scsi: libfc: Remove get_cpu() semantics in fc_exch_em_alloc()

The get_cpu() in fc_exch_em_alloc() was introduced in commit f018b73af6db
("[SCSI] libfc, libfcoe, fcoe: use smp_processor_id() only when preempt
disabled") for no other reason than to simply use smp_processor_id()
without getting a warning, because everything is done with the pool->lock
held anyway. However, get_cpu(), by disabling preemption, does not play
well with PREEMPT_RT, particularly when acquiring a regular (and thus
sleepable) spinlock.

Therefore remove the get_cpu() and just use the unstable value as we will
have CPU locality guarantees next by taking the lock. The window of
migration, as noted by Sebastian, is small and even if it happens the
result is correct.

Link: https://lore.kernel.org/r/20211117025956.79616-2-dave@stgolabs.net
Link: https://lore.kernel.org/r/20220506105758.283887-4-bigeasy@linutronix.de
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Fix use after free in fc_exch_abts_resp()

fc_exch_release(ep) will decrease the ep's reference count. When the
reference count reaches zero, it is freed. But ep is still used in the
following code, which will lead to a use after free.

Return after the fc_exch_release() call to avoid use after free.

Link: https://lore.kernel.org/r/20220303015115.459778-1-niejianglei2021@163.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Avoid invoking response handler twice if ep is already completed

A race condition exists between the response handler getting called because
of exchange_mgr_reset() (which clears out all the active XIDs) and the
response we get via an interrupt.

Sequence of events:

rport ba0200: Port timeout, state PLOGI
rport ba0200: Port entered PLOGI state from PLOGI state
xid 1052: Exchange timer armed : 20000 msecs  xid timer armed here
rport ba0200: Received LOGO request while in state PLOGI
rport ba0200: Delete port
rport ba0200: work event 3
rport ba0200: lld callback ev 3
bnx2fc: rport_event_hdlr: event = 3, port_id = 0xba0200
bnx2fc: ba0200 - rport not created Yet!!
/* Here we reset any outstanding exchanges before
freeing rport using the exch_mgr_reset() */
xid 1052: Exchange timer canceled
/* Here we got two responses for one xid */
xid 1052: invoking resp(), esb 20000000 state 3
xid 1052: invoking resp(), esb 20000000 state 3
xid 1052: fc_rport_plogi_resp() : ep->resp_active 2
xid 1052: fc_rport_plogi_resp() : ep->resp_active 2

Skip the response if the exchange is already completed.

Link: https://lore.kernel.org/r/20201215194731.2326-1-jhasan@marvell.com
Signed-off-by: Javed Hasan <jhasan@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Fix enum-conversion warning

gcc -Wextra points out an assignment between two different enum types:

drivers/scsi/libfc/fc_exch.c: In function 'fc_exch_setup_hdr':
../drivers/scsi/libfc/fc_exch.c:275:26: warning: implicit conversion from 'enum fc_class' to 'enum fc_sof' [-Wenum-conversion]

This seems to be intentional, as the same numeric values are used here, so
shut up the warning by adding an explicit cast.

Link: https://lore.kernel.org/r/20201026214911.3892701-1-arnd@kernel.org
Fixes: 42e9a92fe6a9 ("[SCSI] libfc: A modular Fibre Channel library")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Move scsi/fc_encode.h to libfc

Most of this file is only used inside of libfc, so move it to where it is
actually used, with only fc_fill_fc_hdr() left inside of the header.

Link: https://lore.kernel.org/r/20201026160705.3706396-1-arnd@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

scsi: libfc: Supply some missing kerneldoc struct/function attributes/params

Fixes the following W=1 kernel build warning(s):

drivers/scsi/libfc/fc_exch.c:66: warning: Function parameter or member 'left' not described in 'fc_exch_pool'
drivers/scsi/libfc/fc_exch.c:66: warning: Function parameter or member 'right' not described in 'fc_exch_pool'
drivers/scsi/libfc/fc_exch.c:100: warning: Function parameter or member 'lport' not described in 'fc_exch_mgr'
drivers/scsi/libfc/fc_exch.c:727: warning: Function parameter or member 'ep' not described in 'fc_invoke_resp'
drivers/scsi/libfc/fc_exch.c:727: warning: Function parameter or member 'sp' not described in 'fc_invoke_resp'
drivers/scsi/libfc/fc_exch.c:727: warning: Function parameter or member 'fp' not described in 'fc_invoke_resp'

Link: https://lore.kernel.org/r/20200713074645.126138-2-lee.jones@linaro.org
Cc: Hannes Reinecke <hare@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: fix null pointer dereference on a null lport

Currently if lport is null then the null lport pointer is dereference when
printing out debug via the FC_LPORT_DB macro. Fix this by using the more
generic FC_LIBFC_DBG debug macro instead that does not use lport.

Addresses-Coverity: ("Dereference after null check")
Fixes: 7414705ea4ae ("libfc: Add runtime debugging with debug_logging module parameter")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 51 franklin st fifth floor boston ma 02110
1301 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: libfc: switch to SPDX tags

Use the the GPLv2 SPDX tag instead of verbose boilerplate text.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Don't have fc_exch_find log errors on a new exchange

With the error message I added in "libfc: sanity check cpu number
extracted from xid" I didn't account for the fact that fc_exch_find is
called with FC_XID_UNKNOWN at the start of a new exchange if we are the
responder.

It doesn't come up with the initiator much, but that's basically every
exchange for a target. By checking the xid for FC_XID_UNKNOWN first, we
not only prevent the erroneous error message, but skip the unnecessary
lookup attempt as well.

