[OpenAFS-devel] possible recursive locking detected

[Troy Benjegerdes]

What does anyone make of this? 
Kernel 2.6.26-rc8, openafs-cvs HEAD

This particular machine used to deadlock userspace without the lock
debugging enabled. It appears to be okay now.

IP-Config: eth0 complete (from 10.1.1.200):
 address: 10.1.4.243[   37.850403]
[   37.850406] =============================================
[   37.947534] [ INFO: possible recursive locking detected ]
[   38.012120] 2.6.26-rc8 #10
[   38.044465] ---------------------------------------------
[   38.109049] afsd/3684 is trying to acquire lock:
[   38.164275]  (&l->mutex){--..}, at: [<d00000000014f0f4>]       broadcast .afs_mutex_enter+0x24/0x70 [libafs]
[   38.282318]
[   38.282319] but task is already holding lock:
[   38.352206]  (&l->mutex){--..}, at: [<d00000000014f0f4>]: 10.1.255.255   .afs_mutex_enter+0x24/0x70 [libafs]
[   38.470250]
[   38.470251] other info that might help us debug this:
[   38.548459] 2 locks held by afsd/3684:
[   38.593282]  #0:  (afs_global_lock){--..}, at: [<d0000000001583fc>]   netmask: 255. .osi_linux_alloc+0x17c/0x4c0 [libafs]
[   38.724950]  #1:  (&l->mutex){--..}, at: [<d00000000014f0f4>]255.0.0
 g .afs_mutex_enter+0x24/0x70 [libafs]
[   38.848298]
[   38.848300] stack backtrace:
[   38.900507] Call Trace:
[   38.929730] [c0000007f95330f0] [c000000000011144] .show_stack+0x64/0x210ateway: 10.1.0.2 (unreliable)
[   39.040389] [c0000007f95331b0] [c000000000011310] .dump_stack+0x20/0x40
[   39.119741] [c0000007f9533230] [c000000000098c90] .__lock_acquire+0xe20/0x1270
[   39.206376] [c0000007f9533330] [c0000000000991b4] .lock_acquire+0xd4/0x120
[   39.288851] [c0000007f95333f0] [c00000000038ce3c] .mutex_lock_nested+0xfc/0x420
[   39.376522] [c0000007f95334f0] [d00000000014f0f4] 54       dns0   .afs_mutex_enter+0x24/0x70 [libafs]
[   39.487078] [c0000007f9533570] [d0000000001462b0]   : 10.1.1.200  .rxi_ReapConnections+0x1b0/0x4e0 [libafs]
[   39.603871] [c0000007f9533690] [d00000000014acec]      dns1   : 0..rx_StartServer+0xac/0xf0 [libafs]
[   39.713388] [c0000007f9533740] [d000000000173c58] 0.0.0
.afs_ResourceInit+0x1b8/0x1f0 [libafs]
[   39.827059] [c0000007f95337d0] [d0000000001b8024]  domain : scl.am.afs_DaemonOp+0x2f4/0x310 [libafs]
[   39.936573] [c0000007f9533970] [d0000000001b8b00] eslab.gov       .afs_syscall_call+0x270/0x1ce0 [libafs]
[   40.051290] [c0000007f9533aa0] [d00000000013ebec]                 .afs_syscall+0x14c/0x6a0 [libafs]
[   40.159763] [c0000007f9533bc0] [d00000000015b248]                 .afs_unlocked_ioctl+0xc8/0x110 [libafs]
[   40.274476] [c0000007f9533c80] [c000000000160a40] .proc_reg_compat_ioctl+0xb0/0x100
 roo
[   40.382952] [c0000007f9533d30] [c00000000014a5d0] .compat_sys_ioctl+0xe0/0x500
[   40.469585] [c0000007f9533e30] [c0000000000086d4] syscall_exit+0x0/0x40
tserver: 10.1.1.[   40.550597] Starting AFS cache scan...200 rootpath: /afs/scl.ameslab.gov/p/nodeimg/powerpc.prodib
 filename  : zImage-2.6.26-rc8-poweMemory cache: Allocating 2048 dcache entries...rpc64
Begin: Running /scripts/ofound 0 non-empty cache files (0%).