Fixes the following warning

In function ‘resp_requests’:
drivers/scsi//scsi_debug.c:1432:15: warning: variable ‘want_dsense’ set
but not used [-Wunused-but-set-variable]
  bool dsense, want_dsense;
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The use case to report 'REPORT LUNS WLUN' described
in scsi_debug documentation didn't work because:
scsi_scan_host_selected() checks for:
	 lun < shost->max_lun

To fix this we set:
	max_lun = SCSI_W_LUN_REPORT_LUNS + 1;
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The function should never be called with cmnd NULL so
put a fat WARN there.
Fix also smatch wraning:
schedule_resp() warn: variable dereferenced before check 'cmnd'
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

fixes warning:
warning: no previous prototype for ‘dump_sector’
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

use SCSI_W_LUN_REPORT_LUNS from scsi.h instead of localy defined
SAM2_WLUN_REPORT_LUNS
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Use pr_fmt with both module name and __func__
Also drop few bare printk leftovers

The log format should stay pretty much intact
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

do_device_access() takes a separate parameter to indicate the direction of
data transfer, which it used to use to select the appropriate function out
of sg_pcopy_{to,from}_buffer().  However these two functions now have

So this patch makes it bypass these wrappers and call the underlying
function sg_copy_buffer() directly; this has the same calling style as
do_device_access() i.e.  a separate direction-of-transfer parameter and no
pointers-to-const, so skipping the wrappers not only eliminates the
warning, it also make the code simpler :)

[akpm@linux-foundation.org: fix very broken build]
Signed-off-by: NDave Gordon <david.s.gordon@intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

* map_show()'s return value is too high by one and the function could
  modify beyond the end of the buffer when the formatted text is long
  enough.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

cppcheck found the following issue:
(warning) Logical conjunction always evaluates to false:
  alloc_len < 4 && alloc_len > 65535.

..the test should be instead:

  if (alloc_len < 4 || alloc_len > 65536)

This error was introduced by recent commit 38d5c833
("scsi_debug: add Report supported opcodes+tmfs; Compare and write")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

resp_rsup_opcodes() may get called from atomic context and would need to
use GFP_ATOMIC for allocations:

