Recently had this Oops reported to me on the 3.10 kernel:

[  807.554955] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[  807.562799] IP: [<ffffffff814e6fc7>] skb_dequeue+0x47/0x70
[  807.568296] PGD 20c889067 PUD 20c8b8067 PMD 0
[  807.572769] Oops: 0002 [#1] SMP
[  807.655597] Hardware name: Dell Inc. PowerEdge R415/0DDT2D, BIOS 1.8.6 12/06/2011
[  807.663079] Workqueue: events fcoe_ctlr_recv_work [libfcoe]
[  807.668656] task: ffff88020b42a160 ti: ffff88020ae6c000 task.ti: ffff88020ae6c000
[  807.676126] RIP: 0010:[<ffffffff814e6fc7>]  [<ffffffff814e6fc7>] skb_dequeue+0x47/0x70
[  807.684046] RSP: 0000:ffff88020ae6dd70  EFLAGS: 00010097
[  807.689349] RAX: 0000000000000246 RBX: ffff8801d04d6700 RCX: 0000000000000000
[  807.696474] RDX: 0000000000000000 RSI: 0000000000000246 RDI: ffff88020df26434
[  807.703598] RBP: ffff88020ae6dd88 R08: 00000000000173e0 R09: ffff880216e173e0
[  807.710723] R10: ffffffff814e5897 R11: ffffea0007413580 R12: ffff88020df26420
[  807.717847] R13: ffff88020df26434 R14: 0000000000000004 R15: ffff8801d04c42ce
[  807.724972] FS:  00007fdaab6048c0(0000) GS:ffff880216e00000(0000) knlGS:0000000000000000
[  807.733049] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  807.738785] CR2: 0000000000000008 CR3: 000000020cbc9000 CR4: 00000000000006f0
[  807.745910] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  807.753033] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  807.760156] Stack:
[  807.762162]  ffff8801d04d6700 0000000000000001 ffff88020df26400 ffff88020ae6de20
[  807.769586]  ffffffffa0444409 ffff88020b046a00 ffff88020ae6dde8 ffffffff810105be
[  807.777008]  ffff88020b42a868 0000000000000000 ffff88020df264a8 ffff88020df26348
[  807.784431] Call Trace:
[  807.786885]  [<ffffffffa0444409>] fcoe_ctlr_recv_work+0x59/0x9a0 [libfcoe]
[  807.793755]  [<ffffffff810105be>] ? __switch_to+0x13e/0x4a0
[  807.799324]  [<ffffffff8107d0e6>] process_one_work+0x176/0x420
[  807.805151]  [<ffffffff8107dd0b>] worker_thread+0x11b/0x3a0
[  807.810717]  [<ffffffff8107dbf0>] ? rescuer_thread+0x350/0x350
[  807.816545]  [<ffffffff810842b0>] kthread+0xc0/0xd0
[  807.821416]  [<ffffffff810841f0>] ? insert_kthread_work+0x40/0x40
[  807.827503]  [<ffffffff8160ce2c>] ret_from_fork+0x7c/0xb0
[  807.832897]  [<ffffffff810841f0>] ? insert_kthread_work+0x40/0x40
[  807.858500] RIP  [<ffffffff814e6fc7>] skb_dequeue+0x47/0x70
[  807.864076]  RSP <ffff88020ae6dd70>
[  807.867558] CR2: 0000000000000008

Looks like the root cause is the fact that the packet recieve function
fcoe_ctlr_recv enqueues the skb to a sk_buff_head_list prior to ensuring that
the skb is unshared.  This can happen when multiple packet listeners recieve an
skb, as the deliver_skb function just increments skb->users for each handler.
As a result, having multiple users of a single skb results in multiple
manipulators of its methods, implying list corruption, and the oops recorded
above.

The fix is pretty easy, just make sure that we clone the skb if its got multiple
users with the skb_share_check function, like other protocols do.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

Declare local variables and functions 'static'. This patch does not
change any functionality.
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

