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 8B2F5ECAAA1 for ; Mon, 12 Sep 2022 04:56:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229575AbiILE4O (ORCPT ); Mon, 12 Sep 2022 00:56:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229536AbiILE4N (ORCPT ); Mon, 12 Sep 2022 00:56:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8254D220CE for ; Sun, 11 Sep 2022 21:56:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E8A5260CA4 for ; Mon, 12 Sep 2022 04:56:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 424EDC433C1; Mon, 12 Sep 2022 04:56:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1662958571; bh=9TEHVj5y9tRujK3JblJTVzzJou6z/NORFJmUVkUX0Hw=; h=Date:To:From:Subject:From; b=ul79IU2wDbRRPE3xgWDe/xqOe2Y7YKGx1xV1YZStTju5d47tuDwUmAqB7j5N2auJ+ 9FcViIe8KZuM3KOYmN5ZIAakXDgUWzRbztkqn/Y6ab0Q9rf9Tkm+KH4e7oYbaXAlRQ F7LjMVxOIJa/g04uu6Ry+C3Fnim8fVxQGvWfRkzM= Date: Sun, 11 Sep 2022 21:56:10 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, songmuchun@bytedance.com, slava@dubeyko.com, keescook@chromium.org, ira.weiny@intel.com, bvanassche@acm.org, axboe@kernel.dk, fmdefrancesco@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-nonmm-stable] hfsplus-unmap-the-page-in-the-fail_page-label.patch removed from -mm tree Message-Id: <20220912045611.424EDC433C1@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: hfsplus: unmap the page in the "fail_page" label has been removed from the -mm tree. Its filename was hfsplus-unmap-the-page-in-the-fail_page-label.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Fabio M. De Francesco" Subject: hfsplus: unmap the page in the "fail_page" label Date: Tue, 9 Aug 2022 22:31:02 +0200 Patch series "hfsplus: Replace kmap() with kmap_local_page()". kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Since its use in fs/hfsplus is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in fs/hfsplus. Where possible, use the suited standard helpers (memzero_page(), memcpy_page()) instead of open coding kmap_local_page() plus memset() or memcpy(). Fix a bug due to a page being not unmapped if the code jumps to the "fail_page" label (1/4). Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. This patch (of 4): Several paths within hfs_btree_open() jump to the "fail_page" label where put_page() is called while the page is still mapped. Call kunmap() to unmap the page soon before put_page(). Link: https://lkml.kernel.org/r/20220809203105.26183-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20220809203105.26183-2-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Matthew Wilcox Cc: Fabio M. De Francesco Cc: Jens Axboe Cc: Bart Van Assche Cc: Kees Cook Cc: Muchun Song Signed-off-by: Andrew Morton --- fs/hfsplus/btree.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/hfsplus/btree.c~hfsplus-unmap-the-page-in-the-fail_page-label +++ a/fs/hfsplus/btree.c @@ -245,6 +245,7 @@ struct hfs_btree *hfs_btree_open(struct return tree; fail_page: + kunmap(page); put_page(page); free_inode: tree->inode->i_mapping->a_ops = &hfsplus_aops; _ Patches currently in -mm which might be from fmdefrancesco@gmail.com are