[ 1237.913419] BUG: sleeping function called from invalid context at mm/slub.c:1262
[ 1237.914865] in_atomic(): 1, irqs_disabled(): 0, pid: 7556, name: trinity-c311
[ 1237.916142] 3 locks held by trinity-c311/7556:
[ 1237.916981] #0: (sb_writers#5){.+.+.+}, at: do_readv_writev (include/linux/fs.h:2346 fs/read_write.c:844)
[ 1237.919713] #1: (&of->mutex){+.+.+.}, at: kernfs_fop_write (fs/kernfs/file.c:297)
[ 1237.922626] Mutex: counter: -1 owner: trinity-c311
[ 1237.924044] #2: (s_active#51){.+.+.+}, at: kernfs_fop_write (fs/kernfs/file.c:297)
[ 1237.925960] Preemption disabled blk_execute_rq_nowait (block/blk-exec.c:95)
[ 1237.927416]
[ 1237.927680] CPU: 24 PID: 7556 Comm: trinity-c311 Not tainted 3.19.0-rc4-next-20150116-sasha-00054-g4ad498c-dirty #1744
[ 1237.929603]  ffff8804fc9d8000 ffff8804d9bc3548 ffffffff9d439fb2 0000000000000000
[ 1237.931097]  0000000000000000 ffff8804d9bc3588 ffffffff9a18389a ffff8804d9bc3598
[ 1237.932466]  ffffffff9a1b1715 ffffffffa15935d8 ffffffff9e6f8cb1 00000000000004ee
[ 1237.933984] Call Trace:
[ 1237.934434] dump_stack (lib/dump_stack.c:52)
[ 1237.935323] ___might_sleep (kernel/sched/core.c:7339)
[ 1237.936259] ? mark_held_locks (kernel/locking/lockdep.c:2549)
[ 1237.937293] __might_sleep (kernel/sched/core.c:7305)
[ 1237.938272] __kmalloc (mm/slub.c:1262 mm/slub.c:2419 mm/slub.c:2491 mm/slub.c:3291)
[ 1237.939137] ? resp_rsup_opcodes (include/linux/slab.h:435 drivers/scsi/scsi_debug.c:1689)
[ 1237.940173] resp_rsup_opcodes (include/linux/slab.h:435 drivers/scsi/scsi_debug.c:1689)
[ 1237.941211] ? add_host_store (drivers/scsi/scsi_debug.c:1584)
[ 1237.942261] scsi_debug_queuecommand (drivers/scsi/scsi_debug.c:5276)
[ 1237.943404] ? blk_rq_map_sg (block/blk-merge.c:254)
[ 1237.944398] ? scsi_init_sgtable (drivers/scsi/scsi_lib.c:1095)
[ 1237.945402] sdebug_queuecommand_lock_or_not (drivers/scsi/scsi_debug.c:5300)
[ 1237.946735] scsi_dispatch_cmd (drivers/scsi/scsi_lib.c:1706)
[ 1237.947720] scsi_queue_rq (drivers/scsi/scsi_lib.c:1996)
[ 1237.948687] __blk_mq_run_hw_queue (block/blk-mq.c:816)
[ 1237.949796] blk_mq_run_hw_queue (block/blk-mq.c:896)
[ 1237.950903] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:154 kernel/locking/spinlock.c:183)
[ 1237.951862] blk_mq_insert_request (block/blk-mq.c:1037)
[ 1237.952876] blk_execute_rq_nowait (block/blk-exec.c:95)
[ 1237.953981] ? lockdep_init_map (kernel/locking/lockdep.c:3034)
[ 1237.954967] blk_execute_rq (block/blk-exec.c:131)
[ 1237.955929] ? blk_rq_bio_prep (block/blk-core.c:2835)
[ 1237.956913] scsi_execute (drivers/scsi/scsi_lib.c:252)
[ 1237.957821] scsi_execute_req_flags (drivers/scsi/scsi_lib.c:281)
[ 1237.958968] scsi_report_opcode (drivers/scsi/scsi.c:956)
[ 1237.960009] sd_revalidate_disk (drivers/scsi/sd.c:2707 drivers/scsi/sd.c:2792)
[ 1237.961139] revalidate_disk (fs/block_dev.c:1081)
[ 1237.962223] sd_rescan (drivers/scsi/sd.c:1532)
[ 1237.963142] scsi_rescan_device (drivers/scsi/scsi_scan.c:1579)
[ 1237.964165] store_rescan_field (drivers/scsi/scsi_sysfs.c:672)
[ 1237.965254] dev_attr_store (drivers/base/core.c:138)
[ 1237.966319] sysfs_kf_write (fs/sysfs/file.c:131)
[ 1237.967289] kernfs_fop_write (fs/kernfs/file.c:311)
[ 1237.968274] do_readv_writev (fs/read_write.c:722 fs/read_write.c:854)
[ 1237.969295] ? __acct_update_integrals (kernel/tsacct.c:145)
[ 1237.970452] ? kernfs_fop_open (fs/kernfs/file.c:271)
[ 1237.971505] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:154 kernel/locking/spinlock.c:183)
[ 1237.972512] ? context_tracking_user_exit (include/linux/vtime.h:89 include/linux/jump_label.h:114 include/trace/events/context_tracking.h:47 kernel/context_tracking.c:140)
[ 1237.973668] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2578 kernel/locking/lockdep.c:2625)
[ 1237.974882] ? trace_hardirqs_on (kernel/locking/lockdep.c:2633)
[ 1237.975850] vfs_writev (fs/read_write.c:893)
[ 1237.976691] SyS_writev (fs/read_write.c:926 fs/read_write.c:917)
[ 1237.977538] system_call_fastpath (arch/x86/kernel/entry_64.S:423)
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Accept the WRITE BUFFER command and do nothing other than
set the appropriate "microcode has been changed" UA on the LU.

