From: bugzilla-daemon@bugzilla.kernel.org
To: linux-scsi@vger.kernel.org
Subject: [Bug 42918] New: fcoe: Enabling VN2VN mode triggers a circular locking complaint
Date: Tue, 13 Mar 2012 12:16:57 GMT [thread overview]
Message-ID: <bug-42918-11613@https.bugzilla.kernel.org/> (raw)
https://bugzilla.kernel.org/show_bug.cgi?id=42918
URL: http://comments.gmane.org/gmane.linux.scsi.open-fcoe.d
evel/11451?set_lines=100000
Summary: fcoe: Enabling VN2VN mode triggers a circular locking
complaint
Product: IO/Storage
Version: 2.5
Kernel Version: 3.3.0-rc7
Platform: All
OS/Version: Linux
Tree: Mainline
Status: NEW
Severity: normal
Priority: P1
Component: SCSI
AssignedTo: linux-scsi@vger.kernel.org
ReportedBy: bvanassche@acm.org
Regression: No
Kernel version: 3.3.0-rc7
How to reproduce:
# modprobe fcoe
# echo eth0 >/sys/module/libfcoe/parameters/create_vn2vn
Result:
# dmesg
device eth0 entered promiscuous mode
scsi3 : FCoE Driver
host3: libfc: Link up on port (000000)
======================================================
[ INFO: possible circular locking dependency detected ]
3.3.0-rc7-scst-debug+ #1 Not tainted
-------------------------------------------------------
kworker/2:0/14 is trying to acquire lock:
(rtnl_mutex){+.+.+.}, at: [<c13a10c4>] rtnl_lock+0x14/0x20
but task is already holding lock:
(&fip->ctlr_mutex){+.+...}, at: [<f89713e7>] fcoe_ctlr_timer_work+0x3e7/0xb60
[libfcoe]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&fip->ctlr_mutex){+.+...}:
[<c1091f70>] lock_acquire+0x80/0x1b0
[<c147655d>] mutex_lock_nested+0x6d/0x340
[<f8970c32>] fcoe_ctlr_link_up+0x22/0x180 [libfcoe]
[<f894620e>] fcoe_create+0x47e/0x6e0 [fcoe]
[<f8973dd3>] fcoe_transport_create+0x143/0x250 [libfcoe]
[<c10527e0>] param_attr_store+0x30/0x60
[<c1052696>] module_attr_store+0x26/0x40
[<c11a201e>] sysfs_write_file+0xae/0x100
[<c11449df>] vfs_write+0x8f/0x160
[<c1144cbd>] sys_write+0x3d/0x70
[<c147a0c4>] syscall_call+0x7/0xb
-> #0 (rtnl_mutex){+.+.+.}:
[<c109164b>] __lock_acquire+0x140b/0x1720
[<c1091f70>] lock_acquire+0x80/0x1b0
[<c147655d>] mutex_lock_nested+0x6d/0x340
[<c13a10c4>] rtnl_lock+0x14/0x20
[<f89445ac>] fcoe_update_src_mac+0x2c/0xb0 [fcoe]
[<f8971712>] fcoe_ctlr_timer_work+0x712/0xb60 [libfcoe]
[<c104fb69>] process_one_work+0x179/0x5d0
[<c10502f1>] worker_thread+0x121/0x2d0
[<c10550ed>] kthread+0x7d/0x90
[<c1481a82>] kernel_thread_helper+0x6/0x10
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&fip->ctlr_mutex);
lock(rtnl_mutex);
lock(&fip->ctlr_mutex);
lock(rtnl_mutex);
*** DEADLOCK ***
3 locks held by kworker/2:0/14:
#0: (events){.+.+.+}, at: [<c104faf5>] process_one_work+0x105/0x5d0
#1: ((&fip->timer_work)){+.+...}, at: [<c104faf5>]
process_one_work+0x105/0x5d0
#2: (&fip->ctlr_mutex){+.+...}, at: [<f89713e7>]
fcoe_ctlr_timer_work+0x3e7/0xb60 [libfcoe]
stack backtrace:
Pid: 14, comm: kworker/2:0 Not tainted 3.3.0-rc7 #1
Call Trace:
[<c14714a6>] ? printk+0x1d/0x1f
[<c1471d4f>] print_circular_bug+0x1b4/0x1be
[<c109164b>] __lock_acquire+0x140b/0x1720
[<c1091f70>] lock_acquire+0x80/0x1b0
[<c13a10c4>] ? rtnl_lock+0x14/0x20
[<c147655d>] mutex_lock_nested+0x6d/0x340
[<c13a10c4>] ? rtnl_lock+0x14/0x20
[<c13a10c4>] ? rtnl_lock+0x14/0x20
[<f89713e7>] ? fcoe_ctlr_timer_work+0x3e7/0xb60 [libfcoe]
[<c13a10c4>] rtnl_lock+0x14/0x20
[<f89445ac>] fcoe_update_src_mac+0x2c/0xb0 [fcoe]
[<f8971712>] fcoe_ctlr_timer_work+0x712/0xb60 [libfcoe]
[<c106a2c5>] ? local_clock+0x65/0x70
[<c104faf5>] ? process_one_work+0x105/0x5d0
[<c10928e4>] ? trace_hardirqs_on_caller+0xf4/0x180
[<c104fb69>] process_one_work+0x179/0x5d0
[<c104faf5>] ? process_one_work+0x105/0x5d0
[<f8971000>] ? fcoe_ctlr_vn_send_claim+0x40/0x40 [libfcoe]
[<c10502f1>] worker_thread+0x121/0x2d0
[<c10501d0>] ? rescuer_thread+0x1d0/0x1d0
[<c10550ed>] kthread+0x7d/0x90
[<c1055070>] ? __init_kthread_worker+0x60/0x60
[<c1481a82>] kernel_thread_helper+0x6/0x10
host3: Assigned Port ID 0092b5
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next reply other threads:[~2012-03-13 12:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-13 12:16 bugzilla-daemon [this message]
2012-03-14 1:22 ` [PATCH] fcoe: Drop the rtnl_mutex before calling fcoe_ctlr_link_up Robert Love
2012-03-15 1:21 ` [Bug 42918] fcoe: Enabling VN2VN mode triggers a circular locking complaint bugzilla-daemon
2012-03-15 1:28 ` Love, Robert W
2012-04-04 14:56 ` bugzilla-daemon
2012-04-04 15:21 ` bugzilla-daemon
2012-06-13 15:17 ` bugzilla-daemon
2012-06-13 15:17 ` bugzilla-daemon
2012-07-01 9:48 ` bugzilla-daemon
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