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path: root/drivers/md/dm-zoned.h
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2022-07-14dm/dm-zoned: Use the enum req_op typeBart Van Assche1-1/+1
Improve static type checking by using the enum req_op type for arguments that represent a request operation. Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20220714180729.1065367-31-bvanassche@acm.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-02dm-zoned: remove the ->name field in struct dmz_devChristoph Hellwig1-5/+4
Just use the %pg format specifier to print the block device name directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: select reclaim zone based on device indexHannes Reinecke1-1/+4
per-device reclaim should select zones on that device only. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: allocate zone by device indexHannes Reinecke1-1/+2
When allocating a zone, pass in an indicator on which device the zone should be allocated; this increases performance for a multi-device setup because reclaim will now allocate zones on the device for which reclaim is running. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: move random and sequential zones into struct dmz_devHannes Reinecke1-4/+14
Random and sequential zones should be part of the respective device structure to make arbitration between devices possible. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: per-device reclaimHannes Reinecke1-18/+20
Instead of having one reclaim workqueue for the entire set we should be allocating a reclaim workqueue per device; doing so will reduce contention and should boost performance for a multi-device setup. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add metadata pointer to struct dmz_devHannes Reinecke1-3/+4
Add a metadata pointer within struct dmz_dev and use it as argument for blkdev_report_zones() instead of the metadata itself. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add device pointer to struct dm_zoneHannes Reinecke1-1/+3
Add a pointer, to the containing device, within struct dm_zone and kill dmz_zone_to_dev(). Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-06-05dm zoned: add a 'reserved' zone flagHannes Reinecke1-0/+2
Instead of counting the number of reserved zones in dmz_free_zone(), mark the zone as 'reserved' during allocation and simplify dmz_free_zone(). Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: terminate reclaim on congestionHannes Reinecke1-0/+3
When dmz_get_chunk_mapping() selects a zone which is under reclaim we should terminate the reclaim copy process. Since we're changing the zone itself, reclaim needs to run afterwards again anyway. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: reclaim random zones when idleHannes Reinecke1-1/+1
When the system is idle we should be starting reclaiming random zones, too. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: separate random and cache zonesHannes Reinecke1-1/+7
Instead of lumping emulated zones together with random zones we should be handling them as separate 'cache' zones. This improves code readability and allows an easier implementation of different cache policies. Also add additional allocation flags, to separate the type (cache, random, or sequential) from the purpose (eg reclaim). Also switch the allocation policy to not use random zones as buffer zones if cache zones are present. This avoids a performance drop when all cache zones are used. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-20dm zoned: metadata version 2Hannes Reinecke1-2/+5
Implement handling for metadata version 2. The new metadata adds a label and UUID for the device mapper device, and additional UUID for the underlying block devices. It also allows for an additional regular drive to be used for emulating random access zones. The emulated zones will be placed logically in front of the zones from the zoned block device, causing the superblocks and metadata to be stored on that device. The first zone of the original zoned device will be used to hold another, tertiary copy of the metadata; this copy carries a generation number of 0 and is never updated; it's just used for identification. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-19dm zoned: remove 'dev' argument from reclaimHannes Reinecke1-2/+2
Use the dmz_zone_to_dev() mapping function to remove the 'dev' argument from reclaim. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm zoned: Introduce dmz_dev_is_dying() and dmz_check_dev()Hannes Reinecke1-0/+3
Introduce accessors dmz_dev_is_dying() and dmz_check_dev() to avoid having to reference the devices directly. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm zoned: introduce dmz_metadata_label() to format device nameHannes Reinecke1-1/+3
Introduce dmz_metadata_label() to format the device-mapper device name and use it instead of the device name of the underlying device. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm zoned: move fields from struct dmz_dev to dmz_metadataHannes Reinecke1-7/+7
Move fields from the device structure into the metadata structure and provide accessor functions. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm zoned: store zone id within the zone structure and kill dmz_id()Hannes Reinecke1-1/+3
Instead of calculating the zone index by the offset within the zone array store the index within the structure itself. With that the helper dmz_id() is pointless and can be replaced with accessing the ->id value directly. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-05-15dm zoned: add 'status' callbackHannes Reinecke1-0/+3
Add callback to supply information for 'dmsetup status' and 'dmsetup table'. The output for 'dmsetup status' is 0 <size> zoned <nr_zones> zones <nr_unmap_rnd>/<nr_rnd> random <nr_unmap_seq>/<nr_seq> sequential where <nr_unmap_rnd> is the number of unmapped (ie free) random zones, <nr_rnd> the total number of random zones, <nr_unmap_seq> the number of unmapped sequential zones, and <nr_seq> the total number of sequential zones. Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Bob Liu <bob.liu@oracle.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-11-07dm zoned: reduce overhead of backing device checksDmitry Fomichev1-0/+2
