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

I was running into several different panics under stress, which I traced down
to a few different possible slab corruption issues in error handling paths.
I have not yet looked into why these exchange sends fail, but with these
fixes my test system is much more stable under stress than before.

fc_elsct_send() could fail and either leave the passed in frame intact
(failure in fc_ct/els_fill) or the frame could have been freed if the
failure was is fc_exch_seq_send().  The caller had no way of knowing, and
there was a potential double free in the error handling in fc_fcp_rec().

Make fc_elsct_send() always free the frame before returning, and remove the
fc_frame_free() call in fc_fcp_rec().

While fc_exch_seq_send() did always consume the frame, there were double free
bugs in the error handling of fc_fcp_cmd_send() and fc_fcp_srr() as well.

Numerous calls to error handling routines (fc_disc_error(),
fc_lport_error(), fc_rport_error_retry() ) were passing in a frame pointer that
had already been freed in the case of an error.  I have changed the call
sites to pass in a NULL pointer, but there may be more appropriate error
codes to use.

Question:  Why do these error routines take a frame pointer anyway?  I
understand passing in a pointer encoded error to the response handlers, but
the error routines take no action on a valid pointer and should never be
called that way.
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>

When an RSCN indicates changes to individual remote ports,
don't blindly log them out and then back in.  Instead, determine
whether they're still in the directory, by doing GPN_ID.

If that is successful, call login, which will send ADISC and reverify,
otherwise, call logoff.  Perhaps we should just delete the rport,
not send LOGO, but it seems safer.

Also, fix a possible issue where if a mix of records in the RSCN
cause us to queue disc_ports for disc_single and then we decide
to do full rediscovery, we leak memory for those disc_ports queued.

So, go through the list of disc_ports even if doing full discovery.
Free the disc_ports in any case.  If any of the disc_single() calls
return error, do a full discovery.

The ability to fill in GPN_ID requests was added to fc_ct_fill().
For this, it needs the FC_ID to be passed in as an arg.
The did parameter for fc_elsct_send() is used for that, since the
actual D_DID will always be 0xfffffc for all CT requests so far.
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>

Currently these values are initialized by the callers. This was exposed
by a later patch that adds PLOGI request support. The patch failed to
initialize the new remote port's roles and it caused problems. This patch
has the rport_create routine initialize the identifiers and then the
callers can override them with real values.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

It's possible to "restart" discovery before it was started if
an RSCN is received early enough.  We were jumping to 0
due to the disc_callback function pointer not getting set.

Don't restart discovery if disc_callback is NULL.
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 discovery code had a special-case for the point-to-point mode,
which used a bunch of code that wasn't really needed.

Now that rport_create adds the rport to the discovery list,
completely skip discovery for the point-to-point case.
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 fc_disc_gpn_ft_parse(), after fc_disc_done() is called, the
disc state is changed by setting buf_len = 0.  This is wrong
since the discovery may have restarted.   Instead, return
after calling fc_disc_done.

Also, return an error on memory allocation failure.
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>

Currently fc_disc_timeout() restarts discovery only if it is not pending.
When the timer is scheduled, the discovery is left pending, so the
timeout never restarts it.

Fix by not checking for pending in the timeout handler.

If discovery is stopped and restarted in the meantime, the timeout will
be canceled.

Also, when a new discovery is started, the retry count wasn't cleared.
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>

On some switches, an empty zone causes GPN_FT to be rejected
with reason 9 (unable) explanation 7 (FC-4 types not registered),
which causes discovery to be retried endlessly.  Treat this as
just an empty response and consider discovery complete.
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>

Abhijeet Joglekar wrote: "In gpn_ft_resp, if the payload is short,
or unexpected response or out of sequence frame, then we just
return and do nothing. We should either enter fc_disc_done()
with DISC_EV_FAIL which will then restart any queued discovery
requests or call lport module which will reset local port,
or we should call fc_disc_error() so that the gpn_ft is retried.

The situation as is causes discovery to remain pending and never
get restarted, in these rare cases.  We saw this due to a coding
bug in fc_disc before.  The only ways it could happen would be
bugs, packet corruption or an FC fabric problem.