>From an earlier patch by Doug Gilbert.
Signed-off-by: NEwan D. Milne <emilne@redhat.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Generate a REPORTED LUNS DATA HAS CHANGED Unit Attention if
sysfs "max_luns" is used to change the number of scsi_debug LUNs.
This is only done if scsi_debug_scsi_level is SPC-3 or above.
Additionally, implement SPC-4 behavior which only generates
this Unit Attention on the first LUN on the target to receive
a command after the change.  This condition is cleared when
a REPORT LUNS command is received.
Signed-off-by: NEwan D. Milne <emilne@redhat.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Tested-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This eliminates a superfluous log message when the capacity is changed:

  "check_readiness: unexpected unit attention code=3"
Signed-off-by: NEwan D. Milne <emilne@redhat.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

All other traversals of the sdebug_host_list take the lock.
Signed-off-by: NEwan D. Milne <emilne@redhat.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Kernel build tools pointed out a memory leak so that has been
fixed and its error paths strengthened with a goto. Testing
showed compare and write was only working for lba=0; correcting
the length of the LBA field fixed that.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

For SPI drivers use the message definitions from scsi.h, and for target
drivers introduce a new TCM_*_TAG namespace.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com

Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete.  The other function
of enabling/disabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
Reviewed-by: NHannes Reinecke <hare@suse.de>

The Report supported operation codes command is very closely integrated
into the table driven parser and very useful for testing it. Its cdb
masks form the basis of the 'strict' parameter's checks. The Report
supported TMFs command is a simple extension. The Compare and write
command may even be useful, as it should be atomic due to the read-write
lock that the driver uses on its backing store (ram).
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The existing 'big switch' parser in queuecommand() is changed to
a table driven parser. The old and new queuecommand() were moved
in the source so diff would not shuffle them. Apart from the new
tables most other changes are refactoring existing response code
to be more easily called out of the table parser. The 'strict'
parameter is added so that cdb_s can be checked for non-zero
values in parts of the cdb that are reserved. Some other changes
include: tweak request sense response when D_SENSE differs; support
NDOB in Write Same(16); and fix crash in Get LBA Status when LBP
was inactive.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Via sysfs the virtual_gb scsi_debug parameter can be changed while
LUs are in use. If that changes, the 'Capacity data has changed'
Unit Attention is queued on all LUs.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The way the existing scsi_debug command parser associated various
inject error flags to a command was difficult to replicate in the
table driven parser. This patch adds infrastructure to append those
flags to the end of a scsi_cmnd object with the cmd_size host
template option.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use Sense Key Specific field in the sense data of an ILLEGAL REQUEST
to optionally pinpoint the location of the problem field. This may
be either in the cdb or the associated parameter list.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

SPC-3 defines SERVICE ACTION IN(12) and SERVICE ACTION IN(16).
So rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16 to be
consistent with SPC and to allow for better distinction.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Tested-by: NRobert Elliott <elliott@hp.com>
Reviewed-by: NRobert Elliott <elliott@hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NVenkatesh Srinivas <venkateshs@google.com>

Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Now that we also get proper values in cmd->request->tag for untagged
commands, there is no need to force tagged_supported to on in drivers
that need host-wide tags.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>

Most drivers use exactly the same implementation, so provide it as a
library function.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NMike Christie <michaelc@cs.wisc.edu>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A deadlock has been reported when the completion
of SCSI commands (simulated by a timer) was surprised
by a module removal. This patch removes one half of
the offending locks around timer deletions. This fix
is applied both to stop_all_queued() which is were
the deadlock was discovered and stop_queued_cmnd()
which has very similar logic.

