block: Cleanup blk_revalidate_zone_cb()

Define the code for checking conventional and sequential write required
zones suing the functions blk_revalidate_conv_zone() and
blk_revalidate_seq_zone() respectively. This simplifies the zone type
switch-case in blk_revalidate_zone_cb().

No functional changes.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240501110907.96950-15-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify zone write plug BIO abort

When BIOs plugged in a zone write plug are aborted,
blk_zone_wplug_bio_io_error() clears the BIO BIO_ZONE_WRITE_PLUGGING
flag so that bio_io_error(bio) does not end up calling
blk_zone_write_plug_bio_endio() and we thus need to manually drop the
reference on the zone write plug held by the aborted BIO.

Move the call to disk_put_zone_wplug() that is alwasy following the call
to blk_zone_wplug_bio_io_error() inside that function to simplify the
code.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-14-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify blk_zone_write_plug_bio_endio()

We already have the disk variable obtained from the bio when calling
disk_get_zone_wplug(). So use that variable instead of dereferencing the
bio bdev again for the disk argument of disk_get_zone_wplug().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-13-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Improve zone write request completion handling

blk_zone_complete_request() must be called to handle the completion of a
zone write request handled with zone write plugging. This function is
called from blk_complete_request(), blk_update_request() and also in
blk_mq_submit_bio() error path. Improve this by moving this function
call into blk_mq_finish_request() as all requests are processed with
this function when they complete as well as when they are freed without
being executed. This also improves blk_update_request() used by scsi
devices as these may repeatedly call this function to handle partial
completions.

To be consistent with this change, blk_zone_complete_request() is
renamed to blk_zone_finish_request() and
blk_zone_write_plug_complete_request() is renamed to
blk_zone_write_plug_finish_request().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-12-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Improve blk_zone_write_plug_bio_merged()

Improve blk_zone_write_plug_bio_merged() to check that we succefully get
a reference on the zone write plug of the merged BIO, as expected since
for a merge we already have at least one request and one BIO referencing
the zone write plug. Comments in this function are also improved to
better explain the references to the BIO zone write plug.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-11-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix handling of non-empty flush write requests to zones

Zone write plugging ignores empty (no data) flush operations but handles
flush BIOs that have data to ensure that the flush machinery generated
write is processed in order. However, the call to
blk_zone_write_plug_attempt_merge() which sets a request
RQF_ZONE_WRITE_PLUGGING flag is called after blk_insert_flush(), thus
missing indicating that a non empty flush request completion needs
handling by zone write plugging.

Fix this by moving the call to blk_zone_write_plug_attempt_merge()
before blk_insert_flush(). And while at it, rename that function as
blk_zone_write_plug_init_request() to be clear that it is not just about
merging plugged BIOs in the request. While at it, also add a WARN_ONCE()
check that the zone write plug for the request is not NULL.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-10-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Do not remove zone write plugs still in use

Large write BIOs that span a zone boundary are split in
blk_mq_submit_bio() before being passed to blk_zone_plug_bio() for zone
write plugging. Such split BIO will be chained with one fragment
targeting one zone and the remainder of the BIO targeting the next
zone. The two BIOs can be executed in parallel, without a predetermine
order relative to eachother and their completion may be reversed: the
remainder first completing and the first fragment then completing. In
such case, bio_endio() will not immediately execute
blk_zone_write_plug_bio_endio() for the parent BIO (the remainder of the
split BIO) as the BIOs are chained. blk_zone_write_plug_bio_endio() for
the parent BIO will be executed only once the first fragment completes.

In the case of a device with small zones and very large BIOs, uch
completion pattern can lead to disk_should_remove_zone_wplug() to return
true for the zone of the parent BIO when the parent BIO request
completes and blk_zone_write_plug_complete_request() is executed. This
triggers the removal of the zone write plug from the hash table using
disk_remove_zone_wplug(). With the zone write plug of the parent BIO
missing, the call to disk_get_zone_wplug() in
blk_zone_write_plug_bio_endio() returns NULL and triggers a warning.

This patterns can be recreated fairly easily using a scsi_debug device
with small zone and btrfs. E.g.

modprobe scsi_debug delay=0 dev_size_mb=1024 sector_size=4096 \
zbc=host-managed zone_cap_mb=3 zone_nr_conv=0 zone_size_mb=4
mkfs.btrfs -f -O zoned /dev/sda
mount -t btrfs /dev/sda /mnt
fio --name=wrtest --rw=randwrite --direct=1 --ioengine=libaio \
--bs=4k --iodepth=16 --size=1M --directory=/mnt --time_based \
--runtime=10
umount /dev/sda

Will result in the warning:

[ 29.035538] WARNING: CPU: 3 PID: 37 at block/blk-zoned.c:1207 blk_zone_write_plug_bio_endio+0xee/0x1e0
...
[ 29.058682] Call Trace:
[ 29.059095] <TASK>
[ 29.059473] ? __warn+0x80/0x120
[ 29.059983] ? blk_zone_write_plug_bio_endio+0xee/0x1e0
[ 29.060728] ? report_bug+0x160/0x190
[ 29.061283] ? handle_bug+0x36/0x70
[ 29.061830] ? exc_invalid_op+0x17/0x60
[ 29.062399] ? asm_exc_invalid_op+0x1a/0x20
[ 29.063025] ? blk_zone_write_plug_bio_endio+0xee/0x1e0
[ 29.063760] bio_endio+0xb7/0x150
[ 29.064280] btrfs_clone_write_end_io+0x2b/0x60 [btrfs]
[ 29.065049] blk_update_request+0x17c/0x500
[ 29.065666] scsi_end_request+0x27/0x1a0 [scsi_mod]
[ 29.066356] scsi_io_completion+0x5b/0x690 [scsi_mod]
[ 29.067077] blk_complete_reqs+0x3a/0x50
[ 29.067692] __do_softirq+0xcf/0x2b3
[ 29.068248] ? sort_range+0x20/0x20
[ 29.068791] run_ksoftirqd+0x1c/0x30
[ 29.069339] smpboot_thread_fn+0xcc/0x1b0
[ 29.069936] kthread+0xcf/0x100
[ 29.070438] ? kthread_complete_and_exit+0x20/0x20
[ 29.071314] ret_from_fork+0x31/0x50
[ 29.071873] ? kthread_complete_and_exit+0x20/0x20
[ 29.072563] ret_from_fork_asm+0x11/0x20
[ 29.073146] </TASK>

either when fio executes or when unmount is executed.

Fix this by modifying disk_should_remove_zone_wplug() to check that the
reference count to a zone write plug is not larger than 2, that is, that
the only references left on the zone are the caller held reference
(blk_zone_write_plug_complete_request()) and the initial extra reference
for the zone write plug taken when it was initialized (and that is
dropped when the zone write plug is removed from the hash table).

To be consistent with this change, make sure to drop the request or BIO
held reference to the zone write plug before calling
disk_zone_wplug_unplug_bio(). All references are also dropped using
disk_put_zone_wplug() instead of atomic_dec() to ensure that the zone
write plug is freed if it needs to be.

Comments are also improved to clarify zone write plugs reference
handling.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240501110907.96950-8-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Unhash a zone write plug only if needed

Fix disk_remove_zone_wplug() to ensure that a zone write plug already
removed from a disk hash table of zone write plugs is not removed
again. Do this by checking the BLK_ZONE_WPLUG_UNHASHED flag of the plug
and calling hlist_del_init_rcu() only if the flag is not set.

Furthermore, since BIO completions can happen at any time, that is,
decrementing of the zone write plug reference count can happen at any
time, make sure to use disk_put_zone_wplug() instead of atomic_dec() to
ensure that the zone write plug is freed when its last reference is
dropped. In order to do this, disk_remove_zone_wplug() is moved after
the definition of disk_put_zone_wplug(). disk_should_remove_zone_wplug()
is moved as well to keep it together with disk_remove_zone_wplug().

