With the removal of the pktcdvd driver, there are no in-kernel users of
the devnode callback in struct block_device_operations, so it can be
safely removed.  If it is needed for new block drivers in the future, it
can be brought back.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20221203140747.1942969-1-gregkh@linuxfoundation.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

The kobject embedded into the request_queue is used for the queue
directory in sysfs, but that is a child of the gendisks directory and is
intimately tied to it.  Move this kobject to the gendisk and use a
refcount_t in the request_queue for the actual request_queue refcounting
that is completely unrelated to the device model.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221114042637.1009333-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Now that dm has been fixed to track of holder registrations before
add_disk, the somewhat buggy block layer code can be safely removed.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20221115141054.1051801-8-yukuai1@huaweicloud.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Drivers that have shared tagsets may need to quiesce potentially a lot
of request queues that all share a single tagset (e.g. nvme). Add an
interface to quiesce all the queues on a given tagset. This interface is
useful because it can speedup the quiesce by doing it in parallel.

Because some queues should not need to be quiesced (e.g. the nvme
connect_q) when quiescing the tagset, introduce a
QUEUE_FLAG_SKIP_TAGSET_QUIESCE flag to allow this new interface to
ski quiescing a particular queue.
Signed-off-by: NChao Leng <lengchao@huawei.com>
[hch: simplify for the per-tag_set srcu_struct]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChao Leng <lengchao@huawei.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221101150050.3510-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All I/O submissions have fairly similar latencies, and a tagset-wide
quiesce is a fairly common operation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChao Leng <lengchao@huawei.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221101150050.3510-12-hch@lst.de
[axboe: fix whitespace]
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Convert current looping-based implementation into bit operation,
which can bring improvement for:

1) bitops is more efficient for its arch-level optimization.

2) Given that blksize_bits() is inline, _if_ @size is compile-time
constant, it's possible that order_base_2() _may_ make output
compile-time evaluated, depending on code context and compiler behavior.
Signed-off-by: NDawei Li <set_pte_at@outlook.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/TYCP286MB23238842958D7C083D6B67CECA349@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COMSigned-off-by: NJens Axboe <axboe@kernel.dk>

bio_start_io_acct_time is not actually used anywhere, so remove it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221025155916.270303-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

request_queue->queue_flags is unsigned long, which is 8-bytes on
64-bit architectures. Most queue flag modifications occur through
bit field helpers, but default flags can be logically OR'd via the
QUEUE_FLAG_MQ_DEFAULT mask. If this mask happens to include bit 31,
the assignment can sign extend the field and set all upper 32 bits.

This exact problem has been observed on a downstream kernel that
happens to use bit 31 for QUEUE_FLAG_NOWAIT. This is not an
immediate problem for current upstream because bit 31 is not
included in the default flag assignment (and is not used at all,
actually). Regardless, fix up the QUEUE_FLAG_MQ_DEFAULT mask
definition to avoid the landmine in the future.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221003133534.1075582-1-bfoster@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The current implementation of blk_mq_plug() disables plugging for all
operations that involves a transfer to the device as we just check if
the last bit in op_is_write() function.

Modify blk_mq_plug() to disable plugging only for REQ_OP_WRITE and
REQ_OP_WRITE_ZEROS as they might require a zone lock.
Suggested-by: NChristoph Hellwig <hch@lst.de>
Suggested-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPankaj Raghav <p.raghav@samsung.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220929074745.103073-2-p.raghav@samsung.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Replace blk_queue_nowait with a bdev_nowait helpers that takes the
block_device given that the I/O submission path should not have to
look into the request_queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20220927075815.269694-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add support for STATX_DIOALIGN to block devices, so that direct I/O
alignment restrictions are exposed to userspace in a generic way.

Note that this breaks the tradition of stat operating only on the block
device node, not the block device itself.  However, it was felt that
doing this is preferable, in order to make the interface useful and
avoid needing separate interfaces for regular files and block devices.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChristian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20220827065851.135710-3-ebiggers@kernel.org

Only non-passthrough requests are split by the block layer and use the
->bio_split bio_set.  Move it from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220727162300.3089193-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The double indirect bio leads to somewhat suboptimal code generation.
Instead return the (original or split) bio, and make sure the
request_queue arguments to the lower level helpers is passed after the
bio to avoid constant reshuffling of the argument passing registers.

Also give it and the helpers used to implement it more descriptive names.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220727162300.3089193-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add bdev_max_segments() like other queue parameters.
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Use the new blk_opf_t type for arguments and variables that represent
request flags or a bitwise combination of a request operation and
request flags. Rename the function arguments and also a structure member
that hold a request operation and flags from 'rw' into 'opf'.

This patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-7-bvanassche@acm.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

All .rw_page() callers pass an enum req_op value as last argument. Make
this explicit by changing the type of the last argument into enum req_op.
See also commit 3f289dcb ("block: make bdev_ops->rw_page() take a
REQ_OP instead of bool").

