linux-next.git/Documentation/admin-guide/blockdev/zoned_loop.rst, branch master

Documentation: block: zloop: clarify capacity alignment

2026-08-04T13:21:44+00:00

zloop divides the requested capacity by the zone size to determine the number of zones. Since it uses one zone size for all zones, a smaller last zone is not supported and an unaligned capacity is rounded down. The capacity_mb description incorrectly states that the capacity is rounded up. Correct it to document the actual behavior. Fixes: 9e4f11c1228c ("Documentation: Document the new zoned loop block device driver") Suggested-by: Damien Le Moal Reviewed-by: Damien Le Moal Signed-off-by: Xu Rao Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/4659F8F0C6C328EA+20260804052942.1186727-1-raoxu@uniontech.com Signed-off-by: Jens Axboe

zloop: truncate finished zones to zone capacity

2026-08-04T12:55:08+00:00

The size of a sequential zone backing file records the amount of data written and is used to restore the zone state. A backing file whose size is equal to the zone capacity is restored as a full zone, while a file larger than the zone capacity is rejected as invalid. However, zloop_finish_zone() currently truncates the backing file to the zone size. For devices with a reduced zone capacity, finishing a zone therefore creates a backing file larger than the zone capacity. After the device is removed and later re-added, that zone file is rejected instead of being restored as a full zone. Truncate finished sequential zones to the zone capacity, matching the persistent representation accepted by zloop_update_seq_zone() for a full zone. Suggested-by: Damien Le Moal Fixes: eb0570c7df23 ("block: new zoned loop block device driver") Cc: stable@vger.kernel.org Signed-off-by: Xu Rao Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal Link: https://patch.msgid.link/B39E5FD81D1A07F4+20260804023403.939767-1-raoxu@uniontech.com Signed-off-by: Jens Axboe

zloop: add max_open_zones option

2026-03-31T14:33:28+00:00

Introduce the new max_open_zones option to allow specifying a limit on the maximum number of open zones of a zloop device. This change allows creating a zloop device that can more closely mimick the characteristics of a physical SMR drive. When set to a non zero value, only up to max_open_zones zones can be in the implicit open (BLK_ZONE_COND_IMP_OPEN) and explicit open (BLK_ZONE_COND_EXP_OPEN) conditions at any time. The transition to the implicit open condition of a zone on a write operation can result in an implicit close of an already implicitly open zone. This is handled in the function zloop_do_open_zone(). This function also handles transitions to the explicit open condition. Implicit close transitions are handled using an LRU ordered list of open zones which is managed using the helper functions zloop_lru_rotate_open_zone() and zloop_lru_remove_open_zone(). Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260326203245.946830-1-dlemoal@kernel.org Signed-off-by: Jens Axboe

zloop: forget write cache on force removal

2026-03-25T12:49:01+00:00

Add a new options that causes zloop to truncate the zone files to the write pointer value recorded at the last cache flush to simulate unclean shutdowns. Signed-off-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Damien Le Moal Reviewed-by: Martin K. Petersen Link: https://patch.msgid.link/20260323071156.2940772-3-hch@lst.de Signed-off-by: Jens Axboe

Documentation: admin-guide: blockdev: replace zone_capacity with zone_capacity_mb when creating devices

2025-12-15T16:56:06+00:00

The "zone_capacity=%umb" option is no longer used. The effective option is now "zone_capacity_mb=%u", so update the documentation accordingly. Signed-off-by: Yongpeng Yang Reviewed-by: Damien Le Moal Signed-off-by: Jens Axboe

Documentation: admin-guide: blockdev: update zloop parameters

2025-11-17T16:40:09+00:00

In Documentation/admin-guide/blockdev/zoned_loop.rst, add the description of the zone_append and ordered_zone_append configuration arguments of zloop "add" command (device creation). Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

Docs: admin-guide: Correct spelling mistake

2025-08-13T11:33:09+00:00

Fix spelling mistake directoy to directory Reported-by: codespell Signed-off-by: Erick Karanja Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20250813071837.668613-1-karanja99erick@gmail.com Signed-off-by: Jens Axboe

Documentation: Document the new zoned loop block device driver

2025-05-01T23:03:56+00:00

Introduce the zoned_loop.rst documentation file under admin-guide/blockdev to document the zoned loop block device driver. An overview of the driver is provided and its usage to create and delete zoned devices described. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20250407075222.170336-3-dlemoal@kernel.org Signed-off-by: Jens Axboe