kernel/linux.git/include/uapi/linux/blkzoned.h, branch v6.19.11

block: make the new blkzoned UAPI constants discoverable

2026-01-21T14:47:44+00:00

The Linux 6.19 merge window added the new BLKREPORTZONESV2 ioctl, and with it the new BLK_ZONE_REP_CACHED and BLK_ZONE_COND_ACTIVE constants. The two constants are defined as part of enums, which makes it very painful for userspace to discover if they are present in the installed system headers. Use the #define to the same name trick to make them trivially discoverable using CPP directives. Fixes: 0bf0e2e46668 ("block: track zone conditions") Fixes: b30ffcdc0c15 ("block: introduce BLKREPORTZONESV2 ioctl") Reported-by: Andrey Albershteyn Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

block: introduce BLKREPORTZONESV2 ioctl

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

Introduce the new BLKREPORTZONESV2 ioctl command to allow user applications access to the fast zone report implemented by blkdev_report_zones_cached(). This new ioctl is defined as number 142 and is documented in include/uapi/linux/fs.h. Unlike the existing BLKREPORTZONES ioctl, this new ioctl uses the flags field of struct blk_zone_report also as an input. If the user sets the BLK_ZONE_REP_CACHED flag as an input, then blkdev_report_zones_cached() is used to generate the zone report using cached zone information. If this flag is not set, then BLKREPORTZONESV2 behaves in the same manner as BLKREPORTZONES and the zone report is generated by accessing the zoned device. Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: track zone conditions

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

The function blk_revalidate_zone_cond() already caches the condition of all zones of a zoned block device in the zones_cond array of a gendisk. However, the zone conditions are updated only when the device is scanned or revalidated. Implement tracking of the runtime changes to zone conditions using the new cond field in struct blk_zone_wplug. The size of this structure remains 112 Bytes as the new field replaces the 4 Bytes padding at the end of the structure. Beause zones that do not have a zone write plug can be in the empty, implicit open, explicit open or full condition, the zones_cond array of a disk is used to track the conditions, of zones that do not have a zone write plug. The condition of such zone is updated in the disk zones_cond array when a zone reset, reset all or finish operation is executed, and also when a zone write plug is removed from the disk hash table when the zone becomes full. Since a device may automatically close an implicitly open zone when writing to an empty or closed zone, if the total number of open zones has reached the device limit, the BLK_ZONE_COND_IMP_OPEN and BLK_ZONE_COND_CLOSED zone conditions cannot be precisely tracked. To overcome this, the zone condition BLK_ZONE_COND_ACTIVE is introduced to represent a zone that has the condition BLK_ZONE_COND_IMP_OPEN, BLK_ZONE_COND_EXP_OPEN or BLK_ZONE_COND_CLOSED. This follows the definition of an active zone as defined in the NVMe Zoned Namespace specifications. As such, for a zoned device that has a limit on the maximum number of open zones, we will never have more zones in the BLK_ZONE_COND_ACTIVE condition than the device limit. This is compatible with the SCSI ZBC and ATA ZAC specifications for SMR HDDs as these devices do not have a limit on the number of active zones. The function disk_zone_wplug_set_wp_offset() is modified to use the new helper disk_zone_wplug_update_cond() to update a zone write plug condition whenever a zone write plug write offset is updated on submission or merging of write BIOs to a zone. The functions blk_zone_reset_bio_endio(), blk_zone_reset_all_bio_endio() and blk_zone_finish_bio_endio() are modified to update the condition of the zones targeted by reset, reset_all and finish operations, either using though disk_zone_wplug_set_wp_offset() for zones that have a zone write plug, or using the disk_zone_set_cond() helper to update the zones_cond array of the disk for zones that do not have a zone write plug. When a zone write plug is removed from the disk hash table (when the zone becomes empty or full), the condition of struct blk_zone_wplug is used to update the disk zones_cond array. Conversely, when a zone write plug is added to the disk hash table, the zones_cond array is used to initialize the zone write plug condition. Signed-off-by: Damien Le Moal Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: Fix a source code comment in include/uapi/linux/blkzoned.h