Change it to fail discovery.  The local port will restart
discovery, although it probably should just give up until
the next link flap.
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>

Code cleanup for fc_disc_gpn_ft_resp().

Some of the fc_disc.c code was poorly formatted. For example, some lines
in fc_disc.c were unnecessarily truncated and the buf variable could
be eliminated.

Also moved the increment of seq_count into fc_disc_gpn_ft_parse(), to
avoid doing it separately before each call.
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 RSCN is received during fabric discovery, it restarts.
After the restart, disc->seq_count was incremented, so when
the first frame was received, it was considered "out of sequence".
That left the state disc->active, preventing further discoveries.

Change to advance the sequence count before parsing, so that it
won't be changed after a potential restart.
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 an RSCN, do not log off all rports.  This is
extremely disruptive.  If, after the GPN_FT response, some
rports haven't been listed, delete them.

Add field disc_id to structs fc_rport_priv and fc_disc.
disc_id is an arbitrary serial number used to identify the
rports found by the latest discovery.  This eliminates the need
to go through the rport list when restarting discovery.
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>

Move the libfc remote port lookup function into fc_rport.c.
This seems like the best place for it.
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>

Since the rport list maintenance is now done in the rport module,
the callback (and ops) are usually not necessary.

Allow rdata->ops to be left NULL if nothing needs
to be done in an event callback.
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 future discovery patches, change rport_create to return a previously
created rport_priv that has the FC_ID as long as it isn't in deleted state.
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 list of remote ports (struct fc_rport_priv) has been
maintained by the discovery module.  In preparation for having
lport->tt.rport_create() do a lookup first, maintain the
rports list in the rport module.  It will still be protected
by the disc_mutex.

The DNS rport is an exception for until after further patches.
For now, do not add it to the list.

The point-to-point rport will be in the discovery list.
So at shutdown, it doesn't need to be separately logged out.
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>

Delete unused disc->delay element.
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>

There was no need to have the discovery status stored in struct fc_disc.

Change fc_disc_done() to take the discovery status as an argument
and just pass it on to the discovery callback.
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>

Don't create a "dummy" remote port to go with fc_rport_priv.

Make the rport truly optional by allocating fc_rport_priv separately
and not requiring a dummy rport to be there if we haven't yet done
fc_remote_port_add().

The fc_rport_libfc_priv remains as a structure attached to the
rport for I/O purposes.

Be sure to hold references on rdata when the lock is dropped in
fc_rport_work().
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>

Remote ports will become READY more than once after
ADISC is implemented in a later patch.

The event callback that has been called "CREATED" will mean "READY".
Rename it now in preparation for those changes.
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>

Allow a struct fc_rport_priv to have no fc_rport associated with it.
This sets up to remove the need for "rogue" rports.

Add a few fields to fc_rport_priv that are needed before the fc_rport
is created.  These are the ids, maxframe_size, classes, and rport pointer.

Remove the macro PRIV_TO_RPORT().  Just use rdata->rport where appropriate.

To take the place of the get_device()/put_device ops that were used to
hold both the rport and rdata, add a reference count to rdata structures
using kref.  When kref_get decrements the refcount to zero, a new template
function releasing the rdata should be called.  This will take care of
freeing the rdata and releasing the hold on the rport (for now).  After
subsequent patches make the rport truly optional, this release function
will simply free the rdata.

Remove the simple inline function fc_rport_set_name(), which becomes
semanticly ambiguous otherwise.  The caller will set the port_name and
node_name in the rdata->Ids, which will later be copied to the rport
when it its created.
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>

tt.elsct_send is used by both FCP and by the rport state machine.
After further patches, these two modules will use different
structures for the remote port.

So, change elsct_send to use the FC_ID instead of the fc_rport_priv
as its argument.  It currently only uses the FC_ID anyway.

For CT requests the destination FC_ID is still implicitly 0xfffffc.
After further patches the did arg on CT requests will be used to
specify the FC_ID being inquired about for GPN_ID or other queries.
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 rport and discovery modules deal with remote ports
before fc_remote_port_add() can be done, because the
full set of rport identifiers is not known at early stages.