To be consistent with this change, add a check in disk_put_zone_wplug()
to ensure that a zone write plug being freed was already removed from
the disk hash table.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-7-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Hold a reference on zone write plugs to schedule submission

Since a zone write plug BIO work is a field of struct blk_zone_wplug, we
must ensure that a zone write plug is never freed when its BIO
submission work is queued or running. Do this by holding a reference on
the zone write plug when the submission work is scheduled for execution
with queue_work() and releasing the reference at the end of the
execution of the work function blk_zone_wplug_bio_work().
The helper function disk_zone_wplug_schedule_bio_work() is introduced to
get a reference on a zone write plug and queue its work. This helper is
used in disk_zone_wplug_unplug_bio() and disk_zone_wplug_handle_error().

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-6-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix reference counting for zone write plugs in error state

When zone is reset or finished, disk_zone_wplug_set_wp_offset() is
called to update the zone write plug write pointer offset and to clear
the zone error state (BLK_ZONE_WPLUG_ERROR flag) if it is set.
However, this processing is missing dropping the reference to the zone
write plug that was taken in disk_zone_wplug_set_error() when the error
flag was first set. Furthermore, the error state handling must release
the zone write plug lock to first execute a report zones command. When
the report zone races with a reset or finish operation that clears the
error, we can end up decrementing the zone write plug reference count
twice: once in disk_zone_wplug_set_wp_offset() for the reset/finish
operation and one more time in disk_zone_wplugs_work() once
disk_zone_wplug_handle_error() completes.

Fix this by introducing disk_zone_wplug_clear_error() as the symmetric
function of disk_zone_wplug_set_error(). disk_zone_wplug_clear_error()
decrements the zone write plug reference count obtained in
disk_zone_wplug_set_error() only if the error handling has not started
yet, that is, only if disk_zone_wplugs_work() has not yet taken the zone
write plug off the error list. This ensure that either
disk_zone_wplug_clear_error() or disk_zone_wplugs_work() drop the zone
write plug reference count.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-5-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix zone write plug initialization from blk_revalidate_zone_cb()

When revalidating the zones of a zoned block device,
blk_revalidate_zone_cb() must allocate a zone write plug for any
sequential write required zone that is not empty nor full. However, the
current code tests the latter case by comparing the zone write pointer
offset to the zone size instead of the zone capacity. Furthermore,
disk_get_and_lock_zone_wplug() is called with a sector argument equal to
the zone start instead of the current zone write pointer position.
This commit fixes both issues by calling disk_get_and_lock_zone_wplug()
for a zone that is not empty and with a write pointer offset lower than
the zone capacity and use the zone capacity sector as the sector
argument for disk_get_and_lock_zone_wplug().

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Exclude conventional zones when faking max open limit

For a device that has no limits for the maximum number of open and
active zones, we default to using the number of zones, limited to
BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE (128), for the maximum number of open
zones indicated to the user. However, for a device that has conventional
zones and less zones than BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, we should
not account conventional zones and set the limit to the number of
sequential write required zones. Furthermore, for cases where the limit
is equal to the number of sequential write required zones, we can
advertize a limit of 0 to indicate "no limits".

Fix this by moving the zone write plug mempool resizing from
disk_revalidate_zone_resources() to disk_update_zone_resources() where
we can safely compute the number of conventional zones and update the
limits.

Fixes: 843283e96e5a ("block: Fake max open zones limit when there is no limit")
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: check if zone_wplugs_hash exists in queue_zone_wplugs_show

Changhui reported a kernel crash when running this simple shell
reproducer:
# cd /sys/kernel/debug/block && find . -type f -exec grep -aH . {} \;

The above results in a NULL pointer dereference if a device does not have
a zone_wplugs_hash allocated.

To fix this, return early if we don't have a zone_wplugs_hash.

Reported-by: Changhui Zhong <czhong@redhat.com>
Fixes: a98b05b02f0f ("block: Replace zone_wlock debugfs entry with zone_wplugs entry")
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/e5fec079dfca448cc21c425cfa5d7b291f5faa67.1714046443.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use a per disk workqueue for zone write plugging

A zone write plug BIO work function blk_zone_wplug_bio_work() calls
submit_bio_noacct_nocheck() to execute the next unplugged BIO. This
function may block. So executing zone plugs BIO works using the block
layer global kblockd workqueue can potentially lead to preformance or
latency issues as the number of concurrent work for a workqueue is
limited to WQ_DFL_ACTIVE (256).
1) For a system with a large number of zoned disks, issuing write
requests to otherwise unused zones may be delayed wiating for a work
thread to become available.
2) Requeue operations which use kblockd but are independent of zone
write plugging may alsoi end up being delayed.

To avoid these potential performance issues, create a workqueue per
zoned device to execute zone plugs BIO work. The workqueue max active
parameter is set to the maximum number of zone write plugs allocated
with the zone write plug mempool. This limit is equal to the maximum
number of open zones of the disk and defaults to 128 for disks that do
not have a limit on the number of open zones.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240420075811.1276893-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Remove zone write locking

Zone write locking is now unused and replaced with zone write plugging.
Remove all code that was implementing zone write locking, that is, the
various helper functions controlling request zone write locking and
the gendisk attached zone bitmaps.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-27-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Replace zone_wlock debugfs entry with zone_wplugs entry

In preparation to completely remove zone write locking, replace the
"zone_wlock" mq-debugfs entry that was listing zones that are
write-locked with the zone_wplugs entry which lists the zones that
currently have a write plug allocated.

The write plug information provided is: the zone number, the zone write
plug flags, the zone write plug write pointer offset and the number of
BIOs currently waiting for execution in the zone write plug BIO list.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-26-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Move zone related debugfs attribute to blk-zoned.c

block/blk-mq-debugfs-zone.c contains a single debugfs attribute
function. Defining this outside of block/blk-zoned.c does not really
help in any way, so move this zone related debugfs attribute to
block/blk-zoned.c and delete block/blk-mq-debugfs-zone.c.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-25-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify blk_revalidate_disk_zones() interface

The only user of blk_revalidate_disk_zones() second argument was the
SCSI disk driver (sd). Now that this driver does not require this
update_driver_data argument, remove it to simplify the interface of
blk_revalidate_disk_zones(). Also update the function kdoc comment to
be more accurate (i.e. there is no gendisk ->revalidate method).

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-21-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Allow BIO-based drivers to use blk_revalidate_disk_zones()

In preparation for allowing BIO based device drivers to use zone write
plugging and its zone append emulation, allow these drivers to call
blk_revalidate_disk_zones() so that all zone resources necessary to zone
write plugging can be initialized.

To do so, remove the check in blk_revalidate_disk_zones() restricting
the use of this function to mq request-based drivers to allow also
BIO-based drivers to use it. This is safe to do as long as the
BIO-based block device queue is already setup and usable, as it should,
and can be safely frozen.

The helper function disk_need_zone_resources() is added to control the
allocation and initialization of the zone write plug hash table and
of the conventional zone bitmap only for mq devices and for BIO-based
devices that require zone append emulation.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-12-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Implement zone append emulation

Given that zone write plugging manages all writes to zones of a zoned
block device and tracks the write pointer position of all zones that are
not full nor empty, emulating zone append operations using regular
writes can be implemented generically, without relying on the underlying
device driver to implement such emulation. This is needed for devices
that do not natively support the zone append command (e.g. SMR
hard-disks).

A device may request zone append emulation by setting its
max_zone_append_sectors queue limit to 0. For such device, the function
blk_zone_wplug_prepare_bio() changes zone append BIOs into
non-mergeable regular write BIOs. Modified zone append BIOs are flagged
with the new BIO flag BIO_EMULATES_ZONE_APPEND. This flag is checked
on completion of the BIO in blk_zone_write_plug_bio_endio() to restore
the original REQ_OP_ZONE_APPEND operation code of the BIO.