When repeatedly doing rmmod and modprobe on the ixgbe
driver while FCoE is active in a VN2VN configuration,
memory leaks would be discovered by kmemleak with the
following backtrace:

unreferenced object 0xffff88003d076000 (size 1024):
  comm "kworker/0:3", pid 2998, jiffies 4295436448 (age 1015.332s)
  hex dump (first 32 bytes):
    48 8a fe 6f 00 88 ff ff 00 00 00 00 00 00 00 00  H..o............
    01 00 00 00 02 00 00 00 7b ac 87 21 1b 00 00 10  ........{..!....
  backtrace:
    [<ffffffff814b308b>] kmemleak_alloc+0x5b/0xc0
    [<ffffffff8115c6e8>] __kmalloc+0xd8/0x1b0
    [<ffffffffa0216638>] fc_rport_create+0x48/0x1f0 [libfc]
    [<ffffffffa023cd86>] fcoe_ctlr_vn_add.isra.10+0x56/0x1a0 [libfcoe]
    [<ffffffffa023f440>] fcoe_ctlr_vn_recv+0x8b0/0xab0 [libfcoe]
    [<ffffffffa023fb06>] fcoe_ctlr_recv_work+0x4c6/0xf60 [libfcoe]
    [<ffffffff81067404>] process_one_work+0x1e4/0x4d0
    [<ffffffff81068def>] worker_thread+0x10f/0x380
    [<ffffffff8107019a>] kthread+0xea/0xf0
    [<ffffffff814d32ec>] ret_from_fork+0x7c/0xb0
    [<ffffffffffffffff>] 0xffffffffffffffff

This patch stops the leak of the fc_rport_priv structure.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

ctlr_dev was initialized to NULL, and never re-assigned. This
caused the log statement to always report failure. This patch
removes the unused variable and fixes the log statement to always
report 'success', as that is what should be logged if the code
reaches this point.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>

Both fcoe_fc_els_lesb and fc_els_lesb are in __be32 already, and both are
exactly the same size in bytes, with somewhat different member names to
reflect the fact the former is for Ethernet media the latter is for Fiber
Channel, so, remove conversion and use __be32 directly. This fixes the warning
from sparse check.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

This patch fixes a smatch warning as below:

smatch warnings:
drivers/scsi/fcoe/fcoe.c:782 fcoe_fdmi_info() warn: 'fdmi' puts 896 bytes on
stack
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NNeerav Parikh <Neerav.Parikh@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

fcoe_xmit was coded such that it would skip the vlan net device/layer
and instead set some vlan flags and transmit on the real net device.
The real net device has code that would add the vlan tag for fcoe skbs.
This avoids some extra processing for data frames and provides a small
performance improvement.

Since fcoe_xmit was not using the vlan net device, __vlan_put_tag
within the real net device's xmit routine was ultimately being
called to set the vlan tag.

With the below change the behavior of __vlan_put_tag changed slightly,
it now sets the skb->protocol = vlan_proto. vlan_proto was not a field
being set by fcoe_xmit, so the skb->protocol is now not being set to
ETH_P_8021Q, as it should be.

This patch converts fcoe_xmit to use the vlan_put_tag routine which
will tag the skb and fcoe will continue to transmit fcoe skbs on the
real net device.

For reference, the below change was the one that altered the
__vlan_put_tag behavior.

  commit 86a9bad3
  Author: Patrick McHardy <kaber@trash.net>
  Date:   Fri Apr 19 02:04:30 2013 +0000

      net: vlan: add protocol argument to packet tagging functions

      Add a protocol argument to the VLAN packet tagging functions. In case of HW
      tagging, we need that protocol available in the ndo_start_xmit functions,
      so it is stored in a new field in the skb. The new field fits into a hole
      (on 64 bit) and doesn't increase the sks's size.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When multiple FCFs in use, and first FIP Advertisement received is
with "Available for Login" i.e A bit set to 0, FCF selection will fail.
The fix is to remove the assumption in the code that first FCF is only
allowed selectable FCF.
Consider the scenario fip->fcfs contains FCF1(fabricname X, marked A=0)
FCF2(fabricname Y, marked A=1). list_first_entry(first) points to FCF1
and 1st iteration we ignore the FCF and on 2nd iteration we compare
FCF1 & FCF2 fabric name and we fails to perform FCF selection.
Signed-off-by: NKrishna Mohan <krmohan@cisco.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

Use preferable function name which implies using a pseudo-random
number generator.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: James Smart <james.smart@emulex.com>
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename the hardware VLAN acceleration features to include "CTAG" to indicate
that they only support CTAGs. Follow up patches will introduce 802.1ad
server provider tagging (STAGs) and require the distinction for hardware not
supporting acclerating both.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The libfc discovery layer is being initialized in the
'create' paths for both legacy libfcoe module parameters
and fcoe_sysfs control interfaces. The problem is that
for VN2VN mode the discovery layer is initialized as if
it were in 'fabric' mode and it is not re-configured when
the mode is changed to 'vn2vn'.