[mkp: applied by hand due to conflict with Hannes' libfc patch series]

Signed-off-by: Chris Leech <cleech@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_release callback with function call

The ->seq_release callback only ever had one implementation,
so call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_assign callback with function call

The ->seq_assign callback only ever had one implementation,
so call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_set_resp callback with direct function call

The ->seq_set_resp callback only ever had one implementation,
so call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_start_next callback with function call

The ->seq_start_next callback only ever had one implementation,
so call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->exch_done callback with function call

The ->exch_done callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_exch_abort callback with function call

The ->seq_exch_abort callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_send callback with function call

The ->seq_send callback only ever had one implementation,
so we can as well call it directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->exch_seq_send callback with function call

The ->exch_seq_send callback only ever had one implementation,
so we can call the function directly and drop the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->lport_recv with function call

The ->lport_recv callback only ever had one implementation,
so call the function directly and remove the callback.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Replace ->seq_els_rsp_send callback with function call

The 'seq_els_rsp_send' callback only ever had one implementation,
so we might as well drop it and use the function directly.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Check xid when looking up REC exchanges

We currently can only lookup the local xid, so we need
to reject REC with empty rxid.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Do not drop out-of-order frames

When receiving packets from the network we cannot guarantee any
frame ordering, so we should be receiving all valid frames and
let the upper layers deal with it.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: quarantine timed out xids

When a sequence times out we have no idea what happened to the
frame. And we do not know if we will ever receive the frame.
Hence we cannot re-use the xid as we would risk data corruption
if the xid had been re-used and the timed out frame would be
received after that.
So we need to quarantine the xid until the lport is reset.
Yes, I know this will (eventually) deplete the xid pool.
But for now it's the safest method.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: safeguard against invalid exchange index

The cached exchange index might be invalid, in which case
we should drop down to allocate a new one.
And we should not try to access an invalid exchange when
responding to a BA_ABTS.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: use configured lport R_A_TOV

We should be using the configured R_A_TOV value when sending the
exchange.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: additional debugging messages

Signed-off-by: Hannes Reinecke <hare@suse.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: libfc: Revert "[SCSI] libfc: use offload EM instance again instead jumping to next EM"

This reverts commit 3e22760d4db6fd89e0be46c3d132390a251da9c6.

This revert came about because of efforts by Ewan Milne, Curtis Taylor
and I. In researching this issue, significant performance issues were
seen on large CPU count systems using the software FCOE stack. Hannes
also weighed in.

The same was not apparent on much smaller low count CPU systems. The
behavior introduced by commit 3e22760d4db6fd89e0be46c3d132390a251da9c6
lands sup with large count CPU systems seeing continual
blk_requeue_request() calls due to ML_QUEUE_HOST_BUSY.

fc_exch_alloc() used to try all the available exchange managers in the
list for an available exchange id, but this was changed in 2010 so that
if the first matched exchange manager couldn't allocate one, it fails
and we end up returning host busy. This was due to commit:

Setting the ddp_min module parameter to fcoe to 128MB prevents the
->match function from permitting the use of the offload exchange manager
for the frame, and we no longer see the problem with host busy status,
since it uses the larger non-offloaded pool.

Reverting commit 3e22760d4db6fd89e0be46c3d132390a251da9c6 was tested to
also prevent the host busy issue due to failing allocations.

Suggested-by: Ewan Milne <emilne@redhat.com>
Suggested-by: Curtis Taylor <cjt@us.ibm.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Laurence Oberman <loberman@redhat.com>

scsi: libfc: do not send ABTS when resetting exchanges

When all exchanges are reset the upper layers have already logged out of
the remote port, so the exchanges can be reset without sending any ABTS.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Chad Dupuis <chad.dupuis@qlogic.com>
Tested-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libfc: sanity check cpu number extracted from xid

In the receive path libfc extracts a cpu number from the ox_id in the
fiber channel header and uses that to do a per_cpu_ptr conversion. If,
for some reason, a frame is received with an invalid ox_id, per_cpu_ptr
will return an invalid pointer and the libfc receive path will panic the
system trying to use it.

I'm currently looking at such a case, and I don't yet know why a cpu
number > nr_cpu_ids is appearing in an exchange id. But adding a sanity
check in libfc prevents a system panic, and seems like good idea when
dealing with frames coming in from the network.

Signed-off-by: Chris Leech <cleech@redhat.com>
Acked-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libfc: Fix fc_exch_recv_req() error path

Due to patch "libfc: Do not invoke the response handler after
fc_exch_done()" (commit ID 7030fd62) the lport_recv() call
in fc_exch_recv_req() is passed a dangling pointer. Avoid this
by moving the fc_frame_free() call from fc_invoke_resp() to its
callers. This patch fixes the following crash:

general protection fault: 0000 [#3] PREEMPT SMP
RIP: fc_lport_recv_req+0x72/0x280 [libfc]
Call Trace:
fc_exch_recv+0x642/0xde0 [libfc]
fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe]
kthread+0x10a/0x120
ret_from_fork+0x42/0x70

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

libfc: Do not invoke the response handler after fc_exch_done()

While the FCoE initiator driver invokes fc_exch_done() from inside
the libfc response handler, FCoE target drivers typically invoke
fc_exch_done() from outside the libfc response handler. The object
fc_exch.arg points at may disappear as soon as fc_exch_done() has
finished. So it's important not to invoke the response handler
function after fc_exch_done() has finished. Modify libfc such that
this guarantee is provided if fc_exch_done() is invoked from
outside a response handler. This patch fixes a sporadic crash in
FCoE target implementations after a command has been aborted.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Reduce exchange lock contention in fc_exch_recv_abts()

Reduce the time during which the exchange lock is held by allocating
a frame before obtaining the exchange lock.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Avoid that sending after an abort triggers a kernel warning

Calling fc_seq_send() after an ABTS message has been received triggers
a kernel warning (WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT))). Avoid
this by returning -ENXIO to the caller if fc_seq_send() is invoked after
an ABTS message has been received.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Protect ep->esb_stat changes via ex_lock

This patch avoids that the WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT))
statement in fc_seq_send_locked() gets triggered sporadically when
running FCoE target code due to concurrent ep->esb_stat modifications.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Fix a race in fc_exch_timer_set_locked()

It is allowed to pass a zero timeout value to fc_seq_exch_abort().
Avoid that this can cause the timeout function to drop the exchange
reference before it has been increased by fc_exch_timer_set_locked().
This patch fixes a crash when running FCoE target code with poisoning
enabled in the memory allocator.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Clarify fc_exch_find()

The condition ep != NULL && ep->xid != xid can never be met. Make
this explicit.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Micro-optimize fc_setup_exch_mgr()

Convert a loop into an ilog2() call. Although this code is not performance
sensitive this conversion makes this code easier to read.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Debug code fixes

The second argument of fc_lport_error() may be a valid frame pointer.
Hence only print it as an error code if it really is an error code.

