block: move blkdev_{get,put} _no_open prototypes out of blkdev.h

These are only to be used by block internal code. Remove the comment
as we grew more users due to reworking block device node openin

block: move blkdev_{get,put} _no_open prototypes out of blkdev.h

These are only to be used by block internal code. Remove the comment
as we grew more users due to reworking block device node opening.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: hoist block size validation code to a separate function

Hoist the block size validation code to bdev_validate_blocksize so that
we can call it from filesystems that don't care about the bdev

block: hoist block size validation code to a separate function

Hoist the block size validation code to bdev_validate_blocksize so that
we can call it from filesystems that don't care about the bdev pagecache
manipulations of set_blocksize.

Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/174543795720.4139148.840349813093799165.stgit@frogsfrogsfrogs
Signed-off-by: Jens Axboe <[email protected]>

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block: introduce zone capacity helper

{bdev,disk}_zone_capacity() takes block_device or gendisk and sector position
and returns the zone capacity of the corresponding zone.

With that, move disk_nr_

block: introduce zone capacity helper

{bdev,disk}_zone_capacity() takes block_device or gendisk and sector position
and returns the zone capacity of the corresponding zone.

With that, move disk_nr_zones() and blk_zone_plug_bio() to consolidate them in
the same #ifdef block.

Signed-off-by: Naohiro Aota <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Chaitanya Kulkarni <[email protected]>
Signed-off-by: David Sterba <[email protected]>

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fs: move the bdex_statx call to vfs_getattr_nosec

Currently bdex_statx is only called from the very high-level
vfs_statx_path function, and thus bypassing it for in-kernel calls
to vfs_getattr or vf

fs: move the bdex_statx call to vfs_getattr_nosec

Currently bdex_statx is only called from the very high-level
vfs_statx_path function, and thus bypassing it for in-kernel calls
to vfs_getattr or vfs_getattr_nosec.

This breaks querying the block ѕize of the underlying device in the
loop driver and also is a pitfall for any other new kernel caller.

Move the call into the lowest level helper to ensure all callers get
the right results.

Fixes: 2d985f8c6b91 ("vfs: support STATX_DIOALIGN on block devices")
Fixes: f4774e92aab8 ("loop: take the file system minimum dio alignment into account")
Reported-by: "Darrick J. Wong" <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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block: protect debugfs attrs using elevator_lock instead of sysfs_lock

Currently, the block debugfs attributes (tags, tags_bitmap, sched_tags,
and sched_tags_bitmap) are protected using q->sysfs_loc

block: protect debugfs attrs using elevator_lock instead of sysfs_lock

Currently, the block debugfs attributes (tags, tags_bitmap, sched_tags,
and sched_tags_bitmap) are protected using q->sysfs_lock. However, these
attributes are updated in multiple scenarios:
- During driver probe method
- During an elevator switch/update
- During an nr_hw_queues update
- When writing to the sysfs attribute nr_requests

All these update paths (except driver probe method, which doesn't
require any protection) are already protected using q->elevator_lock. To
ensure consistency and proper synchronization, replace q->sysfs_lock
with q->elevator_lock for protecting these debugfs attributes.

Signed-off-by: Nilay Shroff <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[axboe: some commit message rewording/fixes]
Signed-off-by: Jens Axboe <[email protected]>

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block: protect hctx attributes/params using q->elevator_lock

Currently, hctx attributes (nr_tags, nr_reserved_tags, and cpu_list)
are protected using `q->sysfs_lock`. However, these attributes can b

block: protect hctx attributes/params using q->elevator_lock

Currently, hctx attributes (nr_tags, nr_reserved_tags, and cpu_list)
are protected using `q->sysfs_lock`. However, these attributes can be
updated in multiple scenarios:
- During the driver's probe method.
- When updating nr_hw_queues.
- When writing to the sysfs attribute nr_requests,
which can modify nr_tags.
The nr_requests attribute is already protected using q->elevator_lock,
but none of the update paths actually use q->sysfs_lock to protect hctx
attributes. So to ensure proper synchronization, replace q->sysfs_lock
with q->elevator_lock when reading hctx attributes through sysfs.

Additionally, blk_mq_update_nr_hw_queues allocates and updates hctx.
The allocation of hctx is protected using q->elevator_lock, however,
updating hctx params happens without any protection, so safeguard hctx
param update path by also using q->elevator_lock.

Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[axboe: wrap comment at 80 chars]
Signed-off-by: Jens Axboe <[email protected]>

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block: protect read_ahead_kb using q->limits_lock

The bdi->ra_pages could be updated under q->limits_lock because it's
usually calculated from the queue limits by queue_limits_commit_update.
So prot

block: protect read_ahead_kb using q->limits_lock

The bdi->ra_pages could be updated under q->limits_lock because it's
usually calculated from the queue limits by queue_limits_commit_update.
So protect reading/writing the sysfs attribute read_ahead_kb using
q->limits_lock instead of q->sysfs_lock.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: protect wbt_lat_usec using q->elevator_lock

The wbt latency and state could be updated while initializing the
elevator or exiting the elevator. It could be also updated while
configuring IO l

block: protect wbt_lat_usec using q->elevator_lock

The wbt latency and state could be updated while initializing the
elevator or exiting the elevator. It could be also updated while
configuring IO latency QoS parameters using cgroup. The elevator
code path is now protected with q->elevator_lock. So we should
protect the access to sysfs attribute wbt_lat_usec using q->elevator
_lock instead of q->sysfs_lock. White we're at it, also protect
ioc_qos_write(), which configures wbt parameters via cgroup, using
q->elevator_lock.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

show more ...

block: protect nr_requests update using q->elevator_lock

The sysfs attribute nr_requests could be simultaneously updated from
elevator switch/update or nr_hw_queue update code path. The update to
nr

block: protect nr_requests update using q->elevator_lock

The sysfs attribute nr_requests could be simultaneously updated from
elevator switch/update or nr_hw_queue update code path. The update to
nr_requests for each of those code paths runs holding q->elevator_lock.
So we should protect access to sysfs attribute nr_requests using q->
elevator_lock instead of q->sysfs_lock.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: introduce a dedicated lock for protecting queue elevator updates

A queue's elevator can be updated either when modifying nr_hw_queues
or through the sysfs scheduler attribute. Currently, elev

block: introduce a dedicated lock for protecting queue elevator updates

A queue's elevator can be updated either when modifying nr_hw_queues
or through the sysfs scheduler attribute. Currently, elevator switching/
updating is protected using q->sysfs_lock, but this has led to lockdep
splats[1] due to inconsistent lock ordering between q->sysfs_lock and
the freeze-lock in multiple block layer call sites.

As the scope of q->sysfs_lock is not well-defined, its (mis)use has
resulted in numerous lockdep warnings. To address this, introduce a new
q->elevator_lock, dedicated specifically for protecting elevator
switches/updates. And we'd now use this new q->elevator_lock instead of
q->sysfs_lock for protecting elevator switches/updates.

While at it, make elv_iosched_load_module() a static function, as it is
only called from elv_iosched_store(). Also, remove redundant parameters
from elv_iosched_load_module() function signature.

[1] https://lore.kernel.org/all/[email protected]/

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Signed-off-by: Nilay Shroff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: Remove zone write plugs when handling native zone append writes

For devices that natively support zone append operations,
REQ_OP_ZONE_APPEND BIOs are not processed through zone write plugging

block: Remove zone write plugs when handling native zone append writes

For devices that natively support zone append operations,
REQ_OP_ZONE_APPEND BIOs are not processed through zone write plugging
and are immediately issued to the zoned device. This means that there is
no write pointer offset tracking done for these operations and that a
zone write plug is not necessary.

However, when receiving a zone append BIO, we may already have a zone
write plug for the target zone if that zone was previously partially
written using regular write operations. In such case, since the write
pointer offset of the zone write plug is not incremented by the amount
of sectors appended to the zone, 2 issues arise:
1) we risk leaving the plug in the disk hash table if the zone is fully
written using zone append or regular write operations, because the
write pointer offset will never reach the "zone full" state.
2) Regular write operations that are issued after zone append operations
will always be failed by blk_zone_wplug_prepare_bio() as the write
pointer alignment check will fail, even if the user correctly
accounted for the zone append operations and issued the regular
writes with a correct sector.

Avoid these issues by immediately removing the zone write plug of zones
that are the target of zone append operations when blk_zone_plug_bio()
is called. The new function blk_zone_wplug_handle_native_zone_append()
implements this for devices that natively support zone append. The
removal of the zone write plug using disk_remove_zone_wplug() requires
aborting all plugged regular write using disk_zone_wplug_abort() as
otherwise the plugged write BIOs would never be executed (with the plug
removed, the completion path will never see again the zone write plug as
disk_get_zone_wplug() will return NULL). Rate-limited warnings are added
to blk_zone_wplug_handle_native_zone_append() and to
disk_zone_wplug_abort() to signal this.

