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142 commits

Author SHA1 Message Date
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Bart Van Assche
d352ae205d blk-mq: Make blk_mq_reinit_tagset() calls easier to read
Since blk_mq_ops.reinit_request is only called from inside
blk_mq_reinit_tagset(), make this function pointer an argument of
blk_mq_reinit_tagset() instead of a member of struct blk_mq_ops.
This patch does not change any functionality but makes
blk_mq_reinit_tagset() calls easier to read and to analyze.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: James Smart <james.smart@broadcom.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18 08:36:58 -06:00
Linus Torvalds
9bd42183b9 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Add the SYSTEM_SCHEDULING bootup state to move various scheduler
     debug checks earlier into the bootup. This turns silent and
     sporadically deadly bugs into nice, deterministic splats. Fix some
     of the splats that triggered. (Thomas Gleixner)

   - A round of restructuring and refactoring of the load-balancing and
     topology code (Peter Zijlstra)

   - Another round of consolidating ~20 of incremental scheduler code
     history: this time in terms of wait-queue nomenclature. (I didn't
     get much feedback on these renaming patches, and we can still
     easily change any names I might have misplaced, so if anyone hates
     a new name, please holler and I'll fix it.) (Ingo Molnar)

   - sched/numa improvements, fixes and updates (Rik van Riel)

   - Another round of x86/tsc scheduler clock code improvements, in hope
     of making it more robust (Peter Zijlstra)

   - Improve NOHZ behavior (Frederic Weisbecker)

   - Deadline scheduler improvements and fixes (Luca Abeni, Daniel
     Bristot de Oliveira)

   - Simplify and optimize the topology setup code (Lauro Ramos
     Venancio)

   - Debloat and decouple scheduler code some more (Nicolas Pitre)

   - Simplify code by making better use of llist primitives (Byungchul
     Park)

   - ... plus other fixes and improvements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
  sched/cputime: Refactor the cputime_adjust() code
  sched/debug: Expose the number of RT/DL tasks that can migrate
  sched/numa: Hide numa_wake_affine() from UP build
  sched/fair: Remove effective_load()
  sched/numa: Implement NUMA node level wake_affine()
  sched/fair: Simplify wake_affine() for the single socket case
  sched/numa: Override part of migrate_degrades_locality() when idle balancing
  sched/rt: Move RT related code from sched/core.c to sched/rt.c
  sched/deadline: Move DL related code from sched/core.c to sched/deadline.c
  sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled
  sched/fair: Spare idle load balancing on nohz_full CPUs
  nohz: Move idle balancer registration to the idle path
  sched/loadavg: Generalize "_idle" naming to "_nohz"
  sched/core: Drop the unused try_get_task_struct() helper function
  sched/fair: WARN() and refuse to set buddy when !se->on_rq
  sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well
  sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
  sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c
  sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
  sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h>
  ...
2017-07-03 13:08:04 -07:00
Bart Van Assche
852ec80983 blk-mq: Make it safe to quiesce and unquiesce from an interrupt handler
Since blk_mq_quiesce_queue_nowait() can be called from interrupt
context, make this safe. Since this function is not in the hot
path, uninline it.

Fixes: commit f4560ffe8c ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-21 12:01:15 -06:00
Bart Van Assche
d280bab305 block: Introduce request_queue.initialize_rq_fn()
Several block drivers need to initialize the driver-private request
data after having called blk_get_request() and before .prep_rq_fn()
is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that
that initialization code has to be repeated after every
blk_get_request() call by adding new callback functions to struct
request_queue and to struct blk_mq_ops.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Bart Van Assche
cd6ce1482f block: Make request operation type argument declarations consistent
Instead of declaring the second argument of blk_*_get_request()
as int and passing it to functions that expect an unsigned int,
declare that second argument as unsigned int. Also because of
consistency, rename that second argument from 'rw' into 'op'.
This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Bart Van Assche
0731967877 blk-mq: Reduce blk_mq_hw_ctx size
Since the srcu structure is rather large (184 bytes on an x86-64
system with kernel debugging disabled), only allocate it if needed.

Reported-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Ingo Molnar
ac6424b981 sched/wait: Rename wait_queue_t => wait_queue_entry_t
Rename:

	wait_queue_t		=>	wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:18:27 +02:00
Ming Lei
1d9e9bc6b5 blk-mq: don't stop queue for quiescing
Queue can be started by other blk-mq APIs and can be used in
different cases, this limits uses of blk_mq_quiesce_queue()
if it is based on stopping queue, and make its usage very
difficult, especially users have to use the stop queue APIs
carefully for avoiding to break blk_mq_quiesce_queue().

