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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

This function shouldn't change the queue type, just the depth.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Unless we want to build a SPI tag message we should just check SCMD_TAGGED
instead of reverse engineering a tag type through the use of
scsi_populate_tag_msg.

Also rename the function to spi_populate_tag_msg, make it behave like the
other spi message helpers, and move it to the spi transport class.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Remove the ordered_tags field, we haven't been issuing ordered tags based
on it since the big barrier rework in 2010.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently scsi piggy backs on the block layer to define the concept
of a tagged command.  But we want to be able to have block-level host-wide
tags assigned even for untagged commands like the initial INQUIRY, so add
a new SCSI-level flag for commands that are tagged at the scsi level, so
that even commands without that set can have tags assigned to them.  Note
that this alredy is the case for the blk-mq code path, and this just lets
the old path catch up with it.

We also set this flag based upon sdev->simple_tags instead of the block
queue flag, so that it is entirely independent of the block layer tagging,
and thus always correct even if a driver doesn't use block level tagging
yet.

Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and
removing it forces them to look for the proper replacement.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

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

Move all code to set up and tear down sdev->scsi_dh_data to common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

All drivers now do their own matching, so there is no more need to expose
a device list as part of the interface.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

We need to grab a reference to the module before calling the attach
routines to avoid a small race vs module removal.  It also cleans up
the code significantly as a side effect.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

The T10 SBC UNMAP command does not provide any hard guarantees that
blocks will return zeroes on a subsequent READ. This is due to the fact
that the device server is free to silently ignore all or parts of the
request.

The only way to ensure that a block consistently returns zeroes after
being unmapped is to use WRITE SAME with the UNMAP bit set. Should the
device be unable to unmap one or more blocks described by the command it
is required to manually write zeroes to them.

Until now we have preferred UNMAP over the WRITE SAME variants to
accommodate thinly provisioned devices that predated the final SBC-3
spec. This patch changes the heuristic so that we favor WRITE SAME(16)
or (10) over UNMAP if these commands are marked as supported in the
Logical Block Provisioning VPD page.

The patch also disables discard_zeroes_data for devices operating in
UNMAP mode.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

No need to verify the passthrough ioctls, the real handler will
take care of that.  Also make sure not to block for resets on
O_NONBLOCK fds.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

The calling conventions for this function are bad as it could return
-ENODEV both for a device not currently online and a not recognized ioctl.

Add a new scsi_ioctl_block_when_processing_errors function that wraps
scsi_block_when_processing_errors with the a special case for the
SG_SCSI_RESET ioctl command, and handle the SG_SCSI_RESET case itself
in scsi_ioctl.  All callers of scsi_ioctl now must call the above helper
to check for the EH state, so that the ioctl handler itself doesn't
have to.
Reported-by: Robert Elliott <Elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Pull the common code from the two callers into the function,
and rename it to scsi_ioctl_reset.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

Modify scsi_find_tag() and scsi_host_find_tag() such that these
functions can translate a tag generated by blk_mq_unique_tag().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Allow a SCSI LLD to declare how many hardware queues it supports
by setting Scsi_Host.nr_hw_queues before calling scsi_add_host().
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The queuecommand() callback functions in SCSI low-level drivers
need to know which hardware context has been selected by the
block layer. Since this information is not available in the
request structure, and since passing the hctx pointer directly to
the queuecommand callback function would require modification of
all SCSI LLDs, add a function to the block layer that allows to
query the hardware context index.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

There can be quite a lot of I/O error messages, even on smaller
machines. So we need to ratelimit them to not overwhelm logging.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The .eh_abort_handler needs to return SUCCESS, FAILED, or
FAST_IO_FAIL. So fixup all callers to adhere to this requirement.
Reviewed-by: Robert Elliott <elliott@hp.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi_try_to_abort_cmd() should only return SUCCESS, FAILED, or
FAST_IO_FAIL. So document that in the function description and simplify
the logging message.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The EH statistics are per host, so we should be using
shost_printk() here.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Suggested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use the matching scope for logging messages to allow for
better command tracing.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Suggested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Simplify scsi_log_(send|completion) by externalizing
scsi_mlreturn_string() and always print the command address.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Open-code scsi_print_result in sd.c, and cleanup logging to
not print duplicate informations.
Also remove the call to scsi_show_result() in ufshcd.c
to be consistent with other callers of scsi_execute().

With that we can remove scsi_show_result in constants.c
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Export functions for later use.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Calling scsi_print_command should not be necessary during abort;
if the information is required one should enable scsi logging.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

print_opcode_name() was only ever called with a '0' argument
from LLDDs and ULDs which were _not_ supporting variable length
CDBs, so the 'if' clause was never triggered.
Instead we should be using the last argument to specify
the cdb length to avoid accidental overflow when reading
the cdb buffer.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Consolidate the CDB opcode lookup in scsi_opcode_sa_name(),
so that we don't have to call several functions to figure
out the CDB opcode string.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Instead of having two versions of print_opcode_name() we
should be consolidating them into one version.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Implement a lookup array for SERVICE ACTION commands instead
of hardcoding it in a large switch statement.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Last caller is gone, so we can remove it.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Convert scsi_normalize_sense() and friends to return 'bool'
instead of an integer.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Yoshihiro Yunomae <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>