Since blk_zone_wplug_handle_native_zone_append() is called in the hot
path for operations that will not be plugged, disk_get_zone_wplug() is
optimized under the assumption that a user issuing zone append
operations is not at the same time issuing regular writes and that there
are no hashed zone write plugs. The struct gendisk atomic counter
nr_zone_wplugs is added to check this, with this counter incremented in
disk_insert_zone_wplug() and decremented in disk_remove_zone_wplug().

To be consistent with this fix, we do not need to fill the zone write
plug hash table with zone write plugs for zones that are partially
written for a device that supports native zone append operations.
So modify blk_revalidate_seq_zone() to return early to avoid allocating
and inserting a zone write plug for partially written sequential zones
if the device natively supports zone append.

Reported-by: Jorgen Hansen <[email protected]>
Fixes: 9b1ce7f0c6f8 ("block: Implement zone append emulation")
Cc: [email protected]
Signed-off-by: Damien Le Moal <[email protected]>
Tested-by: Jorgen Hansen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: make segment size limit workable for > 4K PAGE_SIZE

Using PAGE_SIZE as a minimum expected DMA segment size in consideration
of devices which have a max DMA segment size of < 64k when used on

block: make segment size limit workable for > 4K PAGE_SIZE

Using PAGE_SIZE as a minimum expected DMA segment size in consideration
of devices which have a max DMA segment size of < 64k when used on 64k
PAGE_SIZE systems leads to devices not being able to probe such as
eMMC and Exynos UFS controller [0] [1] you can end up with a probe failure
as follows:

WARNING: CPU: 2 PID: 397 at block/blk-settings.c:339 blk_validate_limits+0x364/0x3c0

Ensure we use min(max_seg_size, seg_boundary_mask + 1) as the new min segment
size when max segment size is < PAGE_SIZE for 16k and 64k base page size systems.

If anyone need to backport this patch, the following commits are depended:

commit 6aeb4f836480 ("block: remove bio_add_pc_page")
commit 02ee5d69e3ba ("block: remove blk_rq_bio_prep")
commit b7175e24d6ac ("block: add a dma mapping iterator")

Link: https://lore.kernel.org/linux-block/[email protected]/ # [0]
Link: https://lore.kernel.org/linux-block/[email protected]/ # [1]
Cc: Yi Zhang <[email protected]>
Cc: John Garry <[email protected]>
Cc: Keith Busch <[email protected]>
Tested-by: Paul Bunyan <[email protected]>
Reviewed-by: Daniel Gomez <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block/bdev: lift block size restrictions to 64k

We now can support blocksizes larger than PAGE_SIZE, so in theory
we should be able to lift the restriction up to the max supported page
cache order.

block/bdev: lift block size restrictions to 64k

We now can support blocksizes larger than PAGE_SIZE, so in theory
we should be able to lift the restriction up to the max supported page
cache order. However bound ourselves to what we can currently validate
and test. Through blktests and fstest we can validate up to 64k today.

Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: "Matthew Wilcox (Oracle)" <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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block: get rid of request queue ->sysfs_dir_lock

The request queue uses ->sysfs_dir_lock for protecting the addition/
deletion of kobject entries under sysfs while we register/unregister
blk-mq. How

block: get rid of request queue ->sysfs_dir_lock

The request queue uses ->sysfs_dir_lock for protecting the addition/
deletion of kobject entries under sysfs while we register/unregister
blk-mq. However kobject addition/deletion is already protected with
kernfs/sysfs internal synchronization primitives. So use of q->sysfs_
dir_lock seems redundant.

Moreover, q->sysfs_dir_lock is also used at few other callsites along
with q->sysfs_lock for protecting the addition/deletion of kojects.
One such example is when we register with sysfs a set of independent
access ranges for a disk. Here as well we could get rid off q->sysfs_
dir_lock and only use q->sysfs_lock.

The only variable which q->sysfs_dir_lock appears to protect is q->
mq_sysfs_init_done which is set/unset while registering/unregistering
blk-mq with sysfs. But use of q->mq_sysfs_init_done could be easily
replaced using queue registered bit QUEUE_FLAG_REGISTERED.

So with this patch we remove q->sysfs_dir_lock from each callsite
and replace q->mq_sysfs_init_done using QUEUE_FLAG_REGISTERED.

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Nilay Shroff <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: Add common atomic writes enable flag

Currently only stacked devices need to explicitly enable atomic writes by
setting BLK_FEAT_ATOMIC_WRITES_STACKED flag.

This does not work well for device

block: Add common atomic writes enable flag

Currently only stacked devices need to explicitly enable atomic writes by
setting BLK_FEAT_ATOMIC_WRITES_STACKED flag.