We have applied the QUIESCED flag for draining and blocking
dispatch, so it isn't necessary to stop queue any more.

After stopping queue is removed, blk_mq_quiesce_queue() can
be used safely and easily, then users won't worry about queue
restarting during quiescing at all.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 14:24:48 -06:00
Ming Lei
f4560ffe8c blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue
It is required that no dispatch can happen any more once
blk_mq_quiesce_queue() returns, and we don't have such requirement
on APIs of stopping queue.

But blk_mq_quiesce_queue() still may not block/drain dispatch in the
the case of BLK_MQ_S_START_ON_RUN, so use the new introduced flag of
QUEUE_FLAG_QUIESCED and evaluate it inside RCU read-side critical
sections for fixing this issue.

Also blk_mq_quiesce_queue() is implemented via stopping queue, which
limits its uses, and easy to cause race, because any queue restart in
other paths may break blk_mq_quiesce_queue(). With the introduced
flag of QUEUE_FLAG_QUIESCED, we don't need to depend on stopping queue
for quiescing any more.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 14:24:27 -06:00
Ming Lei
e4e739131a blk-mq: introduce blk_mq_unquiesce_queue
blk_mq_start_stopped_hw_queues() is used implictly
as counterpart of blk_mq_quiesce_queue() for unquiescing queue,
so we introduce blk_mq_unquiesce_queue() and make it
as counterpart of blk_mq_quiesce_queue() explicitly.

This function is for improving the current quiescing mechanism
in the following patches.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 14:20:04 -06:00
Ming Lei
4f084b41a0 blk-mq: introduce blk_mq_quiesce_queue_nowait()
This patch introduces blk_mq_quiesce_queue_nowait() so
that we can workaround mpt3sas for quiescing its queue.

Once mpt3sas is fixed, we can remove this helper.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 14:20:04 -06:00
Ming Lei
97e0120990 blk-mq: move blk_mq_quiesce_queue() into include/linux/blk-mq.h
We usually put blk_mq_*() into include/linux/blk-mq.h, so
move this API into there.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 14:20:04 -06:00
Christoph Hellwig
fc17b6534e blk-mq: switch ->queue_rq return value to blk_status_t
Use the same values for use for request completion errors as the return
value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig
2a842acab1 block: introduce new block status code type
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Ming Lei
7254a50a5d blk-mq: remove blk_mq_abort_requeue_list()
No one uses it any more, so remove it.

Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-22 20:50:11 +02:00
Omar Sandoval
d332ce0918 blk-mq-debugfs: allow schedulers to register debugfs attributes
This provides the infrastructure for schedulers to expose their internal
state through debugfs. We add a list of queue attributes and a list of
hctx attributes to struct elevator_type and wire them up when switching
schedulers.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>

Add missing seq_file.h header in blk-mq-debugfs.h

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-04 08:24:40 -06:00
Omar Sandoval
9c1051aacd blk-mq: untangle debugfs and sysfs
Originally, I tied debugfs registration/unregistration together with
sysfs. There's no reason to do this, and it's getting in the way of
letting schedulers define their own debugfs attributes. Instead, tie the
debugfs registration to the lifetime of the structures themselves.

The saner lifetimes mean we can also get rid of the extra mq directory
and move everything one level up. I.e., nvme0n1/mq/hctx0/tags is now
just nvme0n1/hctx0/tags.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-04 08:24:13 -06:00
Christoph Hellwig
d6296d39e9 blk-mq: update ->init_request and ->exit_request prototypes
Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq.  Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-02 07:52:08 -06:00
Jens Axboe
21c6e939a9 blk-mq: unify hctx delay_work and run_work
The only difference between ->run_work and ->delay_work, is that
the latter is used to defer running a queue. This is done by
marking the queue stopped, and scheduling ->delay_work to run
sometime in the future. While the queue is stopped, direct runs
or runs through ->run_work will not run the queue.

If we combine the handlers, then we need to handle two things:

1) If a delayed/stopped run is scheduled, then we should not run
   the queue before that has been completed.
2) If a queue is delayed/stopped, the handler needs to restart
   the queue. Normally a run of a queue with the stopped bit set
   would be a no-op.