This patch splits out code that needs to be initialized
once and code that can, and should be, re-configured when
the mode changes. Additionally this patch makes that change
so that the discovery layer can be reconfigured to the
libfcoe implementation when in 'vn2vn' mode.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>

Split discovery initialization in code that is setup once (fcoe_disc_init)
and code that can be re-configured (fcoe_disc_config).
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>

Currently libfcoe is doing some libfc discovery layer initialization outside of
libfc. This patch moves this code into libfc and sets up a split in discovery
(one time) initialization code and (re-configurable) settings that will come in
the next patch.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>
Reviewed-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>

We can deadlock (s_active and fcoe_config_mutex) if a
port is being destroyed at the same time one is being created.

[ 4200.503113] ======================================================
[ 4200.503114] [ INFO: possible circular locking dependency detected ]
[ 4200.503116] 3.8.0-rc5+ #8 Not tainted
[ 4200.503117] -------------------------------------------------------
[ 4200.503118] kworker/3:2/2492 is trying to acquire lock:
[ 4200.503119]  (s_active#292){++++.+}, at: [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503127]
but task is already holding lock:
[ 4200.503128]  (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe]
[ 4200.503133]
which lock already depends on the new lock.

[ 4200.503135]
the existing dependency chain (in reverse order) is:
[ 4200.503136]
-> #1 (fcoe_config_mutex){+.+.+.}:
[ 4200.503139]        [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503143]        [<ffffffff816ca7be>] mutex_lock_nested+0x6e/0x360
[ 4200.503146]        [<ffffffffa02f11bd>] fcoe_enable+0x1d/0xb0 [fcoe]
[ 4200.503148]        [<ffffffffa02f127d>] fcoe_ctlr_enabled+0x2d/0x50 [fcoe]
[ 4200.503151]        [<ffffffffa02ffbe8>] store_ctlr_enabled+0x38/0x90 [libfcoe]
[ 4200.503154]        [<ffffffff81424878>] dev_attr_store+0x18/0x30
[ 4200.503157]        [<ffffffff8122b750>] sysfs_write_file+0xe0/0x150
[ 4200.503160]        [<ffffffff811b334c>] vfs_write+0xac/0x180
[ 4200.503162]        [<ffffffff811b3692>] sys_write+0x52/0xa0
[ 4200.503164]        [<ffffffff816d7159>] system_call_fastpath+0x16/0x1b
[ 4200.503167]
-> #0 (s_active#292){++++.+}:
[ 4200.503170]        [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90
[ 4200.503172]        [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503174]        [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160
[ 4200.503176]        [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503178]        [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0
[ 4200.503180]        [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100
[ 4200.503183]        [<ffffffff814251eb>] device_remove_groups+0x3b/0x60
[ 4200.503185]        [<ffffffff81425534>] device_remove_attrs+0x44/0x80
[ 4200.503187]        [<ffffffff81425e97>] device_del+0x127/0x1c0
[ 4200.503189]        [<ffffffff81425f52>] device_unregister+0x22/0x60
[ 4200.503191]        [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe]
[ 4200.503194]        [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe]
[ 4200.503196]        [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe]
[ 4200.503198]        [<ffffffff8107ee91>] process_one_work+0x1a1/0x580
[ 4200.503203]        [<ffffffff81080c6e>] worker_thread+0x15e/0x440
[ 4200.503205]        [<ffffffff8108715a>] kthread+0xea/0xf0
[ 4200.503207]        [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0

[ 4200.503209]
other info that might help us debug this:

[ 4200.503211]  Possible unsafe locking scenario:

[ 4200.503212]        CPU0                    CPU1
[ 4200.503213]        ----                    ----
[ 4200.503214]   lock(fcoe_config_mutex);
[ 4200.503215]                                lock(s_active#292);
[ 4200.503218]                                lock(fcoe_config_mutex);
[ 4200.503219]   lock(s_active#292);
[ 4200.503221]
 *** DEADLOCK ***

