From patchwork Sun Sep 10 21:52:41 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 9946389 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6BD5D6035D for ; Sun, 10 Sep 2017 21:53:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 542A828A0C for ; Sun, 10 Sep 2017 21:53:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4903F28A69; Sun, 10 Sep 2017 21:53:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B51A28A0C for ; Sun, 10 Sep 2017 21:53:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751722AbdIJVwr (ORCPT ); Sun, 10 Sep 2017 17:52:47 -0400 Received: from mail-io0-f196.google.com ([209.85.223.196]:34278 "EHLO mail-io0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751296AbdIJVwr (ORCPT ); Sun, 10 Sep 2017 17:52:47 -0400 Received: by mail-io0-f196.google.com with SMTP id g32so766417ioj.1 for ; Sun, 10 Sep 2017 14:52:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=o1M8mxlR71w2+aIeFJFDBdn2+9DRaLEk0WqEc8OhgqM=; b=Vw2ZMrxm+dPi0rFgMFNeNIi+1CGGmdPcuoSGOZYT0FPORGS3ugm8liq5aIurhyuu7k OS95/AHvlEf1Jnc+YW6bphsF/n4iGNPdEn5jAHMvFn9TSxJNxnUx+WjEKTuxke9z6tf6 pSXQBJButLW5fv2FdAhPhj6JOk9UcZAjk38//QJmgfhZR1CDUnOfEWz5NlFbIryEWlME FLu2KMzzpEBvDzAgLvHhu2312fGcHmZUZ7srLN6tIXKI4+QcDUKX/4LodRAkAGRtIfAP Ku6Sjh/pEZK62TAPKCe1Z+WiaAuXDW1mOqdP6e1vnlvB4poNEdP5PfH0M21IyW3lZqtb 57RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:subject:date:message-id :mime-version:content-transfer-encoding; bh=o1M8mxlR71w2+aIeFJFDBdn2+9DRaLEk0WqEc8OhgqM=; b=HgS6dzuOYizbmlQX6HrdFSNz7TTqTMWLm4bIz5xOprcSSR6Fsq4K3NbgU7ERTxyZUr tUuSAjW3bcddC+NIjQB7a4T20Sd/k8S0xNrRiyEPC5IzoIU4nakYGFAWQhSScnAVfFyZ iMo8XM6QpZQdQgDAhxvcXBzRVp15isL1WXYd6XZysugt6zTBaw690K9dvrjJEUW6xQ3K zj1spVFeL0PL4/VKBunZlkDopaAokOatXpS7WtcIkWkjSzfTtFWQSFBeitLX3kgS00sg b8A6+W/MBVAOaHweV2aur5H9qzgIrz1tz+db14J2y8Mx52O5hSSZpUvcQp9KxeE8OBGi CApQ== X-Gm-Message-State: AHPjjUj//P5waQqppR9K5Iyp8b0jhxCOdIugss73Q1OqoQXQKeVl+8UJ ldZvG7Ac9bB56BIYOnY= X-Google-Smtp-Source: AOwi7QBoPboumO5K6s/cA6xtgvfEipcmgOOc34LSKWHljkWWz+QzdFwg4I19mEkbJ2zHQUeNTk5QyQ== X-Received: by 10.107.202.133 with SMTP id a127mr12333756iog.22.1505080366018; Sun, 10 Sep 2017 14:52:46 -0700 (PDT) Received: from localhost.localdomain (c-68-49-162-121.hsd1.mi.comcast.net. [68.49.162.121]) by smtp.gmail.com with ESMTPSA id a100sm1351439ioj.47.2017.09.10.14.52.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 10 Sep 2017 14:52:45 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH 1/2] NFS: Don't hold the group lock when calling nfs_release_request() Date: Sun, 10 Sep 2017 17:52:41 -0400 Message-Id: <20170910215242.4212-1-trond.myklebust@primarydata.com> X-Mailer: git-send-email 2.13.5 MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP That can deadlock if this is the last reference since nfs_page_group_destroy() calls nfs_page_group_sync_on_bit(). Note that even if the page was removed from the subpage list, the req->wb_head could still be pointing to the old head. Signed-off-by: Trond Myklebust --- fs/nfs/write.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 121218d4e5ed..36d34a4c86bd 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -532,9 +532,9 @@ nfs_lock_and_join_requests(struct page *page) } else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset || ((subreq->wb_offset + subreq->wb_bytes) > (head->wb_offset + total_bytes)))) { + nfs_page_group_unlock(head); nfs_unroll_locks(inode, head, subreq); nfs_unlock_and_release_request(subreq); - nfs_page_group_unlock(head); nfs_unlock_and_release_request(head); return ERR_PTR(-EIO); }