inc(&server->cell->fs_s_break); if (!list_empty(&server->cell->fs_open_mmaps)) - queue_work(system_unbound_wq, &server->initcb_work); + afs_server_init_callback(server); } while ((server = rcu_dereference(server->uuid_next))); - rcu_read_unlock(); + + up_read(&cell->vs_lock); } /* @@ -112,7 +115,7 @@ static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell, struct rb_node *p; int seq = 0; - do { + for (;;) { /* Unfortunately, rbtree walking doesn't give reliable results * under just the RCU read lock, so we have to check for * changes. @@ -132,7 +135,12 @@ static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell, volume = NULL; } - } while (need_seqretry(&cell->volume_lock, seq)); + if (volume && afs_try_get_volume(volume, afs_volume_trace_get_callback)) + break; + if (!need_seqretry(&cell->volume_lock, seq)) + break; + seq |= 1; /* Want a lock next time */ + } done_seqretry(&cell->volume_lock, seq); return volume; @@ -187,12 +195,11 @@ static void afs_break_some_callbacks(struct afs_server *server, afs_volid_t vid = cbb->fid.vid; size_t i; + rcu_read_lock(); volume = afs_lookup_volume_rcu(server->cell, vid); - /* TODO: Find all matching volumes if we couldn't match the server and * break them anyway. */ - for (i = *_count; i > 0; cbb++, i--) { if (cbb->fid.vid == vid) { _debug("- Fid { vl=%08llx n=%llu u=%u }", @@ -206,6 +213,9 @@ static void afs_break_some_callbacks(struct afs_server *server, *residue++ = *cbb; } } + + rcu_read_unlock(); + afs_put_volume(volume, afs_volume_trace_put_callback); } /* @@ -218,11 +228,6 @@ void afs_break_callbacks(struct afs_server *server, size_t count, ASSERT(server != NULL); - rcu_read_lock(); - while (count > 0) afs_break_some_callbacks(server, callbacks, &count); - - rcu_read_unlock(); - return; } diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 6b389f2bcd0c..1e5cb0f6ee07 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -161,7 +161,7 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net, refcount_set(&cell->ref, 1); atomic_set(&cell->active, 0); INIT_WORK(&cell->manager, afs_manage_cell_work); - spin_lock_init(&cell->vs_lock); + init_rwsem(&cell->vs_lock); cell->volumes = RB_ROOT; INIT_HLIST_HEAD(&cell->proc_volumes); seqlock_init(&cell->volume_lock); diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 0a4ecfc250bf..73f0a456ab98 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -414,7 +414,7 @@ struct afs_cell { unsigned int debug_id; /* The volumes belonging to this cell */ - spinlock_t vs_lock; /* Lock for server->volumes */ + struct rw_semaphore vs_lock; /* Lock for server->volumes */ struct rb_root volumes; /* Tree of volumes on this server */ struct hlist_head proc_volumes; /* procfs volume list */ seqlock_t volume_lock; /* For volumes */ @@ -566,7 +566,6 @@ struct afs_server { struct hlist_node addr6_link; /* Link in net->fs_addresses6 */ struct hlist_node proc_link; /* Link in net->fs_proc */ struct list_head volumes; /* RCU list of afs_server_entry objects */ - struct work_struct initcb_work; /* Work for CB.InitCallBackState* */ struct afs_server *gc_next; /* Next server in manager's list */ time64_t unuse_time; /* Time at which last unused */ unsigned long flags; @@ -1040,7 +1039,6 @@ void afs_get_address_preferences(struct afs_net *net, struct afs_addr_list *alis * callback.c */ extern void afs_invalidate_mmap_work(struct work_struct *); -extern void afs_server_init_callback_work(struct work_struct *work); extern void afs_init_callback_state(struct afs_server *); extern void __afs_break_callback(struct afs_vnode *, enum afs_cb_break_reason); extern void afs_break_callback(struct afs_vnode *, enum afs_cb_break_reason); @@ -1619,6 +1617,8 @@ extern struct afs_volume *afs_get_volume(struct afs_volume *, enum afs_volume_tr void afs_put_volume(struct afs_volume *volume, enum afs_volume_trace reason); extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *); +bool afs_try_get_volume(struct afs_volume *volume, enum afs_volume_trace reason); + /* * write.c */ diff --git a/fs/afs/server.c b/fs/afs/server.c index 811dbda88f9c..c97617366557 100644 --- a/fs/afs/server.c +++ b/fs/afs/server.c @@ -217,7 +217,6 @@ static struct afs_server *afs_alloc_server(struct afs_cell *cell, server->uuid = *uuid; rwlock_init(&server->fs_lock); INIT_LIST_HEAD(&server->volumes); - INIT_WORK(&server->initcb_work, afs_server_init_callback_work); init_waitqueue_head(&server->probe_wq); INIT_LIST_HEAD(&server->probe_link); spin_lock_init(&server->probe_lock); @@ -469,7 +468,6 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server) if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags)) afs_give_up_callbacks(net, server); - flush_work(&server->initcb_work); afs_put_server(net, server, afs_server_trace_destroy); } diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c index 4d6369477f54..cfd900eb09ed 100644 --- a/fs/afs/server_list.c +++ b/fs/afs/server_list.c @@ -136,7 +136,7 @@ void afs_attach_volume_to_servers(struct afs_volume *volume, struct afs_server_l struct list_head *p; unsigned int i; - spin_lock(&volume->cell->vs_lock); + down_write(&volume->cell->vs_lock); for (i = 0; i < slist->nr_servers; i++) { se = &slist->servers[i]; @@ -147,11 +147,11 @@ void afs_attach_volume_to_servers(struct afs_volume *volume, struct afs_server_l if (volume->vid <= pe->volume->vid) break; } - list_add_tail_rcu(&se->slink, p); + list_add_tail(&se->slink, p); } slist->attached = true; - spin_unlock(&volume->cell->vs_lock); + up_write(&volume->cell->vs_lock); } /* @@ -164,7 +164,7 @@ void afs_reattach_volume_to_servers(struct afs_volume *volume, struct afs_server { unsigned int n = 0, o = 0; - spin_lock(&volume->cell->vs_lock); + down_write(&volume->cell->vs_lock); while (n < new->nr_servers || o < old->nr_servers) { struct afs_server_entry *pn = n < new->nr_servers ? &new->servers[n] : NULL; @@ -174,7 +174,7 @@ void afs_reattach_volume_to_servers(struct afs_volume *volume, struct afs_server int diff; if (pn && po && pn->server == po->server) { - list_replace_rcu(&po->slink, &pn->slink); + list_replace(&po->slink, &pn->slink); n++; o++; continue; @@ -192,15 +192,15 @@ void afs_reattach_volume_to_servers(struct afs_volume *volume, struct afs_server if (volume->vid <= s->volume->vid) break; } - list_add_tail_rcu(&pn->slink, p); + list_add_tail(&pn->slink, p); n++; } else { - list_del_rcu(&po->slink); + list_del(&po->slink); o++; } } - spin_unlock(&volume->cell->vs_lock); + up_write(&volume->cell->vs_lock); } /* @@ -213,11 +213,11 @@ void afs_detach_volume_from_servers(struct afs_volume *volume, struct afs_server if (!slist->attached) return; - spin_lock(&volume->cell->vs_lock); + down_write(&volume->cell->vs_lock); for (i = 0; i < slist->nr_servers; i++) - list_del_rcu(&slist->servers[i].slink); + list_del(&slist->servers[i].slink); slist->attached = false; - spin_unlock(&volume->cell->vs_lock); + up_write(&volume->cell->vs_lock); } diff --git a/fs/afs/volume.c b/fs/afs/volume.c index 1d3bd14dfa2f..00253032ccca 100644 --- a/fs/afs/volume.c +++ b/fs/afs/volume.c @@ -242,6 +242,21 @@ static void afs_destroy_volume(struct work_struct *work) _leave(" [destroyed]"); } + +/* + * Try to get a reference on a volume record. + */ +bool afs_try_get_volume(struct afs_volume *volume, enum afs_volume_trace reason) +{ + int r; + + if (__refcount_inc_not_zero(&volume->ref, &r)) { + trace_afs_volume(volume->vid, r + 1, reason); + return true; + } + return false; +} + /* * Get a reference on a volume record. */ diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index cf2fa4fddd5b..63ab23876be8 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -151,9 +151,11 @@ enum yfs_cm_operation { EM(afs_volume_trace_alloc, "ALLOC ") \ EM(afs_volume_trace_free, "FREE ") \ EM(afs_volume_trace_get_alloc_sbi, "GET sbi-alloc ") \ + EM(afs_volume_trace_get_callback, "GET callback ") \ EM(afs_volume_trace_get_cell_insert, "GET cell-insrt") \ EM(afs_volume_trace_get_new_op, "GET op-new ") \ EM(afs_volume_trace_get_query_alias, "GET cell-alias") \ + EM(afs_volume_trace_put_callback, "PUT callback ") \ EM(afs_volume_trace_put_cell_dup, "PUT cell-dup ") \ EM(afs_volume_trace_put_cell_root, "PUT cell-root ") \ EM(afs_volume_trace_put_destroy_sbi, "PUT sbi-destry") \