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Dave Young 1905f6c736 bluetooth : __rfcomm_dlc_close lock fix 
Lockdep warning will be trigged while rfcomm connection closing.

The locks taken in rfcomm_dev_add:
rfcomm_dev_lock --> d->lock

In __rfcomm_dlc_close:
d->lock --> rfcomm_dev_lock (in rfcomm_dev_state_change)

There's two way to fix it, one is in rfcomm_dev_add we first locking
d->lock then the rfcomm_dev_lock

The other (in this patch), remove the locking of d->lock for
rfcomm_dev_state_change because just locking "d->state = BT_CLOSED;"
is enough.

[  295.002046] =======================================================
[  295.002046] [ INFO: possible circular locking dependency detected ]
[  295.002046] 2.6.25-rc7 #1
[  295.002046] -------------------------------------------------------
[  295.002046] krfcommd/2705 is trying to acquire lock:
[  295.002046]  (rfcomm_dev_lock){-.--}, at: [<f89a090a>] rfcomm_dev_state_change+0x6a/0xd0 [rfcomm]
[  295.002046] 
[  295.002046] but task is already holding lock:
[  295.002046]  (&d->lock){--..}, at: [<f899c533>] __rfcomm_dlc_close+0x43/0xd0 [rfcomm]
[  295.002046] 
[  295.002046] which lock already depends on the new lock.
[  295.002046] 
[  295.002046] 
[  295.002046] the existing dependency chain (in reverse order) is:
[  295.002046] 
[  295.002046] -> #1 (&d->lock){--..}:
[  295.002046]        [<c0149b23>] check_prev_add+0xd3/0x200
[  295.002046]        [<c0149ce5>] check_prevs_add+0x95/0xe0
[  295.002046]        [<c0149f6f>] validate_chain+0x23f/0x320
[  295.002046]        [<c014b7b1>] __lock_acquire+0x1c1/0x760
[  295.002046]        [<c014c349>] lock_acquire+0x79/0xb0
[  295.002046]        [<c03d6b99>] _spin_lock+0x39/0x80
[  295.002046]        [<f89a01c0>] rfcomm_dev_add+0x240/0x360 [rfcomm]
[  295.002046]        [<f89a047e>] rfcomm_create_dev+0x6e/0xe0 [rfcomm]
[  295.002046]        [<f89a0823>] rfcomm_dev_ioctl+0x33/0x60 [rfcomm]
[  295.002046]        [<f899facc>] rfcomm_sock_ioctl+0x2c/0x50 [rfcomm]
[  295.002046]        [<c0363d38>] sock_ioctl+0x118/0x240
[  295.002046]        [<c0194196>] vfs_ioctl+0x76/0x90
[  295.002046]        [<c0194446>] do_vfs_ioctl+0x56/0x140
[  295.002046]        [<c0194569>] sys_ioctl+0x39/0x60
[  295.002046]        [<c0104faa>] syscall_call+0x7/0xb
[  295.002046]        [<ffffffff>] 0xffffffff
[  295.002046] 
[  295.002046] -> #0 (rfcomm_dev_lock){-.--}:
[  295.002046]        [<c0149a84>] check_prev_add+0x34/0x200
[  295.002046]        [<c0149ce5>] check_prevs_add+0x95/0xe0
[  295.002046]        [<c0149f6f>] validate_chain+0x23f/0x320
