Report the fc_host_port_type as FC_PORTTYPE_NPIV when the subchannel
is running in NPIV mode. This allows to see the correct type with
lsscsi -H -t --list
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Use the I/O blocking mechanism in the FC transport class to allow
faster failovers for multipathing:
- Call fc_remote_port_delete early to set the rport to BLOCKED.
- Check the rport status in queuecommand with fc_remote_portchkready
to no longer accept new I/O for this port and fail the I/O with the
appropriate scsi_cmnd result.
- Implement the terminate_rport_io handler to abort all pending I/O
requests
- Return SCSI commands with DID_TRANSPORT_DISRUPTED while erp is
running.
- When updating the remote port status, check for late changes and
update the remote ports status accordingly.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
After an error condition resolved a remote storage port was never
re-opened. The incoming RSCN was not processed accordingly due
to a misinterpreted status flag / return value combination.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The current number based id ERP logging is replaced by a string
based tag version. The benefit is an easier location of the code in
question and the removal of the lengthy array referencing the
individual messages.
The string (7 bytes) based version does not use more space since those
bytes were "used" anyway due to the alignment of the structure.
The encoding of the 7 byte string is as follows
[0-1] = filename
[2-5] = task/function
[6] = section
Due to the character of this string (fixed length) a string
termination is not required here.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The status read response FSF_STATUS_READ_SUB_ERROR_PORT is not
defined in the specs and therefore not valid.
All occurrences are removed from the code.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Issue ELS ADISC requests from workqueue. This allows the link test
request to be sent when the request queue is full due to I/O load for
other remote ports. It also simplifies request queue locking,
zfcp_fsf_send_fcp_command_task is now the only function that has
interrupts disabled from the caller. This is also a prereq for the FC
passthrough support that issues ELS requests from userspace.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
When the SCSI midlayer is running error recovery, the low-level error
recovery in zfcp could be running and preventing the SCSI midlayer to
issue error recovery requests. To avoid unnecessary error recovery
escalation, wait for the zfcp erp to finish and retry if necessary.
While reworking the SCSI eh handlers, alsa cleanup the code and
simplify the interface from zfcp_scsi to the fsf layer.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
For calls from zfcp erp, scsi_eh and sysfs switch the calls issuing
FSF requests to zfcp_fsf_req_sbal_get to wait for free SBALs.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Only increment the req_id for successfully issued requests. This
avoids some confusion when debugging issued fsf requests.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The lock only needs to protect the softirq context called from qdio
against the userspace context called from sysfs. spin_lock and
spin_lock_bh is enough.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
PORT_PHYS_CLOSING is only set and cleared, but not actually used
for status checking.
PORT_INVALID_WWPN is set when the GID_PN request does not return
a d_id for a remote port, e.g. when a remote port has been
unplugged. For this case, the d_id is zero. In the erp we can
check the d_id and use the normal escalation procedure that gives
up after three retries and remove the special case.
PORT_NO_WWPN is unused: Each port in the remote port list has a
valid wwpn. The WKA ports are now tracked outside the port
list. Remove the PORT_NO_WWPN flag, since this is no longer set
for any port.
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The SUGGEST_* flags in the SCSI command result have been out of fashion
for a while and we don't actually use them in the error handling.
Remove the remaining occurrences.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Remove a message that was emitted for a port that could not initially
be opened. This is a rare case when the port discovery hits an
initiator port and only confuses the user with an initator port logged
in the message. Remove the whole special case: The failed "open port"
request triggers required follow-up actions anyway.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Felix Beck <felix@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add the support to send CT and ELS requests as unchained FSF requests. This is
required for older hardware and was somehow omitted during the cleanup of the
FSF layer. The req_count and resp_count attributes are unused, so remove them
instead of adding a special case for setting them. Also add debug data and a
warning, when the ct request hits a limit.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The port flag DID_DID indicates whether we know the current id of the
port. This is always set in parallel. Since the id 0 is invalid
(because the port id 0 is invalid) we can remove the DID_DID flag:
d_id of 0 indicates an invalid d_id != 0 is a valid one.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Felix Beck <felix@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
When waiting for a request claim the SBAL before waiting. This way,
locking before each check of the free counter is not required and
sparse does not emit warnings for the complicated locking scheme.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Felix Beck <felix@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Move the closing parenthesis before the line break.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Felix Beck <felix@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The check of having a valid pointer was performed before the
processing was secured by the lock. Between those two steps the
pointer can turn invalid. During further processing another value is
used (referenced by the pointer described above) as a function pointer
which is never verified to be valid either, resulting under some
circumstances in an invalid function call. This patch is fixing both
issues.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Aborting a SCSI cmnd might requrie to send a abort_fsf_cmnd. If the
creation of this fsf_req fails an ERR_PTR is returned where a NULL
value would be expected as an error indicator. This ERR_PTR is
dereferenced as valid fsf_req in succeeding processing leading to
an error.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Running two wka_port_get calls in parallel could issue two open_port
requests, overwriting the port handle. Don't issue an open_port
for the state PORT_OPENING, and only read the data from GOOD
responses.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fix the handling of the request list in the error path:
- Use irqsave for the lock as in the good path.
