The functon dm_blk_report_zones reads md->zone_revalidate_map, however it
may change while the function is running. Use READ_ONCE.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 37f53a2c60 ("dm: fix dm_blk_report_zones")
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
The function dm_blk_report_zones tests if the device is suspended with
the "dm_suspended_md" call. However, this function is called without
holding any locks, so the device may be suspended just after it.
Move the call to dm_suspended_md after dm_get_live_table, so that the
device can't be suspended after the suspended state was tested.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 37f53a2c60 ("dm: fix dm_blk_report_zones")
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Pull device mapper updates from Mikulas Patocka:
- convert crypto_shash users to direct crypto library use with simpler
and faster code and reduced stack usage (Eric Biggers):
- the dm-verity SHA-256 conversion also teaches it to do two-way
interleaved hashing for added performance
- dm-crypt MD5 conversion (used for Loop-AES compatibility)
- added document for for takeover/reshape raid1 -> raid5 examples (Heinz Mauelshagen)
- fix dm-vdo kerneldoc warnings (Matthew Sakai)
- various random fixes and cleanups
* tag 'for-6.19/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (29 commits)
dm pcache: fix segment info indexing
dm pcache: fix cache info indexing
dm-pcache: advance slot index before writing slot
dm raid: add documentation for takeover/reshape raid1 -> raid5 table line examples
dm log-writes: Add missing set_freezable() for freezable kthread
dm-raid: fix possible NULL dereference with undefined raid type
dm-snapshot: fix 'scheduling while atomic' on real-time kernels
dm: ignore discard return value
MAINTAINERS: add Benjamin Marzinski as a device mapper maintainer
dm-mpath: Simplify the setup_scsi_dh code
dm vdo: fix kerneldoc warnings
dm-bufio: align write boundary on physical block size
dm-crypt: enable DM_TARGET_ATOMIC_WRITES
dm: test for REQ_ATOMIC in dm_accept_partial_bio()
dm-verity: remove useless mempool
dm-verity: disable recursive forward error correction
dm-ebs: Mark full buffer dirty even on partial write
dm mpath: enable DM_TARGET_ATOMIC_WRITES
dm verity fec: Expose corrected block count via status
dm: Don't warn if IMA_DISABLE_HTABLE is not enabled
...
dm_zone_get_reset_bitmap() is used to generate a bitmap of the zones of
a zoned device target when a REQ_OP_ZONE_RESET_ALL request is being
processed. This bitmap is built by executing a zone report with a report
callback set to the function dm_zone_need_reset_cb() in struct
dm_report_zones_args. However, the cb callback pointer is not anymore
the same as the callback specified by callers of the
blkdev_report_zones() function. Rather, this is a DM internal callback
and report zones callback functions from blkdev_report_zones() are
passed using struct blk_report_zones_args, introduced with commit
db9aed869f34 ("block: introduce disk_report_zone()").
This commit changed the DM main report zones callback handler function
dm_report_zones_cb() to call the new disk_report_zone() so that callback
functions from blkdev_report_zones() are executed, and this change
resulted in the DM internal dm_zone_need_reset_cb() callback function to
not be executed anymore, turning any REQ_OP_ZONE_RESET_ALL request into
a no-op.
Fix this by calling in dm_report_zones_cb() the DM internal cb function
specified in struct dm_report_zones_args.
Fixes: db9aed869f34 ("block: introduce disk_report_zone()").
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit b76b840fd9 ("dm: Fix dm-zoned-reclaim zone write pointer
alignment") introduced an indirect call for the callback function of a
report zones executed with blkdev_report_zones(). This is necessary so
that the function disk_zone_wplug_sync_wp_offset() can be called to
refresh a zone write plug zone write pointer offset after a write error.
However, this solution makes following the path of a zone information
harder to understand.
Clean this up by introducing the new blk_report_zones_args structure to
define a zone report callback and its private data and introduce the
helper function disk_report_zone() which calls both
disk_zone_wplug_sync_wp_offset() and the zone report user callback
function for all zones of a zone report. This helper function must be
called by all block device drivers that implement the report zones
block operation in order to correctly report a zone information.
