kernel/linux.git/drivers/md/dm.h, branch v6.19.11

block: introduce disk_report_zone()

2025-11-05T15:07:21+00:00

Commit b76b840fd933 ("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 Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

dm: limit swapping tables for devices with zone write plugs

2025-05-04T09:35:05+00:00

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: bb37d77239af2 ("dm: introduce zone append emulation") Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka

dm: handle failures in dm_table_set_restrictions

2025-04-11T11:38:53+00:00

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: 7f91ccd8a608d ("dm: Call dm_revalidate_zones() after setting the queue limits") Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka

dm: Remove unused dm_table_bio_based

2024-11-20T10:38:04+00:00

dm_table_bio_based() is unused since commit 29dec90a0f1d ("dm: fix bio_set allocation") Remove it. Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Mikulas Patocka

dm: Remove unused dm_set_md_type

2024-11-20T10:38:04+00:00

dm_set_md_type() has been unused since commit ba30585936b0 ("dm: move setting md->type into dm_setup_md_queue") Remove it. Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Mikulas Patocka

dm: Remove unused declaration and empty definition "dm_zone_map_bio"

2024-08-21T11:12:12+00:00

dm_zone_map_bio() has beed removed since commit f211268ed1f9 ("dm: Use the block layer zone append emulation"), remain the declaration unused in header files. So, let's remove this unused declaration and empty definition. Signed-off-by: Zhang Zekun Reviewed-by: Damien Le Moal Signed-off-by: Mikulas Patocka

dm: handle REQ_OP_ZONE_RESET_ALL

2024-07-05T06:42:04+00:00

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 Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240704052816.623865-4-dlemoal@kernel.org Signed-off-by: Jens Axboe

dm: Call dm_revalidate_zones() after setting the queue limits

2024-06-16T02:42:20+00:00

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: 1c0e720228ad ("dm: use queue_limits_set") Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Benjamin Marzinski Reviewed-by: Niklas Cassel Link: https://lore.kernel.org/r/20240611023639.89277-3-dlemoal@kernel.org Signed-off-by: Jens Axboe

dm: make dm_set_zones_restrictions work on the queue limits

2024-05-27T15:16:39+00:00

Don't stuff the values directly into the queue without any synchronization, but instead delay applying the queue limits in the caller and let dm_set_zones_restrictions work on the limit structure. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20240527123634.1116952-4-hch@lst.de Signed-off-by: Jens Axboe

dm: Use the block layer zone append emulation

2024-04-17T14:44:03+00:00

For targets requiring zone append operation emulation with regular writes (e.g. dm-crypt), we can use the block layer emulation provided by zone write plugging. Remove DM implemented zone append emulation and enable the block layer one. This is done by setting the max_zone_append_sectors limit of the mapped device queue to 0 for mapped devices that have a target table that cannot support native zone append operations (e.g. dm-crypt). Such mapped devices are flagged with the DMF_EMULATE_ZONE_APPEND flag. dm_split_and_process_bio() is modified to execute blk_zone_write_plug_bio() for such device to let the block layer transform zone append operations into regular writes. This is done after ensuring that the submitted BIO is split if it straddles zone boundaries. Both changes are implemented unsing the inline helpers dm_zone_write_plug_bio() and dm_zone_bio_needs_split() respectively. dm_revalidate_zones() is also modified to use the block layer provided function blk_revalidate_disk_zones() so that all zone resources needed for zone append emulation are initialized by the block layer without DM core needing to do anything. Since the device table is not yet live when dm_revalidate_zones() is executed, enabling the use of blk_revalidate_disk_zones() requires adding a pointer to the device table in struct mapped_device. This avoids errors in dm_blk_report_zones() trying to get the table with dm_get_live_table(). The mapped device table pointer is set to the table passed as argument to dm_revalidate_zones() before calling blk_revalidate_disk_zones() and reset to NULL after this function returns to restore the live table handling for user call of report zones. All the code related to zone append emulation is removed from dm-zone.c. This leads to simplifications of the functions __map_bio() and dm_zone_endio(). This later function now only needs to deal with completions of real zone append operations for targets that support it. Signed-off-by: Damien Le Moal Reviewed-by: Mike Snitzer Reviewed-by: Hannes Reinecke Tested-by: Hans Holmberg Tested-by: Dennis Maisenbacher Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20240408014128.205141-13-dlemoal@kernel.org Signed-off-by: Jens Axboe