[  295.002046]        [<c014b7b1>] __lock_acquire+0x1c1/0x760
[  295.002046]        [<c014c349>] lock_acquire+0x79/0xb0
[  295.002046]        [<c03d6639>] _read_lock+0x39/0x80
[  295.002046]        [<f89a090a>] rfcomm_dev_state_change+0x6a/0xd0 [rfcomm]
[  295.002046]        [<f899c548>] __rfcomm_dlc_close+0x58/0xd0 [rfcomm]
[  295.002046]        [<f899d44f>] rfcomm_recv_ua+0x6f/0x120 [rfcomm]
[  295.002046]        [<f899e061>] rfcomm_recv_frame+0x171/0x1e0 [rfcomm]
[  295.002046]        [<f899e357>] rfcomm_run+0xe7/0x550 [rfcomm]
[  295.002046]        [<c013c18c>] kthread+0x5c/0xa0
[  295.002046]        [<c0105c07>] kernel_thread_helper+0x7/0x10
[  295.002046]        [<ffffffff>] 0xffffffff
[  295.002046] 
[  295.002046] other info that might help us debug this:
[  295.002046] 
[  295.002046] 2 locks held by krfcommd/2705:
[  295.002046]  #0:  (rfcomm_mutex){--..}, at: [<f899e2eb>] rfcomm_run+0x7b/0x550 [rfcomm]
[  295.002046]  #1:  (&d->lock){--..}, at: [<f899c533>] __rfcomm_dlc_close+0x43/0xd0 [rfcomm]
[  295.002046] 
[  295.002046] stack backtrace:
[  295.002046] Pid: 2705, comm: krfcommd Not tainted 2.6.25-rc7 #1
[  295.002046]  [<c0128a38>] ? printk+0x18/0x20
[  295.002046]  [<c014927f>] print_circular_bug_tail+0x6f/0x80
[  295.002046]  [<c0149a84>] check_prev_add+0x34/0x200
[  295.002046]  [<c0149ce5>] check_prevs_add+0x95/0xe0
[  295.002046]  [<c0149f6f>] validate_chain+0x23f/0x320
[  295.002046]  [<c014b7b1>] __lock_acquire+0x1c1/0x760
[  295.002046]  [<c014c349>] lock_acquire+0x79/0xb0
[  295.002046]  [<f89a090a>] ? rfcomm_dev_state_change+0x6a/0xd0 [rfcomm]
[  295.002046]  [<c03d6639>] _read_lock+0x39/0x80
[  295.002046]  [<f89a090a>] ? rfcomm_dev_state_change+0x6a/0xd0 [rfcomm]
[  295.002046]  [<f89a090a>] rfcomm_dev_state_change+0x6a/0xd0 [rfcomm]
[  295.002046]  [<f899c548>] __rfcomm_dlc_close+0x58/0xd0 [rfcomm]
[  295.002046]  [<f899d44f>] rfcomm_recv_ua+0x6f/0x120 [rfcomm]
[  295.002046]  [<f899e061>] rfcomm_recv_frame+0x171/0x1e0 [rfcomm]
[  295.002046]  [<c014abd9>] ? trace_hardirqs_on+0xb9/0x130
[  295.002046]  [<c03d6e89>] ? _spin_unlock_irqrestore+0x39/0x70
[  295.002046]  [<f899e357>] rfcomm_run+0xe7/0x550 [rfcomm]
[  295.002046]  [<c03d4559>] ? __sched_text_start+0x229/0x4c0
[  295.002046]  [<c0120000>] ? cpu_avg_load_per_task+0x20/0x30
[  295.002046]  [<f899e270>] ? rfcomm_run+0x0/0x550 [rfcomm]
[  295.002046]  [<c013c18c>] kthread+0x5c/0xa0
[  295.002046]  [<c013c130>] ? kthread+0x0/0xa0
[  295.002046]  [<c0105c07>] kernel_thread_helper+0x7/0x10
[  295.002046]  =======================

