There is no point in sleeping for the expected I/O completion timeout
in the io_uring async polling model as we never poll for a specific
I/O.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NMark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Switch the boolean spin argument to blk_poll to passing a set of flags
instead.  This will allow to control polling behavior in a more fine
grained way.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NMark Wunderlich <mark.wunderlich@intel.com>
Link: https://lore.kernel.org/r/20211012111226.760968-10-hch@lst.de
[axboe: adapt to changed io_uring iopoll]
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The caller typically has a good (or even exact) idea of how many requests
it needs to submit. We can make the request/tag allocation a lot more
efficient if we just allocate N requests/tags upfront when we queue the
first bio from the batch.

Provide a new plug start helper that allows the caller to specify how many
IOs are expected. This sets plug->nr_ios, and we can use that for smarter
request allocation. The plug provides a holding spot for requests, and
request allocation will check it before calling into the normal request
allocation path.

The blk_finish_plug() is called, check if there are unused requests and
free them. This should not happen in normal operations. The exception is
if we get merging, then we may be left with requests that need freeing
when done.

This raises the per-core performance on my setup from ~5.8M to ~6.1M
IOPS.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Particularly for NVMe with efficient deferred submission for many
requests, there are nice benefits to be seen by bumping the default max
plug count from 16 to 32. This is especially true for virtualized setups,
where the submit part is more expensive. But can be noticed even on
native hardware.

Reduce the multiple queue factor from 4 to 2, since we're changing the
default size.

While changing it, move the defines into the block layer private header.
These aren't values that anyone outside of the block layer uses, or
should use.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now that shared sbitmap support really means shared tags, rename symbols
to match that.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1633429419-228500-15-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently we use separate sbitmap pairs and active_queues atomic_t for
shared sbitmap support.

However a full sets of static requests are used per HW queue, which is
quite wasteful, considering that the total number of requests usable at
any given time across all HW queues is limited by the shared sbitmap depth.

As such, it is considerably more memory efficient in the case of shared
sbitmap to allocate a set of static rqs per tag set or request queue, and
not per HW queue.

So replace the sbitmap pairs and active_queues atomic_t with a shared
tags per tagset and request queue, which will hold a set of shared static
rqs.

Since there is now no valid HW queue index to be passed to the blk_mq_ops
.init and .exit_request callbacks, pass an invalid index token. This
changes the semantics of the APIs, such that the callback would need to
validate the HW queue index before using it. Currently no user of shared
sbitmap actually uses the HW queue index (as would be expected).
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1633429419-228500-13-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

struct request is only used by blk-mq drivers, so move it and all
related declarations to blk-mq.h.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-18-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Split the integrity/metadata handling definitions out into a new header.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-17-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

These are block-layer internal helpers, so move them to block/blk.h and
block/blk-merge.c.  Also update a comment a bit to use better grammar.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Drop various include not actually used in blkdev.h itself.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Except for the features passed to blk_queue_required_elevator_features,
elevator.h is only needed internally to the block layer.  Move the
ELEVATOR_F_* definitions to blkdev.h, and the move elevator.h to
block/, dropping all the spurious includes outside of that.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

This type doesn't exist at all, so no need to forward declare it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Entirely unused.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add alternative_gpt_sector() block device operation which specifies
alternative location of a GPT entry. This allows us to support Android
devices that have GPT entry at a non-standard location and can't be
repartitioned easily.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Suggested-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDmitry Osipenko <digetx@gmail.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210820004536.15791-2-digetx@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Replace the magic lookup through the kobject tree with an explicit
backpointer, given that the device model links are set up and torn
down at times when I/O is still possible, leading to potential
NULL or invalid pointer dereferences.

Fixes: edb0872f ("block: move the bdi from the request_queue to the gendisk")
Reported-by: Nsyzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move them (PAGE_SECTORS_SHIFT, PAGE_SECTORS and SECTOR_MASK) to the
generic header file to remove redundancy.
Signed-off-by: NGuoqing Jiang <jiangguoqing@kylinos.cn>
Link: https://lore.kernel.org/r/20210721025315.1729118-1-guoqing.jiang@linux.devSigned-off-by: NJens Axboe <axboe@kernel.dk>

When merging one bio to request, if they are discard IO and the queue
supports multi-range discard, we need to return ELEVATOR_DISCARD_MERGE
because both block core and related drivers(nvme, virtio-blk) doesn't
handle mixed discard io merge(traditional IO merge together with
discard merge) well.

Fix the issue by returning ELEVATOR_DISCARD_MERGE in this situation,
so both blk-mq and drivers just need to handle multi-range discard.
Reported-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Tested-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Fixes: 2705dfb2 ("block: fix discard request merge")
Link: https://lore.kernel.org/r/20210729034226.1591070-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The backing device information only makes sense for file system I/O,
and thus belongs into the gendisk and not the lower level request_queue
structure.  Move it there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add a helper to check if a gendisk is associated with a request_queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

.. and rename the function to disk_update_readahead.  This is in
preparation for moving the BDI from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Now that we've stopped using inode references for anything meaninful
in the block layer get rid of the helper to put it and just open code
the call to iput on the block_device inode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NChaitanya Kulkarni <ckulkarnilinux@gmail.com>
Link: https://lore.kernel.org/r/20210722075402.983367-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers are gone, and no one should grab a pure inode reference to
a block device anymore.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210722075402.983367-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move the sg_timeout and sg_reserved_size fields into the bsg_device and
scsi_device structures as they have nothing to do with generic block I/O.
Note that these values are now separate for bsg vs. SCSI device node
access, but that just matches how /dev/sg vs the other nodes has always
behaved.