Debug statements must end in a newline. Add one where it is missing.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Source code comment spelling fixes

Change 'initiaive' into 'initiative', 'remainig' into 'remaining'
and change 'exected' into 'expected'.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Robert Love <robert.w.love@intel.com>

libfc: Differentiate echange timer cancellation debug statements

There are two debug statements with the same output string regarding
echange timer cancellation. This patch simply changes the output of
one string so that they can be differentiated.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Jack Morgan <jack.morgan@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>

libfc: Remove extra space in fc_exch_timer_cancel definition

Simply remove an extra space that violates coding style.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Tested-by: Jack Morgan <jack.morgan@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>

libfc: extend ex_lock to protect all of fc_seq_send

This warning was reported recently:

WARNING: at drivers/scsi/libfc/fc_exch.c:478 fc_seq_send+0x14f/0x160 [libfc]()
(Not tainted)
Hardware name: ProLiant DL120 G7
Modules linked in: tcm_fc target_core_iblock target_core_file target_core_pscsi
target_core_mod configfs dm_round_robin dm_multipath 8021q garp stp llc bnx2fc
cnic uio fcoe libfcoe libfc scsi_transport_fc scsi_tgt autofs4 sunrpc
pcc_cpufreq ipv6 hpilo hpwdt e1000e microcode iTCO_wdt iTCO_vendor_support
serio_raw shpchp ixgbe dca mdio sg ext4 mbcache jbd2 sd_mod crc_t10dif pata_acpi
ata_generic ata_piix hpsa dm_mirror dm_region_hash dm_log dm_mod [last unloaded:
scsi_wait_scan]
Pid: 5464, comm: target_completi Not tainted 2.6.32-272.el6.x86_64 #1
Call Trace:
[<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
[<ffffffff8106b79a>] ? warn_slowpath_null+0x1a/0x20
[<ffffffffa025f7df>] ? fc_seq_send+0x14f/0x160 [libfc]
[<ffffffffa035cbce>] ? ft_queue_status+0x16e/0x210 [tcm_fc]
[<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod]
[<ffffffffa030a766>] ? target_complete_ok_work+0x106/0x4b0 [target_core_mod]
[<ffffffffa030a660>] ? target_complete_ok_work+0x0/0x4b0 [target_core_mod]
[<ffffffff8108c760>] ? worker_thread+0x170/0x2a0
[<ffffffff810920d0>] ? autoremove_wake_function+0x0/0x40
[<ffffffff8108c5f0>] ? worker_thread+0x0/0x2a0
[<ffffffff81091d66>] ? kthread+0x96/0xa0
[<ffffffff8100c14a>] ? child_rip+0xa/0x20
[<ffffffff81091cd0>] ? kthread+0x0/0xa0
[<ffffffff8100c140>] ? child_rip+0x0/0x20

It occurs because fc_seq_send can have multiple contexts executing within it at
the same time, and fc_seq_send doesn't consistently use the ep->ex_lock that
protects this structure. Because of that, its possible for one context to clear
the INIT bit in the ep->esb_state field while another checks it, leading to the
above stack trace generated by the WARN_ON in the function.

We should probably undertake the effort to convert access to the fc_exch
structures to use rcu, but that a larger work item. To just fix this specific
issue, we can just extend the ex_lock protection through the entire fc_seq_send
path

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Gris Ge <fge@redhat.com>
CC: Robert Love <robert.w.love@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>

[SCSI] libfc: add exch timer debug info

Add exch timeout info to have debug log with exch timeout
value to match with retries, also add debug info
on exch timer cancel.

Added common fc_exch_timer_cancel() func and grouped this
along with fc_exch_timer_set() function, so that
added debug code is not repeated.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: update fcp and exch stats

Updates newly added stats from fc_get_host_stats,
added new function fc_exch_update_stats to
update exches related stats from fc_exch.c
by going thru internal ema_list elements.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc, fcoe, bnx2fc: cleanup fcoe_dev_stats

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: Vasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Acked-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: fcoe_transport_create fails in single-CPU environment

Starting fcoe fails at fcoe_transport_create when attempting to allocate a
pool of 4K exchanges on a 64-bit single-CPU environment because the call to
__alloc_percpu() is greater than the max of 32K. This patch reduces the
number of exchanges to fit within the maximum allowed space.

[ Whitespace problems fixed by Robert Love to satisfy chechpatch.pl ]

Signed-off-by: Steven Clark <sclark@crossbeam.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: Fix panic in fc_exch_recv

Adding and removing the host into the zone causes this panic.

BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
IP: [<ffffffffa0491707>] fc_exch_recv+0xc57/0xe70 [libfc]
Call Trace:
[<ffffffffa050e04b>] bnx2fc_l2_rcv_thread+0x37b/0x430 [bnx2fc]
[<ffffffffa050dcd0>] ? bnx2fc_l2_rcv_thread+0x0/0x430 [bnx2fc]
[<ffffffff81090886>] kthread+0x96/0xa0
[<ffffffff8100c14a>] child_rip+0xa/0x20
[<ffffffff810907f0>] ? kthread+0x0/0xa0
[<ffffffff8100c140>] ? child_rip+0x0/0x20

During fc_exch_reset, the active exchanges are aborted and the exch is deleted.
As part of processing ABTS response, due to 'ep' being NULL, any access to ep in
fc_exch_recv_bls() causes this panic. Fixed to access 'ep' only if non-NULL.

Reviewed-by: Neerav Parikh <neerav.parikh@intel.com>
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: Declare local functions static

Avoid that sparse complains about missing declarations for local
functions by declaring these static or by adding an #include directive.
Add the __percpu annotation where it is missing.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required

For the basic SCSI infrastructure files that are exporting symbols
but not modules themselves, add in the basic export.h header file
to allow the exports.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[SCSI] libfc: avoid exchanges collision during lport reset

Currently timer delay is large and is using msleep to avoid
avoid exchanges collision across lport reset, so instead
do this by initializing exches pool indexes during
reset also.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: fix checking FC_TYPE_BLS

Its checked after skb freed, so instead have fh_type
cached and then check FC_TYPE_BLS against cached
fh_type value.

This wrong check was causing double exch locking as
reported by Bhanu at
https://lists.open-fcoe.org/pipermail/devel/2011-October/011793.html

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: cache align fc_exch_pool

fix holes and better cache aligned fields.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: fix referencing to fc_fcp_pkt from the frame pointer via fr_fsp()

In commit 6a716a8, while releasing the DDP context in case frame_send() failed,
the frame may already be freed, so we should store the pointer to fc_fcp_pkt and
release the DDP context using the locally stored fsp instead of getting fsp from
the fr_fsp(fp) on a frame.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Reported-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: fix fc_eh_host_reset

Current fc_eh_host_reset leaves lport offline
permanently due to FLOGI response getting
handled by LOGO response from last reset as both
had same exchange id.