Cc: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-4-bvanassche@acm.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Change the type of the arguments that are used to pass a REQ_OP_* value
from int or unsigned int into enum req_op to improve static type
checking.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-3-bvanassche@acm.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

The type name enum req_opf is misleading since it suggests that values of
this type include both an operation type and flags. Since values of this
type represent an operation only, change the type name into enum req_op.

Convert the enum req_op documentation into kernel-doc format. Move a few
definitions such that the enum req_op documentation occurs just above
the enum req_op definition.

The name "req_opf" was introduced by commit ef295ecf ("block: better op
and flags encoding").

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-2-bvanassche@acm.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Replace the remaining calls of bdevname with snprintf using the %pg
format specifier.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220713055317.1888500-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move the zone related fields that are currently stored in
struct request_queue to struct gendisk as these are part of the highlevel
block layer API and are only used for non-passthrough I/O that requires
the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-17-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Always use bdev_zone_sectors instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass a block_device instead of a request_queue as that is what most
callers have at hand.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Always use the bdev based helpers instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Prepare for storing the zone related field in struct gendisk instead
of struct request_queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

It doesn't hurt to always have the blk_zone_cond_str prototype, and the
two inlines can also be defined unconditionally.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Independent access ranges only matter for file system I/O and are only
valid with a registered gendisk, so move them there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220629062013.1331068-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Set the queue dying flag and call blk_mq_exit_queue from del_gendisk for
all disks that do not have separately allocated queues, and thus remove
the need to call blk_cleanup_queue for them.

Rename blk_cleanup_disk to blk_mq_destroy_queue to make it clear that
this function is intended only for separately allocated blk-mq queues.

This saves an extra queue freeze for devices without a separately
allocated queue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Disallow setting the blk-mq state on any queue that is already dying as
setting the state even then is a bad idea, and remove the now unused
QUEUE_FLAG_DEAD flag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

blk_queue_get_max_sectors is private to the block layer, so move it out
of blkdev.h.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220614090934.570632-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Now that blk_max_size_offset has a single caller left, fold it into that
and clean up the naming convention for the local variables there.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPankaj Raghav <p.raghav@samsung.com>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220614090934.570632-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Factor out a helper from blk_max_size_offset so that it can be reused
independently.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: NPankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20220614090934.570632-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Use the address alignment requirements from the block_device for direct
io instead of requiring addresses be aligned to the block size. User
space can discover the alignment requirements from the dma_alignment
queue attribute.

User space can specify any hardware compatible DMA offset for each
segment, but every segment length is still required to be a multiple of
the block size.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-11-kbusch@fb.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Provide a convenient function for this repeatable coding pattern.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-10-kbusch@fb.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Preparing for upcoming dma_alignment users that have a block_device, but
don't need the request_queue.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220610195830.3574005-5-kbusch@fb.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

The request queue pointer in struct blk_independent_access_range is
unused. Remove it.
Signed-off-by: NDamien Le Moal <damien.lemoal@opensource.wdc.com>
Fixes: 41e46b3c ("block: Fix potential deadlock in blk_ia_range_sysfs_show()")
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220603053529.76405-1-damien.lemoal@opensource.wdc.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Various places like I/O schedulers or the QOS infrastructure try to
register debugfs files on demans, which can race with creating and
removing the main queue debugfs directory.  Use the existing
debugfs_mutex to serialize all debugfs operations that rely on
q->debugfs_dir or the directories hanging off it.

To make the teardown code a little simpler declare all debugfs dentry
pointers and not just the main one uncoditionally in blkdev.h.

Move debugfs_mutex next to the dentries that it protects and document
what it is used for.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220614074827.458955-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

q->elevator is referred in blk_mq_has_sqsched() without any protection,
no .q_usage_counter is held, no queue srcu and rcu read lock is held,
so potential use-after-free may be triggered.

Fix the issue by adding one queue flag for checking if the elevator
uses single queue style dispatch. Meantime the elevator feature flag
of ELEVATOR_F_MQ_AWARE isn't needed any more.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220616014401.817001-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Historically we did distinguish between a flag that surpressed partition
scanning, and a combinations of the minors variable and another flag if
any partitions were supported.  This was generally confusing and doesn't
make much sense, but some corner case uses of the loop driver actually
do want to support manually added partitions on a device that does not
actively scan for partitions.  To make things worsee the loop driver
also wants to dynamically toggle the scanning for partitions on a live
gendisk, which makes the disk->flags updates non-atomic.

Introduce a new GD_SUPPRESS_PART_SCAN bit in disk->state that disables
just scanning for partitions, and toggle that instead of GENHD_FL_NO_PART
in the loop driver.

Fixes: 1ebe2e5f ("block: remove GENHD_FL_EXT_DEVT")
Reported-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220527055806.1972352-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>