Unpinning an unpinned lock warning triggered by wake_up_new_task()

[Bart Van Assche <bart.vanassche@sandisk.com>]

Hello,

Here is another warning that was reported while I was retesting the SRP
initiator driver in kernel v4.2-rc4. Has anyone seen this before ?

Thanks,

Bart.

Jul 31 15:22:42 srp-ini multipathd: 66:32: mark as failed
Jul 31 15:22:42 srp-ini multipathd: mpatha: remaining active paths: 0
Jul 31 15:22:42 srp-ini kernel: sd 12:0:0:2: Parameters changed
Jul 31 15:22:43 srp-ini kernel: ------------[ cut here ]------------
Jul 31 15:22:43 srp-ini kernel: WARNING: CPU: 0 PID: 358 at kernel/locking/lockdep.c:3497 lock_unpin_lock+0x105/0x110()
Jul 31 15:22:43 srp-ini kernel: unpinning an unpinned lock
Jul 31 15:22:43 srp-ini kernel: Modules linked in: dm_queue_length scsi_dh_alua af_packet xt_tcpudp ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_con
ntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack msr iptable_mangle iptable_raw iptable_filter ip_tables x_tables sg x86_pkg_temp_thermal coretemp cr
ct10dif_pclmul crc32c_intel aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd microcode pcspkr tg3 libphy lpc_ich mfd_core wmi acpi_power_meter ib_srp scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm processor thermal_sys 
hwmon button dm_multipath scsi_dh dm_mod ext4 crc16 mbcache jbd2 mlx4_en ptp pps_core mlx4_ib ib_sa ib_mad ib_core ib_addr sd_mod sr_mod cdrom hid_generic usbhid hid ahci libahci libata ehci_pci ehci_hcd mlx4_core usbcore scsi_mod usb_common autofs4
Jul 31 15:22:43 srp-ini multipathd: mpatha: sdc - tur checker reports path is up
Jul 31 15:22:43 srp-ini multipathd: 8:32: reinstated
Jul 31 15:22:43 srp-ini multipathd: mpatha: remaining active paths: 1
Jul 31 15:22:43 srp-ini multipathd: mpatha: sdr - tur checker reports path is up
Jul 31 15:22:43 srp-ini multipathd: 65:16: reinstated
Jul 31 15:22:43 srp-ini multipathd: mpatha: remaining active paths: 2
Jul 31 15:22:43 srp-ini kernel: CPU: 0 PID: 358 Comm: multipathd Not tainted 4.2.0-rc4-debug+ #1
Jul 31 15:22:43 srp-ini kernel: Hardware name: Dell Inc. PowerEdge R430/03XKDV, BIOS 1.0.2 11/17/2014
Jul 31 15:22:43 srp-ini kernel: ffffffff817a80ba ffff88044faf7d58 ffffffff814f9cde 0000000000000000
Jul 31 15:22:43 srp-ini kernel: ffff88044faf7da8 ffff88044faf7d98 ffffffff810746ba 0000000000000003
Jul 31 15:22:43 srp-ini kernel: 0000000000000001 ffff88044e4742c0 ffff88047fc15618 0000000000000092
Jul 31 15:22:43 srp-ini kernel: Call Trace:
Jul 31 15:22:43 srp-ini kernel: [<ffffffff814f9cde>] dump_stack+0x4c/0x65
Jul 31 15:22:43 srp-ini kernel: [<ffffffff810746ba>] warn_slowpath_common+0x8a/0xc0
Jul 31 15:22:43 srp-ini kernel: [<ffffffff81074736>] warn_slowpath_fmt+0x46/0x50
Jul 31 15:22:43 srp-ini kernel: [<ffffffff810bbd75>] lock_unpin_lock+0x105/0x110
Jul 31 15:22:43 srp-ini kernel: [<ffffffff810a32f1>] wake_up_new_task+0x171/0x2e0
Jul 31 15:22:43 srp-ini kernel: [<ffffffff81073852>] _do_fork+0x162/0x760
Jul 31 15:22:43 srp-ini kernel: [<ffffffff81003044>] ? lockdep_sys_exit_thunk+0x12/0x14
Jul 31 15:22:43 srp-ini kernel: [<ffffffff81073ef9>] SyS_clone+0x19/0x20
Jul 31 15:22:43 srp-ini kernel: [<ffffffff815022f2>] entry_SYSCALL_64_fastpath+0x16/0x7a
Jul 31 15:22:43 srp-ini kernel: ---[ end trace c764daa6543cd2b6 ]---
Jul 31 15:22:43 srp-ini kernel: device-mapper: multipath: Failing path 8:32.
Jul 31 15:22:43 srp-ini kernel: sd 14:0:0:0: alua: port group 101 state S preferred supports tOlUSNA
Jul 31 15:22:44 srp-ini kernel: sd 14:0:0:0: alua: stpg sense code: 04/67/0a
Jul 31 15:22:44 srp-ini kernel: device-mapper: multipath: Failing path 65:16.