So fix this by having end to end exches clean-up
using exchange abort along exches reset
done from fc_eh_host_reset. This would avoid
exchanges collision between the sessions across
the reset. In this case implicit login should have
done that but no aborting support for FIP
frames, so just wait till lport->r_a_tov before
restarting next flogi to ensure all exchanges
are good to use again for next session.

Below is the trace of LOGO from older session
coming ahead of FLOGI response with same exche id
0x203:-

617 86.435165 4e.00.0b -> ff.ff.fc FC ELS LOGO 0x203
618 86.435195 4e.00.0b -> b6.02.00 FC ELS LOGO 0x213
619 86.435220 4e.00.0b -> 18.03.00 FC ELS LOGO 0x223
620 86.435244 4e.00.0b -> 18.02.00 FC ELS LOGO 0x233
621 86.435267 4e.00.0b -> 18.01.00 FC ELS LOGO 0x243
622 86.435349 00.00.00 -> ff.ff.fe FC ELS FLOGI 0x203
623 86.435549 ff.ff.fc -> 4e.00.0b FC ELS ACC (LOGO) 0x203
624 86.438721 ff.ff.fe -> 4e.00.0b FC ELS ACC (FLOGI) 0x203
625 86.442059 18.03.00 -> 4e.00.0b FC ELS ACC (LOGO) 0x223
626 86.443683 b6.02.00 -> 4e.00.0b FC ELS ACC (LOGO) 0x213
627 86.447693 18.01.00 -> 4e.00.0b FC ELS ACC (LOGO) 0x243
628 86.453499 18.02.00 -> 4e.00.0b FC ELS ACC (LOGO) 0x233

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Reviewed-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc, fcoe: ignore rx frame with wrong xid info

Drop the rx frame having xid with wrong cpu info
or received with xid not matching to our xid.

Not dropping such frame is causing panic as
that causes accessing data struct beyond their
bounds.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: release exchg cache

If fail to create workqueue, the newly created cache for exchg has to be
released.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc:Fix for exchange/seq loopup failure when FCoE stack is used as target and connected to windows initaitor

Problem: Linux based SW target (TCM) connected to windows initiator
was unable to satisfy write request of size > 2K.

Fix: Existing linux implememtation of FCoE stack is expecting sequence
number to match w.r.t incoming framme. When DDP is used on target in
response to write request from initiator, SW stack is notified only
when last data frame arrives and only the pakcket header of last data
frame is posted to NetRx queue of storage. When that last packet was
processed in libfc:Exchange layer, implementation was expecting
sequence number to match, but in this case sequence number which is
embedded in FC Header is assigned by windows initaitor, hence due to
sequence number mismatch post-processing which shall result into
sending RSP is not done. Enhanced the code to utilize the sequence
number of incoming last frame and process the packet so that, it will
eventually complete the write request by sending write response (RSP)
GOOD.

Notes/Dependencies: This patch is validated using windows and linux
initiator to make sure, it doesn't break anything.

Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libfc: don't call resp handler after FC_EX_TIMEOUT

In cases exch is already timed out then exch layer could
end up calling resp handler again for its response frame
received after timeout, though in this case fc_exch_timeout
handler would have already called resp with FC_EX_TIMEOUT.

This would cause REC response handler to release its
fsp pkt hold twice instead once and possibly similar issues
with other ELS exchanges in this race.

To avoid this race have resp updated under exch lock
in rx path, the resp would get set to NULL in case
of FC_EX_TIMEOUT under the same lock to prevent resp
callback after FC_EX_TIMEOUT.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

[SCSI] libfc: release DDP context if frame_send() fails

In case frame_send() fails, make sure to let the underlying HW release the DDP
context that has already been set up before calling frame_send().

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

[SCSI] fcoe, libfc: initialize EM anchors list and then update npiv EMs

EM anchors list initialization for only master port was not enough to
keep npiv working as described here:-
https://lists.open-fcoe.org/pipermail/devel/2011-January/011063.html

So this patch moves fc_exch_mgr_list_clone to update npiv ports
EMs once EM anchors list initialized.

Also some cleanup, no need to set lport = NULL as that always
get initialized later.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] Revert "[SCSI] libfc: fix exchange being deleted when the abort itself is timed out"

When abort for an exchange timed out it didn't release the reference to
the exchange resulting in a memory leak.

After discussion with the author of the patch (CC) that introduced this
bug it was suggested to revert that patch.

This reverts commit ea3e2e72eeb3e8a9440a5da965914f9b12088626.

Signed-off by: Neerav Parikh <Neerav.Parikh@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Enhanced exchange ID selection mechanism and fix related EMA selection logic.

Problem:

In case of exchange responder case, EMA selection was defaulted to the
last EMA from EMA list (lport.ema_list). If exchange ID is selected
from offload pool and not setup DDP, resulting into incorrect
selection of EMA, and eventually dropping the packet because unable to
find exchange.

Fix:

Enhanced the exchange ID selection (depending upon request type and
exchange responder) Made necessary enhancement in EMA selection
algorithm.

Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: export seq_release() for users of seq_assign()

Target modules using lport->tt.seq_assign() get a hold on the
exchange but have no way of releasing it. Add that.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: add method for setting handler for incoming exchange

Add a method for setting handler for incoming exchange.
For multi-sequence exchanges, this allows the target driver
to add a response handler for handling subsequent sequences,
and exchange manager resets.

The new function is called fc_seq_set_resp().

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix sparse static and non-ANSI warnings

Fix sparse warning for non-ANSI function declaration.
Declare workqueue structs as static.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Robert Love <robert.w.love@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix exchange being deleted when the abort itself is timed out

Should not continue when the abort itself is being timeout since in that case
the exchange will be deleted and relesased. We still want to call the
associated response handler to let the layer, e.g., fcp, know the exchange
itself is being timed out.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix mem leak in fc_seq_assign()

There is a typo cleaned, which triggers memory leakage.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: tune fc_exch_em_alloc() to be O(2)

For allocating new exch from pool, scanning for free slot in exch
array fluctuates when exch pool is close to exhaustion.

The fluctuation is smoothed, and the scan looks to be O(2).