2023-07-25T02:11:54+00:00

Fix the symbolic names for zone conditions in the blkzoned.h header file. Cc: Hannes Reinecke Cc: Damien Le Moal Fixes: 6a0cb1bc106f ("block: Implement support for zoned block devices") Signed-off-by: Bart Van Assche Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20230706201422.3987341-1-bvanassche@acm.org Signed-off-by: Jens Axboe

treewide: uapi: Replace zero-length arrays with flexible-array members

2022-06-28T19:26:05+00:00

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. This code was transformed with the help of Coccinelle: (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch) @@ identifier S, member, array; type T1, T2; @@ struct S { ... T1 member; T2 array[ - 0 ]; }; -fstrict-flex-arrays=3 is coming and we need to land these changes to prevent issues like these in the short future: ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destination buffer has size 0, but the source string has length 2 (including NUL byte) [-Wfortify-source] strcpy(de3->name, "."); ^ Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If this breaks anything, we can use a union with a new member name. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78 Build-tested-by: kernel test robot Link: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%25lkp@intel.com/ Acked-by: Dan Williams # For ndctl.h Signed-off-by: Gustavo A. R. Silva

block: fix uapi blkzoned.h comments

2020-10-09T18:47:02+00:00

Update the kdoc comments for struct blk_zone (capacity field description missing) and for struct blk_zone_report (flags field description missing). Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

block: add capacity field to zone descriptors

2020-07-08T14:16:19+00:00

In the zoned storage model, the sectors within a zone are typically all writeable. With the introduction of the Zoned Namespace (ZNS) Command Set in the NVM Express organization, the model was extended to have a specific writeable capacity. Extend the zone descriptor data structure with a zone capacity field to indicate to the user how many sectors in a zone are writeable. Introduce backward compatibility in the zone report ioctl by extending the zone report header data structure with a flags field to indicate if the capacity field is available. Reviewed-by: Jens Axboe Reviewed-by: Javier González Reviewed-by: Chaitanya Kulkarni Reviewed-by: Himanshu Madhani Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Daniel Wagner Signed-off-by: Matias Bjørling Signed-off-by: Christoph Hellwig

block: add zone open, close and finish ioctl support

2019-11-07T13:31:50+00:00

Introduce three new ioctl commands BLKOPENZONE, BLKCLOSEZONE and BLKFINISHZONE to allow applications to control the condition of zones on a zoned block device through the execution of the REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH operations. Contains contributions from Matias Bjorling, Hans Holmberg, Dmitry Fomichev, Keith Busch, Damien Le Moal and Christoph Hellwig. Reviewed-by: Javier González Reviewed-by: Christoph Hellwig Signed-off-by: Ajay Joshi Signed-off-by: Matias Bjorling Signed-off-by: Hans Holmberg Signed-off-by: Dmitry Fomichev Signed-off-by: Keith Busch Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

uapi: fix ioctl documentation

2019-01-24T18:11:42+00:00

The description of the BLKGETNRZONES zoned block device ioctl was not added as a comment together with this ioctl definition in commit 65e4e3eee83d7 ("block: Introduce BLKGETNRZONES ioctl"). Add its description here. Signed-off-by: Damien Le Moal Signed-off-by: Jens Axboe

uapi: linux/blkzoned.h: fix BLKGETZONESZ and BLKGETNRZONES definitions

2018-12-17T02:52:02+00:00

According to the documentation in include/uapi/asm-generic/ioctl.h, _IOW means userspace is writing and kernel is reading, and _IOR means userspace is reading and kernel is writing. In case of these two ioctls, kernel is writing and userspace is reading, so they have to be _IOR instead of _IOW. Fixes: 72cd87576d1d8 ("block: Introduce BLKGETZONESZ ioctl") Fixes: 65e4e3eee83d7 ("block: Introduce BLKGETNRZONES ioctl") Reviewed-by: Damien Le Moal Signed-off-by: Dmitry V. Levin Signed-off-by: Jens Axboe