This patch should be applied both to the lk 3.17 tree
and Christoph's drivers-for-3.18 tree.
Tested-and-reported-by: NMilan Broz <gmazyland@gmail.com>
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Since a lot of functionality from SPC-4 is supported by this
driver (e.g. LBP and PI) then bump the default INQUIRY version
from SPC-3 to SPC-4. Also update the INQUIRY version
descriptors.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Give existing errors priority over the generation of Task
Set Full (TSF) errors. So that max_queue is not exceeded,
existing errors may be sent back in the invocation thread.
This is done so errors like Unit Attentions are not hidden
and lost by either max_queue exceeded or real/injected
TSFs.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This patch removes a NULL check for the scsi_cmnd::cmnd pointer
since many other instances in this driver and elsewhere assume
it is valid. Also redundant casts to 'unsigned char *' are removed
as the pointer has that type.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

 - add host_lock option whose default value is 0 which removes the
   host_lock around all queued commands
 - accept delay=-1 (_hi_) or -2 which use a tasklet to invoke
   the scsi_done callback into the mid-layer. The default
   is still delay=1 which uses a timer to delay 1 jiffy
 - wire .change_queue_depth and .change_queue_type
   functions to better simulate queueing in a modern LLD
 - add SCSI_DEBUG_OPT_Q_NOISE (0x200) mask to only produce
   debug output associated with queue full, plus from
   .change_queue_depth and .change_queue_type functions
 - add SCSI_DEBUG_OPT_ALL_TSF (0x400) mask which reports
   all queued_arr fulls at TASK_SET_FULL, otherwise
   SCSI_MLQUEUE_HOST_BUSY is returned
 - add SCSI_DEBUG_OPT_RARE_TSF (0x800) mask which works
   together with the every_nth option (> 0) to count
   occurrences of num_in_q==queue_depth. When every_nth
   is reached the victim (a command) yields TASK SET FULL
 - clean up many debug messages.
 - add ndelay=<nanosecs> option that uses high resolution
   timers; active if > 0 and then overrides delay= option
 - expand Unit Attention handling: POR, BUS_RESET and
   MODE PARAMETERS CHANGED
 - support .eh_target_reset_handler and drop .bios_param
 - add OPT_N_WCE mask so caching page yields WCE=0
 - add OPT_RESET_NOISE mask to log aborts and resets
 - add OPT_NO_CDB_NOISE mask to not log each cdb
 - MODE SELECT support for changing caching page's WCE
 - name common ioctls in log
 - when fake_rw=1, do not vmalloc fake store; make
   UNMAP and WRITE SAME obey fake_rw
 - more logging and code improvements including better
   sense buffer handling

With fio and four (pseudo) devices I have observed 1.2 M IOPS
on my equipment. Rob Elliott who has done much testing and made
numerous suggestions, has better IOPS results than mine.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NRobert Elliott <elliott@hp.com>
Tested-by: NRobert Elliott <elliott@hp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This change enables to test read/write commands with huge transfer
length such as 1GB.  For example:

	# modprobe scsi_debug dev_size_mb=1024 clustering=1 opts=1
	# cat /sys/block/$DEV/queue/max_hw_sectors_kb > \
		/sys/block/$DEV/queue/max_sectors_kb
	# fio --name=test --rw=write --bs=1g --size=1g --filename=/dev/$DEV \
		--mem=mmaphuge  --direct=1

The data type of max_sectors in scsi_host_template has been extended
to unsigned int by the previous change.  So we can increase it from
0xffff to 0xffffffff to allow such huge transfer length.

Also, this increases sg_tablesize and max_segment_size, otherwise the
maximum transfer length is limited to 64MB.
(sg_tablesize * max_segment_size = 256 * 256KB)
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Acked by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add an option to only transfer half the data for every n-th command.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NNicholas Bellinger <nab@linux-iscsi.org>

This adds a module parameter to enable clustering.

Without enabling clustering support, the transfer length for read and
write scsi commands is limited upto 8MB when page size is 4KB and
sg_tablesize is 2048 (= SCSI_MAX_SG_CHAIN_SEGMENTS).  I would like to
test commands with more than that transfer length.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>