In preparation for splitting the fc_rport/fc_rport_priv allocation,
make fc_rport_priv the primary interface for the remote port and
discovery engines.

The FCP / SCSI layers still deal with fc_rport and
fc_rport_libfc_priv, however.
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 interface for lport->tt.rport_create() takes a fc_disc_port arg,
which is unnatural for most calls.   The only reason for this was
to avoid passing in the local port as an argument, but otherwise
added to complexity.

Simplify by just using lport and fc_rport_identifiers.
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>

While the I/O and LLD interfaces use fc_rport_libfc_priv, the
disc and rport interfaces will use fc_rport_priv, which will
be separately allocated.

Change the disc and rport usage of fc_rport_libfc_priv to fc_rport_priv.

Use #define temporarily to make both names equivalent until a
subsequent patch splits 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>

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

Rogue ports are currently not tracked on any list. The only reference
to them is through any outstanding exchanges pending on the rogue ports.
If the module is removed while a retry is set on a rogue port
(say a Plogi retry for instance), this retry is not cancelled because there
is no reference to the rogue port in the discovery rports list. Thus the
local port can clean itself up, delete the exchange pool, and then the
rogue port timeout can fire and try to start up another exchange.

This patch tracks the rogue ports in a new list disc->rogue_rports. Creating
a new list instead of using the disc->rports list keeps remote port code
change to a minimum.

1)  Whenever a rogue port is created, it is immediately added to the
disc->rogue_rports list.

2) When the rogues port goes to ready, it is removed from the rogue list
and the real remote port is added to the disc->rports list

3) The removal of the rogue from the disc->rogue_rports list is done in
the context of the fc_rport_work() workQ thread in discovery callback.

4) Real rports are removed from the disc->rports list like before. Lookup
is done only in the real rports list. This avoids making large changes
to the remote port code.

5) In fc_disc_stop_rports, the rogues list is traversed in addition to the
real list to stop the rogue ports and issue logoffs on them. This way, rogue
ports get cleaned up when the local port goes away.

6) rogue remote ports are not removed from the list right away, but
removed late in fc_rport_work() context, multiple threads can find the same
remote port in the list and call rport_logoff(). Rport_logoff() only
continues with the logoff if port is not in NONE state, thus preventing
multiple logoffs and multiple list deletions.

7) Since the rport is removed from the disc list at a later stage
(in the disc callback), incoming frames can find the rport even if
rport_logoff() has been called on the rport. When rport_logoff() is called,
the rport state is set to NONE, and we are trying to cancel all exchanges
and retries on that port. While in this state, if an incoming
Plogi/Prli/Logo or other frames match the rport, we should not reply
because the rport is in the NONE state. Just drop the frame, since the
rport will be deleted soon in the disc callback (fc_rport_work)

8)  In fc_disc_single(), remove rport lookup and call to fc_disc_del_target.
fc_disc_single() is called from recv_rscn_req() where rport lookup
and rport_logoff is already done.
Signed-off-by: NAbhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

gpn_ft_resp processing currently does not hold the discovery lock.
disc_done() thus gets called from gpn_ft_resp or from gpn_ft_parse
without the lock held. This then sets disc->pending to zero or calls
gpn_ft_req() without disc_lock held.

- Hold disc mutex during gpn_ft resp processing
- In disc_done, release the disc mutex while calling lport callback
Signed-off-by: NAbhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

1) Added '()' for function names in kerneldoc comments

2) Changed comment bookends from '**/' to '*/'. The comment on the the
   mailing list was that '**/' "is consistently unconventional.  Not
   wrong, just odd." The Documentation/kernel-doc-nano-HOWTO.txt
   states that kerneldoc comment blocks should end with '**/' but most
   (if not all) instance I found under drivers/scsi/ were only using
   the '*/' so I converted to that style.

3) Removed incorrect linebreaks in kerneldoc comments where found

4) Removed a few unnecessary blank comment lines in kerneldoc comment
   blocks
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Just rename the variable as per our naming convention.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

We only need to use this macro when assigning a value to
rport->dd_data. All other accesses should just use dd_data.
Signed-off-by: NRobert Love <robert.w.love@intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

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

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