Link: https://lore.kernel.org/r/20210729064845.1044147-4-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This was used for the table based SCSI passthough permission checking that
is gone now.

Link: https://lore.kernel.org/r/20210729064845.1044147-3-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use the per-device cdev_device_interface to store the bsg data in the char
device inode, and thus remove the need to embedd the bsg_class_device
structure in the request_queue.

Link: https://lore.kernel.org/r/20210729064845.1044147-2-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Merge the ioctl handling in block/scsi_ioctl.c into its only caller in
drivers/scsi/scsi_ioctl.c.

Link: https://lore.kernel.org/r/20210724072033.1284840-19-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove the separate command filter structure and just use a switch
statement (which also cought two duplicate commands), return a bool and
give the function a sensible name.

Link: https://lore.kernel.org/r/20210724072033.1284840-18-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Move the SCSI-specific bsg code in the SCSI midlayer instead of in the
common bsg code.  This just keeps the common bsg code block/ and also
allows building it as a module.

Link: https://lore.kernel.org/r/20210724072033.1284840-15-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Return the max_sectors value in bytes.  Lifted from scsi_ioctl.c.

Link: https://lore.kernel.org/r/20210724072033.1284840-13-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Manually verify that the device is not a partition and the caller has admin
privіleges at the beginning of the sr ioctl method and open code the
trivial check for sd as well.

Link: https://lore.kernel.org/r/20210724072033.1284840-11-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Open code scsi_cmd_blk_ioctl() in its two callers.

Link: https://lore.kernel.org/r/20210724072033.1284840-10-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

After mq-deadline learned to deal with cgroups, the BLKCG_MAX_POLS value
became too small for all the elevators to be registered properly. The
following issue is seen:

```
calling  bfq_init+0x0/0x8b @ 1
blkcg_policy_register: BLKCG_MAX_POLS too small
initcall bfq_init+0x0/0x8b returned -28 after 507 usecs
```

which renders BFQ non-functional.

Increase BLKCG_MAX_POLS to allow enough space for everyone.

Fixes: 08a9ad8b ("block/mq-deadline: Add cgroup support")
Link: https://lore.kernel.org/lkml/8988303.mDXGIdCtx8@natalenko.name/Signed-off-by: NOleksandr Natalenko <oleksandr@natalenko.name>
Link: https://lore.kernel.org/r/20210717123328.945810-1-oleksandr@natalenko.nameSigned-off-by: NJens Axboe <axboe@kernel.dk>

The synchronous blk_execute_rq() had not provided a way for its callers
to know if its request was successful or not. Return the blk_status_t
result of the request.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210610214437.641245-4-kbusch@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

With the legacy IDE driver gone drivers now use either REQ_OP_DRV_*
or REQ_OP_SCSI_*, so unify the two concepts of passthrough requests
into a single one.
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Introduce the helper functions bio_zone_no() and bio_zone_is_seq().
Both are the BIO counterparts of the request helpers blk_rq_zone_no()
and blk_rq_zone_is_seq(), respectively returning the number of the
target zone of a bio and true if the BIO target zone is sequential.
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

blk_alloc_queue is just an internal helper now, unexport it and remove
it from the public header.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210521055116.1053587-27-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The tags used for an IO scheduler are currently per hctx.

As such, when q->nr_hw_queues grows, so does the request queue total IO
scheduler tag depth.

This may cause problems for SCSI MQ HBAs whose total driver depth is
fixed.

Ming and Yanhui report higher CPU usage and lower throughput in scenarios
where the fixed total driver tag depth is appreciably lower than the total
scheduler tag depth:
https://lore.kernel.org/linux-block/440dfcfc-1a2c-bd98-1161-cec4d78c6dfc@huawei.com/T/#mc0d6d4f95275a2743d1c8c3e4dc9ff6c9aa3a76b

In that scenario, since the scheduler tag is got first, much contention
is introduced since a driver tag may not be available after we have got
the sched tag.

Improve this scenario by introducing request queue-wide tags for when
a tagset-wide sbitmap is used. The static sched requests are still
allocated per hctx, as requests are initialised per hctx, as in
blk_mq_init_request(..., hctx_idx, ...) ->
set->ops->init_request(.., hctx_idx, ...).

For simplicity of resizing the request queue sbitmap when updating the
request queue depth, just init at the max possible size, so we don't need
to deal with the possibly with swapping out a new sbitmap for old if
we need to grow.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/1620907258-30910-3-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Last users of blk_account_rq gone with patch commit a1ce35fa
("block: remove dead elevator code") and now it gets no caller, it can
be safely removed.
Signed-off-by: NLin Feng <linf@wangsu.com>
Link: https://lore.kernel.org/r/20210512100124.173769-1-linf@wangsu.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

This reverts commit cd2c7545.

Alex reports that the commit causes corruption with LUKS on ext4. Revert
it for now so that this can be investigated properly.

Link: https://lore.kernel.org/linux-block/1620493841.bxdq8r5haw.none@localhost/Reported-by: NAlex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: NJens Axboe <axboe@kernel.dk>