From patchwork Tue Jul 18 06:38:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 13316780 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 2FB1BEB64DA for ; Tue, 18 Jul 2023 06:39:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231299AbjGRGjZ (ORCPT ); Tue, 18 Jul 2023 02:39:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230506AbjGRGjX (ORCPT ); Tue, 18 Jul 2023 02:39:23 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66F4F1A6 for ; Mon, 17 Jul 2023 23:39:21 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 1DCFB2193C; Tue, 18 Jul 2023 06:39:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1689662360; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xg2RgBEO/rX8EeCfAvefOHhgjcQoKsl3XKkN4lPtPJM=; b=Oif/wl/htNbnHLV3KASreO6JYFdZkC6UuY2nWMKRnbSXpuQqZCYlVLK7DpWm5J18CF79rw y9AraUPccgmPXweLRN+6ou/NoQxUTaVli7tSJKt8RwwkRWtTZeqXQ1b4v37yvg2cpCp8Xr JZ9mKv+ElQ9qQpf94GIzq7EJOOxoXQc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1689662360; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xg2RgBEO/rX8EeCfAvefOHhgjcQoKsl3XKkN4lPtPJM=; b=yM2LKqmaVEkYQBXinx/su0UiRIzmO5D3o7f5m1fWCcmOQXcWGBCNHWir+4UbiMX1jXXdTL QG9l3Kl6KAa0swAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id D50D913494; Tue, 18 Jul 2023 06:39:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 9hXDIZYztmRhDAAAMHmgww (envelope-from ); Tue, 18 Jul 2023 06:39:18 +0000 Subject: [PATCH 04/14] SUNRPC: change svc_recv() to return void. From: NeilBrown To: Chuck Lever , Jeff Layton Cc: linux-nfs@vger.kernel.org Date: Tue, 18 Jul 2023 16:38:08 +1000 Message-ID: <168966228862.11075.10086063375287695723.stgit@noble.brown> In-Reply-To: <168966227838.11075.2974227708495338626.stgit@noble.brown> References: <168966227838.11075.2974227708495338626.stgit@noble.brown> User-Agent: StGit/1.5 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org svc_recv() currently returns a 0 on success or one of two errors: - -EAGAIN means no message was successfully received - -EINTR means the thread has been told to stop Previously nfsd would stop as the result of a signal as well as following kthread_stop(). In that case the difference was useful: EINTR means stop unconditionally. EAGAIN means stop if kthread_should_stop(), continue otherwise. Now threads only exit when kthread_should_stop() so we don't need the distinction. So have all threads test kthread_should_stop() (most do), and return simple success/failure from svc_recv(). Also change some helpers that svc_recv() uses to not bother with an error code, returning a bool in once case, and NULL for failure in another. Signed-off-by: NeilBrown --- fs/lockd/svc.c | 9 +++------ fs/nfs/callback.c | 5 +---- fs/nfsd/nfssvc.c | 8 ++------ include/linux/sunrpc/svcsock.h | 2 +- net/sunrpc/svc_xprt.c | 27 +++++++++++---------------- 5 files changed, 18 insertions(+), 33 deletions(-) diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 91ef139a7757..a43b63e46127 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -116,7 +116,6 @@ static void set_grace_period(struct net *net) static int lockd(void *vrqstp) { - int err = 0; struct svc_rqst *rqstp = vrqstp; struct net *net = &init_net; struct lockd_net *ln = net_generic(net, lockd_net_id); @@ -139,12 +138,10 @@ lockd(void *vrqstp) timeout = nlmsvc_retry_blocked(); /* - * Find a socket with data available and call its - * recvfrom routine. + * Find any work to do, such as a socket with data available, + * and do the work. */ - err = svc_recv(rqstp, timeout); - if (err == -EAGAIN || err == -EINTR) - continue; + svc_recv(rqstp, timeout); } if (nlmsvc_ops) nlmsvc_invalidate_all(); diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c index 2d94384bd6a9..914d2402ca98 100644 --- a/fs/nfs/callback.c +++ b/fs/nfs/callback.c @@ -74,7 +74,6 @@ static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net) static int nfs4_callback_svc(void *vrqstp) { - int err; struct svc_rqst *rqstp = vrqstp; set_freezable(); @@ -83,9 +82,7 @@ nfs4_callback_svc(void *vrqstp) /* * Listen for a request on the socket */ - err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); - if (err == -EAGAIN || err == -EINTR) - continue; + svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); } svc_exit_thread(rqstp); diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 3e08cc746870..5bf48c33986e 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -953,7 +953,6 @@ nfsd(void *vrqstp) struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list); struct net *net = perm_sock->xpt_net; struct nfsd_net *nn = net_generic(net, nfsd_net_id); - int err; /* At this point, the thread shares current->fs * with the init process. We need to create files with the @@ -972,7 +971,7 @@ nfsd(void *vrqstp) /* * The main request loop */ - for (;;) { + while (!kthread_should_stop()) { /* Update sv_maxconn if it has changed */ rqstp->rq_server->sv_maxconn = nn->max_connections; @@ -980,10 +979,7 @@ nfsd(void *vrqstp) * Find a socket with data available and call its * recvfrom routine. */ - while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN) - ; - if (err == -EINTR) - break; + svc_recv(rqstp, 60*60*HZ); validate_process_creds(); } diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h index 55446136499f..fb5c98069356 100644 --- a/include/linux/sunrpc/svcsock.h +++ b/include/linux/sunrpc/svcsock.h @@ -64,7 +64,7 @@ static inline u32 svc_sock_final_rec(struct svc_sock *svsk) * Function prototypes. */ void svc_close_net(struct svc_serv *, struct net *); -int svc_recv(struct svc_rqst *, long); +void svc_recv(struct svc_rqst *, long); void svc_send(struct svc_rqst *rqstp); void svc_drop(struct svc_rqst *); void svc_sock_update_bufs(struct svc_serv *serv); diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index c808f6d60c99..67825eef8646 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -664,7 +664,7 @@ static void svc_check_conn_limits(struct svc_serv *serv) } } -static int svc_alloc_arg(struct svc_rqst *rqstp) +static bool svc_alloc_arg(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; struct xdr_buf *arg = &rqstp->rq_arg; @@ -689,7 +689,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) set_current_state(TASK_IDLE); if (kthread_should_stop()) { set_current_state(TASK_RUNNING); - return -EINTR; + return false; } trace_svc_alloc_arg_err(pages, ret); memalloc_retry_wait(GFP_KERNEL); @@ -708,7 +708,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) arg->tail[0].iov_len = 0; rqstp->rq_xid = xdr_zero; - return 0; + return true; } static bool @@ -773,9 +773,9 @@ static struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout) if (!time_left) percpu_counter_inc(&pool->sp_threads_timedout); if (kthread_should_stop()) - return ERR_PTR(-EINTR); + return NULL; percpu_counter_inc(&pool->sp_threads_no_work); - return ERR_PTR(-EAGAIN); + return NULL; out_found: /* Normally we will wait up to 5 seconds for any required * cache information to be provided. @@ -856,32 +856,27 @@ static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt) * organised not to touch any cachelines in the shared svc_serv * structure, only cachelines in the local svc_pool. */ -int svc_recv(struct svc_rqst *rqstp, long timeout) +void svc_recv(struct svc_rqst *rqstp, long timeout) { struct svc_xprt *xprt = NULL; struct svc_serv *serv = rqstp->rq_server; - int len, err; + int len; - err = svc_alloc_arg(rqstp); - if (err) + if (!svc_alloc_arg(rqstp)) goto out; try_to_freeze(); cond_resched(); - err = -EINTR; if (kthread_should_stop()) goto out; xprt = svc_get_next_xprt(rqstp, timeout); - if (IS_ERR(xprt)) { - err = PTR_ERR(xprt); + if (!xprt) goto out; - } len = svc_handle_xprt(rqstp, xprt); /* No data, incomplete (TCP) read, or accept() */ - err = -EAGAIN; if (len <= 0) goto out_release; @@ -896,12 +891,12 @@ int svc_recv(struct svc_rqst *rqstp, long timeout) percpu_counter_inc(&rqstp->rq_pool->sp_messages_arrived); rqstp->rq_stime = ktime_get(); svc_process(rqstp); - return 0; + return; out_release: rqstp->rq_res.len = 0; svc_xprt_release(rqstp); out: - return err; + return; } EXPORT_SYMBOL_GPL(svc_recv);