All block device drivers supporting the report_zones block operation are
updated to use this new scheme.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The return statement at the end of dm_zone_endio() is not needed.
Remove it.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
If a DM device that can pass down zone append commands is stacked on top
of a device that emulates zone append commands, it will allocate zone
append emulation resources, even though it doesn't use them. This is
because the underlying device will have max_hw_zone_append_sectors set
to 0 to request zone append emulation. When the DM device is stacked on
top of it, it will inherit that max_hw_zone_append_sectors limit,
despite being able to pass down zone append bios. Solve this by making
sure max_hw_zone_append_sectors is non-zero for DM devices that do not
need zone append emulation.
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
dm_revalidate_zones() only allowed new or previously unzoned devices to
call blk_revalidate_disk_zones(). If the device was already zoned,
disk->nr_zones would always equal md->nr_zones, so dm_revalidate_zones()
returned without doing any work. This would make the zoned settings for
the device not match the new table. If the device had zone write plug
resources, it could run into errors like bdev_zone_is_seq() reading
invalid memory because disk->conv_zones_bitmap was the wrong size.
If the device doesn't have any zone write plug resources, calling
blk_revalidate_disk_zones() will always correctly update device. If
blk_revalidate_disk_zones() fails, it can still overwrite or clear the
current disk->nr_zones value. In this case, DM must restore the previous
value of disk->nr_zones, so that the zoned settings will continue to
match the previous value that it fell back to.
If the device already has zone write plug resources,
blk_revalidate_disk_zones() will not correctly update them, if it is
called for arbitrary zoned device changes. Since there is not much need
for this ability, the easiest solution is to disallow any table reloads
that change the zoned settings, for devices that already have zone plug
resources. Specifically, if a device already has zone plug resources
allocated, it can only switch to another zoned table that also emulates
zone append. Also, it cannot change the device size or the zone size. A
device can switch to an error target.
Fixes: bb37d77239 ("dm: introduce zone append emulation")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
If dm_get_live_table() returned NULL, dm_put_live_table() was never
called. Also, it is possible that md->zone_revalidate_map will change
while calling this function. Only read it once, so that we are always
using the same value. Otherwise we might miss a call to
dm_put_live_table().
Finally, while md->zone_revalidate_map is set and a process is calling
blk_revalidate_disk_zones() to set up the zone append emulation
resources, it is possible that another process, perhaps triggered by
blkdev_report_zones_ioctl(), will call dm_blk_report_zones(). If
blk_revalidate_disk_zones() fails, these resources can be freed while
the other process is still using them, causing a use-after-free error.
blk_revalidate_disk_zones() will only ever be called when initially
setting up the zone append emulation resources, such as when setting up
a zoned dm-crypt table for the first time. Further table swaps will not
set md->zone_revalidate_map or call blk_revalidate_disk_zones().
However it must be called using the new table (referenced by
md->zone_revalidate_map) and the new queue limits while the DM device is
suspended. dm_blk_report_zones() needs some way to distinguish between a
call from blk_revalidate_disk_zones(), which must be allowed to use
md->zone_revalidate_map to access this not yet activated table, and all
other calls to dm_blk_report_zones(), which should not be allowed while
the device is suspended and cannot use md->zone_revalidate_map, since
the zone resources might be freed by the process currently calling
blk_revalidate_disk_zones().
Solve this by tracking the process that sets md->zone_revalidate_map in
dm_revalidate_zones() and only allowing that process to make use of it
in dm_blk_report_zones().
Fixes: f211268ed1 ("dm: Use the block layer zone append emulation")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
If dm_table_set_restrictions() fails while swapping tables,
device-mapper will continue using the previous table. It must be sure to
leave the mapped_device in it's previous state on failure. Otherwise
device-mapper could end up using the old table with settings from the
unused table.
Do not update the mapped device in dm_set_zones_restrictions(). Wait
till after dm_table_set_restrictions() is sure to succeed to update the
md zoned settings. Do the same with the dax settings, and if
dm_revalidate_zones() fails, restore the original queue limits.
Fixes: 7f91ccd8a6 ("dm: Call dm_revalidate_zones() after setting the queue limits")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper. This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.
Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper. This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.
Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit implements processing of the REQ_OP_ZONE_RESET_ALL operation
for zoned mapped devices. Given that this operation always has a BIO
sector of 0 and a 0 size, processing through the regular BIO
__split_and_process_bio() function does not work because this function
would always select the first target. Instead, handling of this
operation is implemented using the function __send_zone_reset_all().
Similarly to the __send_empty_flush() function, the new
__send_zone_reset_all() function manually goes through all targets of a
mapped device table doing the following:
1) If the target can natively support REQ_OP_ZONE_RESET_ALL,
__send_duplicate_bios() is used to forward the reset all operation to
the target. This case is handled with the
__send_zone_reset_all_native() function.
2) For other targets, the function __send_zone_reset_all_emulated() is
executed to emulate the execution of REQ_OP_ZONE_RESET_ALL using
regular REQ_OP_ZONE_RESET operations.
Targets that can natively support REQ_OP_ZONE_RESET_ALL are identified
using the new target field zone_reset_all_supported. This boolean is set
to true in for targets that have reliable zone limits, that is, targets
that map all sequential write required zones of their zoned device(s).
Setting this field is handled in dm_set_zones_restrictions() and
device_get_zone_resource_limits().
For targets with unreliable zone limits, REQ_OP_ZONE_RESET_ALL must be
emulated (case 2 above). This is implemented with
__send_zone_reset_all_emulated() and is similar to the block layer
function blkdev_zone_reset_all_emulated(): first a report zones is done
for the zones of the target to identify zones that need reset, that is,
any sequential write required zone that is not already empty. This is
done using a bitmap and the function dm_zone_get_reset_bitmap() which
sets to 1 the bit corresponding to a zone that needs reset. Next, this
zone bitmap is inspected and a clone BIO modified to use the
REQ_OP_ZONE_RESET operation issued for any zone with its bit set in the
zone bitmap.
This implementation is more efficient than what the block layer does
with blkdev_zone_reset_all_emulated(), which is always used for DM zoned
devices currently: as we can natively use REQ_OP_ZONE_RESET_ALL on
targets mapping all sequential write required zones, resetting all zones
of a zoned mapped device can be much faster compared to always emulating
this operation using regular per-zone reset. In the worst case, this
implementation is as-efficient as the block layer emulation. This
reduction in the time it takes to reset all zones of a zoned mapped
device depends directly on the mapped device targets mapping (reliable
zone limits or not).
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge in last round of queue limits changes from Christoph.
* for-6.11/block-limits: (26 commits)
block: move the bounce flag into the features field
block: move the skip_tagset_quiesce flag to queue_limits
block: move the pci_p2pdma flag to queue_limits
block: move the zone_resetall flag to queue_limits
block: move the zoned flag into the features field
block: move the poll flag to queue_limits
block: move the dax flag to queue_limits
block: move the nowait flag to queue_limits
block: move the synchronous flag to queue_limits
block: move the stable_writes flag to queue_limits
block: move the io_stat flag setting to queue_limits
block: move the add_random flag to queue_limits
block: move the nonrot flag to queue_limits
block: move cache control settings out of queue->flags
block: remove blk_flush_policy
block: freeze the queue in queue_attr_store
nbd: move setting the cache control flags to __nbd_set_size
virtio_blk: remove virtblk_update_cache_mode
loop: fold loop_update_rotational into loop_reconfigure_limits
loop: also use the default block size from an underlying block device
...
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The generic stacking of limits implemented in the block layer cannot
correctly handle stacking of zone resource limits (max open zones and
max active zones) because these limits are for an entire device but the
stacking may be for a portion of that device (e.g. a dm-linear target
that does not cover an entire block device). As a result, when DM
devices are created on top of zoned block devices, the DM device never
has any zone resource limits advertized, which is only correct if all
underlying target devices also have no zone resource limits.