This does not work well for device mapper stacking devices, as there many
sets of limits are stacked and what is the 'bottom' and 'top' device can
swapped. This means that BLK_FEAT_ATOMIC_WRITES_STACKED needs to be set
for many queue limits, which is messy.

Generalize enabling atomic writes enabling by ensuring that all devices
must explicitly set a flag - that includes NVMe, SCSI sd, and md raid.

Signed-off-by: John Garry <[email protected]>
Reviewed-by: Mike Snitzer <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: Ensure start sector is aligned for stacking atomic writes

For stacking atomic writes, ensure that the start sector is aligned with
the device atomic write unit min and any boundary. Otherwise

block: Ensure start sector is aligned for stacking atomic writes

For stacking atomic writes, ensure that the start sector is aligned with
the device atomic write unit min and any boundary. Otherwise, we may
permit misaligned atomic writes.

Rework bdev_can_atomic_write() into a common helper to resuse the
alignment check. There also use atomic_write_hw_unit_min, which is more
proper (than atomic_write_unit_min).

Fixes: d7f36dc446e89 ("block: Support atomic writes limits for stacked devices")
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: John Garry <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: add a queue_limits_commit_update_frozen helper

Add a helper that freezes the queue, updates the queue limits and
unfreezes the queue and convert all open coded versions of that to the
new hel

block: add a queue_limits_commit_update_frozen helper

Add a helper that freezes the queue, updates the queue limits and
unfreezes the queue and convert all open coded versions of that to the
new helper.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Nilay Shroff <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: fix docs for freezing of queue limits updates

queue_limits_commit_update is the function that needs to operate on a
frozen queue, not queue_limits_start_update. Update the kerneldoc
comments

block: fix docs for freezing of queue limits updates

queue_limits_commit_update is the function that needs to operate on a
frozen queue, not queue_limits_start_update. Update the kerneldoc
comments to reflect that.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Ming Lei <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Nilay Shroff <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: John Garry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: track queue dying state automatically for modeling queue freeze lockdep

Now we only verify the outmost freeze & unfreeze in current context in case
that !q->mq_freeze_depth, so it is reliable

block: track queue dying state automatically for modeling queue freeze lockdep

Now we only verify the outmost freeze & unfreeze in current context in case
that !q->mq_freeze_depth, so it is reliable to save queue lying state when
we want to lock the freeze queue since the state is one per-task variable
now.

Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: track disk DEAD state automatically for modeling queue freeze lockdep

Now we only verify the outmost freeze & unfreeze in current context in case
that !q->mq_freeze_depth, so it is reliable t

block: track disk DEAD state automatically for modeling queue freeze lockdep

Now we only verify the outmost freeze & unfreeze in current context in case
that !q->mq_freeze_depth, so it is reliable to save disk DEAD state when
we want to lock the freeze queue since the state is one per-task variable
now.

Doing this way can kill lots of false positive when freeze queue is
called before adding disk[1].

[1] https://lore.kernel.org/linux-block/[email protected]/

Signed-off-by: Ming Lei <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: Prevent potential deadlocks in zone write plug error recovery

Zone write plugging for handling writes to zones of a zoned block
device always execute a zone report whenever a write BIO to a z

block: Prevent potential deadlocks in zone write plug error recovery

Zone write plugging for handling writes to zones of a zoned block
device always execute a zone report whenever a write BIO to a zone
fails. The intent of this is to ensure that the tracking of a zone write
pointer is always correct to ensure that the alignment to a zone write
pointer of write BIOs can be checked on submission and that we can
always correctly emulate zone append operations using regular write
BIOs.

However, this error recovery scheme introduces a potential deadlock if a
device queue freeze is initiated while BIOs are still plugged in a zone
write plug and one of these write operation fails. In such case, the
disk zone write plug error recovery work is scheduled and executes a
report zone. This in turn can result in a request allocation in the
underlying driver to issue the report zones command to the device. But
with the device queue freeze already started, this allocation will
block, preventing the report zone execution and the continuation of the
processing of the plugged BIOs. As plugged BIOs hold a queue usage
reference, the queue freeze itself will never complete, resulting in a
deadlock.

Avoid this problem by completely removing from the zone write plugging
code the use of report zones operations after a failed write operation,
instead relying on the device user to either execute a report zones,
reset the zone, finish the zone, or give up writing to the device (which
is a fairly common pattern for file systems which degrade to read-only
after write failures). This is not an unreasonnable requirement as all
well-behaved applications, FSes and device mapper already use report
zones to recover from write errors whenever possible by comparing the
current position of a zone write pointer with what their assumption
about the position is.