[ 4200.503223] 3 locks held by kworker/3:2/2492:
[ 4200.503224]  #0:  (fcoe){.+.+.+}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580
[ 4200.503228]  #1:  ((&port->destroy_work)){+.+.+.}, at: [<ffffffff8107ee2b>] process_one_work+0x13b/0x580
[ 4200.503232]  #2:  (fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02f3338>] fcoe_destroy_work+0xe8/0x120 [fcoe]
[ 4200.503236]
stack backtrace:
[ 4200.503238] Pid: 2492, comm: kworker/3:2 Not tainted 3.8.0-rc5+ #8
[ 4200.503240] Call Trace:
[ 4200.503243]  [<ffffffff816c2f09>] print_circular_bug+0x1fb/0x20c
[ 4200.503246]  [<ffffffff810c680f>] __lock_acquire+0x135f/0x1c90
[ 4200.503248]  [<ffffffff810c463a>] ? debug_check_no_locks_freed+0x9a/0x180
[ 4200.503250]  [<ffffffff810c7711>] lock_acquire+0xa1/0x140
[ 4200.503253]  [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70
[ 4200.503255]  [<ffffffff8122c626>] sysfs_deactivate+0x116/0x160
[ 4200.503258]  [<ffffffff8122d20b>] ? sysfs_addrm_finish+0x3b/0x70
[ 4200.503260]  [<ffffffff8122d20b>] sysfs_addrm_finish+0x3b/0x70
[ 4200.503262]  [<ffffffff8122b2eb>] sysfs_hash_and_remove+0x5b/0xb0
[ 4200.503265]  [<ffffffff8122f3d1>] sysfs_remove_group+0x61/0x100
[ 4200.503273]  [<ffffffff814251eb>] device_remove_groups+0x3b/0x60
[ 4200.503275]  [<ffffffff81425534>] device_remove_attrs+0x44/0x80
[ 4200.503277]  [<ffffffff81425e97>] device_del+0x127/0x1c0
[ 4200.503279]  [<ffffffff81425f52>] device_unregister+0x22/0x60
[ 4200.503282]  [<ffffffffa0300970>] fcoe_ctlr_device_delete+0xe0/0xf0 [libfcoe]
[ 4200.503285]  [<ffffffffa02f1b5c>] fcoe_interface_cleanup+0x6c/0xa0 [fcoe]
[ 4200.503287]  [<ffffffffa02f3355>] fcoe_destroy_work+0x105/0x120 [fcoe]
[ 4200.503290]  [<ffffffff8107ee91>] process_one_work+0x1a1/0x580
[ 4200.503292]  [<ffffffff8107ee2b>] ? process_one_work+0x13b/0x580
[ 4200.503295]  [<ffffffffa02f3250>] ? fcoe_if_destroy+0x230/0x230 [fcoe]
[ 4200.503297]  [<ffffffff81080c6e>] worker_thread+0x15e/0x440
[ 4200.503299]  [<ffffffff81080b10>] ? busy_worker_rebind_fn+0x100/0x100
[ 4200.503301]  [<ffffffff8108715a>] kthread+0xea/0xf0
[ 4200.503304]  [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160
[ 4200.503306]  [<ffffffff816d70ac>] ret_from_fork+0x7c/0xb0
[ 4200.503308]  [<ffffffff81087070>] ? kthread_create_on_node+0x160/0x160
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NJack Morgan <jack.morgan@intel.com>

When there are multiple FCFs in the fabric, and one of them becomes
unavailable, the fabric name for the unavailable FCF becomes 0 along
with FIP_FL_AVAIL getting reset. In this case, FCF selection logic does
not select any FCF as it first checks for conflicting FCFs (since fabric
name is 0, it fails the condition), instead of first checking if it is
usable or not. Fix it by first checking if FCF is usable and skip that
FCF, and go to the next one in the list to check if it can be selected.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

When a CVL is received while we wait to select best FCF, we drop it
without handling it. This causes initiator and the switch to go
out-of-sync. Initiator proceeds selecting one of the FCFs and tries to
send FIP FLOGI. However the switch may reject the FLOGI, as it has
cleared its internal state, and expects the initiator to start FIP
discovery protocol. Fix this condition by resetting the fcoe
controller.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Reviewed-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

This patch fixes following deadlock caused by destroying of
an FCoE interface with active NPIV ports on that interface.

    Call Trace:
    [<ffffffff814b7e88>] schedule+0x64/0x66
    [<ffffffff814b6b4f>] schedule_timeout+0x36/0xe3
    [<ffffffff81070c55>] ? update_curr+0xd6/0x110
    [<ffffffff81071f6b>] ? hrtick_update+0x1b/0x4d
    [<ffffffff81072405>] ? dequeue_task_fair+0x1ca/0x1d9
    [<ffffffff8106a369>] ? need_resched+0x1e/0x28
    [<ffffffff814b7d14>] wait_for_common+0x9b/0xf1
    [<ffffffff8106e7be>] ? try_to_wake_up+0x1e0/0x1e0
    [<ffffffff814b7e22>] wait_for_completion+0x1d/0x1f
    [<ffffffff8105ae82>] flush_workqueue+0x116/0x2a1
    [<ffffffff8105b357>] drain_workqueue+0x66/0x14c
    [<ffffffff8105b8ef>] destroy_workqueue+0x1a/0xcf
    [<ffffffffa009211e>] fc_remove_host+0x154/0x17f [scsi_transport_fc]
    [<ffffffffa00edbb8>] fcoe_if_destroy+0x184/0x1c9 [fcoe]
    [<ffffffffa00edc28>] fcoe_destroy_work+0x2b/0x44 [fcoe]
    [<ffffffff8105a82a>] process_one_work+0x1a8/0x2a4
    [<ffffffffa00edbfd>] ? fcoe_if_destroy+0x1c9/0x1c9 [fcoe]
    [<ffffffff8105c396>] worker_thread+0x1db/0x268
    [<ffffffff810604a3>] ? wake_up_bit+0x2a/0x2a
    [<ffffffff8105c1bb>] ? manage_workers.clone.16+0x1f6/0x1f6
    [<ffffffff8105ffd6>] kthread+0x6f/0x77
    [<ffffffff814c0304>] kernel_thread_helper+0x4/0x10
    [<ffffffff8105ff67>] ? kthread_freezable_should_stop+0x4b/0x4b

