linux-toradex.git/include/scsi, branch v2.6.29

[SCSI] fcoe: Out of order tx frames was causing several check condition SCSI status

2009-03-10T14:09:21+00:00

frames followed by these errors in log.

	[sdp] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE,SUGGEST_OK
	[sdp] Sense Key : Aborted Command [current]
	[sdp] Add. Sense: Data phase error

This was causing some test apps to exit due to write failure under heavy
load.

This was due to a race around adding and removing tx frame skb in
fcoe_pending_queue, Chris Leech helped me to find that brief unlocking
period when pulling skb from fcoe_pending_queue in various contexts
(fcoe_watchdog and fcoe_xmit) and then adding skb back into fcoe_pending_queue
up on a failed fcoe_start_io could change skb/tx frame order in
fcoe_pending_queue. Thanks Chris.

This patch allows only single context to pull skb from fcoe_pending_queue
at any time to prevent above described ordering issue/race by use of
fcoe_pending_queue_active flag.

This patch simplified fcoe_watchdog with modified fcoe_check_wait_queue by
use of FCOE_LOW_QUEUE_DEPTH instead previously used several conditionals
to clear and set lp->qfull.

I think FCOE_MAX_QUEUE_DEPTH with FCOE_LOW_QUEUE_DEPTH  will work better
in re/setting lp->qfull and these could be fine tuned for performance.

Signed-off-by: Vasu Dev 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] fcoe: ETH_P_8021Q is already in if_ether and fcoe is not using it anyway

2009-03-10T14:07:09+00:00

Signed-off-by: Yi Zou 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc, fcoe: Remove unnecessary cast by removing inline wrapper

2009-03-10T14:05:35+00:00

Comment from "Andrew Morton "

> +{
> +     return (struct fcoe_softc *)lport_priv(lp);

unneeded/undesirable cast of void*.  There are probably zillions of
instances of this - there always are.

This whole inline function was unnecessary. The FCoE layer knows
that it's data structure is stored in the lport private data, it
can just access it from lport_priv().

Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc, fcoe: Fix kerneldoc comments

2009-03-10T14:04:40+00:00

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: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc: Cleanup libfc_function_template comments

2009-03-06T21:45:32+00:00

Made the comments more like the comments for struct scsi_host_template.

Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc: Don't violate transport template for rogue port creation

2009-03-06T21:41:01+00:00

Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

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

2009-03-06T21:39:34+00:00

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 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc, fcoe: fixed locking issues with lport->lp_mutex around lport->link_status

2009-03-06T21:37:49+00:00

The fcoe_xmit could call fc_pause in case the pending skb queue len is larger
than FCOE_MAX_QUEUE_DEPTH, the fc_pause was trying to grab lport->lp_muex to
change lport->link_status and that had these issues :-

1. The fcoe_xmit was getting called with bh disabled, thus causing
"BUG: scheduling while atomic" when grabbing lport->lp_muex with bh disabled.

2. fc_linkup and fc_linkdown function calls lport_enter function with
lport->lp_mutex held and these enter function in turn calls fcoe_xmit to send
lport related FC frame, e.g. fc_linkup => fc_lport_enter_flogi to send flogi
req. In this case grabbing the same lport->lp_mutex again in fc_puase from
fcoe_xmit would cause deadlock.

The lport->lp_mutex was used for setting FC_PAUSE in fcoe_xmit path but
FC_PAUSE bit was not used anywhere beside just setting and clear this
bit in lport->link_status, instead used a separate field qfull in fc_lport
to eliminate need for lport->lp_mutex to track pending queue full condition
and in turn avoid above described two locking issues.

Also added check for lp->qfull in fc_fcp_lport_queue_ready to trigger
SCSI_MLQUEUE_HOST_BUSY when lp->qfull is set to prevent more scsi-ml cmds
while lp->qfull is set.

This patch eliminated FC_LINK_UP and FC_PAUSE and instead used dedicated
fields in fc_lport for this, this simplified all related conditional
code.

Also removed fc_pause and fc_unpause functions and instead used newly added
lport->qfull directly in fcoe.

Signed-off-by: Vasu Dev 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] libfc: Pass lport in exch_mgr_reset

2009-03-06T21:35:47+00:00

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 
Signed-off-by: Robert Love 
Signed-off-by: James Bottomley

[SCSI] iscsi_tcp: make padbuf non-static

2009-01-13T16:41:34+00:00

virt_to_page() call should not be used on kernel text and data
addresses.  virt_to_page() is used by sg_init_one(). So change padbuf
to be allocated within iscsi_segment.

Signed-off-by: Karen Xie 
Acked-by: Mike Christie 
Signed-off-by: James Bottomley