The block layer internal inline helper function bio_is_zone_append() is
added to test if a BIO is either a native zone append operation
(REQ_OP_ZONE_APPEND operation code) or if it is flagged with
BIO_EMULATES_ZONE_APPEND. Given that both native and emulated zone
append BIO completion handling should be similar, The functions
blk_update_request() and blk_zone_complete_request_bio() are modified to
use bio_is_zone_append() to execute blk_zone_update_request_bio() for
both native and emulated zone append operations.

This commit contains contributions from Christoph Hellwig <hch@lst.de>.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-11-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Allow zero value of max_zone_append_sectors queue limit

In preparation for adding a generic zone append emulation using zone
write plugging, allow device drivers supporting zoned block device to
set a the max_zone_append_sectors queue limit of a device to 0 to
indicate the lack of native support for zone append operations and that
the block layer should emulate these operations using regular write
operations.

blk_queue_max_zone_append_sectors() is modified to allow passing 0 as
the max_zone_append_sectors argument. The function
queue_max_zone_append_sectors() is also modified to ensure that the
minimum of the max_hw_sectors and chunk_sectors limit is used whenever
the max_zone_append_sectors limit is 0. This minimum is consistent with
the value set for the max_zone_append_sectors limit by the function
blk_validate_zoned_limits() when limits for a queue are validated.

The helper functions queue_emulates_zone_append() and
bdev_emulates_zone_append() are added to test if a queue (or block
device) emulates zone append operations.

In order for blk_revalidate_disk_zones() to accept zoned block devices
relying on zone append emulation, the direct check to the
max_zone_append_sectors queue limit of the disk is replaced by a check
using the value returned by queue_max_zone_append_sectors(). Similarly,
queue_zone_append_max_show() is modified to use the same accessor so
that the sysfs attribute advertizes the non-zero limit that will be
used, regardless if it is for native or emulated commands.

For stacking drivers, a top device should not need to care if the
underlying devices have native or emulated zone append operations.
blk_stack_limits() is thus modified to set the top device
max_zone_append_sectors limit using the new accessor
queue_limits_max_zone_append_sectors(). queue_max_zone_append_sectors()
is modified to use this function as well. Stacking drivers that require
zone append emulation, e.g. dm-crypt, can still request this feature by
calling blk_queue_max_zone_append_sectors() with a 0 limit.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-10-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fake max open zones limit when there is no limit

For a zoned block device that has no limit on the number of open zones
and no limit on the number of active zones, the zone write plug mempool
is created with a size of 128 zone write plugs. For such case, set the
device max_open_zones queue limit to this value to indicate to the user
the potential performance penalty that may happen when writing
simultaneously to more zones than the mempool size.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-9-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Introduce zone write plugging

Zone write plugging implements a per-zone "plug" for write operations
to control the submission and execution order of write operations to
sequential write required zones of a zoned block device. Per-zone
plugging guarantees that at any time there is at most only one write
request per zone being executed. This mechanism is intended to replace
zone write locking which implements a similar per-zone write throttling
at the scheduler level, but is implemented only by mq-deadline.

Unlike zone write locking which operates on requests, zone write
plugging operates on BIOs. A zone write plug is simply a BIO list that
is atomically manipulated using a spinlock and a kblockd submission
work. A write BIO to a zone is "plugged" to delay its execution if a
write BIO for the same zone was already issued, that is, if a write
request for the same zone is being executed. The next plugged BIO is
unplugged and issued once the write request completes.

This mechanism allows to:
- Untangle zone write ordering from block IO schedulers. This allows
removing the restriction on using mq-deadline for writing to zoned
block devices. Any block IO scheduler, including "none" can be used.
- Zone write plugging operates on BIOs instead of requests. Plugged
BIOs waiting for execution thus do not hold scheduling tags and thus
are not preventing other BIOs from executing (reads or writes to
other zones). Depending on the workload, this can significantly
improve the device use (higher queue depth operation) and
performance.
- Both blk-mq (request based) zoned devices and BIO-based zoned devices
(e.g. device mapper) can use zone write plugging. It is mandatory
for the former but optional for the latter. BIO-based drivers can
use zone write plugging to implement write ordering guarantees, or
the drivers can implement their own if needed.
- The code is less invasive in the block layer and is mostly limited to
blk-zoned.c with some small changes in blk-mq.c, blk-merge.c and
bio.c.

Zone write plugging is implemented using struct blk_zone_wplug. This
structure includes a spinlock, a BIO list and a work structure to
handle the submission of plugged BIOs. Zone write plugs structures are
managed using a per-disk hash table.

Plugging of zone write BIOs is done using the function
blk_zone_write_plug_bio() which returns false if a BIO execution does
not need to be delayed and true otherwise. This function is called
from blk_mq_submit_bio() after a BIO is split to avoid large BIOs
spanning multiple zones which would cause mishandling of zone write
plugs. This ichange enables by default zone write plugging for any mq
request-based block device. BIO-based device drivers can also use zone
write plugging by expliclty calling blk_zone_write_plug_bio() in their
->submit_bio method. For such devices, the driver must ensure that a
BIO passed to blk_zone_write_plug_bio() is already split and not
straddling zone boundaries.

Only write and write zeroes BIOs are plugged. Zone write plugging does
not introduce any significant overhead for other operations. A BIO that
is being handled through zone write plugging is flagged using the new
BIO flag BIO_ZONE_WRITE_PLUGGING. A request handling a BIO flagged with
this new flag is flagged with the new RQF_ZONE_WRITE_PLUGGING flag.
The completion of BIOs and requests flagged trigger respectively calls
to the functions blk_zone_write_bio_endio() and
blk_zone_write_complete_request(). The latter function is used to
trigger submission of the next plugged BIO using the zone plug work.
blk_zone_write_bio_endio() does the same for BIO-based devices.
This ensures that at any time, at most one request (blk-mq devices) or
one BIO (BIO-based devices) is being executed for any zone. The
handling of zone write plugs using a per-zone plug spinlock maximizes
parallelism and device usage by allowing multiple zones to be writen
simultaneously without lock contention.

Zone write plugging ignores flush BIOs without data. Hovever, any flush
BIO that has data is always plugged so that the write part of the flush
sequence is serialized with other regular writes.

Given that any BIO handled through zone write plugging will be the only
BIO in flight for the target zone when it is executed, the unplugging
and submission of a BIO will have no chance of successfully merging with
plugged requests or requests in the scheduler. To overcome this
potential performance degradation, blk_mq_submit_bio() calls the
function blk_zone_write_plug_attempt_merge() to try to merge other
plugged BIOs with the one just unplugged and submitted. Successful
merging is signaled using blk_zone_write_plug_bio_merged(), called from
bio_attempt_back_merge(). Furthermore, to avoid recalculating the number
of segments of plugged BIOs to attempt merging, the number of segments
of a plugged BIO is saved using the new struct bio field
__bi_nr_segments. To avoid growing the size of struct bio, this field is
added as a union with the bio_cookie field. This is safe to do as
polling is always disabled for plugged BIOs.

When BIOs are plugged in a zone write plug, the device request queue
usage counter is always incremented. This reference is kept and reused
for blk-mq devices when the plugged BIO is unplugged and submitted
again using submit_bio_noacct_nocheck(). For this case, the unplugged
BIO is already flagged with BIO_ZONE_WRITE_PLUGGING and
blk_mq_submit_bio() proceeds directly to allocating a new request for
the BIO, re-using the usage reference count taken when the BIO was
plugged. This extra reference count is dropped in
blk_zone_write_plug_attempt_merge() for any plugged BIO that is
successfully merged. Given that BIO-based devices will not take this
path, the extra reference is dropped after a plugged BIO is unplugged
and submitted.

