From patchwork Sat Apr 10 07:23:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12195449 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 1B1E9C43461 for ; Sat, 10 Apr 2021 07:24:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BE771610CB for ; Sat, 10 Apr 2021 07:24:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BE771610CB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B56396B0073; Sat, 10 Apr 2021 03:24:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B09376B0074; Sat, 10 Apr 2021 03:24:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7ADED6B0078; Sat, 10 Apr 2021 03:24:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id 62BDC6B0074 for ; Sat, 10 Apr 2021 03:24:52 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0D8D7181F598F for ; Sat, 10 Apr 2021 07:24:52 +0000 (UTC) X-FDA: 78015620424.09.4421FA1 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by imf27.hostedemail.com (Postfix) with ESMTP id 52D7F80192D5 for ; Sat, 10 Apr 2021 07:24:43 +0000 (UTC) Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4FHRJk69hrzNvPY; Sat, 10 Apr 2021 15:21:58 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Sat, 10 Apr 2021 15:24:38 +0800 From: Miaohe Lin To: , CC: , , , Subject: [PATCH v2 4/5] mm/hugeltb: handle the error case in hugetlb_fix_reserve_counts() Date: Sat, 10 Apr 2021 03:23:47 -0400 Message-ID: <20210410072348.20437-5-linmiaohe@huawei.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20210410072348.20437-1-linmiaohe@huawei.com> References: <20210410072348.20437-1-linmiaohe@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected X-Stat-Signature: 96k4yjm797ckzoq1dj5s6tosgb6awz57 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 52D7F80192D5 Received-SPF: none (huawei.com>: No applicable sender policy available) receiver=imf27; identity=mailfrom; envelope-from=""; helo=szxga05-in.huawei.com; client-ip=45.249.212.191 X-HE-DKIM-Result: none/none X-HE-Tag: 1618039483-109858 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: A rare out of memory error would prevent removal of the reserve map region for a page. hugetlb_fix_reserve_counts() handles this rare case to avoid dangling with incorrect counts. Unfortunately, hugepage_subpool_get_pages and hugetlb_acct_memory could possibly fail too. We should correctly handle these cases. Fixes: b5cec28d36f5 ("hugetlbfs: truncate_hugepages() takes a range of pages") Signed-off-by: Miaohe Lin Reviewed-by: Mike Kravetz --- mm/hugetlb.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 387c9a62615e..a14bb1a03ee4 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -745,13 +745,20 @@ void hugetlb_fix_reserve_counts(struct inode *inode) { struct hugepage_subpool *spool = subpool_inode(inode); long rsv_adjust; + bool reserved = false; rsv_adjust = hugepage_subpool_get_pages(spool, 1); - if (rsv_adjust) { + if (rsv_adjust > 0) { struct hstate *h = hstate_inode(inode); - hugetlb_acct_memory(h, 1); + if (!hugetlb_acct_memory(h, 1)) + reserved = true; + } else if (!rsv_adjust) { + reserved = true; } + + if (!reserved) + pr_warn("hugetlb: Huge Page Reserved count may go negative.\n"); } /*