This allows drivers to specify the size of their per-command private
data in the host template and then get extra memory allocated for
each command instead of needing another allocation in ->queuecommand.

With the current SCSI code that already does multiple allocations for
each command this probably doesn't make a big performance impact, but
it allows to clean up the drivers, and prepare them for using the
blk-mq infrastructure where the common allocation will make a difference.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

When a command runs into a timeout we need to send an 'ABORT TASK'
TMF. This is typically done by the 'eh_abort_handler' LLDD callback.

Conceptually, however, this function is a normal SCSI command, so
there is no need to enter the error handler.

This patch implements a new scsi_abort_command() function which
invokes an asynchronous function scsi_eh_abort_handler() to
abort the commands via the usual 'eh_abort_handler'.

If abort succeeds the command is either retried or terminated,
depending on the number of allowed retries. However, 'eh_eflags'
records the abort, so if the retry would fail again the
command is pushed onto the error handler without trying to
abort it (again); it'll be cleared up from SCSI EH.

[hare: smatch detected stray switch fixed]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: stable@kernel.org
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

This patchs adds an 'eh_deadline' sysfs attribute to the scsi
host which limits the overall runtime of the SCSI EH.
The 'eh_deadline' value is stored in the now obsolete field
'resetting'.
When a command is failed the start time of the EH is stored
in 'last_reset'. If the overall runtime of the SCSI EH is longer
than last_reset + eh_deadline, the EH is short-circuited and
falls through to issue a host reset only.

[jejb: add comments in Scsi_Host about new fields]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Field is now unused, so this is dead code.

[jejb: remove resetting and last_reset from Scsi_Host]
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

all users converted to ->show_info()/->write_info()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

It's still an obsolete interface; don't introduce those in new drivers.
However, it's saner than the ->proc_info() and commits after this one
will convert the existing ->proc_info() users to it.

The read side is ->show_info(seq_file *, struct Scsi_Host *); use
seq_... for generating contents.

The write side is ->write_info(struct Scsi_Host *, char *, int).

Again, this is driven by procfs needs; we are going to kill ->write_proc()
and ->read_proc() and this is the main obstacle to burying that piece of
shit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The range checking from fe542396 was bad. We would still end up walking
beyond the array as Type 3 is defined to be 4 in the protection
bitmask. Instead use ARRAY_SIZE() for the range check.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

We set the capacity to zero when we discovered a device formatted with
an unknown DIF protection type. However, the read_capacity code would
override the capacity and cause the device to be enabled regardless.

Make sd_read_protection_type() return an error if the protection type is
unknown. Also prevent duplicate printk lines when the device is being
revalidated.
Reported-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

With previous change, now the ata port runtime suspend will happen as:

disk suspend --> scsi target suspend --> scsi host suspend --> ata port
suspend

ata port(parent device) suspend need to schedule scsi EH which will resume
scsi host(child device). Then the child device resume will in turn make
parent device resume first. This is kind of recursive.

This patch adds a new flag Scsi_Host::eh_noresume.
ata port will set this flag to skip the runtime PM calls on scsi host.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The problem is that if we are doing a scsi scan then the device goes
into recovery then we will wait for the recovery to complete. It waits
because scsi-ml will send inquiries or report luns and the queueing code
will have been blocked due to the host not being ready. However, if we
are in recovery and then a scan is started the scan will silently fail
and some devices will not be added.

It is easy to hit the problem where devices do not show up with
FC where we are doing tests that disrupt the target controllers.
When the controller is disruprted (reboot, or setting firmware, etc),
and we cause the dev loss tmo to fire then devices will be removed
Then when the problem has been fixed, the rport will be scanned and
devices should be added back. But if we cause another disruption before
scanning has started then devices will not get added back. If the problem
is not started until the scan is started then the devices will be added
back.

This patch fixes that problem by not failing scans when the host
is in recovery. We will let scsi-ml send the IO and let the queueing
and scsi error handling deal with it like is done if we went into
recovery while scanning.

For recovery cases where the host is being torn down then with the
patch we will still fail the scan since there is not point in scanning.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Added new sysfs attr 'host_reset' in scsi_sysfs.c to
perform adapter or firmware reset as suggested by
Mike Christie here:
http://marc.info/?l=linux-scsi&m=127359347111167&w=2

user/application can write "adapter" or "firmware" on
this attr and it will call newly added function hook
in scsi_host_template to call LDD adapter or firmware
reset implementation.
Signed-off-by: NVikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

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: NJeff Garzik <jgarzik@redhat.com>
Acked-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.

Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.

Add support for honoring the integrity segment limit when merging both
bios and requests.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@carl.home.kernel.dk>

Implement sd_unlock_native_capacity() method which calls into
hostt->unlock_native_capacity() if implemented.  This will be invoked
by block layer if partitions extend beyond the end of the device and
can be used to implement, for example, on-demand ATA host protected
area unlocking.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Some of our virtual SCSI hosts don't have a proper bus parent at the
top, which can be a problem for doing DMA on them

This patch makes the host device cache a pointer to the physical bus
device and provides an extra API for setting it (the normal API picks
it up from the parent).  This patch also modifies the qla2xxx and lpfc
vport logic to use the new DMA host setting API.
Acked-By: NJames Smart  <james.smart@emulex.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

This patch modifies scsi_host_template->change_queue_depth so that
it takes an argument indicating why it is being called. This will be
used so that if a LLD needs to do some extra processing when
handling queue fulls or later ramp ups, it can do so.

This is a simple port of the drivers setting a change_queue_depth
callback. In the patch I just have these LLDs adjust the queue depth
if the user was requesting it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>

[Vasu.Dev: v2
	Also converted pmcraid_change_queue_depth and then verified
all modules compile  using "make allmodconfig" for any new build
warnings on X86_64.

	Updated original description after combing two original
patches from Mike to make this patch git bisectable.]
Signed-off-by: NVasu Dev <vasu.dev@intel.com>
[jejb: fixed up 53c700]
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

The advent of DIF Type 2 devices exposed some missing break statements
in the protection mask switch constructs.  However, rewriting the code
to use an index into a small static array seemed like a more elegant
solution.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

So far we have only issued DIF commands if CONFIG_BLK_DEV_INTEGRITY is
enabled.  However, communication between initiator and target should be
independent of protection information DMA.  There are DIF-only host
adapters coming out that will be able to take advantage of this.

Move the relevant DIF bits to sd.c.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

Attached is the ELS/CT pass-thru patch for the FC Transport. The patch
creates a generic framework that lays on top of bsg and the SGIO v4 ioctl
in order to pass transaction requests to LLDD's.

The interface supports the following operations:
  On an fc_host basis:
    Request login to the specified N_Port_ID, creating an fc_rport.
    Request logout of the specified N_Port_ID, deleting an fc_rport
    Send ELS request to specified N_Port_ID w/o requiring a login, and
      wait for ELS response.
    Send CT request to specified N_Port_ID and wait for CT response.
      Login is required, but LLDD is allowed to manage login and decide
      whether it stays in place after the request is satisfied.
    Vendor-Unique request. Allows a LLDD-specific request to be passed
      to the LLDD, and the passing of a response back to the application.
  On an fc_rport basis:
    Send ELS request to nport and wait for ELS response.
    Send CT request to nport and wait for CT response.

The patch also exports several headers from include/scsi such that
they can be available to user-space applications:
  include/scsi/scsi.h
  include/scsi/scsi_netlink.h
  include/scsi/scsi_netlink_fc.h
  include/scsi/scsi_bsg_fc.h

For further information, refer to the last RFC:
http://marc.info/?l=linux-scsi&m=123436574018579&w=2

Note: Documentation is still spotty and will be added later.

[bharrosh@panasas.com: update for new block API]
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.

Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: NMike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Controllers that support protection information must indicate this to
the SCSI midlayer so that the ULD can prepare scsi_cmnds accordingly.

This patch implements a host mask and various types of protection:

 - DIF Type 1-3 (between HBA and disk)
 - DIX Type 0-3 (between OS and HBA)

The patch also allows the HBA to set the guard type to something
different than the T10-mandated CRC.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Daniel Debonzi reports that he has managed to wrap host_no.  Increasing
the number of host numbers available to 32-bit from 16-bit allows the
problem to be evaded for another hundred years.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Kobjects do not have a limit in name size since a while, so stop
pretending that they do.
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).

- clean-up some code paths that did not expect commands to be
  larger than 16, and change cmd_len members' type to short as
  char is not enough.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

It's big, but there doesn't seem to be a way to split it up smaller...
Signed-off-by: NTony Jones <tonyj@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The problem is that serveral drivers are sending a target reset from the
device reset handler, and if we have multiple devices a target reset gets
sent for each device when only one would be sufficient. And if we do a target
reset it affects all the commands on the target so the device reset handler
code only cleaning up one devices's commands makes programming the driver a
little more difficult than it should be.