- Before removing the request, check if it is still in the list, a
call to dismiss_all might have changed the list in between.
- zfcp_qdio_send does not change the queue counters on failure,
trying revert something is wrong, so remove this.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
When allocating fsf requests without qtcb, store the pointer to the
mempool in the fsf requests for later call to mempool_free. This
codepath is only used by the status_read requests.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The per adapter req_list_lock must be held with interrupts disabled, otherwise
we might end up with nice deadlocks as lockdep tells us (see below).
zfcp 0.0.1804: QDIO problem occurred.
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.27-rc8-00035-g4a77035-dirty #86
---------------------------------------------------------
swapper/0 just changed the state of lock:
(&adapter->erp_lock){++..}, at: [<00000000002c82ae>] zfcp_erp_adapter_reopen+0x4e/0x8c
but this lock took another, hard-irq-unsafe lock in the past:
(&adapter->req_list_lock){-+..}
and interrupts could create inverse lock ordering between them.
[tons of backtraces, but only the interesting part follows]
the second lock's dependencies:
-> (&adapter->req_list_lock){-+..} ops: 2280627634176 {
initial-use at:
[<0000000000071f10>] __lock_acquire+0x504/0x18bc
[<000000000007335c>] lock_acquire+0x94/0xbc
[<00000000003d7224>] _spin_lock_irqsave+0x6c/0xb0
[<00000000002cf684>] zfcp_fsf_req_dismiss_all+0x50/0x140
[<00000000002c87ee>] zfcp_erp_adapter_strategy_generic+0x66/0x3d0
[<00000000002c9498>] zfcp_erp_thread+0x88c/0x1318
[<000000000001b0d2>] kernel_thread_starter+0x6/0xc
[<000000000001b0cc>] kernel_thread_starter+0x0/0xc
in-softirq-W at:
[<0000000000072172>] __lock_acquire+0x766/0x18bc
[<000000000007335c>] lock_acquire+0x94/0xbc
[<00000000003d7224>] _spin_lock_irqsave+0x6c/0xb0
[<00000000002ca73e>] zfcp_qdio_int_resp+0xbe/0x2ac
[<000000000027a1d6>] qdio_kick_inbound_handler+0x82/0xa0
[<000000000027daba>] tiqdio_inbound_processing+0x62/0xf8
[<0000000000047ba4>] tasklet_action+0x100/0x1f4
[<0000000000048b5a>] __do_softirq+0xae/0x154
[<0000000000021e4a>] do_softirq+0xea/0xf0
[<00000000000485de>] irq_exit+0xde/0xe8
[<0000000000268c64>] do_IRQ+0x160/0x1fc
[<00000000000261a2>] io_return+0x0/0x8
[<000000000001b8f8>] cpu_idle+0x17c/0x224
hardirq-on-W at:
[<0000000000072190>] __lock_acquire+0x784/0x18bc
[<000000000007335c>] lock_acquire+0x94/0xbc
[<00000000003d702c>] _spin_lock+0x5c/0x9c
[<00000000002caff6>] zfcp_fsf_req_send+0x3e/0x158
[<00000000002ce7fe>] zfcp_fsf_exchange_config_data+0x106/0x124
[<00000000002c8948>] zfcp_erp_adapter_strategy_generic+0x1c0/0x3d0
[<00000000002c98ea>] zfcp_erp_thread+0xcde/0x1318
[<000000000001b0d2>] kernel_thread_starter+0x6/0xc
[<000000000001b0cc>] kernel_thread_starter+0x0/0xc
}
... key at: [<0000000000e356c8>] __key.26629+0x0/0x8
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmit@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch writes the channel and fabric latencies in nanoseconds per
request via blktrace for later analysis. The utilization of the inbound
and outbound adapter queue is also reported.
Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Trace ids 107 and 3 are used twice, fix this to have unique ids for
the erp triggers.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Each adapter reopen trigger automatically a scan_port task which
is waiting for the ERP to be finished before further processing.
Since the initial device setup enqueues adapter, port and LUN which
are individual ERP actions, this process would start after
everything is done. Unfortunately the port_reopen requires another
scheduled work to be finished which is queued after the automatic
scan_port -> deadlock !
This fix creates an own work queue for ERP based nameserver requests.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Now that we removed the long messages for the bit error threshold
data, put the data in the hba trace. This way, we get a short warning
for the threshold event from the hardware and have the data in the
trace for further analysis.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reduce the size of zfcp data structures by removing unused and
redundant members. scsi_lun is only the mangled version of the
fcp_lun. So, remove the redundant field and use the fcp_lun instead.
