1. 17 10月, 2010 1 次提交
  2. 17 3月, 2010 1 次提交
    • N
      tipc: fix lockdep warning on address assignment · a2f46ee1
      Neil Horman 提交于
      So in the forward porting of various tipc packages, I was constantly
      getting this lockdep warning everytime I used tipc-config to set a network
      address for the protocol:
      
      [ INFO: possible circular locking dependency detected ]
      2.6.33 #1
      tipc-config/1326 is trying to acquire lock:
      (ref_table_lock){+.-...}, at: [<ffffffffa0315148>] tipc_ref_discard+0x53/0xd4 [tipc]
      
      but task is already holding lock:
      (&(&entry->lock)->rlock#2){+.-...}, at: [<ffffffffa03150d5>] tipc_ref_lock+0x43/0x63 [tipc]
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #1 (&(&entry->lock)->rlock#2){+.-...}:
      [<ffffffff8107b508>] __lock_acquire+0xb67/0xd0f
      [<ffffffff8107b78c>] lock_acquire+0xdc/0x102
      [<ffffffff8145471e>] _raw_spin_lock_bh+0x3b/0x6e
      [<ffffffffa03152b1>] tipc_ref_acquire+0xe8/0x11b [tipc]
      [<ffffffffa031433f>] tipc_createport_raw+0x78/0x1b9 [tipc]
      [<ffffffffa031450b>] tipc_createport+0x8b/0x125 [tipc]
      [<ffffffffa030f221>] tipc_subscr_start+0xce/0x126 [tipc]
      [<ffffffffa0308fb2>] process_signal_queue+0x47/0x7d [tipc]
      [<ffffffff81053e0c>] tasklet_action+0x8c/0xf4
      [<ffffffff81054bd8>] __do_softirq+0xf8/0x1cd
      [<ffffffff8100aadc>] call_softirq+0x1c/0x30
      [<ffffffff810549f4>] _local_bh_enable_ip+0xb8/0xd7
      [<ffffffff81054a21>] local_bh_enable_ip+0xe/0x10
      [<ffffffff81454d31>] _raw_spin_unlock_bh+0x34/0x39
      [<ffffffffa0308eb8>] spin_unlock_bh.clone.0+0x15/0x17 [tipc]
      [<ffffffffa0308f47>] tipc_k_signal+0x8d/0xb1 [tipc]
      [<ffffffffa0308dd9>] tipc_core_start+0x8a/0xad [tipc]
      [<ffffffffa01b1087>] 0xffffffffa01b1087
      [<ffffffff8100207d>] do_one_initcall+0x72/0x18a
      [<ffffffff810872fb>] sys_init_module+0xd8/0x23a
      [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b
      
      -> #0 (ref_table_lock){+.-...}:
      [<ffffffff8107b3b2>] __lock_acquire+0xa11/0xd0f
      [<ffffffff8107b78c>] lock_acquire+0xdc/0x102
      [<ffffffff81454836>] _raw_write_lock_bh+0x3b/0x6e
      [<ffffffffa0315148>] tipc_ref_discard+0x53/0xd4 [tipc]
      [<ffffffffa03141ee>] tipc_deleteport+0x40/0x119 [tipc]
      [<ffffffffa0316e35>] release+0xeb/0x137 [tipc]
      [<ffffffff8139dbf4>] sock_release+0x1f/0x6f
      [<ffffffff8139dc6b>] sock_close+0x27/0x2b
      [<ffffffff811116f6>] __fput+0x12a/0x1df
      [<ffffffff811117c5>] fput+0x1a/0x1c
      [<ffffffff8110e49b>] filp_close+0x68/0x72
      [<ffffffff8110e552>] sys_close+0xad/0xe7
      [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b
      
      Finally decided I should fix this.  Its a straightforward inversion,
      tipc_ref_acquire takes two locks in this order:
      ref_table_lock
      entry->lock
      
      while tipc_deleteport takes them in this order:
      entry->lock (via tipc_port_lock())
      ref_table_lock (via tipc_ref_discard())
      
      when the same entry is referenced, we get the above warning.  The fix is equally
      straightforward.  Theres no real relation between the entry->lock and the
      ref_table_lock (they just are needed at the same time), so move the entry->lock
      aquisition in tipc_ref_acquire down, after we unlock ref_table_lock (this is
      safe since the ref_table_lock guards changes to the reference table, and we've
      already claimed a slot there.  I've tested the below fix and confirmed that it
      clears up the lockdep issue
      Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
      CC: Allan Stephens <allan.stephens@windriver.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a2f46ee1
  3. 15 7月, 2008 1 次提交
  4. 13 5月, 2008 1 次提交
  5. 17 4月, 2008 3 次提交
  6. 25 2月, 2008 1 次提交
  7. 11 2月, 2007 1 次提交
  8. 22 7月, 2006 1 次提交
  9. 28 6月, 2006 1 次提交
  10. 26 6月, 2006 1 次提交
  11. 21 3月, 2006 1 次提交
  12. 18 1月, 2006 1 次提交
  13. 13 1月, 2006 4 次提交