    Call Trace:
    [<ffffffff814b7e88>] schedule+0x64/0x66
    [<ffffffff814b8041>] schedule_preempt_disabled+0xe/0x10
    [<ffffffff814b70a1>] __mutex_lock_common.clone.5+0x117/0x17a
    [<ffffffff814b7117>] __mutex_lock_slowpath+0x13/0x15
    [<ffffffff814b6f76>] mutex_lock+0x23/0x37
    [<ffffffff8125b890>] ? list_del+0x11/0x30
    [<ffffffffa00edc84>] fcoe_vport_destroy+0x43/0x5f [fcoe]
    [<ffffffffa009130a>] fc_vport_terminate+0x48/0x110 [scsi_transport_fc]
    [<ffffffffa00913ef>] fc_vport_sched_delete+0x1d/0x79 [scsi_transport_fc]
    [<ffffffff8105a82a>] process_one_work+0x1a8/0x2a4
    [<ffffffffa00913d2>] ? fc_vport_terminate+0x110/0x110 [scsi_transport_fc]
    [<ffffffff8105c396>] worker_thread+0x1db/0x268
    [<ffffffff8105c1bb>] ? manage_workers.clone.16+0x1f6/0x1f6
    [<ffffffff8105ffd6>] kthread+0x6f/0x77
    [<ffffffff814c0304>] kernel_thread_helper+0x4/0x10
    [<ffffffff8105ff67>] ? kthread_freezable_should_stop+0x4b/0x4b
    [<ffffffff814c0300>] ? gs_change+0x13/0x13

A prior attempt to fix this issue is posted here:
http://lists.open-fcoe.org/pipermail/devel/2012-October/012318.html
or
http://article.gmane.org/gmane.linux.scsi.open-fcoe.devel/11924

Based on feedback and discussion with Neil Horman it seems that the above patch
may have a case where the fcoe_vport_destroy() and fcoe_destroy_work() can
race; hence that patch has been withdrawn with this patch that is trying to
solve the same problem in a different way.

In the current approach instead of removing the fcoe_config_mutex from the
vport_delete callback function; I've chosen to delete all the NPIV ports first
on a given root lport before continuing with the removal of the root lport.
Signed-off-by: NNeerav Parikh <Neerav.Parikh@intel.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

When creating an fcoe interfce, we call fcoe_link_speed_update before we add the
lports fcoe interface to the fc_hostlist.  Since network device events like
NETDEV_CHANGE are only processed if an fcoe interface is found with an
underlying netdev that matches the netdev of the event.  Since this processing
in fcoe_device_notification is how link_speed changes get communicated to the
libfc  code (via fcoe_link_speed_update), we have a race condition - if a
NETDEV_CHANGE event is sent after the call to fcoe_link_speed_update in
fcoe_netdev_config, but before we add the interface to the fc_hostlist, we will
loose the event and attributes like /sys/class/fc_host/hostX/speed will not get
updated properly.

Fix this by moving the add to the fc_hostlist above the serialized call to
fcoe_netdev_config, ensuring that we catch netdev envents before we make a
direct call to fcoe_link_speed_update.

Also use this opportunity to clean up access to the fc_hostlist a bit by
creating a fcoe_hostlist_del accessor and replacing the cleanup in fcoe_exit to
use it properly.

Tested by myself successfully

[ Comment over 80 chars broken into multi-line by Robert Love to
  satisfy checkpatch.pl ]
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reviewed-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

This renames all random32 functions to have 'prandom_' prefix as follows:

  void prandom_seed(u32 seed);	/* rename from srandom32() */
  u32 prandom_u32(void);		/* rename from random32() */
  void prandom_seed_state(struct rnd_state *state, u64 seed);
  				/* rename from prandom32_seed() */
  u32 prandom_u32_state(struct rnd_state *state);
  				/* rename from prandom32() */

The purpose of this renaming is to prevent some kernel developers from
assuming that prandom32() and random32() might imply that only
prandom32() was the one using a pseudo-random number generator by
prandom32's "p", and the result may be a very embarassing security
exposure.  This concern was expressed by Theodore Ts'o.