Zone write plugs are dynamically allocated and managed using a hash
table (an array of struct hlist_head) with RCU protection.
A zone write plug is allocated when a write BIO is received for the
zone and not freed until the zone is fully written, reset or finished.
To detect when a zone write plug can be freed, the write state of each
zone is tracked using a write pointer offset which corresponds to the
offset of a zone write pointer relative to the zone start. Write
operations always increment this write pointer offset. Zone reset
operations set it to 0 and zone finish operations set it to the zone
size.

If a write error happens, the wp_offset value of a zone write plug may
become incorrect and out of sync with the device managed write pointer.
This is handled using the zone write plug flag BLK_ZONE_WPLUG_ERROR.
The function blk_zone_wplug_handle_error() is called from the new disk
zone write plug work when this flag is set. This function executes a
report zone to update the zone write pointer offset to the current
value as indicated by the device. The disk zone write plug work is
scheduled whenever a BIO flagged with BIO_ZONE_WRITE_PLUGGING completes
with an error or when bio_zone_wplug_prepare_bio() detects an unaligned
write. Once scheduled, the disk zone write plugs work keeps running
until all zone errors are handled.

To match the new data structures used for zoned disks, the function
disk_free_zone_bitmaps() is renamed to the more generic
disk_free_zone_resources(). The function disk_init_zone_resources() is
also introduced to initialize zone write plugs resources when a gendisk
is allocated.

In order to guarantee that the user can simultaneously write up to a
number of zones equal to a device max active zone limit or max open zone
limit, zone write plugs are allocated using a mempool sized to the
maximum of these 2 device limits. For a device that does not have
active and open zone limits, 128 is used as the default mempool size.

If a change to the device active and open zone limits is detected, the
disk mempool is resized when blk_revalidate_disk_zones() is executed.

This commit contains contributions from Christoph Hellwig <hch@lst.de>.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240408014128.205141-8-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Remember zone capacity when revalidating zones

In preparation for adding zone write plugging, modify
blk_revalidate_disk_zones() to get the capacity of zones of a zoned
block device. This capacity value as a number of 512B sectors is stored
in the gendisk zone_capacity field.

Given that host-managed SMR disks (including zoned UFS drives) and all
known NVMe ZNS devices have the same zone capacity for all zones
blk_revalidate_disk_zones() returns an error if different capacities are
detected for different zones.

This also adds check to verify that the values reported by the device
for zone capacities are correct, that is, that the zone capacity is
never 0, does not exceed the zone size and is equal to the zone size for
conventional zones.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240408014128.205141-7-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Do not include rbtree.h in blk-zoned.c

The block zone code does not use RB-tree. So remove the include of
linux/rbtree.h as it is not needed.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240222131724.1803520-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove gfp_flags from blkdev_zone_mgmt

Now that all callers pass in GFP_KERNEL to blkdev_zone_mgmt() and use
memalloc_no{io,fs}_{save,restore}() to define the allocation scope, we can
drop the gfp_mask parameter from blkdev_zone_mgmt() as well as
blkdev_zone_reset_all() and blkdev_zone_reset_all_emulated().

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20240128-zonefs_nofs-v3-5-ae3b7c8def61@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Treat sequential write preferred zone type as invalid

With the removal of the support for host-aware zoned devices,
blk_revalidate_zone_cb() should never see the zone type
BLK_ZONE_TYPE_SEQWRITE_PREF (sequential write preffered zones). Treat
this zone type as being invalid.

Fixes: 7437bb73f087 ("block: remove support for the host aware zone model")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240107072212.1071080-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove disk_clear_zoned

disk_clear_zoned is unused now that the last warts of the host-aware
model support in sd are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231228075141.362560-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: export disk_clear_zoned()

A previous commit split disk_set_zoned(..., bool) into not taking an
argument for whether to set or clear, and instead added
disk_clear_zoned() as the counterpart. However, that commit neglected
to export the new symbol, causing failures for modular drivers that
used it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: d73e93b4dfab ("block: simplify disk_set_zoned")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: simplify disk_set_zoned

Only use disk_set_zoned to actually enable zoned device support.
For clearing it, call disk_clear_zoned, which is renamed from
disk_clear_zone_settings and now directly clears the zoned flag as
well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: block: Improve checks in blk_revalidate_disk_zones()

blk_revalidate_disk_zones() implements checks of the zones of a zoned
block device, verifying that the zone size is a power of 2 number of
sectors, that all zones (except possibly the last one) have the same
size and that zones cover the entire addressing space of the device.

While these checks are appropriate to verify that well tested hardware
devices have an adequate zone configurations, they lack in certain areas
which may result in issues with emulated devices implemented with user
drivers such as ublk or tcmu. Specifically, this function does not
check if the device driver indicated support for the mandatory zone
append writes, that is, if the device max_zone_append_sectors queue
limit is set to a non-zero value. Additionally, invalid zones such as
a zero length zone with a start sector equal to the device capacity will
not be detected and result in out of bounds use of the zone bitmaps
prepared with the callback function blk_revalidate_zone_cb().

Improve blk_revalidate_disk_zones() to address these inadequate checks,
relying on the fact that all device drivers supporting zoned block
devices must set the device zone size (chunk_sectors queue limit) and
the max_zone_append_sectors queue limit before executing this function.

The check for a non-zero max_zone_append_sectors value is done in
blk_revalidate_disk_zones() before executing the zone report. The zone
report callback function blk_revalidate_zone_cb() is also modified to
add a check that a zone start is below the device capacity.

The check that the zone size is a power of 2 number of sectors is moved
to blk_revalidate_disk_zones() as the zone size is already known.
Similarly, the number of zones of the device can be calculated in
blk_revalidate_disk_zones() before executing the zone report.

The kdoc comment for blk_revalidate_disk_zones() is also updated to
mention that device drivers must set the device zone size and the
max_zone_append_sectors queue limit before calling this function.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230703024812.76778-6-dlemoal@kernel.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove unused fmode_t arguments from ioctl handlers

A few ioctl handlers have fmode_t arguments that are entirely unused,
remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Introduce blk_rq_is_seq_zoned_write()

Introduce the function blk_rq_is_seq_zoned_write(). This function will
be used in later patches to preserve the order of zoned writes that
require write serialization.

This patch includes an optimization: instead of using
rq->q->disk->part0->bd_queue to check whether or not the queue is
associated with a zoned block device, use rq->q->disk->queue.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230517174230.897144-6-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify blk_req_needs_zone_write_lock()

Remove the blk_rq_is_passthrough() check because it is redundant:
blk_req_needs_zone_write_lock() also calls bdev_op_is_zoned_write()
and the latter function returns false for pass-through requests.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230517174230.897144-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: remove more NULL checks after bdev_get_queue()

bdev_get_queue() never returns NULL. Several commits [1][2] have been made
before to remove such superfluous checks, but some still remained.

For places where bdev_get_queue() is called solely for NULL checks, it is
removed entirely.

[1] commit ec9fd2a13d74 ("blk-lib: don't check bdev_get_queue() NULL check")
[2] commit fea127b36c93 ("block: remove superfluous check for request queue in bdev_is_zoned()")

Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20230203024029.48260-1-qkrwngud825@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a new helper bdev_{is_zone_start, offset_from_zone_start}

Instead of open coding to check for zone start, add a helper to improve
readability and store the logic in one place.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230110143635.77300-3-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: adapt blk_mq_plug() to not plug for writes that require a zone lock

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: Christoph Hellwig <hch@lst.de>
Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220929074745.103073-2-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: Rename enum req_opf into enum req_op

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 ef295ecf090d ("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: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-2-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move zone related fields to struct gendisk

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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-17-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use bdev based helpers in blkdev_zone_mgmt{,all}

Use the bdev based helpers instead of the queue based ones to clean up
the code a bit and prepare for storing all zone related fields in
struct gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: replace blkdev_nr_zones with bdev_nr_zones

Pass a block_device instead of a request_queue as that is what most
callers have at hand.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a gendisk to blk_queue_free_zone_bitmaps

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a gendisk to blk_queue_clear_zone_settings

Switch to a gendisk based API in preparation for moving all zone related
fields from the request_queue to the gendisk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: use bdev_is_zoned instead of open coding it

Use bdev_is_zoned in all places where a block_device is available instead
of open coding it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220706070350.1703384-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: block: Remove REQ_OP_WRITE_SAME support

No more users of REQ_OP_WRITE_SAME or drivers implementing it are left,
so remove the infrastructure.