The changes to remove the automatic error recovery are as follows:
- Completely remove the error recovery work and its associated
resources (zone write plug list head, disk error list, and disk
zone_wplugs_work work struct). This also removes the functions
disk_zone_wplug_set_error() and disk_zone_wplug_clear_error().

- Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into
BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write
plug whenever a write opration targetting the zone of the zone write
plug fails. This flag indicates that the zone write pointer offset is
not reliable and that it must be updated when the next report zone,
reset zone, finish zone or disk revalidation is executed.

- Modify blk_zone_write_plug_bio_endio() to set the
BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed
write BIO.

- Modify the function disk_zone_wplug_set_wp_offset() to clear this
new flag, thus implementing recovery of a correct write pointer
offset with the reset (all) zone and finish zone operations.

- Modify blkdev_report_zones() to always use the disk_report_zones_cb()
callback so that disk_zone_wplug_sync_wp_offset() can be called for
any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag.
This implements recovery of a correct write pointer offset for zone
write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within
the range of the report zones operation executed by the user.

- Modify blk_revalidate_seq_zone() to call
disk_zone_wplug_sync_wp_offset() for all sequential write required
zones when a zoned block device is revalidated, thus always resolving
any inconsistency between the write pointer offset of zone write
plugs and the actual write pointer position of sequential zones.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Cc: [email protected]
Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

show more ...

dm: Fix dm-zoned-reclaim zone write pointer alignment

The zone reclaim processing of the dm-zoned device mapper uses
blkdev_issue_zeroout() to align the write pointer of a zone being used
for reclai

dm: Fix dm-zoned-reclaim zone write pointer alignment

The zone reclaim processing of the dm-zoned device mapper uses
blkdev_issue_zeroout() to align the write pointer of a zone being used
for reclaiming another zone, to write the valid data blocks from the
zone being reclaimed at the same position relative to the zone start in
the reclaim target zone.

The first call to blkdev_issue_zeroout() will try to use hardware
offload using a REQ_OP_WRITE_ZEROES operation if the device reports a
non-zero max_write_zeroes_sectors queue limit. If this operation fails
because of the lack of hardware support, blkdev_issue_zeroout() falls
back to using a regular write operation with the zero-page as buffer.
Currently, such REQ_OP_WRITE_ZEROES failure is automatically handled by
the block layer zone write plugging code which will execute a report
zones operation to ensure that the write pointer of the target zone of
the failed operation has not changed and to "rewind" the zone write
pointer offset of the target zone as it was advanced when the write zero
operation was submitted. So the REQ_OP_WRITE_ZEROES failure does not
cause any issue and blkdev_issue_zeroout() works as expected.

However, since the automatic recovery of zone write pointers by the zone
write plugging code can potentially cause deadlocks with queue freeze
operations, a different recovery must be implemented in preparation for
the removal of zone write plugging report zones based recovery.

Do this by introducing the new function blk_zone_issue_zeroout(). This
function first calls blkdev_issue_zeroout() with the flag
BLKDEV_ZERO_NOFALLBACK to intercept failures on the first execution
which attempt to use the device hardware offload with the
REQ_OP_WRITE_ZEROES operation. If this attempt fails, a report zone
operation is issued to restore the zone write pointer offset of the
target zone to the correct position and blkdev_issue_zeroout() is called
again without the BLKDEV_ZERO_NOFALLBACK flag. The report zones
operation performing this recovery is implemented using the helper
function disk_zone_sync_wp_offset() which calls the gendisk report_zones
file operation with the callback disk_report_zones_cb(). This callback
updates the target write pointer offset of the target zone using the new
function disk_zone_wplug_sync_wp_offset().

dmz_reclaim_align_wp() is modified to change its call to
blkdev_issue_zeroout() to a call to blk_zone_issue_zeroout() without any
other change needed as the two functions are functionnally equivalent.

Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Cc: [email protected]
Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Mike Snitzer <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: return bool from get_disk_ro and bdev_read_only

get_disk_ro and bdev_read_only return boolean conditions,
don't masquerade them as int.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed

block: return bool from get_disk_ro and bdev_read_only

get_disk_ro and bdev_read_only return boolean conditions,
don't masquerade them as int.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: remove a duplicate definition for bdev_read_only

bdev_read_only is already defined as an inline function in blkdev.h.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <j

block: remove a duplicate definition for bdev_read_only

bdev_read_only is already defined as an inline function in blkdev.h.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

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block: return bool from blk_rq_aligned

blk_rq_aligned returns a boolean condition, don't mascquerade it as int.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <john.g.garry@o

block: return bool from blk_rq_aligned

blk_rq_aligned returns a boolean condition, don't mascquerade it as int.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: John Garry <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

show more ...