And furthermore, I'm going to introduce new functions for getting the
requested number of pseudo-random bytes.  If I continue to use both
prandom32 and random32 prefixes for these functions, the confusion
is getting worse.

As a result of this renaming, "prandom_" is the common prefix for
pseudo-random number library.

Currently, srandom32() and random32() are preserved because it is
difficult to rename too many users at once.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: David Laight <david.laight@aculab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

	AFAICS, the situation for fcoe_transport_disable() seems to be
the same as for fcoe_transport_enable().  IOW, shouldn't it have
restart_syscall() removed as well?  I don't see any in-tree ->disable()
instances that could return -ERESTARTSYS, anyway...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

Similarly they can be moved into libfcoe instead of being private to fcoe now.
Also add comments particularly on the term LESB to the corresponding function.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Cc: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

With the previous patch, fcoe_link_speed_update() can be moved into libfcoe and
exported to used by fcoe, bnx2fc, and etc.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Cc: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

Adds support to fcoe_port's newly added get_netdev fucntion pointer.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Cc: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>

Convert libfc, libfcoe and fcoe's debug_logging macros
to use pr_info() instead of printk(KERN_INFO, ...). checkpatch.pl
now complains about this, so convert libfcoe to preferred
method.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>

This patch adds support for the new fcoe_sysfs
control interface to fcoe.ko. It keeps the deprecated
interface in tact and therefore either the legacy
or the new control interfaces can be used. A mixed mode
is not supported. A user must either use the new
interfaces or the old ones, but not both.

The fcoe_ctlr's link state is now driven by both the
netdev link state as well as the fcoe_ctlr_device's
enabled attribute. The link must be up and the
fcoe_ctlr_device must be enabled before the FCoE
Controller starts discovery or login.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>

This patch does a few things.

1) Makes /sys/bus/fcoe/ctlr_{create,destroy} interfaces.
   These interfaces take an <ifname> and will either
   create an FCoE Controller or destroy an FCoE
   Controller depending on which file is written to.

   The new FCoE Controller will start in a DISABLED
   state and will not do discovery or login until it
   is ENABLED. This pause will allow us to configure
   the FCoE Controller before enabling it.

2) Makes the 'mode' attribute of a fcoe_ctlr_device
   writale. This allows the user to configure the mode
   in which the FCoE Controller will start in when it
   is ENABLED.

   Possible modes are 'Fabric', or 'VN2VN'.

   The default mode for a fcoe_ctlr{,_device} is 'Fabric'.
   Drivers must implement the set_fcoe_ctlr_mode routine
   to support this feature.

   libfcoe offers an exported routine to set a FCoE
   Controller's mode. The mode can only be changed
   when the FCoE Controller is DISABLED.

   This patch also removes the get_fcoe_ctlr_mode pointer
   in the fcoe_sysfs function template, the code in
   fcoe_ctlr.c to get the mode and the assignment of
   the fcoe_sysfs function pointer to the fcoe_ctlr.c
   implementation (in fcoe and bnx2fc). fcoe_sysfs can
   return that value for the mode without consulting the
   LLD.

3) Make a 'enabled' attribute of a fcoe_ctlr_device. On a
   read, fcoe_sysfs will return the attribute's value. On
   a write, fcoe_sysfs will call the LLD (if there is a
   callback) to notifiy that the enalbed state has changed.

This patch maintains the old FCoE control interfaces as
module parameters, but it adds comments pointing out that
the old interfaces are deprecated.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>

Add a macro to print fcoe_sysfs debug statements.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>

Instead of creating a structure with an enum and a pointer
to a string, simply allocate an array of strings and use
the enum values for the indicies.

This means that we do not need to iterate through the list
of entries when looking up a string name by its enum key.

This will also help with a latter patch that will add
more fcoe_sysfs attributes that will also use the
fcoe_enum_name_search macro. One attribute will also do
a reverse lookup which requires less code when the
enum-to-string mappings are organized as this patch makes
them to be.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>

SCSI errors were generated while writing to LUNs
connected via NPIV ports.

Debugging this it was found that the FCoE packets
transmitted via the NPIV ports were not tagged with
correct user priority as negotiated with peer by DCB
agent. This resulted in FCoE traffic going with priority
zero(0) that did not have priority flow control (PFC)
enabled for it. The initiator after transferring data
to the target never saw any reply indicating the transfer
was complete. This resulted in error recovery (ABTS) and
SCSI command retries by the scsi-mid layer; eventually
resulting in I/O errors.