[mkp: fold in and tweak sysfs reporting fix]

Link: https://lore.kernel.org/r/20220209082828.2629273-8-hch@lst.de
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: pass a block_device and opf to bio_init

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment. A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: pass a block_device and opf to blk_next_bio

All callers need to set the block_device and operation, so lift that into
the common code.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Hold invalidate_lock in BLKRESETZONE ioctl

When BLKRESETZONE ioctl and data read race, the data read leaves stale
page cache. The commit e5113505904e ("block: Discard page cache of zone
reset target range") added page cache truncation to avoid stale page
cache after the ioctl. However, the stale page cache still can be read
during the reset zone operation for the ioctl. To avoid the stale page
cache completely, hold invalidate_lock of the block device file mapping.

Fixes: e5113505904e ("block: Discard page cache of zone reset target range")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Cc: stable@vger.kernel.org # v5.15
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211111085238.942492-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN

A user space process should not need the CAP_SYS_ADMIN capability set
in order to perform a BLKREPORTZONE ioctl.

Getting the zone report is required in order to get the write pointer.
Neither read() nor write() requires CAP_SYS_ADMIN, so it is reasonable
that a user space process that can read/write from/to the device, also
can get the write pointer. (Since e.g. writes have to be at the write
pointer.)

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Reviewed-by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: stable@vger.kernel.org # v4.10+
Link: https://lore.kernel.org/r/20210811110505.29649-3-Niklas.Cassel@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-zoned: allow zone management send operations without CAP_SYS_ADMIN

Zone management send operations (BLKRESETZONE, BLKOPENZONE, BLKCLOSEZONE
and BLKFINISHZONE) should be allowed under the same permissions as write().
(write() does not require CAP_SYS_ADMIN).

Additionally, other ioctls like BLKSECDISCARD and BLKZEROOUT only check if
the fd was successfully opened with FMODE_WRITE.
(They do not require CAP_SYS_ADMIN).

Currently, zone management send operations require both CAP_SYS_ADMIN
and that the fd was successfully opened with FMODE_WRITE.

Remove the CAP_SYS_ADMIN requirement, so that zone management send
operations match the access control requirement of write(), BLKSECDISCARD
and BLKZEROOUT.

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Reviewed-by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: stable@vger.kernel.org # v4.10+
Link: https://lore.kernel.org/r/20210811110505.29649-2-Niklas.Cassel@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: improve handling of all zones reset operation

SCSI, ZNS and null_blk zoned devices support resetting all zones using
a single command (REQ_OP_ZONE_RESET_ALL), as indicated using the device
request queue flag QUEUE_FLAG_ZONE_RESETALL. This flag is not set for
device mapper targets creating zoned devices. In this case, a user
request for resetting all zones of a device is processed in
blkdev_zone_mgmt() by issuing a REQ_OP_ZONE_RESET operation for each
zone of the device. This leads to different behaviors of the
BLKRESETZONE ioctl() depending on the target device support for the
reset all operation. E.g.

blkzone reset /dev/sdX

will reset all zones of a SCSI device using a single command that will
ignore conventional, read-only or offline zones.

But a dm-linear device including conventional, read-only or offline
zones cannot be reset in the same manner as some of the single zone
reset operations issued by blkdev_zone_mgmt() will fail. E.g.:

blkzone reset /dev/dm-Y
blkzone: /dev/dm-0: BLKRESETZONE ioctl failed: Remote I/O error

To simplify applications and tools development, unify the behavior of
the all-zone reset operation by modifying blkdev_zone_mgmt() to not
issue a zone reset operation for conventional, read-only and offline
zones, thus mimicking what an actual reset-all device command does on a
device supporting REQ_OP_ZONE_RESET_ALL. This emulation is done using
the new function blkdev_zone_reset_all_emulated(). The zones needing a
reset are identified using a bitmap that is initialized using a zone
report. Since empty zones do not need a reset, also ignore these zones.
The function blkdev_zone_reset_all() is introduced for block devices
natively supporting reset all operations. blkdev_zone_mgmt() is modified
to call either function to execute an all zone reset request.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
[hch: split into multiple functions]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

blk-zoned: Remove the definition of blk_zone_start()

Commit e76239a3748c ("block: add a report_zones method") removed the last
blk_zone_start() call. Hence also remove the definition of this function.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210406200820.15180-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Discard page cache of zone reset target range

When zone reset ioctl and data read race for a same zone on zoned block
devices, the data read leaves stale page cache even though the zone
reset ioctl zero clears all the zone data on the device. To avoid
non-zero data read from the stale page cache after zone reset, discard
page cache of reset target zones in blkdev_zone_mgmt_ioctl(). Introduce
the helper function blkdev_truncate_zone_range() to discard the page
cache. Ensure the page cache discarded by calling the helper function
before and after zone reset in same manner as fallocate does.

This patch can be applied back to the stable kernel version v5.10.y.
Rework is needed for older stable kernels.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Cc: <stable@vger.kernel.org> # 5.10+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210311072546.678999-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix REQ_OP_ZONE_RESET_ALL handling

Similarly to a single zone reset operation (REQ_OP_ZONE_RESET), execute
REQ_OP_ZONE_RESET_ALL operations with REQ_SYNC set.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: introduce blk_queue_clear_zone_settings()

Introduce the internal function blk_queue_clear_zone_settings() to
cleanup all limits and resources related to zoned block devices. This
new function is called from blk_queue_set_zoned() when a disk zoned
model is set to BLK_ZONED_NONE. This particular case can happens when a
partition is created on a host-aware scsi disk.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@edc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Improve blk_revalidate_disk_zones() checks

Improves the checks on the zones of a zoned block device done in
blk_revalidate_disk_zones() by making sure that the device report_zones
method did report at least one zone and that the zones reported exactly
cover the entire disk capacity, that is, that there are no missing zones
at the end of the disk sector range.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't do revalidate zones on invalid devices

When we loose a device for whatever reason while (re)scanning zones, we
trip over a NULL pointer in blk_revalidate_zone_cb, like in the following
log:

sd 0:0:0:0: [sda] 3418095616 4096-byte logical blocks: (14.0 TB/12.7 TiB)
sd 0:0:0:0: [sda] 52156 zones of 65536 logical blocks
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 37 00 00 08
sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
sd 0:0:0:0: [sda] REPORT ZONES start lba 1065287680 failed
sd 0:0:0:0: [sda] REPORT ZONES: Result: hostbyte=0x00 driverbyte=0x08
sd 0:0:0:0: [sda] Sense Key : 0xb [current]
sd 0:0:0:0: [sda] ASC=0x0 ASCQ=0x6
sda: failed to revalidate zones
sd 0:0:0:0: [sda] 0 4096-byte logical blocks: (0 B/0 B)
sda: detected capacity change from 14000519643136 to 0
==================================================================
BUG: KASAN: null-ptr-deref in blk_revalidate_zone_cb+0x1b7/0x550
Write of size 8 at addr 0000000000000010 by task kworker/u4:1/58

