From patchwork Tue Sep 12 21:53:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Aring X-Patchwork-Id: 13382221 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 7416BBA35 for ; Tue, 12 Sep 2023 21:53:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694555633; 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=IckdSVzMK+BSFRjaA/U5gFIv6MBdqOAoK8cZbMlk/7Y=; b=YRX5ZjEr6Ddtpf9LK9DfZnQvgdXAFvdD9SShaTfjw+mfUbYbXaG2IZhRbZuLfXbk4Xtadv npAgYTVXXTrSgUKFw7sNFAxvzem20wJ3EyGUFnoE7NezY2I52OImJv+MDdLCYORkISdQ6+ reLl8+fsXytl5chuSFoX9EnumcEmfhk= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-606-FlW2D6UtODqTg0xXP3PKsQ-1; Tue, 12 Sep 2023 17:53:49 -0400 X-MC-Unique: FlW2D6UtODqTg0xXP3PKsQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6D5673806702; Tue, 12 Sep 2023 21:53:48 +0000 (UTC) Received: from fs-i40c-03.fs.lab.eng.bos.redhat.com (fs-i40c-03.fs.lab.eng.bos.redhat.com [10.16.224.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1FD2440C200A; Tue, 12 Sep 2023 21:53:48 +0000 (UTC) From: Alexander Aring To: linux-nfs@vger.kernel.org Cc: gfs2@lists.linux.dev, ocfs2-devel@lists.linux.dev, linux-fsdevel@vger.kernel.org, teigland@redhat.com, rpeterso@redhat.com, agruenba@redhat.com, trond.myklebust@hammerspace.com, anna@kernel.org, chuck.lever@oracle.com, jlayton@kernel.org, aahringo@redhat.com Subject: [PATCHv2 nfsd/master 4/7] lockd: add doc to enable EXPORT_OP_ASYNC_LOCK Date: Tue, 12 Sep 2023 17:53:21 -0400 Message-Id: <20230912215324.3310111-5-aahringo@redhat.com> In-Reply-To: <20230912215324.3310111-1-aahringo@redhat.com> References: <20230912215324.3310111-1-aahringo@redhat.com> Precedence: bulk X-Mailing-List: ocfs2-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 This patch adds a note to enable EXPORT_OP_ASYNC_LOCK for asynchronous lock request handling. Reviewed-by: Jeff Layton Signed-off-by: Alexander Aring --- fs/locks.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 76ad05f8070a..d4e49a990a8d 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2264,11 +2264,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX * locks, the ->lock() interface may return asynchronously, before the lock has * been granted or denied by the underlying filesystem, if (and only if) - * lm_grant is set. Callers expecting ->lock() to return asynchronously - * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) - * the request is for a blocking lock. When ->lock() does return asynchronously, - * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock - * request completes. + * lm_grant is set. Additionally EXPORT_OP_ASYNC_LOCK in export_operations + * flags need to be set. + * + * Callers expecting ->lock() to return asynchronously will only use F_SETLK, + * not F_SETLKW; they will set FL_SLEEP if (and only if) the request is for a + * blocking lock. When ->lock() does return asynchronously, it must return + * FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock request completes. * If the request is for non-blocking lock the file system should return * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine * with the result. If the request timed out the callback routine will return a