Since the queue lock and the pci_batch indicator are only used in the
request queue, move them from the common queue struct to the adapter
struct.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Changing the zfcp behaviour from always having the nameserver port
open to an on-demand strategy. This strategy reduces the use of
limited resources like port connections. The patch provides a common
infrastructure which could be used for all WKA ports in future.
Also reduce the number of nameserver lookups by changing the zfcp
behaviour of always querying the nameserver for the corresponding
destination ID of the remote port. If the destination ID has changed
during the reopen process we will be informed and then trigger a
nameserver query on demand.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- Remove unused references and declarations, including one instance
of the FC ls_adisc struct that has been defined twice.
- Also remove the flags COMMON_OPENING, COMMON_CLOSING,
ADAPTER_REGISTERED and XPORT_OK that are only set and cleared, but
not checked anywhere.
- Remove the zfcp specific atomic_test_mask makro. Simply use
atomic_read directly instead.
- Remove the zfcp internal sg helper functions and switch the places
where it is still used to call sg_virt directly.
- With the update of the QDIO code, the QDIO data structures no
longer use the volatile type qualifier. Now we can also remove the
volatile qualifiers from the zfcp code.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Update the kernel messages in zfcp with input from the message review
and remove some messages that have been identified as redundant.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Adds a new sysfs attribute queue_full for adapters that records the number
of incidents where a requests could not be submitted due to insufficient
free space on the request queue.
Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Some drivers have duplicated unlikely() macros. IS_ERR() already
has unlikely() in itself. This patch cleans up such pointless
codes although there is no real effect on the kernel's behaviour.
Signed-off-by: Hirofumi Nakagawa <hnakagawa@miraclelinux.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The request queue lock can be acquired from softirq context when the
SCSI midlayer issues commands. Disable softirqs for this lock when
commands are issued from zfcp.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cleanup the code in zfcp_erp.c, move erp internal definititions to
this file and move FSF timeout handling to the FSF layer.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cleanup code in zfcp_scsi.c, fix coding style issues and simplify the
code.
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Move the accessor functions for the scsi_cmnd status from zfcp to the
SCSI include file. Change the interface to the functions to pass the
scsi_cmnd pointer instead of the status pointer.
Signed-off-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Automatically attach the remote ports in zfcp when the adapter is set
online. This is done by querying all available ports from the FC
namesever. The scan for remote ports is also triggered by RSCNs and
can be triggered manually with the sysfs attribute 'port_rescan'.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cleanup the messages used in the zfcp driver: Remove unnecessary debug
and trace message and convert the remaining messages to standard
kernel macros. Remove the zfcp message macros and while updating the
whole flie also update the copyright headers.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cleanup the interface code from zfcp to qdio. Also move code that
belongs to the qdio interface from the erp to the qdio file.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
zfcp implements a device file to allow Linux guests changing the
Access Control Tables stored in the adapter. The code for the device
file has nothing to do with the other parts of the driver, so move it
to a new file and cleanup the code while doing so.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Move all Fibre Channel related code to new file and cleanup the code
while doing so.
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sbal_last is more appropriate, because it matches sbal_first.
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
If allocation of a status buffer failed the function incorrectly
returned 0 instead of -ENOMEM.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Processing of an unsolicted status request can lead to a locking race
of the request_queue's queue_lock during the recreation of the
used up status read request while still in interrupt context
of the response handler.
Detaching the 'refill' of the long running status read requests from
the handler to a scheduled work is solving this issue.
In addition, each refill-run is trying to re-establish the full amount
of status read requests, which might have failed in earlier runs.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Add the infrastructure to retrieve the fabric and channel latencies
from FSF commands for each SCSI command that has been processed. For
each unit, the sum, min, max and number of requests is tracked.
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- struct scsi_cmnd had a 16 bytes command buffer of its own.
This is an unnecessary duplication and copy of request's
cmd. It is probably left overs from the time that scsi_cmnd
could function without a request attached. So clean that up.
- Once above is done, few places, apart from scsi-ml, needed
adjustments due to changing the data type of scsi_cmnd->cmnd.
- Lots of drivers still use MAX_COMMAND_SIZE. So I have left
that #define but equate it to BLK_MAX_CDB. The way I see it
and is reflected in the patch below is.
MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
as per the SCSI standard and is not related
to the implementation.
BLK_MAX_CDB. - The allocated space at the request level
- I have audit all ISA drivers and made sure none use ->cmnd in a DMA
Operation. Same audit was done by Andi Kleen.
(*)fixed-length here means commands that their size can be determined
by their opcode and the CDB does not carry a length specifier, (unlike
the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
true and the SCSI standard also defines extended commands and
vendor specific commands that can be bigger than 16 bytes. The kernel
will support these using the same infrastructure used for VARLEN CDB's.
So in effect MAX_COMMAND_SIZE means the maximum size command
scsi-ml supports without specifying a cmd_len by ULD's
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
