linux.git/include/linux/blk_types.h, branch v7.0

block: fix enum descriptions kernel-doc

2026-02-16T17:21:01+00:00

Fix all kernel-doc warnings in blk_types.h:

Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_READ' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_WRITE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_FLUSH' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DISCARD' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_SECURE_ERASE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_APPEND' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_WRITE_ZEROES' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_OPEN' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_CLOSE' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_FINISH' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_RESET' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_ZONE_RESET_ALL' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DRV_IN' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_DRV_OUT' not described in enum 'req_op'
Warning: include/linux/blk_types.h:371 Enum value 'REQ_OP_LAST' not described in enum 'req_op'

Signed-off-by: Randy Dunlap 
Signed-off-by: Jens Axboe

block: update docs for bio and bvec_iter

2026-02-14T14:43:27+00:00

The documentation for bio and bvec_iter refers to a vector named bvl_vec.
This does not exist. Update the documentation comment with correct use.

Also update documentation comments for remaining fields of `bvec_iter` to
improve readability.

The fields of `bvec_iter` is using a mix of tabs and spaces for
indentation. While at it, change them all to tabs, which is most prevalent
in this struct definition.

Signed-off-by: Andreas Hindborg 
Signed-off-by: Jens Axboe

block: add a BIO_MAX_SIZE constant and use it

2026-01-28T12:16:39+00:00

Currently the only constant for the maximum bio size is BIO_MAX_SECTORS,
which is in units of 512-byte sectors, but a lot of user need a byte
limit.

Add a BIO_MAX_SIZE constant, redefine BIO_MAX_SECTORS in terms of it, and
switch all bio-related uses of UINT_MAX for the maximum size to use the
symbolic names instead.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Darrick J. Wong 
Reviewed-by: Anuj Gupta 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Damien Le Moal 
Signed-off-by: Jens Axboe

block: use bvec iterator helper for bio_may_need_split()

2026-01-07T15:06:33+00:00

bio_may_need_split() uses bi_vcnt to determine if a bio has a single
segment, but bi_vcnt is unreliable for cloned bios. Cloned bios share
the parent's bi_io_vec array but iterate over a subset via bi_iter,
so bi_vcnt may not reflect the actual segment count being iterated.

Replace the bi_vcnt check with bvec iterator access via
__bvec_iter_bvec(), comparing bi_iter.bi_size against the current
bvec's length. This correctly handles both cloned and non-cloned bios.

Move bi_io_vec into the first cache line adjacent to bi_iter. This is
a sensible layout since bi_io_vec and bi_iter are commonly accessed
together throughout the block layer - every bvec iteration requires
both fields. This displaces bi_end_io to the second cache line, which
is acceptable since bi_end_io and bi_private are always fetched
together in bio_endio() anyway.

The struct layout change requires bio_reset() to preserve and restore
bi_io_vec across the memset, since it now falls within BIO_RESET_BYTES.

Nitesh verified that this patch doesn't regress NVMe 512-byte IO perf [1].

Link: https://lore.kernel.org/linux-block/20251220081607.tvnrltcngl3cc2fh@green245.gost/ [1]
Signed-off-by: Ming Lei 
Reviewed-by: Nitesh Shetty 
Signed-off-by: Jens Axboe

block: fix comment for op_is_zone_mgmt() to include RESET_ALL

2025-12-04T22:43:28+00:00

REQ_OP_ZONE_RESET_ALL is a zone management request, and op_is_zone_mgmt()
has returned true for it.

Update the comment to remove the misleading exception note so
the documentation matches the implementation.

Fixes: 12a1c9353c47 ("block: fix op_is_zone_mgmt() to handle REQ_OP_ZONE_RESET_ALL")
Signed-off-by: shechenglong 
Reviewed-by: Damien Le Moal 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

Merge tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

2025-12-04T03:26:18+00:00

Pull block updates from Jens Axboe:

 - Fix head insertion for mq-deadline, a regression from when priority
   support was added

 - Series simplifying and improving the ublk user copy code

 - Various ublk related cleanups

 - Fixup REQ_NOWAIT handling in loop/zloop, clearing NOWAIT when the
   request is punted to a thread for handling

 - Merge and then later revert loop dio nowait support, as it ended up
   causing excessive stack usage for when the inline issue code needs to
   dip back into the full file system code

 - Improve auto integrity code, making it less deadlock prone

 - Speedup polled IO handling, but manually managing the hctx lookups

 - Fixes for blk-throttle for SSD devices

 - Small series with fixes for the S390 dasd driver

 - Add support for caching zones, avoiding unnecessary report zone
   queries

 - MD pull requests via Yu:
      - fix null-ptr-dereference regression for dm-raid0
      - fix IO hang for raid5 when array is broken with IO inflight
      - remove legacy 1s delay to speed up system shutdown
      - change maintainer's email address
      - data can be lost if array is created with different lbs devices,
        fix this problem and record lbs of the array in metadata
      - fix rcu protection for md_thread
      - fix mddev kobject lifetime regression
      - enable atomic writes for md-linear
      - some cleanups

