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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F217DC83F01 for ; Sun, 27 Aug 2023 20:45:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 292078E000E; Sun, 27 Aug 2023 16:45:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 244098E0001; Sun, 27 Aug 2023 16:45:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 130CA8E000E; Sun, 27 Aug 2023 16:45:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 050608E0001 for ; Sun, 27 Aug 2023 16:45:47 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 2C40AA0199 for ; Sun, 27 Aug 2023 20:45:46 +0000 (UTC) X-FDA: 81171065892.23.1AD9E42 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf03.hostedemail.com (Postfix) with ESMTP id F0E5C20016 for ; Sun, 27 Aug 2023 20:45:43 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=rh2eHyjf; dmarc=none; spf=none (imf03.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693169144; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=b31OO6Xd9+jxzKw5QB3n4d33iA6sZ4nPi+nMylKSno4=; b=d8eMAWxrNEFin+YeqGv768JHn/CEcbXpciCIjsUUDpqkcn1SuGauXa7xuYjI7SfgvK4AQO v2Ak/rl0MF+ij1t6WAcX6GXfjA4tCtLL05OzZYmKXurPjKCiin0pJ1OrcmW54ft16BB8iu FGm2Nq3536jkmMzJxYKa+AIehg5D3AY= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=rh2eHyjf; dmarc=none; spf=none (imf03.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693169144; a=rsa-sha256; cv=none; b=ej6ob3CHpcgDaqfr4SxWFZseDWezQDLvzmdv4eTbM0H8RyLrl4fSKlznEEnKtCtj4hghBs MZP9U0FwlgTNDp38KvQKqEWCRF5+g0AJ3SwvRm88OnW3lKMg3TyN7i4D+E2zGmGKLwsLCl Jm/DIzhnv69Se35X3eitfYvsDmXmBxY= 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> X-Rspam-User: X-Stat-Signature: trg3hmao3p8i4k3gzz5kus1zhybn57jq X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: F0E5C20016 X-HE-Tag: 1693169143-571704 X-HE-Meta: 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 2Ly4E/Ai iWOQIJpJf97mybf5ISMIt1IxA3sOSGq1xqzgq1ZnpjVqABRmKrtsNnGBvCIOUUI+Vu6YgDj8WuNeRURlUdAUgLs8zaDLSGz/p+hrGbLpp7SttA9+D/a0GrBia4NIrjTjJyPQLa12v7f4tWiVA32pai5D3fMHCBpbl7L6dQl8KqT29wr6/IOzE213Vzbl9yCNzevfTt6ErDHq0TihayGjT+QD9RA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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().