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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT 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 72E4CC43441 for ; Thu, 29 Nov 2018 02:32:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 30FF3206B2 for ; Thu, 29 Nov 2018 02:32:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QUa5K2/g" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30FF3206B2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727500AbeK2NgA (ORCPT ); Thu, 29 Nov 2018 08:36:00 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:45165 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727022AbeK2NgA (ORCPT ); Thu, 29 Nov 2018 08:36:00 -0500 Received: by mail-pf1-f193.google.com with SMTP id g62so221540pfd.12; Wed, 28 Nov 2018 18:32:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=ly6p341eePfycK8xgoPA+gkH5QlCh1GYoI5eKaSBF/s=; b=QUa5K2/g0Q2MdBbv4qtrGXKOUOafz/xwaUxhqDUL+V8/loYqAhUHHbxSBV4HrLIidT YwYfJrvJHewnRKpahZnajFnkQfH/+fNgAgcYnvdPABePmR8lsLbBOUtb/73BUAheRORi hUjfCHStMR8+6fwJtJzzdqWfDUd49Ad60T9RDF1IRzFM4jNwt6J5KgqJ5KT8z0lOkLCa JAeujCBn1vAozGKxfgm7EMpbbFmeqb34MeOE1+28nNT5xbIeSSi49J4fJw4ptezPlAP1 s4kgGVlBtj0Sx5BG8RIPDXTwYC+fkIuyV4OMMY1vAaNcN4BAexEE1w8T6nCkxm5wtek7 dynw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=ly6p341eePfycK8xgoPA+gkH5QlCh1GYoI5eKaSBF/s=; b=Tdx5nvM7LsvqFkNygOTvsDsUfcHS+Iun31SGhbhsP6eHXbsmQMBaM6RNCpXPjnva5B sDMNEB74ezwSakYRLtszrZZbVSpz3e77Wyqsrh/08DnqPI1sWpPX/Xu9JO1vhJlhegFS 3iLEDY0vrDV/1VSGJ/u1w8DBWGeWfAbjWmILxczGDit65cUz/qElNGuUDJ/fm5C+POdi sgJvRDT18OcPQj0C3Ydpf2upSxMni6w+RHyzmYT8XjbHYxN1TJP8ZNgDiMHuTJxS9zn9 UmUJVn+Xf/HMRItlh+G+v1UplYu0SHEWbaV7X3hsGiSvk6uanwdHyAg0tuqX3fRNTrKD MhpA== X-Gm-Message-State: AA+aEWaMvWycGi6TMUf8DleusvPovjTmzWSCCRbQSgU1V/lZ/M5wJ6ww tuke6h5PQchdUevvwpOxgBI= X-Google-Smtp-Source: AJdET5ctRGqHpvG9VeSOILVNeDY4NjQU9DROKUDdgzM94TMo3Hl+arGNdT8SoR9llt0+BZNacpTbxA== X-Received: by 2002:a63:4926:: with SMTP id w38mr33991354pga.353.1543458734628; Wed, 28 Nov 2018 18:32:14 -0800 (PST) Received: from localhost ([175.223.15.27]) by smtp.gmail.com with ESMTPSA id f62sm306996pgc.67.2018.11.28.18.32.13 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 28 Nov 2018 18:32:13 -0800 (PST) Date: Thu, 29 Nov 2018 11:32:10 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Andrew Morton , LKML , Sergey Senozhatsky , Joey Pabalinas , stable@vger.kernel.org Subject: Re: [PATCH v3 2/7] zram: fix double free backing device Message-ID: <20181129023210.GC6379@jagdpanzerIV> References: <20181127055429.251614-1-minchan@kernel.org> <20181127055429.251614-3-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181127055429.251614-3-minchan@kernel.org> User-Agent: Mutt/1.11.0 (2018-11-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (11/27/18 14:54), Minchan Kim wrote: > If blkdev_get fails, we shouldn't do blkdev_put. Otherwise, > kernel emits below log. This patch fixes it. > > [ 31.073006] WARNING: CPU: 0 PID: 1893 at fs/block_dev.c:1828 blkdev_put+0x105/0x120 > [ 31.075104] Modules linked in: > [ 31.075898] CPU: 0 PID: 1893 Comm: swapoff Not tainted 4.19.0+ #453 > [ 31.077484] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > [ 31.079589] RIP: 0010:blkdev_put+0x105/0x120 > [ 31.080606] Code: 48 c7 80 a0 00 00 00 00 00 00 00 48 c7 c7 40 e7 40 96 e8 6e 47 73 00 48 8b bb e0 00 00 00 e9 2c ff ff ff 0f 0b e9 75 ff ff ff <0f> 0b e9 5a ff ff ff 48 c7 80 a0 00 00 00 00 00 00 00 eb 87 0f 1f > [ 31.085080] RSP: 0018:ffffb409005c7ed0 EFLAGS: 00010297 > [ 31.086383] RAX: ffff9779fe5a8040 RBX: ffff9779fbc17300 RCX: 00000000b9fc37a4 > [ 31.088105] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff9640e740 > [ 31.089850] RBP: ffff9779fbc17318 R08: ffffffff95499a89 R09: 0000000000000004 > [ 31.091201] R10: ffffb409005c7e50 R11: 7a9ef6088ff4d4a1 R12: 0000000000000083 > [ 31.092276] R13: ffff9779fe607b98 R14: 0000000000000000 R15: ffff9779fe607a38 > [ 31.093355] FS: 00007fc118d9b840(0000) GS:ffff9779fc600000(0000) knlGS:0000000000000000 > [ 31.094582] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 31.095541] CR2: 00007fc11894b8dc CR3: 00000000339f6001 CR4: 0000000000160ef0 > [ 31.096781] Call Trace: > [ 31.097212] __x64_sys_swapoff+0x46d/0x490 > [ 31.097914] do_syscall_64+0x5a/0x190 > [ 31.098550] entry_SYSCALL_64_after_hwframe+0x49/0xbe > [ 31.099402] RIP: 0033:0x7fc11843ec27 > [ 31.100013] Code: 73 01 c3 48 8b 0d 71 62 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 62 2c 00 f7 d8 64 89 01 48 > [ 31.103149] RSP: 002b:00007ffdf69be648 EFLAGS: 00000206 ORIG_RAX: 00000000000000a8 > [ 31.104425] RAX: ffffffffffffffda RBX: 00000000011d98c0 RCX: 00007fc11843ec27 > [ 31.105627] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000011d98c0 > [ 31.106847] RBP: 0000000000000001 R08: 00007ffdf69be690 R09: 0000000000000001 > [ 31.108038] R10: 00000000000002b1 R11: 0000000000000206 R12: 0000000000000001 > [ 31.109231] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > [ 31.110433] irq event stamp: 4466 > [ 31.111001] hardirqs last enabled at (4465): [] __free_pages_ok+0x1e3/0x490 > [ 31.112437] hardirqs last disabled at (4466): [] trace_hardirqs_off_thunk+0x1a/0x1c > [ 31.113973] softirqs last enabled at (3420): [] __do_softirq+0x333/0x446 > [ 31.115364] softirqs last disabled at (3407): [] irq_exit+0xd1/0xe0 > > Cc: stable@vger.kernel.org # 4.14+ > Signed-off-by: Minchan Kim Good catch. Reviewed-by: Sergey Senozhatsky -ss