Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753467Ab3JUIyp (ORCPT ); Mon, 21 Oct 2013 04:54:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39906 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754592Ab3JUIxd (ORCPT ); Mon, 21 Oct 2013 04:53:33 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Mike Christie" , "James Bottomley" , "Sasha Levin" Date: Mon, 21 Oct 2013 09:46:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 140/149] [SCSI] iscsi: don't hang in endless loop if no targets present In-Reply-To: X-SA-Exim-Connect-IP: 212.20.242.100 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3558 Lines: 71 3.2.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Sasha Levin commit 46a7c17d26967922092f3a8291815ffb20f6cabe upstream. iscsi_if_send_reply() may return -ESRCH if there were no targets to send data to. Currently we're ignoring this value and looping in attempt to do it over and over, which will usually lead in a hung task like this one: [ 4920.817298] INFO: task trinity:9074 blocked for more than 120 seconds. [ 4920.818527] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4920.819982] trinity D 0000000000000000 5504 9074 2756 0x00000004 [ 4920.825374] ffff880003961a98 0000000000000086 ffff8800001aa000 ffff8800001aa000 [ 4920.826791] 00000000001d4340 ffff880003961fd8 ffff880003960000 00000000001d4340 [ 4920.828241] 00000000001d4340 00000000001d4340 ffff880003961fd8 00000000001d4340 [ 4920.833231] [ 4920.833519] Call Trace: [ 4920.834010] [] schedule+0x3a/0x50 [ 4920.834953] [] __mutex_lock_common+0x209/0x5b0 [ 4920.836226] [] ? iscsi_if_rx+0x2d/0x990 [ 4920.837281] [] ? sched_clock+0x13/0x20 [ 4920.838305] [] ? iscsi_if_rx+0x2d/0x990 [ 4920.839336] [] mutex_lock_nested+0x40/0x50 [ 4920.840423] [] iscsi_if_rx+0x2d/0x990 [ 4920.841434] [] ? sub_preempt_count+0x9d/0xd0 [ 4920.842548] [] ? _raw_read_unlock+0x30/0x60 [ 4920.843666] [] netlink_unicast+0x1ae/0x1f0 [ 4920.844751] [] netlink_sendmsg+0x227/0x350 [ 4920.845850] [] ? sock_update_netprioidx+0xdd/0x1b0 [ 4920.847060] [] ? sock_update_netprioidx+0x52/0x1b0 [ 4920.848276] [] sock_aio_write+0x166/0x180 [ 4920.849348] [] ? get_parent_ip+0x11/0x50 [ 4920.850428] [] do_sync_write+0xda/0x120 [ 4920.851465] [] ? sub_preempt_count+0x9d/0xd0 [ 4920.852579] [] ? get_parent_ip+0x11/0x50 [ 4920.853608] [] ? security_file_permission+0x27/0xb0 [ 4920.854821] [] vfs_write+0x16c/0x180 [ 4920.855781] [] sys_write+0x4f/0xa0 [ 4920.856798] [] system_call_fastpath+0x16/0x1b [ 4920.877487] 1 lock held by trinity/9074: [ 4920.878239] #0: (rx_queue_mutex){+.+...}, at: [] iscsi_if_rx+0x2d/0x990 [ 4920.880005] Kernel panic - not syncing: hung_task: blocked tasks Signed-off-by: Sasha Levin Acked-by: Mike Christie Signed-off-by: James Bottomley Signed-off-by: Ben Hutchings --- drivers/scsi/scsi_transport_iscsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2105,7 +2105,7 @@ iscsi_if_rx(struct sk_buff *skb) break; err = iscsi_if_send_reply(group, nlh->nlmsg_seq, nlh->nlmsg_type, 0, 0, ev, sizeof(*ev)); - } while (err < 0 && err != -ECONNREFUSED); + } while (err < 0 && err != -ECONNREFUSED && err != -ESRCH); skb_pull(skb, rlen); } mutex_unlock(&rx_queue_mutex); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/