This is per Mile Christie feedback since in this case IO
could get retried for tape devices and therefore DID_REQUEUE
cannot be used, more details in this thread.

http://marc.info/?l=linux-scsi&m=127970522630136&w=2Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

There does not seem to be a reason why libfc adds a 5
second delay to the user requested value for the dev loss
tmo. There also does not seem to be a reason to allow
setting it to 0 (or really close).

This patch removes the extra 5 sec delay, and for 0 it
sets it to 1 like other fc drivers. We should actually
be able to set it to 0 since the queue_delayed_work API
will just call queue_work, but other drivers set it to 1 in
that case.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The rport port state and flags are set under the host lock,
so this patch calls fc_remote_port_chkready with the host lock
held like is also done in the other fc drivers.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Call fc_lport_error to retry upto max retry count when
FLOGI/SCR/NS gets rejected.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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

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

Add functions to fill in an FC header given a request header.
These reduces code lines in fc_lport and fc_rport and works
without an exchange/sequence assigned.

fc_fill_reply_hdr() fills a header for a final reply frame.

fc_fill_hdr() which is similar but allows specifying the
f_ctl parameter.

Add defines for F_CTL values FC_FCTL_REQ and FC_FCTL_RESP.
These can be used for most request and response sequences.

v2 of patch adds a line to copy the frame encapsulation
info from the received frame.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

To pave the way for eliminating exchanges from incoming requests,
add simple inline fc_frame_sid() and fc_frame_did() functions
which get the FC_IDs from the frame header.  This can be almost
as efficient as getting them from the sequence/exchange.

Move ntohll, htonll, ntoh24 and hton24 to <scsi/fc_frame.h>
since we need them there and that's included by <scsi/libfc.h>
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The LOGO state hasn't been used in a while, except in a brief
transition to DELETE state while holding the rport mutex.
All port LOGO responses have been ignored as well as any timeout
if we don't get a response.

So this patch just removes LOGO state and simplifies the response handler.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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

The FIP proposal for VN_port to VN_port point-to-multipoint
operation requires a FLOGI be sent to each remote port.
The FLOGI is sent with the assigned S_ID and D_IDs of the
local and remote ports.  This and the response get
FIP-encapsulated for Ethernet.

Add FLOGI state to the remote port state machine.
This will be skipped if not in point-to-multipoint mode.

To reduce a little duplication between PLOGI and FLOGI
response handling, added fc_rport_login_complete(), which
handles the parameters for the rdata struct.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

For VN_port to VN_port mode, the transport sets the port_id and
there's no lport FLOGI.  This is similar to FC loop mode.

Add a point_to_multipoint flag that indicates the local port is in
point-to-multipoint mode.  This skips FLOGI and discovery.
It also skips resetting the port_id on resets other than link down.

Add function fc_lport_set_local_id() that sets the local port_id.
This is called by libfcoe on behalf of the low-level driver
to set the port_id when the link comes up.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

For VN_port to VN_port mode, FIP will do discovery and needs a
way to find its state from the local port or discovery structure.
It seems that any other LLD that implements its own discovery
would also need something like this.

Replace disc->lport with disc->priv, and use container_of to
find the lport.  We could use disc->priv for that, but
container_of is smaller and faster.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Add pre-zeroed space after the allocation for fc_rport_priv
for use by the lower-level driver.

This is primarily for VN2VN FIP mode, but could be used in
other ways someday.

The space required is specified in lport->rport_priv_size.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

To allow LLD to do lookups on rports without grabbing a mutex,
make them RCU-safe.  The caller of lport->tt.rport_lookup will
have the choice of holding disc_mutex or the rcu_read_lock().
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

In this case, sync IO fails with EIO(5) errors as:-

"Thread:1 System call error:5 - Input/output error (::pwrite() failed)".

This is due to IO time out while libfc doing link down processing
to block all rports and if timed out IO was at last retry
attempt then it fails to user with EIO error followed by
these log messages.

[77848.612169] host2: rport bf0015: Delete port
[77848.612221] host2: rport e10aef: work delete
[77848.612232] host2: rport e10002: work event 3
[77848.612422] sd 2:0:1:1: [sdi] Unhandled error code
[77848.612426] sd 2:0:1:1: [sdi] Result: hostbyte=DID_ERROR
driverbyte=DRIVER_OK
[77848.612431] sd 2:0:1:1: [sdi] CDB: Write(10): 2a 00 00 00 11 20 00 00 20 00
[77848.612445] end_request: I/O error, dev sdi, sector 4384
[77848.612553] sd 2:0:1:2: [sdj] Unhandled error code

To fix these EIO errors, such timed out incomplete IOs needs
to be re-queued without counting retry attempt and this patch
does that using DID_REQUEUE scsi code.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This is exposed by a mpio test using EMC CLARiiON targets when LUN
tresspassing happens, the burst length from the XFER_READY for the
MODE SELECT(10) is 19 bytes, much smaller than FC_MIN_MAX_PAYLOAD as
256 bytes. This patch removes the related two WARN_ON()s.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Remote ports were restarting indefinitely after getting
rejects in PRLI.

Fix by adding a counter of restarts and limiting that with
the port login retry limit as well.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch somewhat combines two fixes to remote port handing in libfc.

The first problem was that rport work could be queued on a deleted
and freed rport.  This is handled by not resetting rdata->event
ton NONE if the rdata is about to be deleted.