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix mem leak in fc_exch_recv_seq_resp()

There seems that ep should get released, or it will no longer get freed.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: remove define of fc_seq_exch in fc_exch.c

The define for fc_seq_exch is unnecessary, since it also appears in scsi/libfc.h

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: don't require a local exchange for incoming requests

Incoming requests shouldn't require a local exchange if we're
just going to reply with one or two frames and don't expect
anything further. Don't allocate exchanges for such requests
until requested by the upper-layer protocol.

The sequence is always NULL for new requests, so remove
that as an argument to request handlers.

Also change the first argument to lport->tt.seq_els_rsp_send
from the sequence pointer to the received frame pointer, to
supply the exchange IDs and destination ID info.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: add interface to allocate a sequence for incoming requests

For incoming ELS and FCP requests, we often don't require an
exchange and sequence, however, sometimes we do. For those cases,
(primarily FCP requests for targets) add a function to set up
the exchange and sequence.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: track FIP exchanges

When an exchange is received with a FIP encapsulation, we need
to know that the response must be sent via FIP and what the original
ELS opcode was. This becomes important for VN2VN mode, where we may
receive FLOGI or LOGO from several peer VN_ports, and the LS_ACC or
LS_RJT must be sent FIP-encapsulated with the correct sub-type.

Add a field to the struct fc_frame, fr_encaps, to indicate the
encapsulation values. That term is chosen to be neutral and
LLD-agnostic in case non-FCoE/FIP LLDs might find it useful.

The frame fr_encaps is transferred from the ingress frame to the
exchange by fc_exch_recv_req(), and back to the outgoing frame
by fc_seq_send().

This is taking the last byte in the skb->cb array. If needed,
we could combine the info in sof, eof, flags, and encaps
together into one field, but it'd be better to do that if
and when its needed.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

libfc: use ARRAY_SIZE

Change sizeof(x) / sizeof(*x) to ARRAY_SIZE(x).

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

[SCSI] libfc: Move the port_id into lport

This patch creates a port_id member in struct fc_lport.
This allows libfc to just deal with fc_lport instances
instead of calling into the fc_host to get the port_id.

This change helps in only using symbols necessary for
operation from the libfc structures. libfc still needs
to change the fc_host_port_id() if the port_id changes
so the presentation layer (scsi_transport_fc) can provide
the user with the correct value, but libfc shouldn't
rely on the presentation layer for operational values.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: set seq_id for incoming sequence

After the recent patch "fixes unnecessary seq id jump"
the SCST module fcst stopped working because multi-sequence
write data wasn't finding the sequence after the first frame.

Add back the setting of the seq_id when the first frame arrives.
Also fix indentation on two lines.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: remove unneeded variables in fc_exch_recv_req()

fc_exch_recv_req has variables eof, sof, and f_ctl,
which are set but never used. Delete them.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc, libfcoe, fcoe: use smp_processor_id() only when preempt disabled

When the kernel is configured for preemption, using smp_processor_id()
when preemption is enabled causes a warning backtrace and is wrong
since we could move off of that CPU as soon as we get the ID,
and we would be referencing the wrong CPU, and possibly an invalid one
if it could be hotswapped out.

Remove the fc_lport_get_stats() function and explicitly use per_cpu_ptr()
to get the statistics. Where preemption has been disabled by holding
a _bh lock continue to use smp_processor_id(), but otherwise use
get_cpu()/put_cpu().

In fcoe_recv_frame() also changed the cases where we return in the
middle to do a goto to the code which bumps ErrorFrames and does
a put_cpu(). Two of these cases didn't bump ErrorFrames before, but
doing so is harmless because they "can't happen", due to prior length
checks.

Also rearranged code in fcoe_recv_frame() to have only one call to
fc_exch_recv(). It's just as efficient and saves a call to put_cpu().

In fc_fcp.c, adjusted a FIXME comment for code which doesn't need fixing.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: use offload EM instance again instead jumping to next EM

Since use of offloads is more efficient than switching
to non-offload EM. However kept logic same to call em_match
if it is provided in the list of EMs.

Converted fc_exch_alloc to inline being now tiny a function
and already not an exported libfc API any more.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fixes unnecessary seq id jump

In some cases seq is incremented twice causing unnecessary
seq jump, for instance fc_exch_recv_seq_resp increments
seq id when fc_sof_is_init is true and that is true for
each incoming xfer ready but then fc_fcp_send_data does
another seq increment to send data for xfer ready.

This patch removes all such seq id jumps, at least it
eliminates few calls to fc_seq_start_next using ex_lock.

Also removes seq id update with incoming frame's seq id
as this is not needed since each end (I or T) just need
to send incremented their own seq id on each TSI from
other end & before sending new sequence within a
exchange.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix sequence-initiative WARN in fc_seq_start_next

When starting a new response sequence in a multi-sequence
exchange, a warning was issued that sequence initiative
wasn't held.

The bug was that sequence initiative was cleared by the previous
sequence due to the END_SEQ flag being on. The intent may have
been to check LAST_SEQ. Change just to check SEQ_INIT.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[SCSI] libfc: call ddp setup for only FCP reads to avoid accessing junk fsp pointer

Adds check to call fc_fcp_ddp_setup for only FCP read cmds to avoid
accessing junk fsp pointer at least in ESX since non FCP frame had
junk fsp value, though fsp is implicitly initialized to null
by __alloc_skb but with this patch no more relying on fsp
initialized to null value and hitting junk fsp ptr access.

Removes fsp pointer checking in fc_fcp_ddp_setup as this is not
needed any more since its only caller for FCP read will always
have a valid fsp.

Reported by: Frank Zhang <frank_1.zhang@intel.com>
Reported by: Rob Love <robert.w.love@intel.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: call ddp setup for only FCP reads to avoid accessing junk fsp pointer

Adds check to call fc_fcp_ddp_setup for only FCP read cmds to avoid
accessing junk fsp pointer at least in ESX since non FCP frame had
junk fsp value, though fsp is implicitly initialized to null
by __alloc_skb but with this patch no more relying on fsp
initialized to null value and hitting junk fsp ptr access.

Removes fsp pointer checking in fc_fcp_ddp_setup as this is not
needed any more since its only caller for FCP read will always
have a valid fsp.

