->queue_flags is generally not set or cleared in the fast path, and also
generally set or cleared one flag at a time.  Make use of the normal
atomic bitops for it so that we don't need to take the queue_lock,
which is otherwise mostly unused in the core block layer now.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There is nothing it could synchronize against, so don't go through
the pains of acquiring the lock.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

No users left since the removal of the legacy request interface, we can
remove all the magic bit stealing now and make it a normal field.

But use WRITE_ONCE/READ_ONCE on the new deadline field, given that we
don't seem to have any mechanism to guarantee a new value actually
gets seen by other threads.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Unused since the removal of the legacy request code.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

blk_try_req_merge() is only used in block/blk-merge.c, so make it
static.

This addresses a gcc warning when -Wmissing-prototypes is enabled.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

No more users of ->in_flight[] or ->nr_sorted, get rid of them.

Fixes: a1ce35fa ("block: remove dead elevator code")
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The boolean next_sorted is set to false and is never changed, hence
the code that checks if it is true is dead code and can now be
removed.  This dead code occurred from a previous commit that cleaned
up the elevator and removed the setting of next_sorted to true.

Detected by CoverityScan, CID#1475401 ("'Constant' variable guards
dead code")

Fixes: a1ce35fa ("block: remove dead elevator code")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

NVMe always asks for io_queues + 1 worth of IRQ vectors, which
means that even when we scale all the way down, we still ask
for 2 vectors and get -ENOSPC in return if the system can't
support more than 1.

Getting just 1 vector is fine, it just means that we'll have
1 IO queue and 1 admin queue, with a shared vector between them.
Check for this case and don't add our + 1 if it happens.

Fixes: 3b6592f7 ("nvme: utilize two queue maps, one for reads and one for writes")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We can't use RQF_DONTPREP to see if we should clear ->special,
as someone could have set that while inserting the request. Make
sure we clear it in our ->initialize_rq_fn() helper instead.

Fixes: 22ce0a7c ("ide: don't use req->special")
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit 0a42e99b ("loop: Get rid of loop_index_mutex") forgot to
remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when
replacing loop_index_mutex with loop_ctl_mutex.

Fixes: 0a42e99b ("loop: Get rid of loop_index_mutex")
Reported-by: Nsyzbot <syzbot+c0138741c2290fc5e63f@syzkaller.appspotmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The compiler rightfully complains:

drivers/block/null_blk_main.c: In function ‘null_complete_rq’:
drivers/block/null_blk_main.c:647:16: warning: unused variable ‘nullb’ [-Wunused-variable]
  struct nullb *nullb = rq->q->queuedata;
                ^~~~~

Fixes: 49f66136 ("nullb: remove leftover legacy request code")
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Just replace it with a field of the same name in struct ide_req.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Makes the code a whole lot easier to read.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a retries field to the internal request structure instead, which gets
set to zero on the first submission.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

null_softirq_done_fn is only used for the blk-mq path, so remove the
other branch.  Also rename the function to better match the method name.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The way these functions abuse ->special to try to store the dummy
request looks completely broken, given that it actually stores the
original scsi command.

Instead switch to ->host_scribble and store the actual dummy command.
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fixes gcc '-Wunused-but-set-variable' warning:

block/blk-ioc.c: In function 'put_io_context_active':
block/blk-ioc.c:174:24: warning:
 variable 'et' set but not used [-Wunused-but-set-variable]

It not used any more after commit
a1ce35fa ("block: remove dead elevator code")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Unused now.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Remove the last use of the old BLKPREP_* values, which get converted
to BLK_STS_* later anyway.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace the old BLKPREP_* values with the BLK_STS_ ones that they are
converted to later anyway.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There is no need to call scsi_mq_free_sgtables until we have actually
allocated sgtables.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This just moves the prep_to_mq calls up in preparation of further removal
of BLKPREP_* usage.
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Return a blk_status_t directly, and make the code a little more compact
by handling the fast path in the caller.
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The return value is just used as a binary yes/no decision, so switch
it to a bool instead of the old BLKPREP_* values returned as an int.

Also clean up a few related comments.
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Unused now that the legacy request path is gone.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use the proper helper instead of manually iterating the scatterlist,
which is broken in the presence of chained S/G lists.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Instead create add to the icmd into struct mtip_cmd which can be unioned
with the scatterlist used for the normal I/O path.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Merging this function into the only callers makes the code flow easier.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There isn't much need for this helper - we can just calculate the offset
for the command header once late in the submission path and fill out
the ctba and ctbau fields there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There is no good excuse not to use proper __le16/32 types.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This allows for better error propagation and simpler code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Factor out a new is_stopped helper that matches the existing
is_se_active helper, and merge the trivial amount of remaining code
into the only caller.  This also allows better error handling by
returning a BLK_STS_* directly instead of explicitly calling
blk_mq_end_request, and moving blk_mq_start_request closer to the
actual issue to hardware.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We have all arguments at hand in mtip_hw_submit_io, so keep the
rq to sg mapping close to the dma_map_sg call.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The current sx8 code spends a lot of effort dealing with the fact that
tags are per-host, but there might be multiple queues.  Now that the
driver has been converted to blk-mq it can take care of the blk-mq
tag_set concept that has been designed just for that.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Make the disk/queue alloc and free helpers per-port by moving the
trivial loops into the callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Document the fact that the strategy function passed in can
control whether to continue iterating or not.
Suggested-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Returns true if the queue currently has requests pending,
false if not.

DM can use this to replace the atomic_inc/dec they do per device
to see if a device is busy.
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We have this functionality in sbitmap, but we don't export it in
blk-mq for users of the tags busy iteration. This can be useful
for stopping the iteration, if the caller doesn't need to find
more requests.
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>