 - bcache updates via Coly
      - remove useless discard and cache device code
      - improve usage of per-cpu workqueues

 - Reorganize the IO scheduler switching code, fixing some lockdep
   reports as well

 - Improve the block layer P2P DMA support

 - Add support to the block tracing code for zoned devices

 - Segment calculation improves, and memory alignment flexibility
   improvements

 - Set of prep and cleanups patches for ublk batching support. The
   actual batching hasn't been added yet, but helps shrink down the
   workload of getting that patchset ready for 6.20

 - Fix for how the ps3 block driver handles segments offsets

 - Improve how block plugging handles batch tag allocations

 - nbd fixes for use-after-free of the configuration on device clear/put

 - Set of improvements and fixes for zloop

 - Add Damien as maintainer of the block zoned device code handling

 - Various other fixes and cleanups

* tag 'for-6.19/block-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits)
  block/rnbd: correct all kernel-doc complaints
  blk-mq: use queue_hctx in blk_mq_map_queue_type
  md: remove legacy 1s delay in md_notify_reboot
  md/raid5: fix IO hang when array is broken with IO inflight
  md: warn about updating super block failure
  md/raid0: fix NULL pointer dereference in create_strip_zones() for dm-raid
  sbitmap: fix all kernel-doc warnings
  ublk: add helper of __ublk_fetch()
  ublk: pass const pointer to ublk_queue_is_zoned()
  ublk: refactor auto buffer register in ublk_dispatch_req()
  ublk: add `union ublk_io_buf` with improved naming
  ublk: add parameter `struct io_uring_cmd *` to ublk_prep_auto_buf_reg()
  kfifo: add kfifo_alloc_node() helper for NUMA awareness
  blk-mq: fix potential uaf for 'queue_hw_ctx'
  blk-mq: use array manage hctx map instead of xarray
  ublk: prevent invalid access with DEBUG
  s390/dasd: Use scnprintf() instead of sprintf()
  s390/dasd: Move device name formatting into separate function
  s390/dasd: Remove unnecessary debugfs_create() return checks
  s390/dasd: Fix gendisk parent after copy pair swap
  ...

block-dma: properly take MMIO path

2025-11-14T12:09:56+00:00

In commit eadaa8b255f3 ("dma-mapping: introduce new DMA attribute to
indicate MMIO memory"), DMA_ATTR_MMIO attribute was added to describe
MMIO addresses, which require to avoid any memory cache flushing, as
an outcome of the discussion pointed in Link tag below.

In case of PCI_P2PDMA_MAP_THRU_HOST_BRIDGE transfer, blk-mq-dm logic
treated this as regular page and relied on "struct page" DMA flow.
That flow performs CPU cache flushing, which shouldn't be done here,
and doesn't set IOMMU_MMIO flag in DMA-IOMMU case.

As a solution, let's encode peer-to-peer transaction type in NVMe IOD
flags variable and provide it to blk-mq-dma API.

Link: https://lore.kernel.org/all/f912c446-1ae9-4390-9c11-00dce7bf0fd3@arm.com/
Reviewed-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Keith Busch 
Signed-off-by: Leon Romanovsky 
Signed-off-by: Jens Axboe

block: accumulate memory segment gaps per bio

2025-11-07T01:11:58+00:00

The blk-mq dma iterator has an optimization for requests that align to
the device's iommu merge boundary. This boundary may be larger than the
device's virtual boundary, but the code had been depending on that queue
limit to know ahead of time if the request is guaranteed to align to
that optimization.

Rather than rely on that queue limit, which many devices may not report,
save the lowest set bit of any boundary gap between each segment in the
bio while checking the segments. The request stores the value for
merging and quickly checking per io if the request can use iova
optimizations.

Signed-off-by: Keith Busch 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

block: make REQ_OP_ZONE_OPEN a write operation

2025-10-28T13:52:55+00:00

A REQ_OP_OPEN_ZONE request changes the condition of a sequential zone of
a zoned block device to the explicitly open condition
(BLK_ZONE_COND_EXP_OPEN). As such, it should be considered a write
operation.

Change this operation code to be an odd number to reflect this. The
following operation numbers are changed to keep the numbering compact.

No problems were reported without this change as this operation has no
data. However, this unifies the zone operation to reflect that they
modify the device state and also allows strengthening checks in the
block layer, e.g. checking if this operation is not issued against a
read-only device.

Fixes: 6c1b1da58f8c ("block: add zone open, close and finish operations")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

block: fix op_is_zone_mgmt() to handle REQ_OP_ZONE_RESET_ALL

2025-10-28T13:52:55+00:00

REQ_OP_ZONE_RESET_ALL is a zone management request. Fix
op_is_zone_mgmt() to return true for that operation, like it already
does for REQ_OP_ZONE_RESET.

While no problems were reported without this fix, this change allows
strengthening checks in various block device drivers (scsi sd,
virtioblk, DM) where op_is_zone_mgmt() is used to verify that a zone
management command is not being issued to a regular block device.

Fixes: 6c1b1da58f8c ("block: add zone open, close and finish operations")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe