From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH 02/11] xfs: add NOWAIT semantics for readdir Date: Sun, 27 Aug 2023 21:44:53 +0100 Message-ID: References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-3-hao.xu@linux.dev> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=rh2eHyjfSChvP5M3GZFqng0djt iCSjqmEmDczFMnSTrKUt8mmVXGPGgbJ4oq2lIEXyRSbFH+YR4YMUxP/z9QQKohjOoCQZks3WE0IMK 3S4hJ/QxWWGwrLIXBI8vnsgZg3HMNGIE+hIRemTa2iQvkDDHCCMd0yz1djBYQiyi1qOQAKg4GjHdy fEL5cINLesPqAO5iR1xTPAPnXU+iFHAHJEGUTx86DeTnZzv1uxgeaR21j4BV+7nscvIXdd9sVE/Si rCIGIbVvaskI417AUCK4HwQeBGpvqIcrg+ypempVGeBQFeEiZBUSg5QboubLY+HaM/1Y954EFPxgD hXmevJ/g==; List-Id: List-Subscribe: List-Unsubscribe: Content-Disposition: inline In-Reply-To: <20230827132835.1373581-3-hao.xu@linux.dev> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Hao Xu Cc: io-uring@vger.kernel.org, Jens Axboe , Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , "Darrick J . Wong" , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-cachefs@redhat.com, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, devel@lists.orangefs. On Sun, Aug 27, 2023 at 09:28:26PM +0800, Hao Xu wrote: > +++ b/fs/xfs/libxfs/xfs_da_btree.c > @@ -2643,16 +2643,32 @@ xfs_da_read_buf( > struct xfs_buf_map map, *mapp = ↦ > int nmap = 1; > int error; > + int buf_flags = 0; > > *bpp = NULL; > error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap); > if (error || !nmap) > goto out_free; > > + /* > + * NOWAIT semantics mean we don't wait on the buffer lock nor do we > + * issue IO for this buffer if it is not already in memory. Caller will > + * retry. This will return -EAGAIN if the buffer is in memory and cannot > + * be locked, and no buffer and no error if it isn't in memory. We > + * translate both of those into a return state of -EAGAIN and *bpp = > + * NULL. > + */ I would not include this comment. > + if (flags & XFS_DABUF_NOWAIT) > + buf_flags |= XBF_TRYLOCK | XBF_INCORE; > error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, > &bp, ops); what tsting did you do with this? Because you don't actually _use_ buf_flags anywhere in this patch (presumably they should be the sixth argument to xfs_trans_read_buf_map() instead of 0). So I can only conclude that either you didn't test, or your testing was inadequate. > if (error) > goto out_free; > + if (!bp) { > + ASSERT(flags & XFS_DABUF_NOWAIT); I don't think this ASSERT is appropriate. > @@ -391,10 +401,17 @@ xfs_dir2_leaf_getdents( > bp = NULL; > } > > - if (*lock_mode == 0) > - *lock_mode = xfs_ilock_data_map_shared(dp); > + if (*lock_mode == 0) { > + *lock_mode = > + xfs_ilock_data_map_shared_generic(dp, > + ctx->flags & DIR_CONTEXT_F_NOWAIT); > + if (!*lock_mode) { > + error = -EAGAIN; > + break; > + } > + } 'generic' doesn't seem like a great suffix to mean 'takes nowait flag'. And this is far too far indented. xfs_dir2_lock(dp, ctx, lock_mode); with: STATIC void xfs_dir2_lock(struct xfs_inode *dp, struct dir_context *ctx, unsigned int lock_mode) { if (*lock_mode) return; if (ctx->flags & DIR_CONTEXT_F_NOWAIT) return xfs_ilock_data_map_shared_nowait(dp); return xfs_ilock_data_map_shared(dp); } ... which I think you can use elsewhere in this patch (reformat it to XFS coding style, of course). And then you don't need xfs_ilock_data_map_shared_generic(). 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27473C83F11 for ; Sun, 27 Aug 2023 20:45:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229705AbjH0UpZ (ORCPT ); Sun, 27 Aug 2023 16:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229546AbjH0UpR (ORCPT ); Sun, 27 Aug 2023 16:45:17 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 892F8BF; Sun, 27 Aug 2023 13:45:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=rh2eHyjfSChvP5M3GZFqng0djt iCSjqmEmDczFMnSTrKUt8mmVXGPGgbJ4oq2lIEXyRSbFH+YR4YMUxP/z9QQKohjOoCQZks3WE0IMK 3S4hJ/QxWWGwrLIXBI8vnsgZg3HMNGIE+hIRemTa2iQvkDDHCCMd0yz1djBYQiyi1qOQAKg4GjHdy fEL5cINLesPqAO5iR1xTPAPnXU+iFHAHJEGUTx86DeTnZzv1uxgeaR21j4BV+7nscvIXdd9sVE/Si rCIGIbVvaskI417AUCK4HwQeBGpvqIcrg+ypempVGeBQFeEiZBUSg5QboubLY+HaM/1Y954EFPxgD hXmevJ/g==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qaMcv-00Dkeb-PH; Sun, 27 Aug 2023 20:44:53 +0000 Date: Sun, 27 Aug 2023 21:44:53 +0100 From: Matthew Wilcox To: Hao Xu Cc: io-uring@vger.kernel.org, Jens Axboe , Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , "Darrick J . Wong" , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-cachefs@redhat.com, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-mtd@lists.infradead.org, Wanpeng Li Subject: Re: [PATCH 02/11] xfs: add NOWAIT semantics for readdir Message-ID: References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-3-hao.xu@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230827132835.1373581-3-hao.xu@linux.dev> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Sun, Aug 27, 2023 at 09:28:26PM +0800, Hao Xu wrote: > +++ b/fs/xfs/libxfs/xfs_da_btree.c > @@ -2643,16 +2643,32 @@ xfs_da_read_buf( > struct xfs_buf_map map, *mapp = ↦ > int nmap = 1; > int error; > + int buf_flags = 0; > > *bpp = NULL; > error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap); > if (error || !nmap) > goto out_free; > > + /* > + * NOWAIT semantics mean we don't wait on the buffer lock nor do we > + * issue IO for this buffer if it is not already in memory. Caller will > + * retry. This will return -EAGAIN if the buffer is in memory and cannot > + * be locked, and no buffer and no error if it isn't in memory. We > + * translate both of those into a return state of -EAGAIN and *bpp = > + * NULL. > + */ I would not include this comment. > + if (flags & XFS_DABUF_NOWAIT) > + buf_flags |= XBF_TRYLOCK | XBF_INCORE; > error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, > &bp, ops); what tsting did you do with this? Because you don't actually _use_ buf_flags anywhere in this patch (presumably they should be the sixth argument to xfs_trans_read_buf_map() instead of 0). So I can only conclude that either you didn't test, or your testing was inadequate. > if (error) > goto out_free; > + if (!bp) { > + ASSERT(flags & XFS_DABUF_NOWAIT); I don't think this ASSERT is appropriate. > @@ -391,10 +401,17 @@ xfs_dir2_leaf_getdents( > bp = NULL; > } > > - if (*lock_mode == 0) > - *lock_mode = xfs_ilock_data_map_shared(dp); > + if (*lock_mode == 0) { > + *lock_mode = > + xfs_ilock_data_map_shared_generic(dp, > + ctx->flags & DIR_CONTEXT_F_NOWAIT); > + if (!*lock_mode) { > + error = -EAGAIN; > + break; > + } > + } 'generic' doesn't seem like a great suffix to mean 'takes nowait flag'. And this is far too far indented. xfs_dir2_lock(dp, ctx, lock_mode); with: STATIC void xfs_dir2_lock(struct xfs_inode *dp, struct dir_context *ctx, unsigned int lock_mode) { if (*lock_mode) return; if (ctx->flags & DIR_CONTEXT_F_NOWAIT) return xfs_ilock_data_map_shared_nowait(dp); return xfs_ilock_data_map_shared(dp); } ... which I think you can use elsewhere in this patch (reformat it to XFS coding style, of course). And then you don't need xfs_ilock_data_map_shared_generic(). 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 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1B6C7C83F11 for ; Sun, 27 Aug 2023 20:45:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1693169151; h=from:from:sender:sender: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:list-id:list-help:list-unsubscribe: list-subscribe:list-post; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=iB0OeUTn5eZS8AYMhiiYcm30rGPqNbLeWwp7vggoBNCYeljSrsKPibIma5UvfFwR42n8Uo ePWvHrmtO8J47IrcyNVDPyrL0VwXZHIpbDKcz6NmBC80A10VVwlSFg47SQ4h3XBdkVmp3Y tuwUXmFulEsWp1BZnhWCGZezedu3Z0k= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-167-jsCJqeRsPo26SY9ie4Khww-1; Sun, 27 Aug 2023 16:45:45 -0400 X-MC-Unique: jsCJqeRsPo26SY9ie4Khww-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1C53C101A52E; Sun, 27 Aug 2023 20:45:45 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id E47EC9A; Sun, 27 Aug 2023 20:45:44 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id A109519465B7; Sun, 27 Aug 2023 20:45:44 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id A4F1819465A8 for ; Sun, 27 Aug 2023 20:45:43 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id 8298E492C14; Sun, 27 Aug 2023 20:45:43 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast10.extmail.prod.ext.rdu2.redhat.com [10.11.55.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7B6E1492C13 for ; Sun, 27 Aug 2023 20:45:43 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-inbound-delivery-1.mimecast.com [207.211.31.120]) (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 4349D1C05151 for ; Sun, 27 Aug 2023 20:45:43 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-377-0sffH3aeOPGbV_uu0bWmJw-1; Sun, 27 Aug 2023 16:45:38 -0400 X-MC-Unique: 0sffH3aeOPGbV_uu0bWmJw-1 Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qaMcv-00Dkeb-PH; Sun, 27 Aug 2023 20:44:53 +0000 Date: Sun, 27 Aug 2023 21:44:53 +0100 From: Matthew Wilcox To: Hao Xu Message-ID: References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-3-hao.xu@linux.dev> MIME-Version: 1.0 In-Reply-To: <20230827132835.1373581-3-hao.xu@linux.dev> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Subject: Re: [Cluster-devel] [PATCH 02/11] xfs: add NOWAIT semantics for readdir X-BeenThere: cluster-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: "\[Cluster devel\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wanpeng Li , "Darrick J . Wong" , Dominique Martinet , Dave Chinner , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Stefan Roesch , Clay Harris , linux-s390@vger.kernel.org, linux-nilfs@vger.kernel.org, codalist@coda.cs.cmu.edu, cluster-devel@redhat.com, linux-cachefs@redhat.com, linux-ext4@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-block@vger.kernel.org, Alexander Viro , io-uring@vger.kernel.org, Jens Axboe , Christian Brauner , netdev@vger.kernel.org, samba-technical@lists.samba.org, linux-unionfs@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mtd@lists.infradead.org, bpf@vger.kernel.org, Pavel Begunkov , linux-btrfs@vger.kernel.org Errors-To: cluster-devel-bounces@redhat.com Sender: "Cluster-devel" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: infradead.org Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Aug 27, 2023 at 09:28:26PM +0800, Hao Xu wrote: > +++ b/fs/xfs/libxfs/xfs_da_btree.c > @@ -2643,16 +2643,32 @@ xfs_da_read_buf( > struct xfs_buf_map map, *mapp = ↦ > int nmap = 1; > int error; > + int buf_flags = 0; > > *bpp = NULL; > error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap); > if (error || !nmap) > goto out_free; > > + /* > + * NOWAIT semantics mean we don't wait on the buffer lock nor do we > + * issue IO for this buffer if it is not already in memory. Caller will > + * retry. This will return -EAGAIN if the buffer is in memory and cannot > + * be locked, and no buffer and no error if it isn't in memory. We > + * translate both of those into a return state of -EAGAIN and *bpp = > + * NULL. > + */ I would not include this comment. > + if (flags & XFS_DABUF_NOWAIT) > + buf_flags |= XBF_TRYLOCK | XBF_INCORE; > error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, > &bp, ops); what tsting did you do with this? Because you don't actually _use_ buf_flags anywhere in this patch (presumably they should be the sixth argument to xfs_trans_read_buf_map() instead of 0). So I can only conclude that either you didn't test, or your testing was inadequate. > if (error) > goto out_free; > + if (!bp) { > + ASSERT(flags & XFS_DABUF_NOWAIT); I don't think this ASSERT is appropriate. > @@ -391,10 +401,17 @@ xfs_dir2_leaf_getdents( > bp = NULL; > } > > - if (*lock_mode == 0) > - *lock_mode = xfs_ilock_data_map_shared(dp); > + if (*lock_mode == 0) { > + *lock_mode = > + xfs_ilock_data_map_shared_generic(dp, > + ctx->flags & DIR_CONTEXT_F_NOWAIT); > + if (!*lock_mode) { > + error = -EAGAIN; > + break; > + } > + } 'generic' doesn't seem like a great suffix to mean 'takes nowait flag'. And this is far too far indented. xfs_dir2_lock(dp, ctx, lock_mode); with: STATIC void xfs_dir2_lock(struct xfs_inode *dp, struct dir_context *ctx, unsigned int lock_mode) { if (*lock_mode) return; if (ctx->flags & DIR_CONTEXT_F_NOWAIT) return xfs_ilock_data_map_shared_nowait(dp); return xfs_ilock_data_map_shared(dp); } ... which I think you can use elsewhere in this patch (reformat it to XFS coding style, of course). And then you don't need xfs_ilock_data_map_shared_generic(). 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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2E0EEC83F01 for ; Sun, 27 Aug 2023 20:45:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9HouHWEHdP+TY7fWxfGOKbE6LcAHTyujOBBOuZ6nh7s=; b=LOyHmskH96dX4U QdOVj8+X6Ftgz3NQdsjn6ZEISGKRSNmv1HgUpEizdbUxj3o+9ETYLZdCFvK2y148Xpf4h1Nj5cdem WsYjGekmW1LFAcD6M4QKShw9vGI6n+48G579nW2eUFf3dF27RoYVYhn3lU0vDwGgA0m4nO+R4Sadq Ek37aDL1QntPDqokbyMQhHHFc54yLJWPD/+p+oRpiAZsD6mNUD+XfBBw3fPsitmat5VBiaV0sND0B eZtV2iYAR39MeXYox7F3UdTMAdTe3+OHdEcty8Eu0RjxKy3K4UJxEWAnbYE5U0phmULaNHYaif53i JD0PujVc35BBAhqiDA8A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qaMdE-008Rpc-18; Sun, 27 Aug 2023 20:45:12 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qaMdC-008RpV-28 for linux-mtd@bombadil.infradead.org; Sun, 27 Aug 2023 20:45:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=rh2eHyjfSChvP5M3GZFqng0djt iCSjqmEmDczFMnSTrKUt8mmVXGPGgbJ4oq2lIEXyRSbFH+YR4YMUxP/z9QQKohjOoCQZks3WE0IMK 3S4hJ/QxWWGwrLIXBI8vnsgZg3HMNGIE+hIRemTa2iQvkDDHCCMd0yz1djBYQiyi1qOQAKg4GjHdy fEL5cINLesPqAO5iR1xTPAPnXU+iFHAHJEGUTx86DeTnZzv1uxgeaR21j4BV+7nscvIXdd9sVE/Si rCIGIbVvaskI417AUCK4HwQeBGpvqIcrg+ypempVGeBQFeEiZBUSg5QboubLY+HaM/1Y954EFPxgD hXmevJ/g==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qaMcv-00Dkeb-PH; Sun, 27 Aug 2023 20:44:53 +0000 Date: Sun, 27 Aug 2023 21:44:53 +0100 From: Matthew Wilcox To: Hao Xu Cc: io-uring@vger.kernel.org, Jens Axboe , Dominique Martinet , Pavel Begunkov , Christian Brauner , Alexander Viro , Stefan Roesch , Clay Harris , Dave Chinner , "Darrick J . Wong" , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-cachefs@redhat.com, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, codalist@coda.cs.cmu.edu, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-mtd@lists.infradead.org, Wanpeng Li Subject: Re: [PATCH 02/11] xfs: add NOWAIT semantics for readdir Message-ID: References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-3-hao.xu@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230827132835.1373581-3-hao.xu@linux.dev> X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Sun, Aug 27, 2023 at 09:28:26PM +0800, Hao Xu wrote: > +++ b/fs/xfs/libxfs/xfs_da_btree.c > @@ -2643,16 +2643,32 @@ xfs_da_read_buf( > struct xfs_buf_map map, *mapp = ↦ > int nmap = 1; > int error; > + int buf_flags = 0; > > *bpp = NULL; > error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap); > if (error || !nmap) > goto out_free; > > + /* > + * NOWAIT semantics mean we don't wait on the buffer lock nor do we > + * issue IO for this buffer if it is not already in memory. Caller will > + * retry. This will return -EAGAIN if the buffer is in memory and cannot > + * be locked, and no buffer and no error if it isn't in memory. We > + * translate both of those into a return state of -EAGAIN and *bpp = > + * NULL. > + */ I would not include this comment. > + if (flags & XFS_DABUF_NOWAIT) > + buf_flags |= XBF_TRYLOCK | XBF_INCORE; > error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, > &bp, ops); what tsting did you do with this? Because you don't actually _use_ buf_flags anywhere in this patch (presumably they should be the sixth argument to xfs_trans_read_buf_map() instead of 0). So I can only conclude that either you didn't test, or your testing was inadequate. > if (error) > goto out_free; > + if (!bp) { > + ASSERT(flags & XFS_DABUF_NOWAIT); I don't think this ASSERT is appropriate. > @@ -391,10 +401,17 @@ xfs_dir2_leaf_getdents( > bp = NULL; > } > > - if (*lock_mode == 0) > - *lock_mode = xfs_ilock_data_map_shared(dp); > + if (*lock_mode == 0) { > + *lock_mode = > + xfs_ilock_data_map_shared_generic(dp, > + ctx->flags & DIR_CONTEXT_F_NOWAIT); > + if (!*lock_mode) { > + error = -EAGAIN; > + break; > + } > + } 'generic' doesn't seem like a great suffix to mean 'takes nowait flag'. And this is far too far indented. xfs_dir2_lock(dp, ctx, lock_mode); with: STATIC void xfs_dir2_lock(struct xfs_inode *dp, struct dir_context *ctx, unsigned int lock_mode) { if (*lock_mode) return; if (ctx->flags & DIR_CONTEXT_F_NOWAIT) return xfs_ilock_data_map_shared_nowait(dp); return xfs_ilock_data_map_shared(dp); } ... which I think you can use elsewhere in this patch (reformat it to XFS coding style, of course). And then you don't need xfs_ilock_data_map_shared_generic(). ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ 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 Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 10AE9C83F01 for ; Sun, 27 Aug 2023 20:46:01 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1qaMdx-0003oE-DU; Sun, 27 Aug 2023 20:45:58 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qaMdw-0003o8-Q0 for linux-f2fs-devel@lists.sourceforge.net; Sun, 27 Aug 2023 20:45:57 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Type:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=eGUZjJ3YUlVYRV093I+t2xqBx1 wJRHC2dZX2GRUR1IITmhmIm9lSYqwVdntEkbxh02HvorJIWaGCD2vNVUWkfRP/PDraIZgVZboakNk DXrgWWAkUGMsqJlPbhY+FwdBPK4P7SCPulV833SG+6AzH0MbEtrnT1DJlefFtzRXcfbE=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To :From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=IxmjDWqmZ0w/thUK9pDTrc96Uc zprAQ+LiP0HZDVJNMLAZhZNpTryigwKrbcITf6AD/zqmDN7GpdHRGCCbfACv3vgc7x8HBob7XL5y3 6NNWuraWIvYwvXCQsM2/iu7qVUT0ax1sPZh4jgzQI70Wl2sgggGqfVSGYk/5imk0gj2Y=; Received: from casper.infradead.org ([90.155.50.34]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1qaMdt-0003Rd-W1 for linux-f2fs-devel@lists.sourceforge.net; Sun, 27 Aug 2023 20:45:57 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=rh2eHyjfSChvP5M3GZFqng0djt iCSjqmEmDczFMnSTrKUt8mmVXGPGgbJ4oq2lIEXyRSbFH+YR4YMUxP/z9QQKohjOoCQZks3WE0IMK 3S4hJ/QxWWGwrLIXBI8vnsgZg3HMNGIE+hIRemTa2iQvkDDHCCMd0yz1djBYQiyi1qOQAKg4GjHdy fEL5cINLesPqAO5iR1xTPAPnXU+iFHAHJEGUTx86DeTnZzv1uxgeaR21j4BV+7nscvIXdd9sVE/Si