Commit 75d66ffb48efb3 added backing device health checks and as a part of these checks, check_events() block ops template call is invoked in dm-zoned mapping path as well as in reclaim and flush path. Calling check_events() with ATA or SCSI backing devices introduces a blocking scsi_test_unit_ready() call being made in sd_check_events(). Even though the overhead of calling scsi_test_unit_ready() is small for ATA zoned devices, it is much larger for SCSI and it affects performance in a very negative way. Fix this performance regression by executing check_events() only in case of any I/O errors. The function dmz_bdev_is_dying() is modified to call only blk_queue_dying(), while calls to check_events() are made in a new helper function, dmz_check_bdev(). Reported-by: zhangxiaoxu <zhangxiaoxu5@huawei.com> Fixes: 75d66ffb48efb3 ("dm zoned: properly handle backing device failure") Cc: stable@vger.kernel.org Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-15dm zoned: add SPDX license identifiersDmitry Fomichev1-0/+1
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-15dm zoned: properly handle backing device failureDmitry Fomichev1-0/+10
dm-zoned is observed to lock up or livelock in case of hardware failure or some misconfiguration of the backing zoned device. This patch adds a new dm-zoned target function that checks the status of the backing device. If the request queue of the backing device is found to be in dying state or the SCSI backing device enters offline state, the health check code sets a dm-zoned target flag prompting all further incoming I/O to be rejected. In order to detect backing device failures timely, this new function is called in the request mapping path, at the beginning of every reclaim run and before performing any metadata I/O. The proper way out of this situation is to do dmsetup remove <dm-zoned target> and recreate the target when the problem with the backing device is resolved. Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-07-17dm zoned: fix zone state management raceDamien Le Moal1-4/+24
dm-zoned uses the zone flag DMZ_ACTIVE to indicate that a zone of the backend device is being actively read or written and so cannot be reclaimed. This flag is set as long as the zone atomic reference counter is not 0. When this atomic is decremented and reaches 0 (e.g. on BIO completion), the active flag is cleared and set again whenever the zone is reused and BIO issued with the atomic counter incremented. These 2 operations (atomic inc/dec and flag set/clear) are however not always executed atomically under the target metadata mutex lock and this causes the warning: WARN_ON(!test_bit(DMZ_ACTIVE, &zone->flags)); in dmz_deactivate_zone() to be displayed. This problem is regularly triggered with xfstests generic/209, generic/300, generic/451 and xfs/077 with XFS being used as the file system on the dm-zoned target device. Similarly, xfstests ext4/303, ext4/304, generic/209 and generic/300 trigger the warning with ext4 use. This problem can be easily fixed by simply removing the DMZ_ACTIVE flag and managing the "ACTIVE" state by directly looking at the reference counter value. To do so, the functions dmz_activate_zone() and dmz_deactivate_zone() are changed to inline functions respectively calling atomic_inc() and atomic_dec(), while the dmz_is_active() macro is changed to an inline function calling atomic_read(). Fixes: 3b1a94c88b79 ("dm zoned: drive-managed zoned block device target") Cc: stable@vger.kernel.org Reported-by: Masato Suzuki <masato.suzuki@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19dm zoned: drive-managed zoned block device targetDamien Le Moal1-0/+228
The dm-zoned device mapper target provides transparent write access to zoned block devices (ZBC and ZAC compliant block devices). dm-zoned hides to the device user (a file system or an application doing raw block device accesses) any constraint imposed on write requests by the device, equivalent to a drive-managed zoned block device model. Write requests are processed using a combination of on-disk buffering using the device conventional zones and direct in-place processing for requests aligned to a zone sequential write pointer position. A background reclaim process implemented using dm_kcopyd_copy ensures that conventional zones are always available for executing unaligned write requests. The reclaim process overhead is minimized by managing buffer zones in a least-recently-written order and first targeting the oldest buffer zones. Doing so, blocks under regular write access (such as metadata blocks of a file system) remain stored in conventional zones, resulting in no apparent overhead. dm-zoned implementation focus on simplicity and on minimizing overhead (CPU, memory and storage overhead). For a 14TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most about 3 MB and as little as 5 zones will be used internally for storing metadata and performing buffer zone reclaim operations. This is achieved using zone level indirection rather than a full block indirection system for managing block movement between zones. dm-zoned primary target is host-managed zoned block devices but it can also be used with host-aware device models to mitigate potential device-side performance degradation due to excessive random writing. Zoned block devices can be formatted and checked for use with the dm-zoned target using the dmzadm utility available at: https://github.com/hgst/dm-zoned-tools Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> [Mike Snitzer partly refactored Damien's original work to cleanup the code] Signed-off-by: Mike Snitzer <snitzer@redhat.com>