* [PATCH] iscsi: don't hang in endless loop if no targets present
@ 2012-01-26 3:16 Sasha Levin
2012-01-26 5:31 ` Mike Christie
0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2012-01-26 3:16 UTC (permalink / raw)
To: michaelc, JBottomley; +Cc: open-iscsi, linux-scsi, linux-kernel, Sasha Levin
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] [<ffffffff826363fa>] schedule+0x3a/0x50
[ 4920.834953] [<ffffffff82634ac9>] __mutex_lock_common+0x209/0x5b0
[ 4920.836226] [<ffffffff81af805d>] ? iscsi_if_rx+0x2d/0x990
[ 4920.837281] [<ffffffff81053943>] ? sched_clock+0x13/0x20
[ 4920.838305] [<ffffffff81af805d>] ? iscsi_if_rx+0x2d/0x990
[ 4920.839336] [<ffffffff82634eb0>] mutex_lock_nested+0x40/0x50
[ 4920.840423] [<ffffffff81af805d>] iscsi_if_rx+0x2d/0x990
[ 4920.841434] [<ffffffff810dffed>] ? sub_preempt_count+0x9d/0xd0
[ 4920.842548] [<ffffffff82637bb0>] ? _raw_read_unlock+0x30/0x60
[ 4920.843666] [<ffffffff821f71de>] netlink_unicast+0x1ae/0x1f0
[ 4920.844751] [<ffffffff821f7997>] netlink_sendmsg+0x227/0x350
[ 4920.845850] [<ffffffff821857bd>] ? sock_update_netprioidx+0xdd/0x1b0
[ 4920.847060] [<ffffffff82185732>] ? sock_update_netprioidx+0x52/0x1b0
[ 4920.848276] [<ffffffff8217f226>] sock_aio_write+0x166/0x180
[ 4920.849348] [<ffffffff810dfe41>] ? get_parent_ip+0x11/0x50
[ 4920.850428] [<ffffffff811d0d9a>] do_sync_write+0xda/0x120
[ 4920.851465] [<ffffffff810dffed>] ? sub_preempt_count+0x9d/0xd0
[ 4920.852579] [<ffffffff810dfe41>] ? get_parent_ip+0x11/0x50
[ 4920.853608] [<ffffffff81791887>] ? security_file_permission+0x27/0xb0
[ 4920.854821] [<ffffffff811d0f4c>] vfs_write+0x16c/0x180
[ 4920.855781] [<ffffffff811d104f>] sys_write+0x4f/0xa0
[ 4920.856798] [<ffffffff82638e79>] system_call_fastpath+0x16/0x1b
[ 4920.877487] 1 lock held by trinity/9074:
[ 4920.878239] #0: (rx_queue_mutex){+.+...}, at: [<ffffffff81af805d>] iscsi_if_rx+0x2d/0x990
[ 4920.880005] Kernel panic - not syncing: hung_task: blocked tasks
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
---
drivers/scsi/scsi_transport_iscsi.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index cfd4914..c26707a 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2110,7 +2110,7 @@ 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);
--
1.7.8.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] iscsi: don't hang in endless loop if no targets present
2012-01-26 3:16 [PATCH] iscsi: don't hang in endless loop if no targets present Sasha Levin
@ 2012-01-26 5:31 ` Mike Christie
0 siblings, 0 replies; 2+ messages in thread
From: Mike Christie @ 2012-01-26 5:31 UTC (permalink / raw)
To: Sasha Levin; +Cc: JBottomley, open-iscsi, linux-scsi, linux-kernel
On 01/25/2012 09:16 PM, Sasha Levin wrote:
> 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] [<ffffffff826363fa>] schedule+0x3a/0x50
> [ 4920.834953] [<ffffffff82634ac9>] __mutex_lock_common+0x209/0x5b0
> [ 4920.836226] [<ffffffff81af805d>] ? iscsi_if_rx+0x2d/0x990
> [ 4920.837281] [<ffffffff81053943>] ? sched_clock+0x13/0x20
> [ 4920.838305] [<ffffffff81af805d>] ? iscsi_if_rx+0x2d/0x990
> [ 4920.839336] [<ffffffff82634eb0>] mutex_lock_nested+0x40/0x50
> [ 4920.840423] [<ffffffff81af805d>] iscsi_if_rx+0x2d/0x990
> [ 4920.841434] [<ffffffff810dffed>] ? sub_preempt_count+0x9d/0xd0
> [ 4920.842548] [<ffffffff82637bb0>] ? _raw_read_unlock+0x30/0x60
> [ 4920.843666] [<ffffffff821f71de>] netlink_unicast+0x1ae/0x1f0
> [ 4920.844751] [<ffffffff821f7997>] netlink_sendmsg+0x227/0x350
> [ 4920.845850] [<ffffffff821857bd>] ? sock_update_netprioidx+0xdd/0x1b0
> [ 4920.847060] [<ffffffff82185732>] ? sock_update_netprioidx+0x52/0x1b0
> [ 4920.848276] [<ffffffff8217f226>] sock_aio_write+0x166/0x180
> [ 4920.849348] [<ffffffff810dfe41>] ? get_parent_ip+0x11/0x50
> [ 4920.850428] [<ffffffff811d0d9a>] do_sync_write+0xda/0x120
> [ 4920.851465] [<ffffffff810dffed>] ? sub_preempt_count+0x9d/0xd0
> [ 4920.852579] [<ffffffff810dfe41>] ? get_parent_ip+0x11/0x50
> [ 4920.853608] [<ffffffff81791887>] ? security_file_permission+0x27/0xb0
> [ 4920.854821] [<ffffffff811d0f4c>] vfs_write+0x16c/0x180
> [ 4920.855781] [<ffffffff811d104f>] sys_write+0x4f/0xa0
> [ 4920.856798] [<ffffffff82638e79>] system_call_fastpath+0x16/0x1b
> [ 4920.877487] 1 lock held by trinity/9074:
> [ 4920.878239] #0: (rx_queue_mutex){+.+...}, at: [<ffffffff81af805d>] iscsi_if_rx+0x2d/0x990
> [ 4920.880005] Kernel panic - not syncing: hung_task: blocked tasks
>
> Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
> ---
> drivers/scsi/scsi_transport_iscsi.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
> index cfd4914..c26707a 100644
> --- a/drivers/scsi/scsi_transport_iscsi.c
> +++ b/drivers/scsi/scsi_transport_iscsi.c
> @@ -2110,7 +2110,7 @@ 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);
Looks ok. Thanks for debugging and the patch.
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
^ permalink raw reply [flat|nested] 2+ messages in thread
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