Reported by: Frank Zhang <frank_1.zhang@intel.com>
Reported by: Rob Love <robert.w.love@intel.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix an issue of pending exch/es after i/f destroyed or rmmod fcoe

All exches must be freed before its EM mempool destroyed in this
case but currently some exches could be still pending in their
scheduled delayed work after EM mempool is destroyed causing
this issue discussed and reported in this latest email thread:-

http://www.open-fcoe.org/pipermail/devel/2009-October/004788.html

This patch fixes this issue by adding dedicated work queue thread
fc_exch_workqueue for exch delayed work and then flush this work
queue before destroying EM mempool.

The cancel_delayed_work_sync cannot be called during final
fc_exch_reset due to lport and exch locking ordering, so removes
related comment block not relevant any more with this patch.

Reported-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Formatting cleanups across libfc

This patch makes a variety of cleanup changes to all libfc files.

This patch adds kernel-doc headers to all functions lacking them
and attempts to better format existing headers. It also add kernel-doc
headers to structures.

This patch ensures that the current naming conventions for local ports,
remote ports and remote port private data is upheld in the following
manner.

struct instance (i.e. variable name)
--------------------------------------------------
fc_lport lport
fc_rport rport
fc_rport_libfc_priv rpriv
fc_rport_priv rdata

I also renamed dns_rp and ptp_rp to dns_rdata and ptp_rdata
respectively.

I used emacs 'indent-region' and 'tabify' on all libfc files
to correct spacing alignments.

I feel sorry for anyone attempting to review this patch.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: add some generic NPIV support routines to libfc

Adds a function to create a new VN_Port instances, which share the EM
list with the N_Port, VN_Port lookup by fabric ID when responding to a new
request (otherwise the exchange lookup from the N_Ports EM list is trusted to
return an exchange with a cached lport value for the correct VN_Port),
a pointer to a fc_vport structure for VN_Ports, and flags to indicate if an
N_Port supports NPIV and if the switch/fabric allows it.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Add libfc/fc_libfc.[ch] for libfc internal routines

include/scsi/libfc.h is currently loaded with common code
shared between libfc's sub-modules as well as shared between
libfc and fcoe. Previous patches attempted to move out
non-common code. This patch creates two files for common
libfc routines that will not be shared with fcoe, fnic or
any other LLDs.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Move non-common routines and prototypes out of libfc.h

This patch moves all non-common routines and function prototypes
out of libfc.h and into the appropriate .c files. It makes these
routines 'static' when necessary and removes any unnecessary EXPORT_SYMBOL
statements.

A result of moving the fc_exch_seq_send, fc_seq_els_rsp_send, fc_exch_alloc
and fc_seq_start_next prototypes out of libfc.h is that they were no longer
being imported into fc_exch.c when libfc.h was included. This caused errors
where routines in fc_exch.c were looking for undefined symbols. To fix this
this patch reorganizes fc_seq_alloc, fc_seq_start_next and
fc_seq_start_next_locked. This move also made it so that
fc_seq_start_next_locked did not need to be prototyped at the top of
fc_exch.c.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: removes unused disc_work and ex_list

Reported-by: Alex Lyakas <alexl@mellanox.co.il>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: adds missing exch release for accepted RRQ

Adds missing exch release when RRQ is accepted by calling
fc_seq_ls_acc. Adds common exch release for fc_exch_els_rrq
by use of out label.

Reported-by: Alex Lyakas <alexl@mellanox.co.il>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: removes initializing fc_cpu_order and fc_cpu_mask per lport

Initializing these libfc globals per lport could mess up exch
allocation/free for existing lport.

So this patch moves their initialization to fc_setup_exch_mgr
so that these globals gets initialized only once for libfc.

Reported-by: Alex Lyakas <alexl@mellanox.co.il>
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc, fcoe: Don't EXPORT_SYMBOLS unnecessarily

These are a few functions that were not used by other
modules. They did not need to be exported so this patch
removes the EXPORT_SYMBOLS call for each.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: don't swap OX_ID and RX_ID when sending BA_RJT

I saw an lport debug message from the exchange manager saying:
"lport 70500: Received response for out of range oxid:ffff"

A trace showed this was a BA_RJT sent due to an incoming ABTS
which arrived on an unknown exchange. So, the sender of the
BA_RJT was in error, but in this case, both the initiator and
responder were the same machine.

The OX_ID and RX_ID should not have been reversed in this case.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: fully makes use of per cpu exch pool and then removes em_lock

1. Updates fcoe_rcv() to queue incoming frames to the fcoe per
cpu thread on which this frame's exch was originated and simply
use current cpu for request exch not originated by initiator.
It is redundant to add this code under CONFIG_SMP, so removes
CONFIG_SMP uses around this code.

2. Updates fc_exch_em_alloc, fc_exch_delete, fc_exch_find to use
per cpu exch pools, here fc_exch_delete is rename of older
fc_exch_mgr_delete_ep since ep/exch are now deleted in pools
of EM and so brief new name is sufficient and better name.

Updates these functions to map exch id to their index into exch
pool using fc_cpu_mask, fc_cpu_order and EM min_xid.
This mapping is as per detailed explanation about this in
last patch and basically this is just as lower fc_cpu_mask
bits of exch id as cpu number and upper bit sum of EM min_xid
and exch index in pool.

Uses pool next_index to keep track of exch allocation from
pool along with pool_max_index as upper bound of exches array
in pool.

3. Adds exch pool ptr to fc_exch to free exch to its pool in
fc_exch_delete.

4. Updates fc_exch_mgr_reset to reset all exch pools of an EM,
this required adding fc_exch_pool_reset func to reset exches
in pool and then have fc_exch_mgr_reset call fc_exch_pool_reset
for each pool within each EM for a lport.

5. Removes no longer needed exches array, em_lock, next_xid, and
total_exches from struct fc_exch_mgr, these are not needed after
use of per cpu exch pool, also removes not used max_read,
last_read from struct fc_exch_mgr.

6. Updates locking notes for exch pool lock with fc_exch lock and
uses pool lock in exch allocation, lookup and reset.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: adds per cpu exch pool within exchange manager(EM)

Adds per cpu exch pool for these reasons:-

1. Currently an EM instance is shared across all cpus to manage
all exches for all cpus. This required em_lock across all
cpus for an exch alloc, free, lookup and reset each frame
and that made em_lock expensive, so instead having per cpu
exch pool with their own per cpu pool lock will likely reduce
locking contention in fast path for an exch alloc, free and
lookup.