Case 1 is handled by modifying a currently pending queue run
to the deadline set by the caller of blk_mq_delay_queue().
Subsequent attempts to queue a queue run will find the work
item already pending, and direct runs will see a stopped queue
as before.

Case 2 is handled by adding a new bit, BLK_MQ_S_START_ON_RUN,
that tells the work handler that it should clear a stopped
queue and run the handler.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-28 08:11:43 -06:00
Jens Axboe
9f99373790 blk-mq: unify hctx delayed_run_work and run_work
They serve the exact same purpose. Get rid of the non-delayed
work variant, and just run it without delay for the normal case.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-28 08:10:15 -06:00
Bart Van Assche
2836ee4b1a blk-mq: Add blk_mq_ops.show_rq()
This new callback function will be used in the next patch to show
more information about SCSI requests.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-26 15:09:04 -06:00
Christoph Hellwig
08e0029aa2 blk-mq: remove the error argument to blk_mq_complete_request
Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Omar Sandoval
5b72727299 blk-mq: export helpers
blk_mq_finish_request() is required for schedulers that define their own
put_request(). blk_mq_run_hw_queue() is required for schedulers that
hold back requests to be run later.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-14 14:06:55 -06:00
Jens Axboe
65f619d253 Merge branch 'for-linus' into for-4.12/block
We've added a considerable amount of fixes for stalls and issues
with the blk-mq scheduling in the 4.11 series since forking
off the for-4.12/block branch. We need to do improvements on
top of that for 4.12, so pull in the previous fixes to make
our lives easier going forward.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-07 12:45:20 -06:00
Bart Van Assche
7587a5ae7e blk-mq: Introduce blk_mq_delay_run_hw_queue()
Introduce a function that runs a hardware queue unconditionally
after a delay. Note: there is already a function that stops and
restarts a hardware queue after a delay, namely blk_mq_delay_queue().

This function will be used in the next patch in this series.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Long Li <longli@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-07 12:27:06 -06:00
Bart Van Assche
f2fbc9dd78 blk-mq: Remove blk_mq_queue_data.list
The block layer core sets blk_mq_queue_data.list but no block
drivers read that member. Hence remove it and also the code that
is used to set this member.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-05 09:40:15 -06:00
Ming Lei
1671d522cd block: rename blk_mq_freeze_queue_start()
As the .q_usage_counter is used by both legacy and
mq path, we need to block new I/O if queue becomes
dead in blk_queue_enter().

So rename it and we can use this function in both
paths.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-29 08:03:42 -06:00
Christoph Hellwig
7642747d67 blk-mq: remove BLK_MQ_F_DEFER_ISSUE
This flag was never used since it was introduced.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-22 20:16:56 -06:00
Keith Busch
f91328c40a blk-mq: Provide freeze queue timeout
A driver may wish to take corrective action if queued requests do not
complete within a set time.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02 08:56:04 -07:00
Keith Busch
6bae363ee3 blk-mq: Export blk_mq_freeze_queue_wait
Drivers can start a freeze, so this provides a way to wait for frozen.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02 08:56:04 -07:00
Omar Sandoval
da55f2cc78 blk-mq: use sbq wait queues instead of restart for driver tags
Commit 50e1dab86a ("blk-mq-sched: fix starvation for multiple hardware
queues and shared tags") fixed one starvation issue for shared tags.
However, we can still get into a situation where we fail to allocate a
tag because all tags are allocated but we don't have any pending
requests on any hardware queue.

One solution for this would be to restart all queues that share a tag
map, but that really sucks. Ideally, we could just block and wait for a
tag, but that isn't always possible from blk_mq_dispatch_rq_list().

However, we can still use the struct sbitmap_queue wait queues with a
custom callback instead of blocking. This has a few benefits:

1. It avoids iterating over all hardware queues when completing an I/O,
   which the current restart code has to do.
2. It benefits from the existing rolling wakeup code.
3. It avoids punting to another thread just to have it block.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-23 11:55:46 -07:00
Jens Axboe
d348499138 blk-mq-sched: allow setting of default IO scheduler
Add Kconfig entries to manage what devices get assigned an MQ
scheduler, and add a blk-mq flag for drivers to opt out of scheduling.
The latter is useful for admin type queues that still allocate a blk-mq
queue and tag set, but aren't use for normal IO.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:31 -07:00
Jens Axboe
bd166ef183 blk-mq-sched: add framework for MQ capable IO schedulers
This adds a set of hooks that intercepts the blk-mq path of
allocating/inserting/issuing/completing requests, allowing
us to develop a scheduler within that framework.