However, that fix led to the second problem, described by
Bhanu Gollapudi, as follows:
> Here is the sequence of events. T1 is first LOGO receive thread, T2 is
> fc_rport_work() scheduled by T1 and T3 is second LOGO receive thread and
> T4 is fc_rport_work scheduled by T3.
>
> 1. (T1)Received 1st LOGO in state Ready
> 2. (T1)Delete port & enter to RESTART state.
> 3. (T1)schdule event_work, since event is RPORT_EV_NONE.
> 4. (T1)set event = RPORT_EV_LOGO
> 5. (T1)Enter RESTART state as disc_id is set.
> 6. (T2)remember to PLOGI, and set event = RPORT_EV_NONE
> 6. (T3)Received 2nd LOGO
> 7. (T3)Delete Port & enter to RESTART state.
> 8. (T3)schedule event_work, since event is RPORT_EV_NONE.
> 9. (T3)Enter RESTART state as disc_id is set.
> 9. (T3)set event = RPORT_EV_LOGO
> 10.(T2)work restart, enter PLOGI state and issues PLOGI
> 11.(T4)Since state is not RESTART anymore, restart is not set, and the
> event is not reset to RPORT_EV_NONE. (current event is RPORT_EV_LOGO).
> 12. Now, PLOGI succeeds and fc_rport_enter_ready() will not schedule
> event_work, and hence the rport will never be created, eventually losing
> the target after dev_loss_tmo.

So, the problem here is that we were tracking the desire for
the rport be restarted by state RESTART, which was otherwise
equivalent to DELETE.  A contributing factor is that we dropped
the lock between steps 6 and 10 in thread T2, which allows the
state to change, and we didn't completely re-evaluate then.

This is hopefully corrected by the following minor redesign:

Simplify the rport restart logic by making the decision to
restart after deleting the transport rport.  That decision
is based on a new STARTED flag that indicates fc_rport_login()
has been called and fc_rport_logoff() has not been called
since then.  This replaces the need for the RESTART state.

Only restart if the rdata is still in DELETED state
and only if it still has the STARTED flag set.

Also now, since we clear the event code much later in the
work thread, allow for the possibility that the rport may
have become READY again via incoming PLOGI, and if so,
queue another event to handle that.

In the problem scenario, the second LOGO received will
cause the LOGO event to occur again.
Reported-by: NBhanu Gollapudi <bprakash@broadcom.com>
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

lport state is enum not bit mask.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Resubmitting after incorporating Joe's review comment.

Unsolicited PRLO request is now handled by sending LS_ACC,
and then relogin to the remote port if an N-port login
session exists for that remote port.

Note that this patch should be applied on top of Joe Eykholt's
"Fix remote port restart problem" patch.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

As per FC-LS Rev 1.62 table 46, response codes are handled as follows:

1. If the Req executed is true, PRLI is accepted.
2. If Req executed is not set,  if resp code is 5,
   PRLI is not retried and port is logged out.
3. If resp code is anything apart from 1 or 5, PRLI is retired
   upto max retry count.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Retry upto max_rport_retry_count when a target responds with
LS_RJT for a PRLI request.
Signed-off-by: NBhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Change sizeof(x) / sizeof(*x) to ARRAY_SIZE(x).
Signed-off-by: NKulikov Vasiliy <segooon@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

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

Remove this unused routine.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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

Print all world wide node names (node, port and fabric) with the same
format specifier of "%16.16llx".  That makes sure they all print as a
16 character hex string, with lower case letters, no 0x prefix, and
without stripping off any leading 0s.
Signed-off-by: NChris Leech <christopher.leech@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Most of the prints of fabric IDs were specified as %6x, which will not
print any leading 0s.  It's nice to see leading 0s for identifiers
like this, which are a fixed length.  This patch sets the precision
modifier as well, making the specifier %6.6x, which forces the
printing of leading 0s.
Signed-off-by: NChris Leech <christopher.leech@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

fc_fcp_resp is assuming when FCP_SNS_LEN_VAL is set, the FCP_RSP_LEN_VAL
is not, which is not true. This leads to not copying the sense data and
error out a valid FCP_RSP.
Signed-off-by: NYi Zou <yi.zou@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

fc_exch_recv_req has variables eof, sof, and f_ctl,
which are set but never used.  Delete them.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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

DID_ERROR cases can be ambigouos. Debugging FCP error cases
will be much easier if we have debug statements when we hit
these error conditions.

This patch simply adds debug messages using the FC_FCP_DBG
macro when we return DID_ERROR to SCSI. This way if a DID_ERROR
is reproducible turning on debug_logging will give a clue
to developers as to what the problem might be.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Currently fc_fcp_recv_data calls fc_fcp_retry_cmd to
retry failed IO but in this case tgt is still sending
data frames, therefore exchange needs to be aborted
first before initiating retry. So this patch fixes
this by aborting exchange first then have retry.

Renames fc_timeout_error to fc_fcp_recovery since
fc_timeout_error is already called from several other
places beside from fcp timeout handler and then
used fc_fcp_recovery for abort & retry from
fc_fcp_recv_data, this rename also required renaming
FC_CMD_TIME_OUT status to FC_CMD_RECOVERY to be
consistent with new fc_fcp_recovery.

Data frames are not expected for an DDPed exchange and
potentially it could be tampered data frame, so does
recovery in this case by calling fc_fcp_recovery.
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

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

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

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

The method we've been using for point-to-point mode requires
that the LS_ACC for the FLOGI uses the D_ID and S_ID assigned
to the remote port and local port, not those in the exchange.

This is not the correct method, but for now, it's what works
with the old target, as well as with new targets based on libfc.

This patch changes the addresses used accordingly.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

When receiving a FLOGI request from a point-to-point peer,
the D_ID of 0xfffffe was not recognized as belonging to one
of the lports, so it was dropped.

Change fc_vport_id_lookup() to treat d_id 0xfffffe as a match.
Signed-off-by: NJoe Eykholt <jeykholt@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>