2. Per cpu exch pool will likely improve cache hit ratio since
all frames of an exch will be processed on the same cpu on
which exch originated.

This patch is only prep work to help in keeping complexity of next
patch low, so this patch only sets up per cpu exch pool and related
helper funcs to be used by next patch. The next patch fully makes
use of per cpu exch pool in all code paths ie. tx, rx and reset.

Divides per EM exch id range equally across all cpus to setup per
cpu exch pool. This division is such that lower bits of exch id
carries cpu number info on which exch originated, later a simple
bitwise AND operation on exch id of incoming frame with fc_cpu_mask
retrieves cpu number info to direct all frames to same cpu on which
exch originated. This required a global fc_cpu_mask and fc_cpu_order
initialized to max possible cpus number nr_cpu_ids rounded up to 2's
power, this will be used in mapping exch id and exch ptr array
index in pool during exch allocation, find or reset code paths.

Adds a check in fc_exch_mgr_alloc() to ensure specified min_xid
lower bits are zero since these bits are used to carry cpu info.

Adds and initializes struct fc_exch_pool with all required fields
to manage exches in pool.

Allocates per cpu struct fc_exch_pool with memory for exches array
for range of exches per pool. The exches array memory is followed
by struct fc_exch_pool.

Adds fc_exch_ptr_get/set() helper functions to get/set exch ptr in
pool exches array at specified array index.

Increases default FCOE_MAX_XID to 0x0FFF from 0x07EF, so that more
exches are available per cpu after above described exch id range
division across all cpus to each pool.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Fix misleading debug statement

The statement reads, "Exchange timed out, notifying the upper layer",
however, this statement is printed whenever the timer is armed. This
is confusing to someone debugging the code because every time an
exchange is initialized, there is an incorrect statement stating that
the timer has already timed out. This patch changes the statement to
read, "Exchange timer armed" which is more accurate.

This patch also adds a debug statement in the timeout handler to
properly indicate that the exchange has timed out.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: adds offload EM per eth device with only single xid range per EM

Updates fcoe_em_config to allocate a single instance of sharable offload
EM for supported lp->lro_xid per eth device, and then share this EM
for subsequently more lports creation on same eth device (e.g when using
VLAN).

Adds tiny fcoe_oem_match function for offload EM to return true for read
types IO to have read IO exchanges allocated from offload shared EM.

Removes fc_em_alloc_xid function completely which was needed to manage
two xid ranges within a EM, this is not needed any more with allocation
of separate sharable offload EM per eth device. Instead this patch adds
simple xid allocation logic to manage single xid range.

Adds fc_exch_em_alloc with mp->next_xid as cursor to allocate new xid
from single xid range of EM, uses mp->next_xid instead removed mp->last_xid
which slightly increase probability of finding empty xid on exch allocation.

Removes restriction of not allowing use of xid zero along with changing
two xid range change to single xid range.

Makes fc_fcp_ddp_setup calling conditional to only xid allocated from
shared offload EM.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, fnic, libfc: modifies current code paths to use EM anchor list

Modifies current code to use EM anchor list in EM allocation, EM free,
EM reset, exch allocation and exch lookup code paths.

1. Modifies fc_exch_mgr_alloc to accept EM match function and then
have allocated EM added to the lport using fc_exch_mgr_add API
while also updating EM kref for newly added EM.

2. Updates fc_exch_mgr_free API to accept only lport pointer instead
EM and then have this API free all EMs of the lport from EM anchor
list.

3. Removes single lport pointer link from the EM, which was used in
associating lport pointer in newly allocated exchange. Instead have
lport pointer passed along new exchange allocation call path and
then store passed lport pointer in newly allocated exchange, this
will allow a single EM instance to be used across more than one
lport and used in EM reset to reset only lport specific exchanges.

4. Modifies fc_exch_mgr_reset to reset all EMs from the EM anchor list
of the lport, adds additional exch lport pointer (ep->lp) check for
shared EM case to reset exchange specific to a lport requested reset.

5. Updates exch allocation API fc_exch_alloc to use EM anchor list and
its anchor match func pointer. The fc_exch_alloc will walk the list
of EMs until it finds a match, a match will be either null match
func pointer or call to match function returning true value.

6. Updates fc_exch_recv to accept incoming frame on local port using
only lport pointer and frame pointer without specifying EM instance
of incoming frame. Instead modified fc_exch_recv to locate EM for the
incoming frame by matching xid of incoming frame against a EM xid range.
This change was required to use EM list in libfc Rx path and after this
change the lport fc_exch_mgr pointer emp is not needed anymore, so
removed emp pointer.

7. Updates fnic for removed lport emp pointer and above modified libfc APIs
fc_exch_recv, fc_exch_mgr_alloc and fc_exch_mgr_free.

8. Removes exch_get and exch_put from libfc_function_template as these
are no longer needed with EM anchor list and its match function use.
Also removes its default function fc_exch_get.

A defect this patch introduced regarding the libfc initialization order in
the fnic driver was fixed by Joe Eykholt <jeykholt@cisco.com>.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: Remove the FC_EM_DBG macro

Currently there is a 1:1 relationship between the lport
and exchange manager. This macro takes an EM as an argument
and determines the lport from it. However, later patches
will use an EM list per lport, so we will no longer have
this 1:1 relationship- this macro must change.

The FC_EM_DBG macro is rarely used. There are four callers,
two can use FC_LPORT_DBG instead and two can be removed
since they're not necessary. This patch makes those changes
and removes the macro.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fcoe, libfc: adds exchange manager(EM) anchor list per lport and related APIs

Adds EM list using a anchor struct fc_exch_mgr_anchor, anchor is used
to allow same EM instance sharing across more than one lport on a eth
device, this implementation is per discussed design posted at
http://www.open-fcoe.org/pipermail/devel/2009-June/002566.html.

The shared EM is required for multiple lports on eth device when
using multiple VLANs or NPIV.

Adds fc_exch_mgr_add API to add a EM to the lport and fc_exch_mgr_del
API to delete previously added EM.

Also adds function fc_exch_mgr_destroy() to destroy allocated EM.
The kref is added to the EM to keep track of EM usage count, the EM is
destroyed when no longer in use upon kref reaching to zero.

The caller can specify match function to fc_exch_mgr_add, this
will be used in determining exchange allocation from its EM or not.

