From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-124.freemail.mail.aliyun.com (out30-124.freemail.mail.aliyun.com [115.124.30.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F01B7156649 for ; Thu, 19 Dec 2024 07:30:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593422; cv=none; b=QLIFNU+yYzw7SE/zvVze8LRAItsIduoWKEnmezYCVJW0OO0y5UmbCbHr/DzF0nxsPeweFrmvzqr7et8+ACcErxfzdl9Sa8nW3nW4+xcTfgPj4BX55ND08mH/Vc80ypiDAgWqWZW/8N2sMNnKHFRugryMwJpW+D8ByaCN7eS6pmA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734593422; c=relaxed/simple; bh=W9O2rsBod/HygNmYJVc5po7uQfQnwta2pEtySz+cDUY=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=KMckHKmUSCrr+oFspn64brpuzVm03tXgpFQhBGpHGKK9nM1ilazOTj8bpdAq5Lr/ocpWUuBVZCKgR6m5JVUZ1PJGcTDEBWsVuf2jm5eG/GeSEe4mrxMnZtDL1/k4TuNQreGPzhQcGpouhVdQGwSaHEIlxXrxmibwxvUo1ydEWJg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=oB3TzVIm; arc=none smtp.client-ip=115.124.30.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="oB3TzVIm" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1734593416; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=M8zYKBBFJV3f7n/1X2H/QO/djeX/cWE2BXzLzdK+uwg=; b=oB3TzVImLUZYqLjQGJxX8V44DxXrNllvzhYpvUmZFK4hlg54RovSS7F4CMTCqKUJs63BKo+85szHf+Tz+4plpF29g28iZrUL6CurEz0jnZ9wyNHeBQ17g/VmG4NjNECRHTDGS6JW+gk3EFfrfpY3FeEn7FbTu/rUFnDezIXDBjE= Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0WLpQru._1734593415 cluster:ay36) by smtp.aliyun-inc.com; Thu, 19 Dec 2024 15:30:16 +0800 From: Baolin Wang To: akpm@linux-foundation.org, hughd@google.com Cc: david@redhat.com, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] mm: shmem: fix incorrect index alignment for within_size policy Date: Thu, 19 Dec 2024 15:30:08 +0800 Message-Id: <77d8ef76a7d3d646e9225e9af88a76549a68aab1.1734593154.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With enabling the shmem per-size within_size policy, using an incorrect 'order' size to round_up() the index can lead to incorrect i_size checks, resulting in an inappropriate large orders being returned. Changing to use '1 << order' to round_up() the index to fix this issue. Additionally, adding an 'aligned_index' variable to avoid affecting the index checks. Fixes: e7a2ab7b3bb5 ("mm: shmem: add mTHP support for anonymous shmem") Signed-off-by: Baolin Wang --- Hi Andrew, These two bugfix patches are based on the mm-hotfixes-unstable branch, and this patch has a slight conflict with my previous patch set: "Support large folios for tmpfs". However, I think the conflicts are easy to resolve. If you need me to rebase and resend the "Support large folios for tmpfs" patch set, please let me know. Sorry for the troubles :) --- mm/shmem.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index f6fb053ac50d..dec659e84562 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1689,6 +1689,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, unsigned long mask = READ_ONCE(huge_shmem_orders_always); unsigned long within_size_orders = READ_ONCE(huge_shmem_orders_within_size); unsigned long vm_flags = vma ? vma->vm_flags : 0; + pgoff_t aligned_index; bool global_huge; loff_t i_size; int order; @@ -1723,9 +1724,9 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode, /* Allow mTHP that will be fully within i_size. */ order = highest_order(within_size_orders); while (within_size_orders) { - index = round_up(index + 1, order); + aligned_index = round_up(index + 1, 1 << order); i_size = round_up(i_size_read(inode), PAGE_SIZE); - if (i_size >> PAGE_SHIFT >= index) { + if (i_size >> PAGE_SHIFT >= aligned_index) { mask |= within_size_orders; break; } -- 2.39.3