This patch adds two new parameters to the scsi_debug driver.

During various fault injection scenarios it would be useful to be able
to pick a specific starting sector and number of follow on sectors where
a MEDIUM ERROR for reads would be returned against a scsi-debug device.

Right now this only works against sector 0x1234 and OPT_MEDIUM_ERR_NUM
follow on sectors.  However during testing of md-raid and other
scenarios I wanted more flexibility.

The idea is add 2 new parameters:

    medium_error_start
    medium_error_count

If medium_error_start is set then we don't use the default of
OPT_MEDIUM_ERR_ADDR, but use that set value.

If medium_error_count is set we use that value otherwise default to
OPT_MEDIUM_ERR_NUM.
Signed-off-by: NLaurence Oberman <loberman@redhat.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Since commit 64d513ac ("scsi: use host wide tags by default") all
SCSI requests have a tag, whether or not scsi-mq is enabled.

Additionally, it is safe to use blk_mq_unique_tag() and
blk_mq_unique_tag_to_hwq() for legacy SCSI queues. Since this means that
the sdebug_mq_active variable is superfluous, remove it.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Introduce a state enum into sdebug_defer objects to indicate which, if
any, defer method has been used with the associated command.  Also add 2
bools to indicate which of the defer methods has been initialized. Those
objects are re-used but the initialization only needs to be done
once. This simplifies command cancellation handling.

Now the delay associated with a deferred response of a command cannot be
changed (once started) by changing the delay (and ndelay) parameters in
sysfs. Command aborts and driver shutdown are still honoured immediately
when received.

[mkp: applied by hand]
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add resp_write_scat() function to support decoding WRITE SCATTERED
(16 and 32). Also weave resp_write_scat() into the cdb decoding
logic.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Reviewer suggested using the ARRAY_SIZE macro. That reduced one of the subtle
inter-dependencies in the parser's tables.

It is important that commands which simulate media access, indicate this in the
flags for that command. The flag to do that was FF_DIRECT_IO. On reflection
FF_MEDIA_IO seems a more accurate description.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

WRITE SCATTERED needs to take several "bites" out of the data-out buffer.
Expand the do_device_access() function to take a sg_skip argument.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Various cdb masks incorrectly assumed the GROUP NUMBER field
was 5 bits long. It is actually 6 bits long. Correct.
Also fix mask failure (in same byte) to allow DLD0 in READ(16)
and WRITE(16).
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Some of my development tools tend to add spaces (my preference) rather
than tabs (kernel convention). Running unexpand to clean these spaces
up found more of them than checkpatch.pl did. Then checkpatch.pl
complained about other style violations in those newly tabbed lines.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Although it is important to be able to trigger the code in the SCSI core
for SCSI_MLQUEUE_HOST_BUSY handling, currently it is nontrivial to
trigger that code. Hence this patch that adds a new error injection
option to the scsi_debug driver for making the .queue_rq()
implementation of this driver return SCSI_MLQUEUE_HOST_BUSY.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

While testing "sd: Micro-optimize READ / WRITE CDB encoding" patches it
was helpful to check various code paths associated with READ/WRITE 6, 10
and 16 byte cdb variants. There seems to be no user space "knobs" to
twiddle use_10_for_rw and friends in the scsi_device structure.  So add
a parameter to scsi_debug called "cdb_len" for this purpose.

[mkp: fixed typo]
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There is no need to go through an intermediate timespec to convert to
ktime_t when we just want a simple multiplication. This gets rid of one
of the few users of jiffies_to_timespec, which I hope to remove as part
of the y2038 cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The scsi_debug driver incorrectly suggests there is an error with the
SCSI WRITE SAME command when the number_of_logical_blocks is greater
than 1. It will also suggest there is an error when NDOB
(no data-out buffer) is set and the number_of_logical_blocks is
greater than 0. Both are valid, fix.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For testing purposes we need to be able to pass in the inquiry vendor
and model.
Signed-off-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bart.vanassche@wdc.com>
Acked-by: NDoug Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

First, number of CPUs can't be negative number.

Second, different signnnedness leads to suboptimal code in the following
cases:

1)
	kmalloc(nr_cpu_ids * sizeof(X));

"int" has to be sign extended to size_t.

2)
	while (loff_t *pos < nr_cpu_ids)

MOVSXD is 1 byte longed than the same MOV.

Other cases exist as well. Basically compiler is told that nr_cpu_ids
can't be negative which can't be deduced if it is "int".

Code savings on allyesconfig kernel: -3KB

	add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370)
	function                                     old     new   delta
	coretemp_cpu_online                          450     512     +62
	rcu_init_one                                1234    1272     +38
	pci_device_probe                             374     399     +25

				...

	pgdat_reclaimable_pages                      628     556     -72
	select_fallback_rq                           446     369     -77
	task_numa_find_cpu                          1923    1807    -116

Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch avoids that gcc reports the following warning when
building with W=1:

drivers/scsi/scsi_debug.c:2264:15: warning: variable ?pcontrol? set but not used [-Wunused-but-set-variable]
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAmir Goldstein <amir73il@gmail.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

It was not possible to enable both T10 PI and TPGS because they share
the same byte in the INQUIRY response. Logically OR the TPGS value
instead of using assignment.
Reported-by: NRitika Srivastava <ritika.srivastava@oracle.com>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

[mkp: whitespace fixes]
Signed-off-by: NLukas Herbolt <lherbolt@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

map_storep was not being vfree()'d in the module_exit call.

Cc: <stable@vger.kernel.org>
Signed-off-by: NEwan D. Milne <emilne@redhat.com>
Reviewed-by: NLaurence Oberman <loberman@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

These should go together with the rest of the T10 protection information
defintions.

[mkp: s/T10_DIF/T10_PI/]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

And remove the declaration of the latter in sd.h as scsi_debug was the
only user.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

In this post: http://www.spinics.net/lists/linux-scsi/msg97124.html the
author shows some kernel infrastructure complaining about a sleep in an
invalid context. Remove offending call to vmalloc().  Instead of using
kzalloc() which reviewers didn't like, use a bucket system (64 bytes on
the stack) and potentially multiple calls to sg_pcopy_from_buffer() to
construct the 'data-in' buffer for the SCSI REPORT LUNS command.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

For reported SAS addresses replace fake IEEE registered NAAs (5) with
locally assigned NAAs (3).
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Permit changing of a LU name from a (fake) IEEE registered NAA (5) to a
locally assigned UUID. Using a UUID (RFC 4122) for a SCSI designation
descriptor (e.g. a LU name) was added in spc5r08.pdf (a draft INCITS
standard) on 25 January 2016. Add parameter uuid_ctl to use a separate
UUID for each LU (storage device) name.  Additional option for all LU
names to have the same UUID (since their storage is shared). Previous
action of using NAA identifier for LU name remains the default.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Cleanup some mode and vpd pages. Stop reporting SBC (disk) pages when
peripheral type is something else (e.g. tape). Update version
descriptors. Expand LBPRZ flag handling.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add submit_queue parameter (minimum and default: 1; maximum: nr_cpu_ids)
that controls how many queues are built, each with their own lock and
in_use bit vector. Add statistics parameter which is default off.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Based on "[PATH V2] scsi_debug: rework resp_report_luns" patch
sent by Tomas Winkler on Thursday, 26 Feb 2015. His notes:
  1. Remove duplicated boundary checks which simplify the fill-in
     loop
  2. Use more of scsi generic API
Replace fixed length response array a with heap allocation
allowing up to 256 normal LUNs per target.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Reviewed-by: NTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use TYPE_* constants for SCSI peripheral device types instead of
numbers. Further cleanups requested by checkpatch.pl.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The most common commands in normal use are the READ and WRITE SCSI
commands. Use likely and unlikely hints along the path taken by these
commands. Rename check_readiness() to make_ua() and remove associated
dead code. Rename devInfoReg() to find_build_dev_info().
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Group most defines together first; followed by struct definitions and
then table and variable definitions. Normalize all function headers.

[mkp: Corrected hex value in WP/DPOFUA MODE SENSE comment]
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When a negative value was placed in the delay parameter, a tasklet was
scheduled. Change the tasklet to a work queue. Previously a delay of -1
scheduled a high priority tasklet; since there are no high priority work
queues, treat -1 like other negative values in delay and schedule a work
item.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Add 'j' to delay names to make it clearer that its unit is jiffies and
to differentiate it from sdebug_ndelay whose unit is nanoseconds.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The driver supports two command delay interfaces, the original one whose
unit is a jiffy, and a newer one whose unit is a nanosecond. Each had
different implementations.  Keep both interfaces but simplify the
implemenation to use a single delay mechanism based on high resolution
timers.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove logic to optionally hold host_lock while each command is
queued. Keep module and sysfs host_lock parameters for backward
compatibility. Note in module parameter description that host_lock is
ignored.
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Shorten file scope static and constant names. Use more
get/put_unaligned calls to hide bit banging. Introduce
sdebug_verbose boolean to replace frequent masking of
option bit flags. Add GPL and bump version.

[mkp: Use logical instead of bitwise OR for LBP VPD flags]
Signed-off-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Rename SCSI_MAX_SG_SEGMENTS to SG_CHUNK_SIZE, which means the amount
we fit into a single scatterlist chunk.

Rename SCSI_MAX_SG_CHAIN_SEGMENTS to SG_MAX_SEGMENTS.

Will move these 2 generic definitions to scatterlist.h later.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Acked-by: Bart Van Assche <bart.vanassche@sandisk.com> (for ib_srp changes)
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Acked-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The OPTIMAL TRANSFER LENGTH reported by scsi_debug is 64 blocks which
translates to 32KB with the default logical block size. That's much
lower than what real storage devices typically report (256KB to 1MB).

Bump the optimal transfer length to 1024 blocks.
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Even for signed types we have to check for bigger positive value first.
Otherwise it will be never happened.
Signed-off-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NEwan Milne <emilne@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

do_div is the wrong way to divide a sector_t, as it is less efficient
when sector_t is 32-bit wide. With the upcoming do_div optimizations,
the kernel starts warning about this:

drivers/scsi/scsi_debug.c: In function 'dif_store':
include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast

This changes the code to use sector_div instead, which always produces
optimal code.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NHannes Reinicke <hare@suse.de>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>