This patch fixes this issue by keeping the FCoE user
priority information in the fcoe_interface instance
that is common for both the physical port as well as
NPIV ports connected to that physical port; instead
of storing it in fcoe_port structure that has a per
port instance.
Signed-off-by: NNeerav Parikh <Neerav.Parikh@intel.com>
Acked-by: NYi Zou <yi.zou@intel.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Tested-by: NMarcus Dennis <marcusx.e.dennis@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Noticed that we can shuffle the code around in fcoe_percpu_receive_thread a bit
and avoid taking the fcoe_rx_list lock twice per iteration.  This should improve
throughput somewhat.  With this change we take the lock, and check for new
frames in a single critical section.  Only if the list is empty do we drop the
lock and re-acquire it after being signaled to wake up.

Change Notes:
v2) did some further cleanup on the patch by replacing the 2nd call of
spin_lock/splice_init with a goto to the top of the outer loop.  This allows me
to change the inner while loop to an if conditional and remove the sencond check
of kthread_should_stop.  Based on suggestion from Vasu Dev.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

strtoul returns an 'unsigned long' so there is no
reason to check if the value is less than zero.

strtoul already checks for the '-' character deep
in its bowels. It will return an error if the user
has provided a negative value and fcoe_str_to_dev_loss
will return that error to its caller.

This patch fixes the following Coverity reported warning:

CID 703581 -  NO_EFFECT Unsigned compared against 0 - This
less-than-zero comparison of an unsigned value is never true. "*val < 0UL".
drivers/scsi/fcoe/fcoe_sysfs.c:105
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Recent changes to add fcoe_sysfs caused libfcoe_init to call fcoe_transport_exit
in a module initialization routine. The change resulted in the below error. This
patch removes the __exit keyword from the fcoe_transport_exit definition such
that it may be called from an __init routine.

WARNING: drivers/scsi/fcoe/libfcoe.o(.init.text+0x21): Section mismatch in reference from the function init_module() to the function .exit.text:fcoe_transp
exit()
The function __init init_module() references
a function __exit fcoe_transport_exit().
This is often seen when error handling in the init function
uses functionality in the exit path.
The fix is often to remove the __exit annotation of
fcoe_transport_exit() so it may be used outside an exit section.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The libfc is used by fcoe but fcoe agnostic,
and therefore should not have any fcoe references.

So renaming fcoe_dev_stats from libfc as its for fc_stats.
After that libfc is fcoe string free except some strings for
Open-FCoE.org.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Acked-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patch has the SW FCoE driver and the bnx2fc
driver make use of the new fcoe_sysfs API added
earlier in this patch series.

After this patch a fcoe_ctlr_device is allocated with
private data in this order.

+------------------+   +------------------+
| fcoe_ctlr_device |   | fcoe_ctlr_device |
+------------------+   +------------------+
| fcoe_ctlr        |   | fcoe_ctlr        |
+------------------+   +------------------+
| fcoe_interface   |   | bnx2fc_interface |
+------------------+   +------------------+

libfcoe also takes part in this new model since it
discovers and manages fcoe_fcf instances. The memory
allocation is different for FCFs. I didn't want to
impact libfcoe's fcoe_fcf processing, so this patch
creates fcoe_fcf_device instances for each discovered
fcoe_fcf. The two are paired using a (void * priv)
member of the fcoe_ctlr_device. This allows libfcoe
to continue maintaining its list of fcoe_fcf instances
and simply attaches and detaches them from existing
or new fcoe_fcf_device instances.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patch adds a 'fcoe bus' infrastructure to the kernel
that is driven by changes to libfcoe which allow LLDs to
present FIP (FCoE Initialization Protocol) discovered
entities and their attributes to user space via sysfs.

This patch adds the following APIs-

fcoe_ctlr_device_add
fcoe_ctlr_device_delete
fcoe_fcf_device_add
fcoe_fcf_device_delete

They allow the LLD to expose the FCoE ENode Controller
and any discovered FCFs (Fibre Channel Forwarders, e.g.
FCoE switches) to the user. Each of these new devices
has their own bus_type so that they are grouped together
for easy lookup from a user space application. Each
new class has an attribute_group to expose attributes
for any created instances. The attributes are-

fcoe_ctlr_device
* fcf_dev_loss_tmo
* lesb_link_fail
* lesb_vlink_fail
* lesb_miss_fka
* lesb_symb_err
* lesb_err_block
* lesb_fcs_error

fcoe_fcf_device
* fabric_name
* switch_name
* priority
* selected
* fc_map
* vfid
* mac
* fka_peroid
* fabric_state
* dev_loss_tmo

A device loss infrastructre similar to the FC Transport's
is also added by this patch. It is nice to have so that a
link flapping adapter doesn't continually advance the count
used to identify the discovered FCF. FCFs will exist in a
"Disconnected" state until either the timer expires or the
FCF is rediscovered and becomes "Connected."

