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=-3.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 7FB06C4360F for ; Fri, 22 Mar 2019 13:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FB2D2183E for ; Fri, 22 Mar 2019 13:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553260004; bh=pTgZyuwEklnFSoFP3xZbqVdIhe9H+vSytZqhGEEjxao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cXXjv/7M2Iekqz5c6Yx+ECha2KraAY7Eq8zKsAJzwLctqoYcdpZIO/2QK5SFqSJ40 5BQM13jIMuIHYKwD4fO5ORb4X4iZRhO4IKcD0FxnkJyXX5gT+/qh43pZ1kr7fLO/bV Il2wptQAgBcNUwK3Xa3PNdQdvk6IBPxC9ZAX041E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731188AbfCVNGn (ORCPT ); Fri, 22 Mar 2019 09:06:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:38762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730399AbfCVLhQ (ORCPT ); Fri, 22 Mar 2019 07:37:16 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3162A2082C; Fri, 22 Mar 2019 11:37:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553254635; bh=pTgZyuwEklnFSoFP3xZbqVdIhe9H+vSytZqhGEEjxao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UqGkSwYGrFmgnhCHRAgtdiCZtOLXphl4AMeoSJuzknGfrBJZgyUqq2QawwSgUYVbK qew/HWF2IsekAdBN0Y+1n+GYzzS0Ehg2tpHWxM1iSfrfcEyBTTcXHW3rj5CS/bqgQY sr/otA37XDh5jdAzSdbmSZrjmeLxOyx3jdj6/X4s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org Subject: [PATCH 4.4 188/230] scsi: target/iscsi: Avoid iscsit_release_commands_from_conn() deadlock Date: Fri, 22 Mar 2019 12:15:26 +0100 Message-Id: <20190322111249.991514428@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322111236.796964179@linuxfoundation.org> References: <20190322111236.796964179@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 32e36bfbcf31452a854263e7c7f32fbefc4b44d8 upstream. When using SCSI passthrough in combination with the iSCSI target driver then cmd->t_state_lock may be obtained from interrupt context. Hence, all code that obtains cmd->t_state_lock from thread context must disable interrupts first. This patch avoids that lockdep reports the following: WARNING: inconsistent lock state 4.18.0-dbg+ #1 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. iscsi_ttx/1800 [HC1[1]:SC0[2]:HE0:SE0] takes: 000000006e7b0ceb (&(&cmd->t_state_lock)->rlock){?...}, at: target_complete_cmd+0x47/0x2c0 [target_core_mod] {HARDIRQ-ON-W} state was registered at: lock_acquire+0xd2/0x260 _raw_spin_lock+0x32/0x50 iscsit_close_connection+0x97e/0x1020 [iscsi_target_mod] iscsit_take_action_for_connection_exit+0x108/0x200 [iscsi_target_mod] iscsi_target_rx_thread+0x180/0x190 [iscsi_target_mod] kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 irq event stamp: 1281 hardirqs last enabled at (1279): [] __local_bh_enable_ip+0xa9/0x160 hardirqs last disabled at (1281): [] interrupt_entry+0xb5/0xd0 softirqs last enabled at (1278): [] lock_sock_nested+0x51/0xc0 softirqs last disabled at (1280): [] ip6_finish_output2+0x124/0xe40 [ipv6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&cmd->t_state_lock)->rlock); lock(&(&cmd->t_state_lock)->rlock); --- drivers/target/iscsi/iscsi_target.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4232,9 +4232,9 @@ static void iscsit_release_commands_from struct se_cmd *se_cmd = &cmd->se_cmd; if (se_cmd->se_tfo != NULL) { - spin_lock(&se_cmd->t_state_lock); + spin_lock_irq(&se_cmd->t_state_lock); se_cmd->transport_state |= CMD_T_FABRIC_STOP; - spin_unlock(&se_cmd->t_state_lock); + spin_unlock_irq(&se_cmd->t_state_lock); } } spin_unlock_bh(&conn->cmd_lock);