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-01 23:59:06 -07:00
..
9p [9P] net/9p/trans_fd.c: remove unused variable 2008-03-22 18:05:33 -07:00
802 [TR] net/802/tr.c: sysctl_tr_rif_timeout static 2008-01-31 19:28:31 -08:00
8021q [VLAN]: Don't copy ALLMULTI/PROMISC flags from underlying device 2008-03-26 00:15:17 -07:00
appletalk [APPLETALK]: Use proc_create() to setup ->proc_fops first 2008-02-28 12:53:32 -08:00
atm [ATM]: When proc_create() fails, do some error handling work and return -ENOMEM. 2008-03-23 21:45:36 -07:00
ax25 [AX25]: Remove obsolete references to BKL from TODO file. 2008-03-26 02:14:38 -07:00
bluetooth bluetooth : __rfcomm_dlc_close lock fix 2008-04-01 23:59:06 -07:00
bridge bridge: use time_before() in br_fdb_cleanup() 2008-03-20 15:54:58 -07:00
can [CAN]: Minor clean-ups 2008-02-07 18:05:04 -08:00
core [NET]: Fix multicast device ioctl checks 2008-03-26 02:12:11 -07:00
dccp [SOCK] proto: Add hashinfo member to struct proto 2008-02-03 04:28:52 -08:00
decnet [DECNET] ROUTE: remove unecessary alignment 2008-02-07 23:29:57 -08:00
econet [NET]: Convert init_timer into setup_timer 2008-01-28 14:53:35 -08:00
ethernet [ETH]: Combine format_addr() with print_mac(). 2008-01-28 15:00:05 -08:00
ieee80211 ieee80211: beacon->capability is little-endian 2008-01-28 15:08:48 -08:00
ipv4 [IP] UDP: Use SEQ_START_TOKEN. 2008-03-31 19:38:15 -07:00
ipv6 [IPV6] MCAST: Ensure to check multicast listener(s). 2008-03-31 19:30:45 -07:00
ipx [IPX]: Use proc_create() to setup ->proc_fops first 2008-02-28 14:06:14 -08:00
irda [IRDA]: Store irnet_socket termios properly. 2008-03-26 00:55:50 -07:00
iucv iucv: fix build error on !SMP 2008-03-03 12:12:33 -08:00
key [IPSEC]: Fix inter address family IPsec tunnel handling. 2008-03-24 14:51:51 -07:00
lapb [LAPB] net/lapb/lapb_iface.c: use LIST_HEAD instead of LIST_HEAD_INIT 2008-01-28 14:56:52 -08:00
llc [LLC]: skb allocation size for responses 2008-03-31 21:02:47 -07:00
mac80211 mac80211: correct use_short_preamble handling 2008-04-01 15:44:08 -04:00
netfilter [NETFILTER]: Replate direct proc_fops assignment with proc_create call. 2008-03-27 16:55:53 -07:00
netlabel [NETLABEL]: Move some initialization code into __init section. 2008-02-17 22:33:57 -08:00
netlink [GENETLINK]: Relax dances with genl_lock. 2008-02-12 22:16:33 -08:00
netrom [NET]: Simple ctl_table to ctl_path conversions. 2008-01-28 15:01:07 -08:00
packet [PACKET]: Fix sparse warnings in af_packet.c 2008-01-28 15:00:48 -08:00
rfkill PM: Introduce PM_EVENT_HIBERNATE callback state 2008-02-23 10:40:04 -08:00
rose [ROSE/AX25] af_rose: rose_release() fix 2008-04-01 23:56:17 -07:00
rxrpc RxRPC: fix rxrpc_recvmsg()'s returning of msg_name 2008-03-05 18:53:55 -08:00
sched [NET]: Add preemption point in qdisc_run 2008-03-28 16:25:26 -07:00
sctp [SCTP]: Fix a race between module load and protosw access 2008-03-20 15:17:14 -07:00
sunrpc Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2008-03-17 23:44:31 -07:00
tipc tipc: fix integer as NULL pointer sparse warnings in tipc 2008-02-24 18:38:31 -08:00
unix Introduce path_put() 2008-02-14 21:13:33 -08:00
wanrouter [WANROUTER]: Use proc_create() to setup ->proc_fops first 2008-02-28 14:15:56 -08:00
wireless WEXT: remove unused variable 2008-01-28 15:10:48 -08:00
x25 [X25]: Use proc_create() to setup ->proc_fops first 2008-02-28 14:16:33 -08:00
xfrm [IPSEC]: Fix inter address family IPsec tunnel handling. 2008-03-24 14:51:51 -07:00
compat.c [NETFILTER]: ip6_tables: add compat support 2008-01-28 14:58:36 -08:00
Kconfig namespaces: mark NET_NS with "depends on NAMESPACES" 2008-02-08 09:22:23 -08:00
Makefile [CAN]: Add PF_CAN core module 2008-01-28 14:54:10 -08:00
nonet.c
socket.c [DLCI]: Fix tiny race between module unload and sock_ioctl. 2008-03-21 15:58:52 -07:00
sysctl_net.c [NET]: Remove the empty net_table 2008-01-28 14:56:29 -08:00
TUNABLE