We reuse the existing elevator scheduler API on the registration
side, but augment that with the scheduler flagging support for
the blk-mq interfce, and with a separate set of ops hooks for MQ
devices.

We split driver and scheduler tags, so we can run the scheduling
independently of device queue depth.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:20 -07:00
Jens Axboe
16a3c2a70c blk-mq: un-export blk_mq_free_hctx_request()
It's only used in blk-mq, kill it from the main exported header
and kill the symbol export as well.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:48 -07:00
Jens Axboe
f8a5b12247 blk-mq: make mq_ops a const pointer
We never change it, make that clear.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
2017-01-11 20:47:44 -07:00
Linus Torvalds
a829a8445f SCSI misc on 20161213
This update includes the usual round of major driver updates (ncr5380,
 lpfc, hisi_sas, megaraid_sas, ufs, ibmvscsis, mpt3sas).  There's also
 an assortment of minor fixes, mostly in error legs or other not very
 user visible stuff.  The major change is the pci_alloc_irq_vectors
 replacement for the old pci_msix_.. calls; this effectively makes IRQ
 mapping generic for the drivers and allows blk_mq to use the
 information.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This update includes the usual round of major driver updates (ncr5380,
  lpfc, hisi_sas, megaraid_sas, ufs, ibmvscsis, mpt3sas).

  There's also an assortment of minor fixes, mostly in error legs or
  other not very user visible stuff. The major change is the
  pci_alloc_irq_vectors replacement for the old pci_msix_.. calls; this
  effectively makes IRQ mapping generic for the drivers and allows
  blk_mq to use the information"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (256 commits)
  scsi: qla4xxx: switch to pci_alloc_irq_vectors
  scsi: hisi_sas: support deferred probe for v2 hw
  scsi: megaraid_sas: switch to pci_alloc_irq_vectors
  scsi: scsi_devinfo: remove synchronous ALUA for NETAPP devices
  scsi: be2iscsi: set errno on error path
  scsi: be2iscsi: set errno on error path
  scsi: hpsa: fallback to use legacy REPORT PHYS command
  scsi: scsi_dh_alua: Fix RCU annotations
  scsi: hpsa: use %phN for short hex dumps
  scsi: hisi_sas: fix free'ing in probe and remove
  scsi: isci: switch to pci_alloc_irq_vectors
  scsi: ipr: Fix runaway IRQs when falling back from MSI to LSI
  scsi: dpt_i2o: double free on error path
  scsi: cxlflash: Migrate scsi command pointer to AFU command
  scsi: cxlflash: Migrate IOARRIN specific routines to function pointers
  scsi: cxlflash: Cleanup queuecommand()
  scsi: cxlflash: Cleanup send_tmf()
  scsi: cxlflash: Remove AFU command lock
  scsi: cxlflash: Wait for active AFU commands to timeout upon tear down
  scsi: cxlflash: Remove private command pool
  ...
2016-12-14 10:49:33 -08:00
Jens Axboe
ae911c5e79 blk-mq: add blk_mq_start_stopped_hw_queue()
We have a variant for all hardware queues, but not one for a single
hardware queue.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-12-09 09:03:02 -07:00
Christoph Hellwig
9e5a7e2295 blk-mq: export blk_mq_map_queues
This will allow SCSI to have a single blk_mq_ops structure that either
lets the LLDD map the queues to PCIe MSIx vectors or use the default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08 17:30:00 -05:00
Bart Van Assche
2b053aca76 blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()
Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
are followed by kicking the requeue list. Hence add an argument to
these two functions that allows to kick the requeue list. This was
proposed by Christoph Hellwig.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
6a83e74d21 blk-mq: Introduce blk_mq_quiesce_queue()
blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations
have finished. This function does *not* wait until all outstanding
requests have finished (this means invocation of request.end_io()).
The algorithm used by blk_mq_quiesce_queue() is as follows:
* Hold either an RCU read lock or an SRCU read lock around
  .queue_rq() calls. The former is used if .queue_rq() does not
  block and the latter if .queue_rq() may block.
* blk_mq_quiesce_queue() first calls blk_mq_stop_hw_queues()
  followed by synchronize_srcu() or synchronize_rcu(). The latter
  call waits for .queue_rq() invocations that started before
  blk_mq_quiesce_queue() was called.
* The blk_mq_hctx_stopped() calls that control whether or not
  .queue_rq() will be called are called with the (S)RCU read lock
  held. This is necessary to avoid race conditions against
  blk_mq_quiesce_queue().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
9b7dd572cc blk-mq: Remove blk_mq_cancel_requeue_work()
Since blk_mq_requeue_work() no longer restarts stopped queues
canceling requeue work is no longer needed to prevent that a
stopped queue would be restarted. Hence remove this function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
fd00144301 blk-mq: Introduce blk_mq_queue_stopped()
The function blk_queue_stopped() allows to test whether or not a
traditional request queue has been stopped. Introduce a helper
function that allows block drivers to query easily whether or not
one or more hardware contexts of a blk-mq queue have been stopped.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Linus Torvalds
24532f7681 Merge branch 'for-4.9/block-smp' of git://git.kernel.dk/linux-block
Pull blk-mq CPU hotplug update from Jens Axboe:
 "This is the conversion of blk-mq to the new hotplug state machine"

