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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 EFFA9C2BB1D for ; Tue, 17 Mar 2020 15:28:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B15BE206EC for ; Tue, 17 Mar 2020 15:28:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nNS0iOdm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B15BE206EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3D4E96B0005; Tue, 17 Mar 2020 11:28:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 385596B0006; Tue, 17 Mar 2020 11:28:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 29A216B0007; Tue, 17 Mar 2020 11:28:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id 0C91B6B0005 for ; Tue, 17 Mar 2020 11:28:52 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id F08A44DD9 for ; Tue, 17 Mar 2020 15:28:51 +0000 (UTC) X-FDA: 76605236862.15.chess97_8795d119b585d X-HE-Tag: chess97_8795d119b585d X-Filterd-Recvd-Size: 2997 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Mar 2020 15:28:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=xJA9FFPfJkuq8fVzTKccTbceOpg3uJs1/00mKyQZnEc=; b=nNS0iOdmgHP2ZIGEAO0g8u8fHS TDvQDiQcFH1hBkh3Q5nsFQz5yj7wNCL9cCORyBIyR7V7GMpP/q/ZoUKULALuLr2IdVltjzsEIP4xU ZxpJAxHApbow3TTrO+kd7z8z5XjPJvXMEpQnHDINerFDHBgzwxx833CnsYL6lxI3noSayyLLf8qoR e4jvJjgerruwRQffudZlNvBPEa8TKXAtVTahVkqvpnOgladbVay0AMUHK92QgVxKvK4RBmQ5/1d1R +yWUabB4oYjjbTWqpMJSPZIicNbXxCNRb7EXNJSzuMNn4VGo1WST+AhzHDaLRUUWT0AbzpC+lzkCj r6J22hMQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jEE9C-0008Sr-5E; Tue, 17 Mar 2020 15:28:50 +0000 Date: Tue, 17 Mar 2020 08:28:50 -0700 From: Matthew Wilcox To: Jan Kara Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 2/8] xarray: Provide xas_erase() helper Message-ID: <20200317152850.GC22433@bombadil.infradead.org> References: <20200204142514.15826-1-jack@suse.cz> <20200204142514.15826-3-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200204142514.15826-3-jack@suse.cz> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Feb 04, 2020 at 03:25:08PM +0100, Jan Kara wrote: > +void *xas_erase(struct xa_state *xas) > +{ > + void *entry; > + > + entry = xas_store(xas, NULL); > + xas_init_marks(xas); > + > + return entry; > +} > +EXPORT_SYMBOL(xas_erase); I didn't have a test case to show this, but ... +static noinline void check_multi_store_4(struct xarray *xa) +{ + XA_BUG_ON(xa, xa_marked(xa, XA_MARK_0)); + XA_BUG_ON(xa, !xa_empty(xa)); + + xa_store_index(xa, 0, GFP_KERNEL); + xa_store_index(xa, 2, GFP_KERNEL); + xa_set_mark(xa, 0, XA_MARK_0); + xa_set_mark(xa, 2, XA_MARK_0); + + xa_store_order(xa, 0, 2, NULL, GFP_KERNEL); + XA_BUG_ON(xa, xa_marked(xa, XA_MARK_0)); + xa_destroy(xa); +} shows a problem. Because we delete all the entries in the tree, xas_delete_node() sets the xas->xa_node to XAS_BOUNDS. This fixes it: @@ -492,7 +492,6 @@ static void xas_delete_node(struct xa_state *xas) if (!parent) { xas->xa->xa_head = NULL; - xas->xa_node = XAS_BOUNDS; return; } (it leaves xas->xa_node set to NULL, which makes the above work correctly because NULL is used to mean the one element at index 0 of the array) Now I'm wondering if it's going to break anything, though. The test suite runs successfully, but it can't be exhaustive.