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path: root/drivers/md/dm-zone.c
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2022-05-06dm: don't grab target io reference in dm_zone_map_bioMing Lei1-10/+0
dm_zone_map_bio() is only called from __map_bio in which the io's reference is grabbed already, and the reference won't be released until the bio is submitted, so not necessary to do it dm_zone_map_bio any more. Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-04-13dm zone: fix NULL pointer dereference in dm_zone_map_bioMike Snitzer1-21/+28
Commit 0fbb4d93b38b ("dm: add dm_submit_bio_remap interface") changed the alloc_io() function to delay the initialization of struct dm_io's orig_bio member, leaving it NULL until after the dm_io and associated user submitted bio is processed by __split_and_process_bio(). This change causes a NULL pointer dereference in dm_zone_map_bio() when the original user bio is inspected to detect the need for zone append command emulation. Fix this NULL pointer by updating dm_zone_map_bio() to not access ->orig_bio when the same info can be accessed from the clone of the ->orig_bio _before_ any ->map processing. Save off the bio_op() and bio_sectors() for the clone and then use the saved orig_bio_details as needed. Fixes: 0fbb4d93b38b ("dm: add dm_submit_bio_remap interface") Reported-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-02-23scsi: dm: Remove WRITE_SAME supportChristoph Hellwig1-4/+0
There are no more end-users of REQ_OP_WRITE_SAME left, so we can start deleting it. Link: https://lore.kernel.org/r/20220209082828.2629273-7-hch@lst.de Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-25dm zone: fix dm_revalidate_zones() memory allocationDamien Le Moal1-2/+8
Make sure that the zone write pointer offset array is allocated with a vmalloc in dm_zone_revalidate_cb() by passing GFP_KERNEL gfp flag to kvcalloc(). However, since we do not want to trigger IOs while revalidating zones, change dm_revalidate_zones() to have the zone scan done in GFP_NOIO context using memalloc_noio_save/restore calls. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: bb37d77239af ("dm: introduce zone append emulation") Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm: introduce zone append emulationDamien Le Moal1-31/+549
For zoned targets that cannot support zone append operations, implement an emulation using regular write operations. If the original BIO submitted by the user is a zone append operation, change its clone into a regular write operation directed at the target zone write pointer position. To do so, an array of write pointer offsets (write pointer position relative to the start of a zone) is added to struct mapped_device. All operations that modify a sequential zone write pointer (writes, zone reset, zone finish and zone append) are intersepted in __map_bio() and processed using the new functions dm_zone_map_bio(). Detection of the target ability to natively support zone append operations is done from dm_table_set_restrictions() by calling the function dm_set_zones_restrictions(). A target that does not support zone append operation, either by explicitly declaring it using the new struct dm_target field zone_append_not_supported, or because the device table contains a non-zoned device, has its mapped device marked with the new flag DMF_ZONE_APPEND_EMULATED. The helper function dm_emulate_zone_append() is introduced to test a mapped device for this new flag. Atomicity of the zones write pointer tracking and updates is done using a zone write locking mechanism based on a bitmap. This is similar to the block layer method but based on BIOs rather than struct request. A zone write lock is taken in dm_zone_map_bio() for any clone BIO with an operation type that changes the BIO target zone write pointer position. The zone write lock is released if the clone BIO is failed before submission or when dm_zone_endio() is called when the clone BIO completes. The zone write lock bitmap of the mapped device, together with a bitmap indicating zone types (conv_zones_bitmap) and the write pointer offset array (zwp_offset) are allocated and initialized with a full device zone report in dm_set_zones_restrictions() using the function dm_revalidate_zones(). For failed operations that may have modified a zone write pointer, the zone write pointer offset is marked as invalid in dm_zone_endio(). Zones with an invalid write pointer offset are checked and the write pointer updated using an internal report zone operation when the faulty zone is accessed again by the user. All functions added for this emulation have a minimal overhead for zoned targets natively supporting zone append operations. Regular device targets are also not affected. The added code also does not impact builds with CONFIG_BLK_DEV_ZONED disabled by stubbing out all dm zone related functions. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm: Forbid requeue of writes to zonesDamien Le Moal1-0/+17
A target map method requesting the requeue of a bio with DM_MAPIO_REQUEUE or completing it with DM_ENDIO_REQUEUE can cause unaligned write errors if the bio is a write operation targeting a sequential zone. If a zoned target request such a requeue, warn about it and kill the IO. The function dm_is_zone_write() is introduced to detect write operations to zoned targets. This change does not affect the target drivers supporting zoned devices and exposing a zoned device, namely dm-crypt, dm-linear and dm-flakey as none of these targets ever request a requeue. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm: Introduce dm_report_zones()Damien Le Moal1-2/+20
To simplify the implementation of the report_zones operation of a zoned target, introduce the function dm_report_zones() to set a target mapping start sector in struct dm_report_zones_args and call blkdev_report_zones(). This new function is exported and the report zones callback function dm_report_zones_cb() is not. dm-linear, dm-flakey and dm-crypt are modified to use dm_report_zones(). Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-06-04dm: move zone related code to dm-zone.cDamien Le Moal1-0/+101
Move core and table code used for zoned targets and conditionally defined with #ifdef CONFIG_BLK_DEV_ZONED to the new file dm-zone.c. This file is conditionally compiled depending on CONFIG_BLK_DEV_ZONED. The small helper dm_set_zones_restrictions() is introduced to initialize a mapped device request queue zone attributes in dm_table_set_restrictions(). Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>