CPU: 1 PID: 58 Comm: kworker/u4:1 Not tainted 5.8.0-rc1 #692
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
Workqueue: events_unbound async_run_entry_fn
Call Trace:
dump_stack+0x7d/0xb0
? blk_revalidate_zone_cb+0x1b7/0x550
kasan_report.cold+0x5/0x37
? blk_revalidate_zone_cb+0x1b7/0x550
check_memory_region+0x145/0x1a0
blk_revalidate_zone_cb+0x1b7/0x550
sd_zbc_parse_report+0x1f1/0x370
? blk_req_zone_write_trylock+0x200/0x200
? sectors_to_logical+0x60/0x60
? blk_req_zone_write_trylock+0x200/0x200
? blk_req_zone_write_trylock+0x200/0x200
sd_zbc_report_zones+0x3c4/0x5e0
? sd_dif_config_host+0x500/0x500
blk_revalidate_disk_zones+0x231/0x44d
? _raw_write_lock_irqsave+0xb0/0xb0
? blk_queue_free_zone_bitmaps+0xd0/0xd0
sd_zbc_read_zones+0x8cf/0x11a0
sd_revalidate_disk+0x305c/0x64e0
? __device_add_disk+0x776/0xf20
? read_capacity_16.part.0+0x1080/0x1080
? blk_alloc_devt+0x250/0x250
? create_object.isra.0+0x595/0xa20
? kasan_unpoison_shadow+0x33/0x40
sd_probe+0x8dc/0xcd2
really_probe+0x20e/0xaf0
__driver_attach_async_helper+0x249/0x2d0
async_run_entry_fn+0xbe/0x560
process_one_work+0x764/0x1290
? _raw_read_unlock_irqrestore+0x30/0x30
worker_thread+0x598/0x12f0
? __kthread_parkme+0xc6/0x1b0
? schedule+0xed/0x2c0
? process_one_work+0x1290/0x1290
kthread+0x36b/0x440
? kthread_create_worker_on_cpu+0xa0/0xa0
ret_from_fork+0x22/0x30
==================================================================

When the device is already gone we end up with the following scenario:
The device's capacity is 0 and thus the number of zones will be 0 as well. When
allocating the bitmap for the conventional zones, we then trip over a NULL
pointer.

So if we encounter a zoned block device with a 0 capacity, don't dare to
revalidate the zones sizes.

Fixes: 6c6b35491422 ("block: set the zone size in blk_revalidate_disk_zones atomically")
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add capacity field to zone descriptors

In the zoned storage model, the sectors within a zone are typically all
writeable. With the introduction of the Zoned Namespace (ZNS) Command
Set in the NVM Express organization, the model was extended to have a
specific writeable capacity.

Extend the zone descriptor data structure with a zone capacity field to
indicate to the user how many sectors in a zone are writeable.

Introduce backward compatibility in the zone report ioctl by extending
the zone report header data structure with a flags field to indicate if
the capacity field is available.

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

block: Modify revalidate zones

Modify the interface of blk_revalidate_disk_zones() to add an optional
driver callback function that a driver can use to extend processing
done during zone revalidation. The callback, if defined, is executed
with the device request queue frozen, after all zones have been
inspected.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: introduce blk_req_zone_write_trylock

Introduce blk_req_zone_write_trylock(), which either grabs the write-lock
for a sequential zone or returns false, if the zone is already locked.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a zone condition debug helper

Add a helper to stringify the zone conditions. We use this helper in the
next patch to track zone conditions in tracepoints.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block, zoned: fix integer overflow with BLKRESETZONE et al

Check for overflow in addition before checking for end-of-block-device.

Steps to reproduce:

#define _GNU_SOURCE 1
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

typedef unsigned long long __u64;

struct blk_zone_range {
__u64 sector;
__u64 nr_sectors;
};

#define BLKRESETZONE _IOW(0x12, 131, struct blk_zone_range)

int main(void)
{
int fd = open("/dev/nullb0", O_RDWR|O_DIRECT);
struct blk_zone_range zr = {4096, 0xfffffffffffff000ULL};
ioctl(fd, BLKRESETZONE, &zr);
return 0;
}

BUG: KASAN: null-ptr-deref in submit_bio_wait+0x74/0xe0
Write of size 8 at addr 0000000000000040 by task a.out/1590

CPU: 8 PID: 1590 Comm: a.out Not tainted 5.6.0-rc1-00019-g359c92c02bfa #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
Call Trace:
dump_stack+0x76/0xa0
__kasan_report.cold+0x5/0x3e
kasan_report+0xe/0x20
submit_bio_wait+0x74/0xe0
blkdev_zone_mgmt+0x26f/0x2a0
blkdev_zone_mgmt_ioctl+0x14b/0x1b0
blkdev_ioctl+0xb28/0xe60
block_ioctl+0x69/0x80
ksys_ioctl+0x3af/0xa50

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: mark zone-mgmt bios with REQ_SYNC

In the current implementation, final zone-mgmt request is issued with
submit_bio_wait() which marks the bio REQ_SYNC. This is needed since
immediate action is expected for zone-mgmt requests as these are
blocking operations. This also bypasses the scheduler in the
blk_mq_make_request() and dispatches the request directly into the
hw ctx.

This patch marks all the chained bios REQ_SYNC so that we can have
above-mentioned behavior for non-final bios also.

Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: set the zone size in blk_revalidate_disk_zones atomically

The current zone revalidation code has a major problem in that it
doesn't update the zone size and q->nr_zones atomically, leading
to a short window where an out of bounds access to the zone arrays
is possible.

To fix this move the setting of the zone size into the crticial
sections blk_revalidate_disk_zones so that it gets updated together
with the zone bitmaps and q->nr_zones. This also slightly simplifies
the caller as it deducts the zone size from the report_zones.

This change also allows to check for a power of two zone size in generic
code.

Reported-by: Hans Holmberg <hans@owltronix.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: don't handle bio based drivers in blk_revalidate_disk_zones

bio based drivers only need to update q->nr_zones. Do that manually
instead of overloading blk_revalidate_disk_zones to keep that function
simpler for the next round of changes that will rely even more on the
request based functionality.

Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: allocate the zone bitmaps lazily

Allocate the conventional zone bitmap and the sequential zone locking
bitmap only when we find a zone of the respective type. This avoids
wasting memory on the conventional zone bitmap for devices that only
have sequential zones, and will also prepare for other future changes.

Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: replace seq_zones_bitmap with conv_zones_bitmap

Invert the meaning of seq_zones_bitmap by keeping a bitmap of
conventional zones. This allows not having a bitmap for devices
that do not have conventional zones.

Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: simplify blkdev_nr_zones

Simplify the arguments to blkdev_nr_zones by passing a gendisk instead
of the block_device and capacity. This also removes the need for
__blkdev_nr_zones as all callers are outside the fast path and can
deal with the additional branch.

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

block: remove the empty line at the end of blk-zoned.c

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

block: rework zone reporting

Avoid the need to allocate a potentially large array of struct blk_zone
in the block layer by switching the ->report_zones method interface to
a callback model. Now the caller simply supplies a callback that is
executed on each reported zone, and private data for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Remove partition support for zoned block devices

No known partitioning tool supports zoned block devices, especially the
host managed flavor with strong sequential write constraints.
Furthermore, there are also no known user nor use cases for partitioned
zoned block devices.

This patch removes partition device creation for zoned block devices,
which allows simplifying the processing of zone commands for zoned
block devices. A warning is added if a partition table is found on the
device.

For report zones operations no zone sector information remapping is
necessary anymore, simplifying the code. Of note is that remapping of
zone reports for DM targets is still necessary as done by
dm_remap_zone_report().

Similarly, remaping of a zone reset bio is not necessary anymore.
Testing for the applicability of the zone reset all request also becomes
simpler and only needs to check that the number of sectors of the
requested zone range is equal to the disk capacity.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify report zones execution

All kernel users of blkdev_report_zones() as well as applications use
through ioctl(BLKZONEREPORT) expect to potentially get less zone
descriptors than requested. As such, the use of the internal report
zones command execution loop implemented by blk_report_zones() is
not necessary and can even be harmful to performance by causing the
execution of inefficient small zones report command to service the
reminder of a requested zone array.

