• T
    NFSv4: Don't call put_rpccred() from an rcu callback · 905f8d16
    Trond Myklebust 提交于
    Doing so would require us to introduce bh-safe locks into put_rpccred().
    This patch fixes the lockdep complaint reported by Marc Dietrich:
    
    inconsistent {softirq-on-W} -> {in-softirq-W} usage.
    swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
     (rpc_credcache_lock){-+..}, at: [<c01dc487>]
    _atomic_dec_and_lock+0x17/0x60
    {softirq-on-W} state was registered at:
      [<c013e870>] __lock_acquire+0x650/0x1030
      [<c013f2b1>] lock_acquire+0x61/0x80
      [<c02db9ac>] _spin_lock+0x2c/0x40
      [<c01dc487>] _atomic_dec_and_lock+0x17/0x60
      [<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
      [<dced56c1>] rpcauth_unbindcred+0x21/0x60 [sunrpc]
      [<dced3fd4>] a0 [sunrpc]
      [<dcecefe0>] rpc_call_sync+0x30/0x40 [sunrpc]
      [<dcedc73b>] rpcb_register+0xdb/0x180 [sunrpc]
      [<dced65b3>] svc_register+0x93/0x160 [sunrpc]
      [<dced6ebe>] __svc_create+0x1ee/0x220 [sunrpc]
      [<dced7053>] svc_create+0x13/0x20 [sunrpc]
      [<dcf6d722>] nfs_callback_up+0x82/0x120 [nfs]
      [<dcf48f36>] nfs_get_client+0x176/0x390 [nfs]
      [<dcf49181>] nfs4_set_client+0x31/0x190 [nfs]
      [<dcf49983>] nfs4_create_server+0x63/0x3b0 [nfs]
      [<dcf52426>] nfs4_get_sb+0x346/0x5b0 [nfs]
      [<c017b444>] vfs_kern_mount+0x94/0x110
      [<c0190a62>] do_mount+0x1f2/0x7d0
      [<c01910a6>] sys_mount+0x66/0xa0
      [<c0104046>] syscall_call+0x7/0xb
      [<ffffffff>] 0xffffffff
    irq event stamp: 5277830
    hardirqs last  enabled at (5277830): [<c017530a>] kmem_cache_free+0x8a/0xc0
    hardirqs last disabled at (5277829): [<c01752d2>] kmem_cache_free+0x52/0xc0
    softirqs last  enabled at (5277798): [<c0124173>] __do_softirq+0xa3/0xc0
    softirqs last disabled at (5277817): [<c01241d7>] do_softirq+0x47/0x50
    
    other info that might help us debug this:
    no locks held by swapper/0.
    
    stack backtrace:
     [<c0104fda>] show_trace_log_lvl+0x1a/0x30
     [<c0105c02>] show_trace+0x12/0x20
     [<c0105d15>] dump_stack+0x15/0x20
     [<c013ccc3>] print_usage_bug+0x153/0x160
     [<c013d8b9>] mark_lock+0x449/0x620
     [<c013e824>] __lock_acquire+0x604/0x1030
     [<c013f2b1>] lock_acquire+0x61/0x80
     [<c02db9ac>] _spin_lock+0x2c/0x40
     [<c01dc487>] _atomic_dec_and_lock+0x17/0x60
     [<dced55fd>] put_rpccred+0x5d/0x100 [sunrpc]
     [<dcf6bf83>] nfs_free_delegation_callback+0x13/0x20 [nfs]
     [<c012f9ea>] __rcu_process_callbacks+0x6a/0x1c0
     [<c012fb52>] rcu_process_callbacks+0x12/0x30
     [<c0124218>] tasklet_action+0x38/0x80
     [<c0124125>] __do_softirq+0x55/0xc0
     [<c01241d7>] do_softirq+0x47/0x50
     [<c0124605>] irq_exit+0x35/0x40
     [<c0112463>] smp_apic_timer_interrupt+0x43/0x80
     [<c0104a77>] apic_timer_interrupt+0x33/0x38
     [<c02690df>] cpuidle_idle_call+0x6f/0x90
     [<c01023c3>] cpu_idle+0x43/0x70
     [<c02d8c27>] rest_init+0x47/0x50
     [<c03bcb6a>] start_kernel+0x22a/0x2b0
     [<00000000>] 0x0
     =======================
    Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
    905f8d16
delegation.c 12.2 KB