This patch adds a target reset handler, which drivers can use to send
a target reset. If successful it cleans up the commands for a devices
accessed through that starget.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Since the sg chaining patches went in, our current value of 255 for
SG_ALL excites chaining on some drivers which cannot support it (and
would thus oops).  Redefine SG_ALL to mean no sg table size
preference, but use the single allocation (non chained) limit.  This
also helps for drivers that use it to size an internal table.

We'll do an opt in system later where truly chaining supporting
drivers can define their sg_tablesize to be anything up to
SCSI_MAX_SG_CHAIN_ELEMENTS.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Small cleanups in scsi_host.h. Few #defines make me wonder if their
description is still up to date..?
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

With the sg table code, every SCSI driver is now either chain capable
or broken (or has sg_tablesize set so chaining is never activated), so
there's no need to have a check in the host template.

Also tidy up the code by moving the scatterlist size defines into the
SCSI includes and permit the last entry of the scatterlist pools not
to be a power of two.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.

- Group all IO members of scsi_cmnd into a scsi_data_buffer
  structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
  scsi_cmnd. And work on it.
- Adjust scsi_init_io() and  scsi_release_buffers() for above
  change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
  accessors where appropriate.

- fix Documentation about scsi_cmnd in scsi_host.h

- scsi_error.c
  * Changed needed members of struct scsi_eh_save.
  * Careful considerations in scsi_eh_prep/restore_cmnd.

- sd.c and sr.c
  * sd and sr would adjust IO size to align on device's block
    size so code needs to change once we move to scsi_data_buff
    implementation.
  * Convert code to use scsi_for_each_sg
  * Use data accessors where appropriate.

- tgt: convert libsrp to use scsi_data_buffer

- isd200: This driver still bangs on scsi_cmnd IO members,
  so need changing

[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This option is true if a low-level driver can support sg
chaining. This will be removed eventually when all the drivers are
converted to support sg chaining. q->max_phys_segments is set to
SCSI_MAX_SG_SEGMENTS if false.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

The pid field is a duplicate of the serial_number field and has been
scheduled for removal for a long time.  A few drivers were still using
it, so just change them to use serial_number instead.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This adds supported_mode and active_mode attributes to
/sys/class/sys_host/hostX/ for specifying the mode that a lld supports
and the currently activated mode. The output format is similar to fc
rport roles:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator
luce:/sys/class/scsi_host/host0$ cat active_mode
Initiator

The mode values uses bitmap since we would support dual-mode llds in
the future like this:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator, Target

The supported_mode attribute looks at a scsi_host_template and the
active_mode attribute looks at a scsi_host. We would add a hook to a
scsi_host_template to change the active_mode attribute
dynamically. But now there is no hook since no lld supports that
feature.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This moves tsk_mgmt_response callback in struct scsi_host_template to
struct scsi_transport_template since struct scsi_transport_template is
more suitable for the task management stuff.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

tgt uses scsi_host as I_T nexus. This works for ibmvstgt because it
creates one scsi_host for one initiator. However, other target drivers
don't work like that.

This adds I_T nexus support, which enable one scsi_host to handle
multiple initiators. New scsi_tgt_it_nexus_create/destroy functions
are expected be called transport classes. For example, ibmvstgt
creates an initiator remote port, then the srp transport calls
tgt_it_nexus_create. tgt doesn't manages I_T nexus, instead it tells
tgtd, user-space daemon, to create a new I_T nexus.

On the receiving the response from tgtd, tgt calls
shost->transportt->it_nexus_response. transports should notify a
lld. The srp transport uses it_nexus_response callback in
srp_function_template to do that.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NKristian Høgsberg <krh@redhat.com>

collapsed with fw-sbp2 patch "Drop cast to non-const char * in host
template initialization." from Kristian Høgsberg
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Currently accessing the scsi host private data is rather messy because
it comes as an unsigned long that always needs a cast first.  This patch
introduces a helper that does the cast called shost_priv.  It's similar
in spirit to netdev_priv for network drivers.

This is the first patch introducing the macro, and the second patch
in the series will convert esp and it's subdrivers as an example.
Further conversion will wait until the helper is in the tree to make
patch juggling easier.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

With libata converted to use sdev->manage_start_stop for suspend and
resume, sht->suspend/resume() has no user left and low level
suspend/ressume should be taken care of by low level driver's
suspend/resume callbacks (e.g. PCI or PCMCIA driver callbacks).  This
patch removes sht->suspend/resume() callbacks.

This change is suggested by Christoph Hellwig.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>