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 X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF949C4332B for ; Fri, 20 Mar 2020 11:52:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9482920732 for ; Fri, 20 Mar 2020 11:52:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DIhlZWHl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726892AbgCTLwB (ORCPT ); Fri, 20 Mar 2020 07:52:01 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:49833 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726814AbgCTLwA (ORCPT ); Fri, 20 Mar 2020 07:52:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584705119; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vay2uE4/QB4envo/zu0nnrwnCqE2yYBaEybF3nmpyuI=; b=DIhlZWHlE5de8jzNNqkuAQUt6w4C6ULIa0bhe+BHzeoqE9BJyjKPkaWRXuiVJW21mVbZH9 0UidhADPR+Bj8uWiVSJVmcgMYDXx2Xx/LJMnsKtYhJMKZV4JvTt18PyqKgB3DPCQRNLTIv njd5cHUJKvbXGueF8RH3qHpOQ3pvy0A= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-235-5_dik0JbM1SlJ5C6SCWWSg-1; Fri, 20 Mar 2020 07:51:55 -0400 X-MC-Unique: 5_dik0JbM1SlJ5C6SCWWSg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2F5F68014D4; Fri, 20 Mar 2020 11:51:54 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A75CD19C58; Fri, 20 Mar 2020 11:51:53 +0000 (UTC) Date: Fri, 20 Mar 2020 07:51:51 -0400 From: Brian Foster To: Christoph Hellwig Cc: linux-xfs@vger.kernel.org, Dave Chinner Subject: Re: [PATCH 6/8] xfs: refactor xlog_state_clean_iclog Message-ID: <20200320115151.GA42814@bfoster> References: <20200320065311.28134-1-hch@lst.de> <20200320065311.28134-7-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200320065311.28134-7-hch@lst.de> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Mar 20, 2020 at 07:53:09AM +0100, Christoph Hellwig wrote: > Factor out a few self-contained helpers from xlog_state_clean_iclog, and > update the documentation so it primarily documents why things happens > instead of how. > > Signed-off-by: Christoph Hellwig > --- Reviewed-by: Brian Foster > fs/xfs/xfs_log.c | 180 +++++++++++++++++++++++------------------------ > 1 file changed, 88 insertions(+), 92 deletions(-) > > diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c > index 4f9303524efb..6facbb91b8a8 100644 > --- a/fs/xfs/xfs_log.c > +++ b/fs/xfs/xfs_log.c > @@ -2540,111 +2540,107 @@ xlog_write( > ***************************************************************************** > */ > > +static void > +xlog_state_activate_iclog( > + struct xlog_in_core *iclog, > + int *iclogs_changed) > +{ > + ASSERT(list_empty_careful(&iclog->ic_callbacks)); > + > + /* > + * If the number of ops in this iclog indicate it just contains the > + * dummy transaction, we can change state into IDLE (the second time > + * around). Otherwise we should change the state into NEED a dummy. > + * We don't need to cover the dummy. > + */ > + if (*iclogs_changed == 0 && > + iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) { > + *iclogs_changed = 1; > + } else { > + /* > + * We have two dirty iclogs so start over. This could also be > + * num of ops indicating this is not the dummy going out. > + */ > + *iclogs_changed = 2; > + } > + > + iclog->ic_state = XLOG_STATE_ACTIVE; > + iclog->ic_offset = 0; > + iclog->ic_header.h_num_logops = 0; > + memset(iclog->ic_header.h_cycle_data, 0, > + sizeof(iclog->ic_header.h_cycle_data)); > + iclog->ic_header.h_lsn = 0; > +} > + > /* > - * An iclog has just finished IO completion processing, so we need to update > - * the iclog state and propagate that up into the overall log state. Hence we > - * prepare the iclog for cleaning, and then clean all the pending dirty iclogs > - * starting from the head, and then wake up any threads that are waiting for the > - * iclog to be marked clean. > - * > - * The ordering of marking iclogs ACTIVE must be maintained, so an iclog > - * doesn't become ACTIVE beyond one that is SYNCING. This is also required to > - * maintain the notion that we use a ordered wait queue to hold off would be > - * writers to the log when every iclog is trying to sync to disk. > - * > - * Caller must hold the icloglock before calling us. > - * > - * State Change: !IOERROR -> DIRTY -> ACTIVE > + * Loop through all iclogs and mark all iclogs currently marked DIRTY as > + * ACTIVE after iclog I/O has completed. > */ > -STATIC void > -xlog_state_clean_iclog( > +static void > +xlog_state_activate_iclogs( > struct xlog *log, > - struct xlog_in_core *dirty_iclog) > + int *iclogs_changed) > { > - struct xlog_in_core *iclog; > - int changed = 0; > - > - /* Prepare the completed iclog. */ > - if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) > - dirty_iclog->ic_state = XLOG_STATE_DIRTY; > + struct xlog_in_core *iclog = log->l_iclog; > > - /* Walk all the iclogs to update the ordered active state. */ > - iclog = log->l_iclog; > do { > - if (iclog->ic_state == XLOG_STATE_DIRTY) { > - iclog->ic_state = XLOG_STATE_ACTIVE; > - iclog->ic_offset = 0; > - ASSERT(list_empty_careful(&iclog->ic_callbacks)); > - /* > - * If the number of ops in this iclog indicate it just > - * contains the dummy transaction, we can > - * change state into IDLE (the second time around). > - * Otherwise we should change the state into > - * NEED a dummy. > - * We don't need to cover the dummy. > - */ > - if (!changed && > - (be32_to_cpu(iclog->ic_header.h_num_logops) == > - XLOG_COVER_OPS)) { > - changed = 1; > - } else { > - /* > - * We have two dirty iclogs so start over > - * This could also be num of ops indicates > - * this is not the dummy going out. > - */ > - changed = 2; > - } > - iclog->ic_header.h_num_logops = 0; > - memset(iclog->ic_header.h_cycle_data, 0, > - sizeof(iclog->ic_header.h_cycle_data)); > - iclog->ic_header.h_lsn = 0; > - } else if (iclog->ic_state == XLOG_STATE_ACTIVE) > - /* do nothing */; > - else > - break; /* stop cleaning */ > - iclog = iclog->ic_next; > - } while (iclog != log->l_iclog); > - > + if (iclog->ic_state == XLOG_STATE_DIRTY) > + xlog_state_activate_iclog(iclog, iclogs_changed); > + /* > + * The ordering of marking iclogs ACTIVE must be maintained, so > + * an iclog doesn't become ACTIVE beyond one that is SYNCING. > + */ > + else if (iclog->ic_state != XLOG_STATE_ACTIVE) > + break; > + } while ((iclog = iclog->ic_next) != log->l_iclog); > +} > > +static int > +xlog_covered_state( > + int prev_state, > + int iclogs_changed) > +{ > /* > - * Wake up threads waiting in xfs_log_force() for the dirty iclog > - * to be cleaned. > + * We usually go to NEED. But we go to NEED2 if the changed indicates we > + * are done writing the dummy record. If we are done with the second > + * dummy recored (DONE2), then we go to IDLE. > */ > - wake_up_all(&dirty_iclog->ic_force_wait); > + switch (prev_state) { > + case XLOG_STATE_COVER_IDLE: > + case XLOG_STATE_COVER_NEED: > + case XLOG_STATE_COVER_NEED2: > + break; > + case XLOG_STATE_COVER_DONE: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_NEED2; > + break; > + case XLOG_STATE_COVER_DONE2: > + if (iclogs_changed == 1) > + return XLOG_STATE_COVER_IDLE; > + break; > + default: > + ASSERT(0); > + } > > - /* > - * Change state for the dummy log recording. > - * We usually go to NEED. But we go to NEED2 if the changed indicates > - * we are done writing the dummy record. > - * If we are done with the second dummy recored (DONE2), then > - * we go to IDLE. > - */ > - if (changed) { > - switch (log->l_covered_state) { > - case XLOG_STATE_COVER_IDLE: > - case XLOG_STATE_COVER_NEED: > - case XLOG_STATE_COVER_NEED2: > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + return XLOG_STATE_COVER_NEED; > +} > > - case XLOG_STATE_COVER_DONE: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_NEED2; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > +STATIC void > +xlog_state_clean_iclog( > + struct xlog *log, > + struct xlog_in_core *dirty_iclog) > +{ > + int iclogs_changed = 0; > > - case XLOG_STATE_COVER_DONE2: > - if (changed == 1) > - log->l_covered_state = XLOG_STATE_COVER_IDLE; > - else > - log->l_covered_state = XLOG_STATE_COVER_NEED; > - break; > + if (dirty_iclog->ic_state != XLOG_STATE_IOERROR) > + dirty_iclog->ic_state = XLOG_STATE_DIRTY; > > - default: > - ASSERT(0); > - } > + xlog_state_activate_iclogs(log, &iclogs_changed); > + wake_up_all(&dirty_iclog->ic_force_wait); > + > + if (iclogs_changed) { > + log->l_covered_state = xlog_covered_state(log->l_covered_state, > + iclogs_changed); > } > } > > -- > 2.25.1 >