Comment 6 for bug 1424342

Still occurring in 16.04, kernel 4.4.0.93.

[44880.327833] INFO: task Thunar:7047 blocked for more than 120 seconds.
[44880.327843] Not tainted 4.4.0-93-generic #116-Ubuntu
[44880.327846] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[44880.327850] Thunar D ffff88000a5b3878 0 7047 1607 0x00000000
[44880.327859] ffff88000a5b3878 ffffffff810bdd63 ffff880215a99c00 ffff880211c93800
[44880.327866] ffff88000a5b4000 ffff88012fa65424 ffff880211c93800 00000000ffffffff
[44880.327872] ffff88012fa65428 ffff88000a5b3890 ffffffff8183f0d5 ffff88012fa65420
[44880.327878] Call Trace:
[44880.327892] [<ffffffff810bdd63>] ? load_balance+0x1d3/0x980
[44880.327902] [<ffffffff8183f0d5>] schedule+0x35/0x80
[44880.327908] [<ffffffff8183f37e>] schedule_preempt_disabled+0xe/0x10
[44880.327914] [<ffffffff81840fb9>] __mutex_lock_slowpath+0xb9/0x130
[44880.327924] [<ffffffff8184104f>] mutex_lock+0x1f/0x30
[44880.327974] [<ffffffffc0a890ed>] cifs_reconnect_tcon+0x9d/0x340 [cifs]
[44880.327979] [<ffffffff810b9b35>] ? put_prev_entity+0x35/0x7d0
[44880.327986] [<ffffffff8102d66c>] ? __switch_to+0x1dc/0x5c0
[44880.328014] [<ffffffffc0a8943a>] smb_init+0x2a/0x50 [cifs]
[44880.328044] [<ffffffffc0a90d93>] CIFSSMBQPathInfo+0x63/0x2e0 [cifs]
[44880.328052] [<ffffffff810b2d1c>] ? __enqueue_entity+0x6c/0x70
[44880.328090] [<ffffffffc0abc9af>] cifs_query_path_info+0x6f/0x1a0 [cifs]
[44880.328096] [<ffffffff810b92fa>] ? enqueue_task_fair+0xaa/0x8b0
[44880.328103] [<ffffffff810b4275>] ? select_task_rq_fair+0x625/0x700
[44880.328109] [<ffffffff81037ef9>] ? sched_clock+0x9/0x10
[44880.328115] [<ffffffff810b1d4f>] ? sched_clock_cpu+0x8f/0xa0
[44880.328120] [<ffffffff810ab614>] ? check_preempt_curr+0x54/0x90
[44880.328128] [<ffffffff811ed723>] ? kmem_cache_alloc_trace+0x183/0x1f0
[44880.328133] [<ffffffff810ab669>] ? ttwu_do_wakeup+0x19/0xe0
[44880.328168] [<ffffffffc0aab110>] cifs_get_inode_info+0x390/0x8f0 [cifs]
[44880.328176] [<ffffffff817236eb>] ? __alloc_skb+0x9b/0x1f0
[44880.328182] [<ffffffff811eedb9>] ? __kmalloc+0x1b9/0x250
[44880.328188] [<ffffffff81224103>] ? pollwake+0x73/0x90
[44880.328220] [<ffffffffc0a9e132>] ? build_path_from_dentry+0xe2/0x3e0 [cifs]
[44880.328249] [<ffffffffc0a9e1a9>] ? build_path_from_dentry+0x159/0x3e0 [cifs]
[44880.328282] [<ffffffffc0aad6b5>] cifs_revalidate_dentry_attr+0x1d5/0x250 [cifs]
[44880.328312] [<ffffffffc0aad773>] cifs_revalidate_dentry+0x13/0x30 [cifs]
[44880.328342] [<ffffffffc0a9de47>] cifs_d_revalidate+0x27/0xb0 [cifs]
[44880.328350] [<ffffffff8121a6ff>] lookup_fast+0x24f/0x330
[44880.328357] [<ffffffff8121bdc9>] walk_component+0x49/0x300
[44880.328363] [<ffffffff8121b7bb>] ? path_init+0x1eb/0x3c0
[44880.328370] [<ffffffff8121d8ed>] path_lookupat+0x5d/0x110
[44880.328377] [<ffffffff8121f531>] filename_lookup+0xb1/0x180
[44880.328384] [<ffffffff811ed9bf>] ? kmem_cache_alloc+0x19f/0x1f0
[44880.328390] [<ffffffff8121f136>] ? getname_flags+0x56/0x1f0
[44880.328395] [<ffffffff8121f6d6>] user_path_at_empty+0x36/0x40
[44880.328402] [<ffffffff8120d784>] SyS_access+0xb4/0x230
[44880.328410] [<ffffffff818431f2>] entry_SYSCALL_64_fastpath+0x16/0x71