scsi: core: Remove the cmd field from struct scsi_request

Now that each scsi_request is backed by a scsi_cmnd, there is no need to
indirect the CDB storage. Change all submitters of SCSI passthrough
requests to store the CDB information directly in the scsi_cmnd, and while
doing so allocate the full 32 bytes that cover all Linux supported SCSI
hosts instead of requiring dynamic allocation for > 16 byte CDBs. On
64-bit systems this does not change the size of the scsi_cmnd at all, while
on 32-bit systems it slightly increases it for now, but that increase will
be made up by the removal of the remaining scsi_request fields.

Link: https://lore.kernel.org/r/20220224175552.988286-4-hch@lst.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Introduce enum scsi_disposition

Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: save/restore command resid for error handling

When a non-passthrough command is terminated with CHECK CONDITION, request
sense is executed by hijacking the command descriptor. Since
scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() do not save/restore the
original command resid, the value returned on failure of the original
command is lost and replaced with the value set by the execution of the
request sense command. This value may in many instances be unaligned to the
device sector size, causing sd_done() to print a warning message about the
incorrect unaligned resid before the command is retried.

Fix this problem by saving the original command residual in struct
scsi_eh_save using scsi_eh_prep_cmnd() and restoring it in
scsi_eh_restore_cmnd(). In addition, to make sure that the request sense
command is executed with a correctly initialized command structure, also
reset the residual to 0 in scsi_eh_prep_cmnd() after saving the original
command value in struct scsi_eh_save.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191001074839.1994-1-damien.lemoal@wdc.com
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove bidirectional command support

No real need for bidi support once the OSD code is gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: Improve scsi_get_sense_info_fld

Use get_unaligned_be32 and get_unaligned_be64 to obtain values from the
sense buffer instead of open coding the operations. Also change the
function return value to a bool and fix the function signature
declaration to remove spaces triggering checkpatch warnings.

No functional change is introduced by this patch.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: make eh_eflags persistent

If a failed command is retried and fails again we need
to enter SCSI EH, otherwise we will never be able to
recover the command.
To detect this situation we must not clear scmd->eh_eflags
when EH finishes but rather make it persistent throughout
the lifetime of the command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libata: evaluate SCSI sense code

Whenever a sense code is set it would need to be evaluated to
update the error mask.

tj: Cosmetic formatting updates.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

Revert "libata-eh: Set 'information' field for autosense"

This reverts commit a1524f226a02aa6edebd90ae0752e97cfd78b159.

As implemented, ACS-4 sense reporting for ATA devices bypasses error
diagnosis and handling in libata degrading EH behavior significantly.
Revert the related changes for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org #v4.1+

scsi: Move sense handling routines to scsi_common

Sense data handling is also done in the target stack.
Hence, move sense handling routines to scsi_common so
the target will be able to use them as well.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Move code that is used both by initiator and target drivers

Move the functions that are used by both the initiator and target
subsystems into scsi_common.c/.h. This change will allow to remove
the initiator SCSI header include directives from most SCSI target
source files in a later patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

libata-eh: Set 'information' field for autosense

If NCQ autosense or the sense data reporting feature is enabled
the LBA of the offending command should be stored in the sense
data 'information' field.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: refactor scsi_reset_provider handling

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>

scsi: use 'bool' as return value for scsi_normalize_sense()

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>

scsi: use sdev as argument for sense code printing

We should be using the standard dev_printk() variants for
sense code printing.

[hch: remove __scsi_print_sense call in xen-scsiback, Acked by Juergen]
[hch: folded bracing fix from Dan Carpenter]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: add SG_SCSI_RESET_NO_ESCALATE flag to SG_SCSI_RESET ioctl

Further to a January 2013 thread titled: "[PATCH] SG_SCSI_RESET ioctl
should only perform requested operation" by Jeremy Linton a patch (v3)
is presented that expands the existing ioctl to include "no_escalate"
versions to the existing resets. This requires no changes to SCSI low
level drivers (LLDs); it adds several more finely tuned reset options
to the user space. For example:

/* This call remains the same, with the same escalating semantics
* if the device (LU) reset fail. That is: on failure to try a
* target reset and if that fails, try a bus reset, and if that fails
* try a host (i.e. LLD) reset. */
val = SG_SCSI_RESET_DEVICE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);

/* What follows is a new option introduced by this patch series. Only
* a device reset is attempted. If that fails then an appropriate
* error code is provided. N.B. There is no reset escalation. */
val = SG_SCSI_RESET_DEVICE | SG_SCSI_RESET_NO_ESCALATE;
res = ioctl(<sg_or_block_fd>, SG_SCSI_RESET, &val);

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Jeremy Linton <jlinton@tributary.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

[SCSI] scsi_eh_prep_cmnd should save scmd->underflow

This patch (as1116) fixes a bug in scsi_eh_prep_cmnd() and
scsi_eh_restore_cmnd(). These routines are supposed to save any
values they change and restore them later, but someone forgot to
save & restore scmd->underflow.

This fixes part of the problem reported in Bugzilla #9638.

[jejb: fix up rejections around DIF/DIX]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Command protection operation

Controllers that support DMA of protection information must be told
explicitly how to handle the I/O. The controller has no knowledge of
the protection capabilities of the target device so this information
must be passed in the scsi_cmnd.

- The protection operation tells the HBA whether to generate, strip or
verify protection information.

- The protection type tells the HBA which layout the target is
formatted with. This is necessary because the controller must be
able to correctly interpret the included protection information in
order to verify it.

- When a scsi_cmnd is reused for error handling the protection
operation must be cleared and saved while error handling is in
progress.

- prot_op and prot_type are placed in an existing hole in scsi_cmnd
and don't cause the structure to grow.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Let scsi_cmnd->cmnd use request->cmd buffer

- struct scsi_cmnd had a 16 bytes command buffer of its own.
This is an unnecessary duplication and copy of request's
cmd. It is probably left overs from the time that scsi_cmnd
could function without a request attached. So clean that up.

- Once above is done, few places, apart from scsi-ml, needed
adjustments due to changing the data type of scsi_cmnd->cmnd.

- Lots of drivers still use MAX_COMMAND_SIZE. So I have left
that #define but equate it to BLK_MAX_CDB. The way I see it
and is reflected in the patch below is.
MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
as per the SCSI standard and is not related
to the implementation.
BLK_MAX_CDB. - The allocated space at the request level

- I have audit all ISA drivers and made sure none use ->cmnd in a DMA
Operation. Same audit was done by Andi Kleen.

(*)fixed-length here means commands that their size can be determined
by their opcode and the CDB does not carry a length specifier, (unlike
the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
true and the SCSI standard also defines extended commands and
vendor specific commands that can be bigger than 16 bytes. The kernel
will support these using the same infrastructure used for VARLEN CDB's.
So in effect MAX_COMMAND_SIZE means the maximum size command
scsi-ml supports without specifying a cmd_len by ULD's

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add scsi_build_sense_buffer helper function

This adds scsi_build_sense_buffer, a simple helper function to build
sense data in a buffer.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_error: add target reset handler

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: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] bidirectional command support

At the block level bidi request uses req->next_rq pointer for a second
bidi_read request.
At Scsi-midlayer a second scsi_data_buffer structure is used for the
bidi_read part. This bidi scsi_data_buffer is put on
request->next_rq->special. Struct scsi_cmnd is not changed.

- Define scsi_bidi_cmnd() to return true if it is a bidi request and a
second sgtable was allocated.

- Define scsi_in()/scsi_out() to return the in or out scsi_data_buffer
from this command This API is to isolate users from the mechanics of
bidi.

- Define scsi_end_bidi_request() to do what scsi_end_request() does but
for a bidi request. This is necessary because bidi commands are a bit
tricky here. (See comments in body)

- scsi_release_buffers() will also release the bidi_read scsi_data_buffer

- scsi_io_completion() on bidi commands will now call
scsi_end_bidi_request() and return.

- The previous work done in scsi_init_io() is now done in a new
scsi_init_sgtable() (which is 99% identical to old scsi_init_io())
The new scsi_init_io() will call the above twice if needed also for
the bidi_read command. Only at this point is a command bidi.

- In scsi_error.c at scsi_eh_prep/restore_cmnd() make sure bidi-lld is not
confused by a get-sense command that looks like bidi. This is done
by puting NULL at request->next_rq, and restoring.

[jejb: update to sg_table and resolve conflicts
also update to blk-end-request and resolve conflicts]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] implement scsi_data_buffer

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: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] include linux/scatterlist.h in scsi_eh.h

Spotted by Paul Jackson <pj@sgi.com>

The error handler rework moved the scatterlist into a globally exposed
structure in scsi_eh.h; unfortunately, the scatterlist include needs
to move from scsi_error.c to scsi_eh.h to allow this to compile
universally.

Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] scsi_error: Refactoring scsi_error to facilitate in synchronous REQUEST_SENSE

- Drivers/transports that want to send a synchronous REQUEST_SENSE command
as part of their .queuecommand sequence, have 2 new API's that facilitate
in doing so and abstract them from scsi-ml internals.

void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
struct scsi_eh_save *sesci, unsigned char *cmnd,
int cmnd_size, int sense_bytes)

Will hijack a command and prepare it for request sense if needed.
And will save any later needed info into a scsi_eh_save structure.

void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *sesci);

Will undo any changes done to a command by above function. Making
it ready for completion.

- Re-factor scsi_send_eh_cmnd() to use above APIs

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] remove scsi_request infrastructure

With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now. Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] SCSI: make scsi_implement_eh() generic API for SCSI transports

libata implemented a feature to schedule EH without an associated EH
by manipulating shost->host_eh_scheduled in ata_scsi_schedule_eh()
directly. Move this function to scsi_error.c and rename it to
scsi_schedule_eh(). It is now an exported API for SCSI transports and
exported via new header file drivers/scsi/scsi_transport_api.h

This patch also de-export scsi_eh_wakeup() which was exported
specifically for ata_scsi_schedule_eh().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

[PATCH] SCSI: implement shost->host_eh_scheduled

libata needs to invoke EH without scmd. This patch adds
shost->host_eh_scheduled to implement such behavior.

Currently the only user of this feature is libata and no general
interface is defined. This patch simply adds handling for
host_eh_scheduled where needed and exports scsi_eh_wakeup() to
modules. The rest is upto libata. This is the result of the
following discussion.

http://thread.gmane.org/gmane.linux.scsi/23853/focus=9760

In short, SCSI host is not supposed to know about exceptions unrelated
to specific device or command. Such exceptions should be handled by
transport layer proper. However, the distinction is not essential to
ATA and libata is planning to depart from SCSI, so, for the time
being, libata will be using SCSI EH to handle such exceptions.

Signed-off-by: Tejun Heo <htejun@gmail.com>

[PATCH] SCSI: export scsi_eh_finish_cmd() and scsi_eh_flush_done_q()

Export two SCSI EH command handling functions. To be used by libata EH.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

[SCSI] unexport scsi_add_timer/scsi_delete_timer

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert SPI transport class to scsi_execute

This one's slightly more difficult. The transport class uses
REQ_FAILFAST, so another interface (scsi_execute) had to be invented to
take the extra flag. Also, the sense functions are shifted around to
allow spi_execute to place data directly into a struct scsi_sense_hdr.
With this change, there's probably a lot of unnecessary sense buffer
allocation going on which we can fix later.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!