If at least one target device has resource limits, the user may see
either performance issues (if the max open zone limit of the device is
exceeded) or write I/O errors if the max active zone limit of one of
the underlying target devices is exceeded.
While it is very difficult to correctly and reliably stack zone resource
limits in general, cases where targets are not sharing zone resources of
the same device can be dealt with relatively easily. Such situation
happens when a target maps all sequential zones of a zoned block device:
for such mapping, other targets mapping other parts of the same zoned
block device can only contain conventional zones and thus will not
require any zone resource to correctly handle write operations.
For a mapped device constructed with such targets, which includes mapped
devices constructed with targets mapping entire zoned block devices, the
zone resource limits can be reliably determined using the non-zero
minimum of the zone resource limits of all targets.
For mapped devices that include targets partially mapping the set of
sequential write required zones of zoned block devices, instead of
advertizing no zone resource limits, it is also better to set the mapped
device limits to the non-zero minimum of the limits of all targets. In
this case the limits for a target depend on the number of sequential
zones being mapped: if this number of zone is larger than the limits,
then the limits of the device apply and can be used. If on the other
hand the target maps a number of zones smaller than the limits, then no
limits is needed and we can assume that the target has no limits (limits
set to 0).
This commit improves zone resource limits handling as described above
by modifying dm_set_zones_restrictions() to iterate the targets of a
mapped device to evaluate the max open and max active zone limits. This
relies on an internal "stacking" of the limits of the target devices
combined with a direct counting of the number of sequential zones
mapped by the targets.
1) For a target mapping an entire zoned block device, the limits for the
target are set to the limits of the device.
2) For a target partially mapping a zoned block device, the number of
mapped sequential zones is used to determine the limits: if the
target maps more sequential write required zones than the device
limits, then the limits of the device are used as-is. If the number
of mapped sequential zones is lower than the limits, then we assume
that the target has no limits (limits set to 0).
As this evaluation is done for each target, the zone resource limits
for the mapped device are evaluated as the non-zero minimum of the
limits of all the targets.
For configurations resulting in unreliable limits, i.e. a table
containing a target partially mapping a zoned device, a warning message
is issued.
The counting of mapped sequential zones for the target is done using the
new function dm_device_count_zones() which performs a report zones on
the entire block device with the callback dm_device_count_zones_cb().
This count of mapped sequential zones is also used to determine if the
mapped device contains only conventional zones. This allows simplifying
dm_set_zones_restrictions() to not do a report zones just for this.
For mapped devices mapping only conventional zones, as before, the
mapped device is changed to a regular device by setting its zoned limit
to false and clearing all its zone related limits.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240611023639.89277-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
dm_revalidate_zones() is called from dm_set_zone_restrictions() when the
mapped device queue limits are not yet set. However,
dm_revalidate_zones() calls blk_revalidate_disk_zones() and this
function consults and modifies the mapped device queue limits. Thus,
currently, blk_revalidate_disk_zones() operates on limits that are not
yet initialized.
Fix this by moving the call to dm_revalidate_zones() out of
dm_set_zone_restrictions() and into dm_table_set_restrictions() after
executing queue_limits_set().
To further cleanup dm_set_zones_restrictions(), the message about the
type of zone append (native or emulated) is also moved inside
dm_revalidate_zones().
Fixes: 1c0e720228 ("dm: use queue_limits_set")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240611023639.89277-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Using targets such as dm-linear, a mapped device can be created to
contain only conventional zones. Such device should not be treated as
zoned as it does not contain any mandatory sequential write required
zone. Since such device can be randomly written, we can modify
dm_set_zones_restrictions() to set the mapped device zoned queue limit
to false to expose it as a regular block device. The function
dm_check_zoned() does this after counting the number of conventional
zones of the mapped device and comparing it to the total number of zones
reported. The special dm_check_zoned_cb() report zones callback function
is used to count conventional zones.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Link: https://lore.kernel.org/r/20240501110907.96950-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