* 'for-4.9/block-smp' of git://git.kernel.dk/linux-block:
  blk-mq: fixup "Convert to new hotplug state machine"
  blk-mq: Convert to new hotplug state machine
  blk-mq/cpu-notif: Convert to new hotplug state machine
2016-10-09 17:32:20 -07:00
Linus Torvalds
12e3d3cdd9 Merge branch 'for-4.9/block-irq' of git://git.kernel.dk/linux-block
Pull blk-mq irq/cpu mapping updates from Jens Axboe:
 "This is the block-irq topic branch for 4.9-rc. It's mostly from
  Christoph, and it allows drivers to specify their own mappings, and
  more importantly, to share the blk-mq mappings with the IRQ affinity
  mappings. It's a good step towards making this work better out of the
  box"

* 'for-4.9/block-irq' of git://git.kernel.dk/linux-block:
  blk_mq: linux/blk-mq.h does not include all the headers it depends on
  blk-mq: kill unused blk_mq_create_mq_map()
  blk-mq: get rid of the cpumask in struct blk_mq_tags
  nvme: remove the post_scan callout
  nvme: switch to use pci_alloc_irq_vectors
  blk-mq: provide a default queue mapping for PCI device
  blk-mq: allow the driver to pass in a queue mapping
  blk-mq: remove ->map_queue
  blk-mq: only allocate a single mq_map per tag_set
  blk-mq: don't redistribute hardware queues on a CPU hotplug event
2016-10-09 17:29:33 -07:00
Jens Axboe
1b792f2f92 blk-mq: add flag for drivers wanting blocking ->queue_rq()
If a driver sets BLK_MQ_F_BLOCKING, it is allowed to block in its
->queue_rq() handler. For that case, blk-mq ensures that we always
calls it from a safe context.

Signed-off-by: Jens Axboe <axboe@fb.com>
Tested-by: Josef Bacik <jbacik@fb.com>
2016-09-22 14:28:38 -06:00
Thomas Gleixner
9467f85960 blk-mq/cpu-notif: Convert to new hotplug state machine
Replace the block-mq notifier list management with the multi instance
facility in the cpu hotplug state machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-block@vger.kernel.org
Cc: rt@linutronix.de
Cc: Christoph Hellwing <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-22 08:05:17 -06:00
Matias Bjørling
b21d5b3017 blk-mq: register device instead of disk
Enable devices without a gendisk instance to register itself with blk-mq
and expose the associated multi-queue sysfs entries.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-21 07:56:16 -06:00
Omar Sandoval
88459642cb blk-mq: abstract tag allocation out into sbitmap library
This is a generally useful data structure, so make it available to
anyone else who might want to use it. It's also a nice cleanup
separating the allocation logic from the rest of the tag handling logic.

The code is behind a new Kconfig option, CONFIG_SBITMAP, which is only
selected by CONFIG_BLOCK for now.

This should be a complete noop functionality-wise.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-17 08:38:44 -06:00
Christoph Hellwig
1b157939f9 blk-mq: get rid of the cpumask in struct blk_mq_tags
Unused now that NVMe sets up irq affinity before calling into blk-mq.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15 08:42:03 -06:00