This patch removes blk_report_zones(), simplifying the code. Also
remove a now incorrect comment in dm_blk_report_zones().

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Javier Gonzalez <javier@javigon.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: cleanup the !zoned case in blk_revalidate_disk_zones

blk_revalidate_disk_zones is never called for non-zoned devices. Just
return early and warn instead of trying to handle this case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Enhance blk_revalidate_disk_zones()

For ZBC and ZAC zoned devices, the scsi driver revalidation processing
implemented by sd_revalidate_disk() includes a call to
sd_zbc_read_zones() which executes a full disk zone report used to
check that all zones of the disk are the same size. This processing is
followed by a call to blk_revalidate_disk_zones(), used to initialize
the device request queue zone bitmaps (zone type and zone write lock
bitmaps). To do so, blk_revalidate_disk_zones() also executes a full
device zone report to obtain zone types. As a result, the entire
zoned block device revalidation process includes two full device zone
report.

By moving the zone size checks into blk_revalidate_disk_zones(), this
process can be optimized to a single full device zone report, leading to
shorter device scan and revalidation times. This patch implements this
optimization, reducing the original full device zone report implemented
in sd_zbc_check_zones() to a single, small, report zones command
execution to obtain the size of the first zone of the device. Checks
whether all zones of the device are the same size as the first zone
size are moved to the generic blk_check_zone() function called from
blk_revalidate_disk_zones().

This optimization also has the following benefits:
1) fewer memory allocations in the scsi layer during disk revalidation
as the potentailly large buffer for zone report execution is not
needed.
2) Implement zone checks in a generic manner, reducing the burden on
device driver which only need to obtain the zone size and check that
this size is a power of 2 number of LBAs. Any new type of zoned
block device will benefit from this.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add zone open, close and finish ioctl support

Introduce three new ioctl commands BLKOPENZONE, BLKCLOSEZONE and
BLKFINISHZONE to allow applications to control the condition of zones
on a zoned block device through the execution of the REQ_OP_ZONE_OPEN,
REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH operations.

Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.

Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add zone open, close and finish operations

Zoned block devices (ZBC and ZAC devices) allow an explicit control
over the condition (state) of zones. The operations allowed are:
* Open a zone: Transition to open condition to indicate that a zone will
actively be written
* Close a zone: Transition to closed condition to release the drive
resources used for writing to a zone
* Finish a zone: Transition an open or closed zone to the full
condition to prevent write operations

To enable this control for in-kernel zoned block device users, define
the new request operations REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE
and REQ_OP_ZONE_FINISH as well as the generic function
blkdev_zone_mgmt() for submitting these operations on a range of zones.
This results in blkdev_reset_zones() removal and replacement with this
new zone magement function. Users of blkdev_reset_zones() (f2fs and
dm-zoned) are updated accordingly.

Contains contributions from Matias Bjorling, Hans Holmberg,
Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig.

Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Simplify REQ_OP_ZONE_RESET_ALL handling

There is no need for the function __blkdev_reset_all_zones() as
REQ_OP_ZONE_RESET_ALL can be handled directly in blkdev_reset_zones()
bio loop with an early break from the loop. This patch removes this
function and modifies blkdev_reset_zones(), simplifying the code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Remove REQ_OP_ZONE_RESET plugging

REQ_OP_ZONE_RESET operations cannot be merged as these bios and requests
do not have a size and are never sequential due to the zone start sector
position required for their execution. As a result, there is no point in
using a plug around blkdev_reset_zones() bio issuing loop. This patch
removes this unnecessary plugging.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

blk-zoned: implement REQ_OP_ZONE_RESET_ALL

This implements REQ_OP_ZONE_RESET_ALL as a special case of the block
device zone reset operations where we just simply issue bio with the
newly introduced req op.

We issue this req op when the number of sectors is equal to the device's
partition's number of sectors and device has no partitions.

We also add support so that blk_op_str() can print the new reset-all
zone operation.

This patch also adds a generic make request check for newly
introduced REQ_OP_ZONE_RESET_ALL req_opf. We simply return error
when queue is zoned and reset-all flag is not set for
REQ_OP_ZONE_RESET_ALL.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Limit zone array allocation size

Limit the size of the struct blk_zone array used in
blk_revalidate_disk_zones() to avoid memory allocation failures leading
to disk revalidation failure. Also further reduce the likelyhood of
such failures by using kvcalloc() (that is vmalloc()) instead of
allocating contiguous pages with alloc_pages().

Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
Fixes: e76239a3748c ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Kill gfp_t argument of blkdev_report_zones()

Only GFP_KERNEL and GFP_NOIO are used with blkdev_report_zones(). In
preparation of using vmalloc() for large report buffer and zone array
allocations used by this function, remove its "gfp_t gfp_mask" argument
and rely on the caller context to use memalloc_noio_save/restore() where
necessary (block layer zone revalidation and dm-zoned I/O error path).

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix potential overflow in blk_report_zones()

For large values of the number of zones reported and/or large zone
sizes, the sector increment calculated with

blk_queue_zone_sectors(q) * n

in blk_report_zones() loop can overflow the unsigned int type used for
the calculation as both "n" and blk_queue_zone_sectors() value are
unsigned int. E.g. for a device with 256 MB zones (524288 sectors),
overflow happens with 8192 or more zones reported.

Changing the return type of blk_queue_zone_sectors() to sector_t, fixes
this problem and avoids overflow problem for all other callers of this
helper too. The same change is also applied to the bdev_zone_sectors()
helper.

Fixes: e76239a3748c ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add SPDX tags to block layer files missing licensing information

Various block layer files do not have any licensing information at all.
Add SPDX tags for the default kernel GPLv2 license to those.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Fix null_blk_zoned creation failure with small number of zones

null_blk_zoned creation fails if the number of zones specified is equal to or is
smaller than 64 due to a memory allocation failure in blk_alloc_zones(). With
such a small number of zones, the required memory size for all zones descriptors
fits in a single page, and the page order for alloc_pages_node() is zero. Allow
this value in blk_alloc_zones() for the allocation to succeed.

Fixes: bf5054569653 "block: Introduce blk_revalidate_disk_zones()"
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add queue_is_mq() helper

Various spots check for q->mq_ops being non-NULL, but provide
a helper to do this instead.

Where the ->mq_ops != NULL check is redundant, remove it.

Since mq == rq-based now that legacy is gone, get rid of the
queue_is_rq_based() and just use queue_is_mq() everywhere.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Introduce blk_revalidate_disk_zones()

Drivers exposing zoned block devices have to initialize and maintain
correctness (i.e. revalidate) of the device zone bitmaps attached to
the device request queue (seq_zones_bitmap and seq_zones_wlock).

To simplify coding this, introduce a generic helper function
blk_revalidate_disk_zones() suitable for most (and likely all) cases.
This new function always update the seq_zones_bitmap and seq_zones_wlock
bitmaps as well as the queue nr_zones field when called for a disk
using a request based queue. For a disk using a BIO based queue, only
the number of zones is updated since these queues do not have
schedulers and so do not need the zone bitmaps.

With this change, the zone bitmap initialization code in sd_zbc.c can be
replaced with a call to this function in sd_zbc_read_zones(), which is
called from the disk revalidate block operation method.

A call to blk_revalidate_disk_zones() is also added to the null_blk
driver for devices created with the zoned mode enabled.

Finally, to ensure that zoned devices created with dm-linear or
dm-flakey expose the correct number of zones through sysfs, a call to
blk_revalidate_disk_zones() is added to dm_table_set_restrictions().

The zone bitmaps allocated and initialized with
blk_revalidate_disk_zones() are freed automatically from
__blk_release_queue() using the block internal function
blk_queue_free_zone_bitmaps().

