From patchwork Mon Jan 28 14:24:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maurizio Lombardi X-Patchwork-Id: 10783773 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2F58391E for ; Mon, 28 Jan 2019 14:24:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D7F12AD77 for ; Mon, 28 Jan 2019 14:24:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 320E42ADEB; Mon, 28 Jan 2019 14:24:47 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI 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 B6B022AD77 for ; Mon, 28 Jan 2019 14:24:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727042AbfA1OYq (ORCPT ); Mon, 28 Jan 2019 09:24:46 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46670 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726945AbfA1OYq (ORCPT ); Mon, 28 Jan 2019 09:24:46 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CEFAC5D61C; Mon, 28 Jan 2019 14:24:45 +0000 (UTC) Received: from manaslu.brq.redhat.com (unknown [10.43.2.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 92F775E7A3; Mon, 28 Jan 2019 14:24:43 +0000 (UTC) From: Maurizio Lombardi To: James.Bottomley@HansenPartnership.com Cc: martin.petersen@oracle.com, cleech@redhat.com, linux-scsi@vger.kernel.org Subject: [PATCH] scsi: iscsi: flush running unbind operations when removing a session Date: Mon, 28 Jan 2019 15:24:42 +0100 Message-Id: <1548685482-1814-1-git-send-email-mlombard@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 28 Jan 2019 14:24:46 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In some cases, the iscsi_remove_session() function is called while an unbind_work operation is still running. This may cause a situation where sysfs objects are removed in an incorrect order, triggering a kernel warning. [ 605.249442] ------------[ cut here ]------------ [ 605.259180] sysfs group 'power' not found for kobject 'target2:0:0' [ 605.321371] WARNING: CPU: 1 PID: 26794 at fs/sysfs/group.c:235 sysfs_remove_group+0x76/0x80 [ 605.341266] Modules linked in: dm_service_time target_core_user target_core_pscsi target_core_file target_core_iblock iscsi_target_mod target_core_mod nls_utf8 isofs ppdev bochs_drm nfit ttm libnvdimm drm_kms_helper syscopyarea sysfillrect sysimgblt joydev pcspkr fb_sys_fops drm i2c_piix4 sg parport_pc parport xfs libcrc32c dm_multipath sr_mod sd_mod cdrom ata_generic 8021q garp mrp ata_piix stp crct10dif_pclmul crc32_pclmul llc libata crc32c_intel virtio_net net_failover ghash_clmulni_intel serio_raw failover sunrpc dm_mirror dm_region_hash dm_log dm_mod be2iscsi bnx2i cnic uio cxgb4i cxgb4 libcxgbi libcxgb qla4xxx iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi [ 605.627479] CPU: 1 PID: 26794 Comm: kworker/u32:2 Not tainted 4.18.0-60.el8.x86_64 #1 [ 605.721401] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20180724_192412-buildhw-07.phx2.fedoraproject.org-1.fc29 04/01/2014 [ 605.823651] Workqueue: scsi_wq_2 __iscsi_unbind_session [scsi_transport_iscsi] [ 605.830940] RIP: 0010:sysfs_remove_group+0x76/0x80 [ 605.922907] Code: 48 89 df 5b 5d 41 5c e9 38 c4 ff ff 48 89 df e8 e0 bf ff ff eb cb 49 8b 14 24 48 8b 75 00 48 c7 c7 38 73 cb a7 e8 24 77 d7 ff <0f> 0b 5b 5d 41 5c c3 0f 1f 00 0f 1f 44 00 00 41 56 41 55 41 54 55 [ 606.122304] RSP: 0018:ffffbadcc8d1bda8 EFLAGS: 00010286 [ 606.218492] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 606.326381] RDX: ffff98bdfe85eb40 RSI: ffff98bdfe856818 RDI: ffff98bdfe856818 [ 606.514498] RBP: ffffffffa7ab73e0 R08: 0000000000000268 R09: 0000000000000007 [ 606.529469] R10: 0000000000000000 R11: ffffffffa860d9ad R12: ffff98bdf978e838 [ 606.630535] R13: ffff98bdc2cd4010 R14: ffff98bdc2cd3ff0 R15: ffff98bdc2cd4000 [ 606.824707] FS: 0000000000000000(0000) GS:ffff98bdfe840000(0000) knlGS:0000000000000000 [ 607.018333] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 607.117844] CR2: 00007f84b78ac024 CR3: 000000002c00a003 CR4: 00000000003606e0 [ 607.117844] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 607.420926] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 607.524236] Call Trace: [ 607.530591] device_del+0x56/0x350 [ 607.624393] ? ata_tlink_match+0x30/0x30 [libata] [ 607.727805] ? attribute_container_device_trigger+0xb4/0xf0 [ 607.829911] scsi_target_reap_ref_release+0x39/0x50 [ 607.928572] scsi_remove_target+0x1a2/0x1d0 [ 608.017350] __iscsi_unbind_session+0xb3/0x160 [scsi_transport_iscsi] [ 608.117435] process_one_work+0x1a7/0x360 [ 608.132917] worker_thread+0x30/0x390 [ 608.222900] ? pwq_unbound_release_workfn+0xd0/0xd0 [ 608.323989] kthread+0x112/0x130 [ 608.418318] ? kthread_bind+0x30/0x30 [ 608.513821] ret_from_fork+0x35/0x40 [ 608.613909] ---[ end trace 0b98c310c8a6138c ]--- Signed-off-by: Maurizio Lombardi Acked-by: Chris Leech --- drivers/scsi/scsi_transport_iscsi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index ff12302..1e872ab 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2182,6 +2182,8 @@ void iscsi_remove_session(struct iscsi_cls_session *session) scsi_target_unblock(&session->dev, SDEV_TRANSPORT_OFFLINE); /* flush running scans then delete devices */ flush_work(&session->scan_work); + /* flush running unbind operations */ + flush_work(&session->unbind_work); __iscsi_unbind_session(&session->unbind_work); /* hw iscsi may not have removed all connections from session */