This patch adds two new IBM storage devices which can use rdac device handlers.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Batch up MODE_SELECT in rdac device handler.

LSI RDAC storage has the capability of handling mode selects for
multiple luns in a same command. Make use of that ability to send
as few MODE SELECTs as possible to the storage controller as possible.

This patch creates a work queue and queues up activate requests
when a MODE SELECT is sent down the wire. When that MODE SELECT
completes, it compiles queued up activate requests for multiple
luns into a single MODE SELECT.

This reduces the time to do failover/failback of large number of LUNS.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The function mode_select_handle_sense returns SCSI_DH_OK even when there is a sense code which is incorrect. Removing it so that it returns SCSI_DH_IO when there is sense that is not handled by this function.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Reviewed-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: NBob Stankey <Robert.stankey@lsi.com>
Reviewed-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Patch to add debugging stuff for rdac device handler.
- Added a bit mask "module parameter" rdac_logging with 2 bits for each type
  of logging.
- currently defined only two types of logging(failover and sense logging). Can
  be enhanced later if required.
- By default only failover logging is enabled which is equivalent of current
  logging.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Reviewed-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: NBob Stankey <Robert.stankey@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Adding the code to read the debug information during initialization. This
patch collects the information about storage and controllers during
rdac_activate.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Reviewed-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: NBob Stankey <Robert.stankey@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Moving the initialization code from rdac_activate to rdac_bus_attach which is
more efficient.  We don't have to collect all the information during every
activate.
Signed-off-by: NBabu Moger <babu.moger@lsi.com>
Reviewed-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Reviewed-by: NBob Stankey <Robert.stankey@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

These storage arrays can use RDAC when configured with 'linux' as the
initiator.

http://www.sun.com/storage/disk_systems/workgroup/2500/
http://www.sun.com/storage/disk_systems/workgroup/2510/
http://www.sun.com/storage/disk_systems/workgroup/2530/Signed-off-by: NCharlie Brady <charlieb@budge.apana.org.au>
Reviewed-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch is to add DM support for next generation of Dell PowerVault
storage array.
Signed-off-by: NYanqing Liu <Yanqing_Liu@Dell.com>
Acked-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Reported-by: NRice Brown <rick.brown@oit.gatech.edu>
Signed-Off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

During device discovery read capacity fails with 0x020401 and sets the
device size to 0. As a reason any I/O submitted to this path gets
killed at sd_prep_fn with BLKPREP_KILL. This patch is to retry for
0x020401. NEED_RETRY in scsi_decide_disposition does not give
sufficient time for the device to become ready.
Signed-off-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch adds retry for NOT_READY check condition - Quiesce in
progress (02/A1/02)

Signed-off-by: Vijay Chauhan<vijay.chauhan@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh_rdac: Retry mode select for NO_SENSE, ABORTED_COMMAND, UNIT_ATTENTION, NOT_READY(02/04/01)

This patch is to add retry for mode select if mode select command is
returned with sense NO_SENSE, UNIT_ATTENTION, ABORTED_COMMAND,
NOT_READY(02/04/01). This patch reorganise the sense keys from if-else
to switch-case format for better maintainability.
Signed-off-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Acked-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

During device discovery read capacity fails with 0x068b02 and sets the
device size to 0. As a reason any I/O submitted to this path gets
killed at sd_prep_fn with BLKPREP_KILL. This patch is to retry for
0x068b02
Signed-off-by: NVijay Chauhan <vijay.chauhan@lsi.com>
Acked-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

[jejb: fixed whitespace damage]
Signed-off-by: NBabu Moger <Babu.Moger@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When the mode select sent to the controller fails with the retryable
error, it is better to retry the mode_select from the hardware handler
itself, instead of propagating the failure to dm-multipath.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Make sure the state of a path is set properly when controller is swapped from passive to active

When the controller ownership is changed (from passive to active),
check_ownership() doesn't set the state of the device to ACTIVE.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Reported-by: N"Moger, Babu" <Babu.Moger@lsi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Set the path state to be passive when we learn that the controller does
not own the path to the LUN.

This will avoid sending even a single i/o thru the passive path at the
probe time.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Multipath is best at handling transport errors. If it gets a device
error then there is not much the multipath layer can do. It will just
access the same device but from a different path.

This patch breaks up failfast into device, transport and driver errors.
The multipath layers (md and dm mutlipath) only ask the lower levels to
fast fail transport errors. The user of failfast, read ahead, will ask
to fast fail on all errors.

Note that blk_noretry_request will return true if any failfast bit
is set. This allows drivers that do not support the multipath failfast
bits to continue to fail on any failfast error like before. Drivers
like scsi that are able to fail fast specific errors can check
for the specific fail fast type. In the next patch I will convert
scsi.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Add Dell Powervault storage arrays into device list of rdac device
handler.
Signed-off-by: NYanqing Liu <yanqing_liu@dell.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

blk_get_request initializes rq->cmd (rq_init does) so the users don't
need to do that.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Change scsi_dh check_sense functions to return ADD_TO_MLQUEUE
to allow retries to occur without restriction of blk_noretry_request
check.
Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

lun_state need to be initialized inside check_ownership().
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

RDAC storage controller doesn't seem to use the scsilun format. It uses
only the last byte for LUN.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This patch makes several needlessly global struct scsi_dh_devlist's
static.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch updates the RDAC device handler to
refuse to attach to devices not supporting the
RDAC vpd pages.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Instead of having each and every driver implement its own
device table scanning code we should rather implement a common
routine and scan the device tables there.
This allows us also to implement a general notifier chain
callback for all device handler instead for one per handler.

[sekharan: Fix rejections caused by conflicting bug fix]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Before accessing the device data structure in hardware handlers,
make sure it is a indeed a sdev device.

Yinghai Lu <yhlu.kernel@gmail.com> found the bug on Jul 16, 2008,
and later tested/verified the following fix.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch provides the device handler to support the LSI RDAC SCSI
based storage devices.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>