This patch generates a few checkpatch.pl WARNINGS that
I'm not sure what to do about. They're macros modeled
around the FC Transport attribute building macros, which
have the same 'feature' where the caller can ommit a cast
in the argument list and no cast occurs in the code. I'm
not sure how to keep the code condensed while keeping the
macros. Any advice would be appreciated.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Currently the fcoe_ctlr associated with an interface is allocated
as a member of struct fcoe_interface. This causes problems when
attempting to use the new fcoe_sysfs APIs which allow us to allocate
the fcoe_interface as private data to the fcoe_ctlr_device instance.
The problem is that libfcoe wants to be able use pointer math to find a
fcoe_ctlr's fcoe_ctlr_device as well as finding a fcoe_ctlr_device's
assocated fcoe_ctlr. To do this we need to allocate the
fcoe_ctlr_device, with private data for the LLD. The private data
contains the fcoe_ctlr and its private data is the fcoe_interface.
This patch only allocates the fcoe_interface with the fcoe_ctlr, the
fcoe_ctlr_device will be added in a later patch, which will complete
the below diagram-

+------------------+
| fcoe_ctlr_device |
+------------------+
| fcoe_ctlr        |
+------------------+
| fcoe_interface   |
+------------------+

This prep work will allow us to go from a fcoe_ctlr_device instance
to its fcoe_ctlr as well as from a fcoe_ctlr to its fcoe_ctlr_device
once the fcoe_sysfs API is in use (later patches in this series).
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NRoss Brattain <ross.b.brattain@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

We moved the locking in dd060e74 "[SCSI] fcoe: remove frame dropping
code from fcoe_percpu_clean" but this unlock was missed.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

FC-BB-6 v1.04 7.9.8.14 N_Port_ID Beacon:

"A N_Port_ID Beacon is multicast and uses the VN_Port MAC address as source
address."

Currently, libfcoe is using ENode MAC, this seems ok and functionality wise
not a problem in my back to back testing setup, however, just fix this to
make libfcoe VN2VN support more spec compliant.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

The rtnl_mutex was held to protect calls to dev_uc_add
and dev_uc_del. Holding rtnl is not required as those
functions make use of the netif_addr_lock* API to
protect the MAC changing.

This change fixes the following regression by removing
the rtnl usage when fcoe_update_src_mac is called.

https://bugzilla.kernel.org/show_bug.cgi?id=42918

the existing dependency chain (in reverse order) is:

-> #1 (&fip->ctlr_mutex){+.+...}:
       [<c1091f70>] lock_acquire+0x80/0x1b0
       [<c147655d>] mutex_lock_nested+0x6d/0x340
       [<f8970c32>] fcoe_ctlr_link_up+0x22/0x180 [libfcoe]
       [<f894620e>] fcoe_create+0x47e/0x6e0 [fcoe]
       [<f8973dd3>] fcoe_transport_create+0x143/0x250 [libfcoe]
       [<c10527e0>] param_attr_store+0x30/0x60
       [<c1052696>] module_attr_store+0x26/0x40
       [<c11a201e>] sysfs_write_file+0xae/0x100
       [<c11449df>] vfs_write+0x8f/0x160
       [<c1144cbd>] sys_write+0x3d/0x70
       [<c147a0c4>] syscall_call+0x7/0xb

-> #0 (rtnl_mutex){+.+.+.}:
       [<c109164b>] __lock_acquire+0x140b/0x1720
       [<c1091f70>] lock_acquire+0x80/0x1b0
       [<c147655d>] mutex_lock_nested+0x6d/0x340
       [<c13a10c4>] rtnl_lock+0x14/0x20
       [<f89445ac>] fcoe_update_src_mac+0x2c/0xb0 [fcoe]
       [<f8971712>] fcoe_ctlr_timer_work+0x712/0xb60 [libfcoe]
       [<c104fb69>] process_one_work+0x179/0x5d0
       [<c10502f1>] worker_thread+0x121/0x2d0
       [<c10550ed>] kthread+0x7d/0x90
       [<c1481a82>] kernel_thread_helper+0x6/0x10

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fip->ctlr_mutex);
                               lock(rtnl_mutex);
                               lock(&fip->ctlr_mutex);
  lock(rtnl_mutex);

 *** DEADLOCK ***
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Tested-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>