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: add a report_zones method

Dispatching a report zones command through the request queue is a major
pain due to the command reply payload rewriting necessary. Given that
blkdev_report_zones() is executing everything synchronously, implement
report zones as a block device file operation instead, allowing major
simplification of the code in many places.

sd, null-blk, dm-linear and dm-flakey being the only block device
drivers supporting exposing zoned block devices, these drivers are
modified to provide the device side implementation of the
report_zones() block device file operation.

For device mappers, a new report_zones() target type operation is
defined so that the upper block layer calls blkdev_report_zones() can
be propagated down to the underlying devices of the dm targets.
Implementation for this new operation is added to the dm-linear and
dm-flakey targets.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[Damien]
* Changed method block_device argument to gendisk
* Various bug fixes and improvements
* Added support for null_blk, dm-linear and dm-flakey.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Improve zone reset execution

There is no need to synchronously execute all REQ_OP_ZONE_RESET BIOs
necessary to reset a range of zones. Similarly to what is done for
discard BIOs in blk-lib.c, all zone reset BIOs can be chained and
executed asynchronously and a synchronous call done only for the last
BIO of the chain.

Modify blkdev_reset_zones() to operate similarly to
blkdev_issue_discard() using the next_bio() helper for chaining BIOs. To
avoid code duplication of that function in blk_zoned.c, rename
next_bio() into blk_next_bio() and declare it as a block internal
function in blk.h.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Limit allocation of zone descriptors for report zones

There is no point in allocating more zone descriptors than the number of
zones a block device has for doing a zone report. Avoid doing that in
blkdev_report_zones_ioctl() by limiting the number of zone decriptors
allocated internally to process the user request.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Introduce blkdev_nr_zones() helper

Introduce the blkdev_nr_zones() helper function to get the total
number of zones of a zoned block device. This number is always 0 for a
regular block device (q->limits.zoned == BLK_ZONED_NONE case).

Replace hard-coded number of zones calculation in dmz_get_zoned_device()
with a call to this helper.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Remove a superfluous cast from blkdev_report_zones()

No cast is necessary when assigning a non-void pointer to a void
pointer.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: kvmalloc() -> kvmalloc_array()

The kvmalloc() function has a 2-factor argument form, kvmalloc_array(). This
patch replaces cases of:

kvmalloc(a * b, gfp)

with:
kvmalloc_array(a * b, gfp)

as well as handling cases of:

kvmalloc(a * b * c, gfp)

with:

kvmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kvmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kvmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kvmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kvmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kvmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kvmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kvmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kvmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kvmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kvmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kvmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kvmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kvmalloc
+ kvmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kvmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kvmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kvmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kvmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kvmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kvmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kvmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kvmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kvmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kvmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kvmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kvmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kvmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kvmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kvmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kvmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kvmalloc(C1 * C2 * C3, ...)
|
kvmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kvmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kvmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kvmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kvmalloc(sizeof(THING) * C2, ...)
|
kvmalloc(sizeof(TYPE) * C2, ...)
|
kvmalloc(C1 * C2 * C3, ...)
|
kvmalloc(C1 * C2, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kvmalloc
+ kvmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

blkdev_report_zones_ioctl(): Use vmalloc() to allocate large buffers

Avoid that complaints similar to the following appear in the kernel log
if the number of zones is sufficiently large:

fio: page allocation failure: order:9, mode:0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null)
Call Trace:
dump_stack+0x63/0x88
warn_alloc+0xf5/0x190
__alloc_pages_slowpath+0x8f0/0xb0d
__alloc_pages_nodemask+0x242/0x260
alloc_pages_current+0x6a/0xb0
kmalloc_order+0x18/0x50
kmalloc_order_trace+0x26/0xb0
__kmalloc+0x20e/0x220
blkdev_report_zones_ioctl+0xa5/0x1a0
blkdev_ioctl+0x1ba/0x930
block_ioctl+0x41/0x50
do_vfs_ioctl+0xaa/0x610
SyS_ioctl+0x79/0x90
do_syscall_64+0x79/0x1b0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Shaun Tancheff <shaun.tancheff@seagate.com>
Cc: Damien Le Moal <damien.lemoal@hgst.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: Suppress kernel-doc warnings triggered by blk-zoned.c

Avoid that building with W=1 causes the kernel-doc tool to complain
about undocumented function arguments for the blk-zoned.c source file.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: introduce zoned block devices zone write locking

Components relying only on the request_queue structure for accessing
block devices (e.g. I/O schedulers) have a limited knowledged of the
device characteristics. In particular, the device capacity cannot be
easily discovered, which for a zoned block device also result in the
inability to easily know the number of zones of the device (the zone
size is indicated by the chunk_sectors field of the queue limits).

Introduce the nr_zones field to the request_queue structure to simplify
access to this information. Also, add the bitmap seq_zone_bitmap which
indicates which zones of the device are sequential zones (write
preferred or write required) and the bitmap seq_zones_wlock which
indicates if a zone is write locked, that is, if a write request
targeting a zone was dispatched to the device. These fields are
initialized by the low level block device driver (sd.c for ZBC/ZAC
disks). They are not initialized by stacking drivers (device mappers)
handling zoned block devices (e.g. dm-linear).

Using this, I/O schedulers can introduce zone write locking to control
request dispatching to a zoned block device and avoid write request
reordering by limiting to at most a single write request per zone
outside of the scheduler at any time.

Based on previous patches from Damien Le Moal.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[Damien]
* Fixed comments and identation in blkdev.h
* Changed helper functions
* Fixed this commit message
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: replace bi_bdev with a gendisk pointer and partitions index

This way we don't need a block_device structure to submit I/O. The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open. Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device. But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.

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

block: Rename blk_queue_zone_size and bdev_zone_size

All block device data fields and functions returning a number of 512B
sectors are by convention named xxx_sectors while names in the form
xxx_size are generally used for a number of bytes. The blk_queue_zone_size
and bdev_zone_size functions were not following this convention so rename
them.

No functional change is introduced by this patch.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

Collapsed the two patches, they were nonsensically split and broke
bisection.

Signed-off-by: Jens Axboe <axboe@fb.com>

block: zoned: fix harmless maybe-uninitialized warning

The blkdev_report_zones produces a harmless warning when
-Wmaybe-uninitialized is set, after gcc gets a little confused
about the multiple 'goto' here:

block/blk-zoned.c: In function 'blkdev_report_zones':
block/blk-zoned.c:188:13: error: 'nz' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Moving the assignment to nr_zones makes this a little simpler
while also avoiding the warning reliably. I'm removing the
extraneous initialization of 'int ret' in the same patch, as
that is semi-related and could cause an uninitialized use of
that variable to not produce a warning.

Fixes: 6a0cb1bc106f ("block: Implement support for zoned block devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-zoned: implement ioctls

Adds the new BLKREPORTZONE and BLKRESETZONE ioctls for respectively
obtaining the zone configuration of a zoned block device and resetting
the write pointer of sequential zones of a zoned block device.

The BLKREPORTZONE ioctl maps directly to a single call of the function
blkdev_report_zones. The zone information result is passed as an array
of struct blk_zone identical to the structure used internally for
processing the REQ_OP_ZONE_REPORT operation. The BLKRESETZONE ioctl
maps to a single call of the blkdev_reset_zones function.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: Implement support for zoned block devices

Implement zoned block device zone information reporting and reset.
Zone information are reported as struct blk_zone. This implementation
does not differentiate between host-aware and host-managed device
models and is valid for both. Two functions are provided:
blkdev_report_zones for discovering the zone configuration of a
zoned block device, and blkdev_reset_zones for resetting the write
pointer of sequential zones. The helper function blk_queue_zone_size
and bdev_zone_size are also provided for, as the name suggest,
obtaining the zone size (in 512B sectors) of the zones of the device.

Signed-off-by: Hannes Reinecke <hare@suse.de>

[Damien: * Removed the zone cache
* Implement report zones operation based on earlier proposal
by Shaun Tancheff <shaun.tancheff@seagate.com>]
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>