Robert Love f9c4358edb fcoe: Fix deadlock between create and destroy paths ... We can deadlock (s_active and fcoe_config_mutex) if a port is being destroyed at the same time one is being created. [ 4200.503113] ====================================================== [ 4200.503114] [ INFO: possible circular locking dependency detected ] [ 4200.503116] 3.8.0-rc5+ #8 Not tainted [ 4200.503117] ------------------------------------------------------- [ 4200.503118] kworker/3:2/2492 is trying to acquire lock: [ 4200.503119] (s_active#292){++++.+}, at: [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70 [ 4200.503127] but task is already holding lock: [ 4200.503128] (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe] [ 4200.503133] which lock already depends on the new lock. [ 4200.503135] the existing dependency chain (in reverse order) is: [ 4200.503136] -> #1 (fcoe_config_mutex){+.+.+.}: [ 4200.503139] [<ffffffff810c7711>] lock_acquire+0xa1/0x140 [ 4200.503143] [<ffffffff816ca7be>] mutex_lock_nested+0x6e/0x360 [ 4200.503146] [<ffffffffa02f11bd>] fcoe_enable+0x1d/0xb0 [fcoe] [ 4200.503148] [<ffffffffa02f127d>] fcoe_ctlr_enabled+0x2d/0x50 [fcoe] [ 4200.503151] [<ffffffffa02ffbe8>] store_ctlr_enabled+0x38/0x90 [libfcoe] [ 4200.503154] [<ffffffff81424878>] dev_attr_store+0x18/0x30 [ 4200.503157] [<ffffffff8122b750>] sysfs_write_file+0xe0/0x150 [ 4200.503160] [<ffffffff811b334c>] vfs_write+0xac/0x180 [ 4200.503162] [<ffffffff811b3692>] sys_write+0x52/0xa0 [ 4200.503164] [<ffffffff816d7159>] system_call_fastpath+0x16/0x1b [ 4200.503167] -> #0 (s_active#292){++++.+}: [ 4200.503170] [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90 [ 4200.503172] [<ffffffff810c7711>] lock_acquire+0xa1/0x140 [ 4200.503174] [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160 [ 4200.503176] [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70 [ 4200.503178] [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0 [ 4200.503180] [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100 [ 4200.503183] [<ffffffff814251eb>] device_remove_groups+0x3b/0x60 [ 4200.503185] [<ffffffff81425534>] device_remove_attrs+0x44/0x80 [ 4200.503187] [<ffffffff81425e97>] device_del+0x127/0x1c0 [ 4200.503189] [<ffffffff81425f52>] device_unregister+0x22/0x60 [ 4200.503191] [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe] [ 4200.503194] [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe] [ 4200.503196] [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe] [ 4200.503198] [<ffffffff8107ee91>] process_one_work+0x1a1/0x580 [ 4200.503203] [<ffffffff81080c6e>] worker_thread+0x15e/0x440 [ 4200.503205] [<ffffffff8108715a>] kthread+0xea/0xf0 [ 4200.503207] [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0 [ 4200.503209] other info that might help us debug this: [ 4200.503211] Possible unsafe locking scenario: [ 4200.503212] CPU0 CPU1 [ 4200.503213] ---- ---- [ 4200.503214] lock(fcoe_config_mutex); [ 4200.503215] lock(s_active#292); [ 4200.503218] lock(fcoe_config_mutex); [ 4200.503219] lock(s_active#292); [ 4200.503221] *** DEADLOCK *** [ 4200.503223] 3 locks held by kworker/3:2/2492: [ 4200.503224] #0: (fcoe){.+.+.+}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580 [ 4200.503228] #1: ((&port->destroy_work)){+.+.+.}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580 [ 4200.503232] #2: (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe] [ 4200.503236] stack backtrace: [ 4200.503238] Pid: 2492, comm: kworker/3:2 Not tainted 3.8.0-rc5+ #8 [ 4200.503240] Call Trace: [ 4200.503243] [<ffffffff816c2f09>] print_circular_bug+0x1fb/0x20c [ 4200.503246] [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90 [ 4200.503248] [<ffffffff810c463a>] ? debug_check_no_locks_freed+0x9a/0x180 [ 4200.503250] [<ffffffff810c7711>] lock_acquire+0xa1/0x140 [ 4200.503253] [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70 [ 4200.503255] [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160 [ 4200.503258] [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70 [ 4200.503260] [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70 [ 4200.503262] [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0 [ 4200.503265] [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100 [ 4200.503273] [<ffffffff814251eb>] device_remove_groups+0x3b/0x60 [ 4200.503275] [<ffffffff81425534>] device_remove_attrs+0x44/0x80 [ 4200.503277] [<ffffffff81425e97>] device_del+0x127/0x1c0 [ 4200.503279] [<ffffffff81425f52>] device_unregister+0x22/0x60 [ 4200.503282] [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe] [ 4200.503285] [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe] [ 4200.503287] [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe] [ 4200.503290] [<ffffffff8107ee91>] process_one_work+0x1a1/0x580 [ 4200.503292] [<ffffffff8107ee2b>] ? process_one_work+0x13b/0x580 [ 4200.503295] [<ffffffffa02f3250>] ? fcoe_if_destroy+0x230/0x230 [fcoe] [ 4200.503297] [<ffffffff81080c6e>] worker_thread+0x15e/0x440 [ 4200.503299] [<ffffffff81080b10>] ? busy_worker_rebind_fn+0x100/0x100 [ 4200.503301] [<ffffffff8108715a>] kthread+0xea/0xf0 [ 4200.503304] [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160 [ 4200.503306] [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0 [ 4200.503308] [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160 Signed-off-by: Robert Love <robert.w.love@intel.com> Tested-by: Jack Morgan <jack.morgan@intel.com>		2013-03-25 15:55:56 -07:00
..
accessibility
acpi
amba
ata	Simple stuff. See one-line summaries.	2013-03-23 12:33:36 -07:00
atm
auxdisplay
base
bcma
block
bluetooth
bus
cdrom
char
clk
clocksource
connector
cpufreq
cpuidle
crypto
dca
devfreq
dio
dma
edac
eisa
extcon
firewire
firmware
gpio
gpu	KMS: fix EDID detailed timing frame rate	2013-03-23 10:46:10 -07:00
hid
hsi
hv
hwmon
hwspinlock
i2c	Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux	2013-03-23 12:32:14 -07:00
ide
idle
iio
infiniband
input
iommu
ipack
irqchip
isdn
leds
lguest
macintosh
mailbox
md	A few bugfixes for md	2013-03-23 15:49:49 -07:00
media
memory
memstick
message
mfd
misc
mmc
mtd
net
nfc
ntb
nubus
of
oprofile
parisc
parport
pci
pcmcia
pinctrl
platform
pnp
power
pps
ps3
ptp
pwm
rapidio
regulator
remoteproc
rpmsg
rtc
s390
sbus
scsi	fcoe: Fix deadlock between create and destroy paths	2013-03-25 15:55:56 -07:00
sfi
sh
sn
spi
ssb
staging
target
tc
thermal
tty
uio
usb
uwb
vfio
vhost	Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending	2013-03-23 16:51:55 -07:00
video
virt
virtio
vlynq
vme
w1
watchdog
xen
zorro
Kconfig
Makefile