Moved calling of fcoe_em_config below fcoe_libfc_config calling,
so that list head lp->ema_list is initialized before configuring
EM.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix WARNING from fc_seq_start_next on closed exchanges

We saw periodic messages like:

WARNING: at drivers/scsi/libfc/fc_exch.c:825 fc_seq_start_next+0x30/0x4b

This was due to trying to allocate a sequence in a request handler
when the exchange had been reset.

Delete the WARN_ON.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: rename lport NONE state to DISABLED

The state NONE was meant to be invalid, but has been used as
the initial state. Rename it to be DISABLED, as more descriptive.
Further patches will make it the like the RESET state, except
it won't transition to FLOGI until fc_lport_fabric_login() is called.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libfc: fix a circular locking warning during sending RRQ

Currently the fc_exch_rrq is called with fc_exch's ex_lock held.
The fc_exch_rrq allocates new exch and that requires taking
ex_lock again after EM lock. This locking order causes warning,
see more details on this warning at :-

http://www.open-fcoe.org/pipermail/devel/2009-July/003251.html

This patch fixes this by dropping the ex_lock before calling
fc_exch_rrq().

The fc_exch_rrq needs to grab ex_lock lock again to schedule
RRQ retry and in the meanwhile fc_exch_reset could occur before
ex_lock is grabbed inside fc_exch_rrq. So to handle this case,
this patch adds additional check to detect fc_exch_reset after
ex_lock acquired and in case the fc_exch_reset occurred then
abandons the RRQ retry and releases the exch.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

libfc: Add runtime debugging with debug_logging module parameter

This patch adds the /sys/module/libfc/parameters/debug_logging
file to sysfs as a module parameter. It accepts an integer
bitmask for logging. Currently it supports:

bit
LSB 0 = general libfc debugging
1 = lport debugging
2 = disc debugging
3 = rport debugging
4 = fcp debugging
5 = EM debugging
6 = exch/seq debugging
7 = scsi logging (mostly error handling)

the other bits are not used at this time.

The patch converts all of the libfc source files to use
these new macros and removes the old FC_DBG macro.

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: Check if exchange is completed when receiving a sequence

When a sequence is received in response to an exchange we issued previously,
we should check to see if the exchange has completed. If yes, the sequence
should be discarded. Since the exchange might be still in the completion
process, it should be untouched.

Signed-off-by: Steve Ma <steve.ma@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: add support of large receive offload by ddp in fc_fcp

When LLD supports direct data placement (ddp) for large receive of an scsi
i/o coming into fc_fcp, we call into libfc_function_template's ddp_setup()
to prepare for a ddp of large receive for this read I/O. When I/O is complete,
we call the corresponding ddp_done() to get the length of data ddped as well
as to let LLD do clean up.

fc_fcp_ddp_setup()/fc_fcp_ddp_done() are added to setup and complete a ddped
read I/O described by the given fc_fcp_pkt. They would call into corresponding
ddp_setup/ddp_done implemented by the fcoe layer. Eventually, fcoe layer calls
into LLD's ddp_setup/ddp_done provided through net_device

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: Correct use of ! and &

!ep->esb_stat is either 1 or 0, and the rightmost bit of ESB_ST_COMPLETE is
always 0, making the result of !ep->esb_stat & ESB_ST_COMPLETE always 0.
Thus parentheses around the argument to ! seem needed.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@ expression E; constant C; @@
(
!E & !C
|
- !E & C
+ !(E & C)
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: do not change the fh_rx_id of a recevied frame

We shouldn't be altering inbound frames.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc, fcoe: Cleanup function formatting and minor typos

1) There were a few functions with a strange layout, i.e. all
arguments on the second line, when not necessary.

Where ever possible I moved the return value to the same line
as the function name. However, when the line was too long
to have a single argument on the same line I moved the
return value to above line. For example:

<short return> <function name>(<arg 1>, <arg2>)

and

<very long return value>
<function name>(<arg1>,
<arg2>)

2) Removed one extra whitespace line

3) Fixed two typos

Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: rport retry on LS_RJT from certain ELS

This allows any rport ELS to retry on LS_RJT.

The rport error handling would only retry on resource allocation failures
and exchange timeouts. I have a target that will occasionally reject PLOGI
when we do a quick LOGO/PLOGI. When a critical ELS was rejected, libfc would
fail silently leaving the rport in a dead state.

The retry count and delay are managed by fc_rport_error_retry. If the retry
count is exceeded fc_rport_error will be called. When retrying is not the
correct course of action, fc_rport_error can be called directly.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: fixed a soft lockup issue in fc_exch_recv_abts

The fc_seq_start_next grabs ep->ex_lock but this lock was already held here,
so instead called fc_seq_start_next_locked to avoid soft lockup.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: handle RRQ exch timeout

Cleanup exchange held due to RRQ when RRQ exch times out, in this case the
ABTS is already done causing RRQ req therefore proceeding with cleanup in
fc_exch_rrq_resp should be okay to restore exch resource.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: Pass lport in exch_mgr_reset

fc_exch_mgr structure is private to fc_exch.c. To export exch_mgr_reset to
transport, transport needs access to the exch manager. Change
exch_mgr_reset to use lport param which is the shared structure between
libFC and transport.

Alternatively, fc_exch_mgr definition can be moved to libfc.h so that lport
can be accessed from mp*.

Signed-off-by: Abhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] libfc: A modular Fibre Channel library

libFC is composed of 4 blocks supported by an exchange manager
and a framing library. The upper 4 layers are fc_lport, fc_disc,
fc_rport and fc_fcp. A LLD that uses libfc could choose to
either use libfc's block, or using the transport template
defined in libfc.h, override one or more blocks with its own
implementation.

The EM (Exchange Manager) manages exhcanges/sequences for all
commands- ELS, CT and FCP.

The framing library frames ELS and CT commands.

The fc_lport block manages the library's representation of the
host's FC enabled ports.

The fc_disc block manages discovery of targets as well as
handling changes that occur in the FC fabric (via. RSCN events).

The fc_rport block manages the library's representation of other
entities in the FC fabric. Currently the library uses this block
for targets, its peer when in point-to-point mode and the
directory server, but can be extended for other entities if
needed.

The fc_fcp block interacts with the scsi-ml and handles all
I/O.

Signed-off-by: Robert Love <robert.w.love@intel.com>
[jejb: added include of delay.h to fix ppc64 compile prob spotted by sfr]
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>