rCIGIbVvaskI417AUCK4HwQeBGpvqIcrg+ypempVGeBQFeEiZBUSg5QboubLY+HaM/1Y954EFPxgD hXmevJ/g==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qaMcv-00Dkeb-PH; Sun, 27 Aug 2023 20:44:53 +0000 Date: Sun, 27 Aug 2023 21:44:53 +0100 From: Matthew Wilcox To: Hao Xu Message-ID: References: <20230827132835.1373581-1-hao.xu@linux.dev> <20230827132835.1373581-3-hao.xu@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230827132835.1373581-3-hao.xu@linux.dev> X-Headers-End: 1qaMdt-0003Rd-W1 Subject: Re: [f2fs-dev] [PATCH 02/11] xfs: add NOWAIT semantics for readdir X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wanpeng Li , "Darrick J . Wong" , Dominique Martinet , Dave Chinner , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Stefan Roesch , Clay Harris , linux-s390@vger.kernel.org, linux-nilfs@vger.kernel.org, codalist@coda.cs.cmu.edu, cluster-devel@redhat.com, linux-cachefs@redhat.com, linux-ext4@vger.kernel.org, devel@lists.orangefs.org, linux-cifs@vger.kernel.org, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-block@vger.kernel.org, Alexander Viro , io-uring@vger.kernel.org, Jens Axboe , Christian Brauner , netdev@vger.kernel.org, samba-technical@lists.samba.org, linux-unionfs@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mtd@lists.infradead.org, bpf@vger.kernel.org, Pavel Begunkov , linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On Sun, Aug 27, 2023 at 09:28:26PM +0800, Hao Xu wrote: > +++ b/fs/xfs/libxfs/xfs_da_btree.c > @@ -2643,16 +2643,32 @@ xfs_da_read_buf( > struct xfs_buf_map map, *mapp = ↦ > int nmap = 1; > int error; > + int buf_flags = 0; > > *bpp = NULL; > error = xfs_dabuf_map(dp, bno, flags, whichfork, &mapp, &nmap); > if (error || !nmap) > goto out_free; > > + /* > + * NOWAIT semantics mean we don't wait on the buffer lock nor do we > + * issue IO for this buffer if it is not already in memory. Caller will > + * retry. This will return -EAGAIN if the buffer is in memory and cannot > + * be locked, and no buffer and no error if it isn't in memory. We > + * translate both of those into a return state of -EAGAIN and *bpp = > + * NULL. > + */ I would not include this comment. > + if (flags & XFS_DABUF_NOWAIT) > + buf_flags |= XBF_TRYLOCK | XBF_INCORE; > error = xfs_trans_read_buf_map(mp, tp, mp->m_ddev_targp, mapp, nmap, 0, > &bp, ops); what tsting did you do with this? Because you don't actually _use_ buf_flags anywhere in this patch (presumably they should be the sixth argument to xfs_trans_read_buf_map() instead of 0). So I can only conclude that either you didn't test, or your testing was inadequate. > if (error) > goto out_free; > + if (!bp) { > + ASSERT(flags & XFS_DABUF_NOWAIT); I don't think this ASSERT is appropriate. > @@ -391,10 +401,17 @@ xfs_dir2_leaf_getdents( > bp = NULL; > } > > - if (*lock_mode == 0) > - *lock_mode = xfs_ilock_data_map_shared(dp); > + if (*lock_mode == 0) { > + *lock_mode = > + xfs_ilock_data_map_shared_generic(dp, > + ctx->flags & DIR_CONTEXT_F_NOWAIT); > + if (!*lock_mode) { > + error = -EAGAIN; > + break; > + } > + } 'generic' doesn't seem like a great suffix to mean 'takes nowait flag'. And this is far too far indented. xfs_dir2_lock(dp, ctx, lock_mode); with: STATIC void xfs_dir2_lock(struct xfs_inode *dp, struct dir_context *ctx, unsigned int lock_mode) { if (*lock_mode) return; if (ctx->flags & DIR_CONTEXT_F_NOWAIT) return xfs_ilock_data_map_shared_nowait(dp); return xfs_ilock_data_map_shared(dp); } ... which I think you can use elsewhere in this patch (reformat it to XFS coding style, of course). And then you don't need xfs_ilock_data_map_shared_generic(). _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel