scsi: don't use disk->private_data to find the scsi_driver

Requiring every ULP to have the scsi_drive as first member of the
private data is rather fragile and not necessary anyway. Just use
the driver hanging off the SCSI device instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220308055200.735835-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

st: do not allocate a gendisk

st is a character driver and thus does not need to allocate a gendisk,
which is only used for file system-like block layer I/O on block
devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210816131910.615153-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: remove the unchecked_isa_dma flag

Remove the unchecked_isa_dma now that all users are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210331073001.46776-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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>

st: Remove obsolete scsi_tape.max_pfn

Its last user was removed 10 years ago, in commit
8b05b773b6030de5 ("[SCSI] convert st to use scsi_execute_async").

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

st: implement tape statistics

This patch implements tape statistics in the st module via
sysfs. Current no statistics are available for tape I/O and there
is no easy way to reuse the block layer statistics for tape
as tape is a character device and does not have perform I/O in
sector sized chunks (the size of the data written to tape
can change). For tapes we also need extra stats related to
things like tape movement (via other I/O).

There have been multiple end users requesting statistics
including AT&T (and some HP customers who have not given
permission to be named). It is impossible for them
to investigate any issues related to tape performance
in a non-invasive way.

[jejb: eliminate PRId64]
Signed-off-by: Shane Seymour <shane.seymour@hp.com>
Tested-by: Shane Seymour <shane.seymour@hp.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

[SCSI] st: raise device limit

The device limit of 128 tape drives was established in 2003 as a
significant increase from the 8 tape drives allowed previously.

We're seeing customer sites that between a large number of drives
and multipath are discovering more than 128 devices and running
into problems.

Now that we're not stuck having to store a pointer in array
and aren't limited by kmalloc failing on higher order allocs we can
lift the limit to fill the entire minor range based on the number
of modes.

Based on the current code, that's 2^17 devices.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] st: clean up device file creation and removal

This patch cleans up the st device file creation and removal.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] st: get rid of scsi_tapes array

st currently allocates an array to store pointers to all of the
scsi_tape objects. It's used to discover available indexes to use as the
base for the minor number selection and later to look up scsi_tape
devices for character devices.

We switch to using an IDR for minor selection and a pointer from
st_modedef back to scsi_tape for the lookups.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] st: fix memory leak with >1MB tape I/O

There is a memory leak in the st driver when sending large enough reads or
writes using st's direct I/O path. As part of mapping the application's
memory, a buffer to hold page pointers is allocated and the count of mapped
pages is stored in field do_dio. A non-zero do_dio marks that direct I/O is
in use.

But do_dio is only 1 byte in size. Mapping 256 4k pages overflows
do_dio and causes it to be set to 0, like direct I/O option was not
used. When the I/O completes, the buffer to hold the page pointers is
not freed, and the page counts of the mapped pages are not reduced.
Every I/O of this size then leaks memory.

The size of do_dio needs to be increased to prevent it wrapping around.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] st: expand ability to write immediate filemarks

The st tape driver recently added the MTWEOFI ioctl, which writes
a tape filemark (EOF), like the MTWEOF ioctl, except that MTWEOFI
returns immediately. This makes certain applications, like backup
software, run much more quickly on buffered tape drives.

Since legacy applications do not know about this new MTWEOFI ioctl,
this patch adds a new ioctl option that tells the st driver to return
immediately when writing an EOF (i.e. a filemark). This new flag
is much like the existing flag that tells the st driver to perform
writes (and certain other IOs) immediately, but this new flag only
applies to writing EOFs.

This new feature is controlled via the MTSETDRVBUFFER ioctl, using
the newly-defined MT_ST_NOWAIT_EOF flag.

Use of this new feature is displayed via the sysfs tape "options"
attribute.

The st documentation was updated to mention this new flag, as well
as the problems that can occur from using it.

Signed-off-by: Lee Duncan <lduncan@suse.com>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] st: fix mdata->page_order handling

dio transfer always resets mdata->page_order to zero. It breaks
high-order pages previously allocated for non-dio transfer.

This patches adds reserved_page_order to st_buffer structure to save
page order for non-dio transfer.

http://bugzilla.kernel.org/show_bug.cgi?id=14563

When enlarge_buffer() allocates 524288 from 0, st uses six-order page
allocation. So mdata->page_order is 6 and frp_seg is 2.

After that, if st uses dio, sgl_map_user_pages() sets
mdata->page_order to 0 for st_do_scsi(). After that, when we call
normalize_buffer(), it frees only free frp_seg * PAGE_SIZE (2 * 4096)
though we should free frp_seg * PAGE_SIZE << 6 (2 * 4096 << 6). So we
see buffer_size is set to 516096 (524288 - 8192).

Reported-by: Joachim Breuer <linux-kernel@jmbreuer.net>
Tested-by: Joachim Breuer <linux-kernel@jmbreuer.net>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] st: remove unused frp_sg_current

frp_sg_current in struct st_buffer is always zero. We don't need it.

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

[SCSI] st: remove unused orig_frp_segs

orig_frp_segs in struct st_buffer is always zero. We don't need it.

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

[SCSI] st: remove struct scatterlist

This removes the usage of struct scatterlist completely.

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

[SCSI] st: kill struct st_buff_fragment

This removes struct st_buff_fragment and use reserved_pages array to
store fragment buffer.

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

[SCSI] st: convert dio path to use st_scsi_execute

This patch converts the dio path (mmap) to use st_scsi_execute. IOW,
it removes scsi_execute_async in the non dio path.

scsi_execute_async has gone! This also remove unused st_sleep_done.

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

[SCSI] st: add st_scsi_execute helper function

st_scsi_execute is a helper function to perform SCSI commands
involving data transfer between user and kernel space (st_read and
st_write).

It's the future plan to combine this with st_scsi_kern_execute helper
function.

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

[SCSI] st: add struct rq_map_data support

This adds struct rq_map_data and the array of pointers to store
fragment buffers to struct st_buffer.

This patch doesn't remove st_buf_fragment but the latter patch does.

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

[SCSI] st: add option to use SILI in variable block reads

Add new option MT_ST_SILI to enable setting the SILI bit in reads in variable
block mode. If SILI is set, reading a block shorter than the byte count does
not result in CHECK CONDITION. The length of the block is determined using the
residual count from the HBA. Avoiding the REQUEST SENSE command for every
block speeds up some real applications considerably.

Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] st: compile fix when DEBUG set to one

Remove the now useless counting of adjacent pages from the debugging code in
to make it compile when DEBUG is set non-zero.

Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] st: Use mutex instead of semaphore

The SCSI Tape driver uses a semaphore as mutex. Use the mutex API
instead of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] st: fix Tape dies if wrong block size used, bug 7919

On Thu, 1 Feb 2007, Andrew Morton wrote:
> On Thu, 1 Feb 2007 15:34:29 -0800
> bugme-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=7919
> >
> > Summary: Tape dies if wrong block size used
> > Kernel Version: 2.6.20-rc5
> > Status: NEW
> > Severity: normal
> > Owner: scsi_drivers-other@kernel-bugs.osdl.org
> > Submitter: dmartin@sccd.ctc.edu
> >
> >
> > Most recent kernel where this bug did *NOT* occur: 2.6.17.14
> >
> > Other Kernels Tested and Results:
> >
> > OK 2.6.15.7
> > OK 2.6.16.37
> > OK 2.6.17.14
> > BAD 2.6.18.6
> > BAD 2.6.18-1.2869.fc6
> > BAD 2.6.19.2 +
> > BAD 2.6.20-rc5
> >
> > NOTE: 2.6.18-1.2869.fc6 is a Fedora modified kernel, all others are from kernel.org
> >
...
> > Steps to reproduce:
> > Get a Adaptec AHA-2940U/UW/D / AIC-7881U card and a tape drive,
> > install a recent kernel
> > set the tape block size - mt setblk 4096
> > read from or write to tape using wrong block size - tar -b 7 -cvf /dev/tape foo
> >
Write does not trigger this bug because the driver refuses in fixed block
mode writes that are not a multiple of the block size. Read does trigger
it in my system.

The bug is not associated with any specific HBA. st tries to do direct i/o
in fixed block mode with reads that are not a multiple of tape block size.

The patch in this message fixes the st problem by switching to using the
driver buffer up to the next close of the device file in fixed block mode
if the user asks for a read like this.

I don't know why the bug has surfaced only after 2.6.17 although the st
problem is old. There may be another bug in the block subsystem and this
patch works around it. However, the patch fixes a problem in st and in
this way it is a valid fix.

This patch may also fix the bug 7900.

The patch compiles and is lightly tested.

Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] st: remove unused st_buffer.in_use

I noticed that in_use in st_buffer is not used. The patch below
against 2.6.17-rc3 removes it, assuming there is no future use for it.
It was tested in a sparc SS20 with a DLT4000.

Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Acked-by: Kai M�kisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert st to use scsi_execute_async

convert st to always send scatterlists and kill scsi_request
usage.

This is the same as last time as it was posted, but with Kai's patches
merged and we now pass the bytes value to scsi_execute_async.

TODO:

- move DIO code to common place or make block layers usable for ULDs.
- move buffer allocation code to common place for all ULDs to use. And
make buffer allocation code handle all queue limits so we can find
out about problems before calling scsi_execute_async.
- move indirect (copy_to/from_user) paths commone place or make block
layers usable for ULDs.

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

[SCSI] drivers/scsi/st.c: add reference count and related fixes

I have rediffed the patch against 2.6.13-rc5, done a couple of cosmetic
cleanups, and run some tests. Brian King has acknowledged that it fixes the
problems he has seen. Seems mature enough for inclusion into 2.6.14 (or
later)?

Nate's explanation of the changes:

I've attached patches against 2.6.13rc2. These are basically identical
to my earlier patches, as I found that all issues I'd seen in earlier
kernels still existed in this kernel.

To summarize, the changes are: (more details in my original email)

- add a kref to the scsi_tape structure, and associate reference
counting stuff

- set sr_request->end_io = blk_end_sync_rq so we get notified when an IO
is rejected when the device goes away

- check rq_status when IOs complete, else we don't know that IOs
rejected for a dead device in fact did not complete

- change last_SRpnt so it's set before an async IO is issued (in case
st_sleep_done is bypassed)

- fix a bogus use of last_SRpnt in st_chk_result

Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
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!