Commit Graph

85 Commits

Author SHA1 Message Date
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Bhanu Prakash Gollapudi
75a2792df2 [SCSI] libfc: introduce LLD event callback
This patch enables LLD to listen to rport events and perform LLD
specific operations based on the rport event. This patch also stores
sp_features and spp_type in rdata for further reference by LLD.

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-12 11:09:04 -06:00
Joe Eykholt
62bdb6455e [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>
2011-02-12 11:03:40 -06:00
Joe Eykholt
70d53b046a [SCSI] libfc: add hook to notify providers of local port changes
When an SCST provider is registered, it needs to know what
local ports are available for configuration as targets.

Add a notifier chain that is invoked when any local port
that is added or deleted.

Maintain a global list of local ports and add an
interator function that calls a given function for
every existing local port.  This is used when first
loading a provider.

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>
2011-02-12 11:02:20 -06:00
Joe Eykholt
baf9fdf076 [SCSI] libfc: add local port hook for provider session lookup
The target provider needs a per-instance lookup table
or other way to lookup sessions quickly without going through
a linear list or serializing too much.

Add a simple void * array indexed by FC-4 type to the fc_lport.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Committed-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-12 11:02:17 -06:00
Joe Eykholt
1a5c2d7e5c [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>
2011-02-12 11:01:21 -06:00
Joe Eykholt
96ad846445 [SCSI] libfc: add hook for FC-4 provider registration
Allow FC-4 provider modules to hook into libfc, mostly for targets.
This should allow any FC-4 module to handle PRLI requests and maintain
process-association states.

Each provider registers its ops with libfc and then will be called for
any incoming PRLI for that FC-4 type on any instance.   The provider
can decide whether to handle that particular instance using any method
it likes, such as ACLs or other configuration information.

A count is kept of the number of successful PRLIs from the remote port.
Providers are called back with an implicit PRLO when the remote port
is about to be deleted or has been reset.

fc_lport_recv_req() now sends incoming FC-4 requests to FC-4 providers,
and there is a built-in provider always registered for handling
incoming ELS requests.

The call to provider recv() routines uses rcu_read_lock()
so that providers aren't removed during the call.  That lock is very
cheap and shouldn't affect any performance on ELS requests.
Providers can rely on the RCU lock to protect a session lookup as well.

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>
2011-02-12 11:00:40 -06:00
Joe Eykholt
5f0e385fda [SCSI] libfc: fix statistics for FCP input/output megabytes
The statistics for InputMegabytes and OutputMegabytes are
misnamed.  They're accumulating bytes, not megabytes.

The statistic returned via /sys must be in megabytes, however,
which is what the HBA-API wants.  The FCP code needs to accumulate
it in bytes and then divide by 1,000,000 (not 2^20) before it
presented via sysfs.

This affects fcoe.ko only, not fnic.  The fnic driver
correctly by accumulating bytes and then converts to megabytes.

I checked that libhbalinux is using the /sys file directly without
conversion.

BTW, qla2xxx does divide by 2^20, which I'm not fixing here.

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>
2010-12-21 12:24:34 -06:00
john fastabend
05fee645e9 [SCSI] libfc: remove tgt_flags from fc_fcp_pkt struct
We can easily remove the tgt_flags from fc_fcp_pkt struct
and use rpriv->tgt_flags directly where needed.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-21 12:24:22 -06:00
Jeff Garzik
f281233d3e SCSI host lock push-down
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16 13:33:23 -08:00
Bhanu Prakash Gollapudi
c531b9b49b [SCSI] libfc: Do not let disc work cancel itself
When number of NPIV ports created are greater than the xids
allocated per pool -- for eg., creating 255 NPIV ports on a
system with nr_cpu_ids of 32, with each pool containing 128
xids -- and then generating a link event - for eg.,
shutdown/no shutdown -- on the switch port causes the hang
with the following stack trace.

Call Trace:
schedule_timeout+0x19d/0x230
wait_for_common+0xc0/0x170
__cancel_work_timer+0xcf/0x1b0
fc_disc_stop+0x16/0x30 [libfc]
fc_lport_reset_locked+0x47/0x90 [libfc]
fc_lport_enter_reset+0x67/0xe0 [libfc]
fc_lport_disc_callback+0xbc/0xe0 [libfc]
fc_disc_done+0xa8/0xf0 [libfc]
fc_disc_timeout+0x29/0x40 [libfc]
run_workqueue+0xb8/0x140
worker_thread+0x96/0x110
kthread+0x96/0xa0
child_rip+0xa/0x20

Fix is to not cancel the disc_work if discovery is already
stopped, thus allowing lport state machine to restart and try
discovery again.

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Acked-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>
2010-10-25 15:11:37 -05:00
Joe Eykholt
9226115695 [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>
2010-07-28 09:06:02 -05:00
Joe Eykholt
239e81048b [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>
2010-07-28 09:06:01 -05:00
Joe Eykholt
24f089e2f2 [SCSI] libfc: add fc_fill_reply_hdr() and fc_fill_hdr()
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:06:00 -05:00
Joe Eykholt
251748a99e [SCSI] libfc: add fc_frame_sid() and fc_frame_did() functions
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:59 -05:00
Joe Eykholt
079ecd8cfe [SCSI] libfc: eliminate rport LOGO state
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:58 -05:00
Joe Eykholt
f60e12e9c7 [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>
2010-07-28 09:05:54 -05:00
Joe Eykholt
a7b12a279f [SCSI] libfc: add FLOGI state to rport for VN2VN
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:53 -05:00
Joe Eykholt
3726f3584e [SCSI] libfc: Add local port point-to-multipoint flag
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:53 -05:00
Joe Eykholt
0685230c59 [SCSI] libfc: add discovery-private pointer for LLD
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:52 -05:00
Joe Eykholt
f90377abca [SCSI] libfc: provide space for LLD after remote port structure
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:49 -05:00
Joe Eykholt
42e9041467 [SCSI] libfc: convert rport lookup to be RCU safe
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-28 09:05:48 -05:00
Joe Eykholt
f034260db3 [SCSI] libfc: fix indefinite rport restart
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: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-07-27 12:01:53 -05:00
Joe Eykholt
4b2164d4d2 [SCSI] libfc: Fix remote port restart problem
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: Bhanu Gollapudi <bprakash@broadcom.com>
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>
2010-07-27 12:01:52 -05:00
Robert Love
7b2787ec15 [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>
2010-05-16 22:22:34 -04:00