kernel/linux.git/block/blk-settings.c, branch v7.1

blk-integrity: support arbitrary buffer alignment

2026-03-14T13:44:30+00:00

A bio segment may have partial interval block data with the rest continuing into the next segments because direct-io data payloads only need to align in memory to the device's DMA limits. At the same time, the protection information may also be split in multiple segments. The most likely way that may happen is if two requests merge, or if we're directly using the io_uring user metadata. The generate/verify, however, only ever accessed the first bip_vec. Further, it may be possible to unalign the protection fields from the user space buffer, or if there are odd additional opaque bytes in front or in back of the protection information metadata region. Change up the iteration to allow spanning multiple segments. This patch is mostly a re-write of the protection information handling to allow any arbitrary alignments, so it's probably easier to review the end result rather than the diff. Many controllers are not able to handle interval data composed of multiple segments when PI is used, so this patch introduces a new integrity limit that a low level driver can set to notify that it is capable, default to false. The nvme driver is the first one to enable it in this patch. Everyone else will force DMA alignment to the logical block size as before to ensure interval data is always aligned within a single segment. Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Link: https://patch.msgid.link/20260313144701.1221652-2-kbusch@meta.com Signed-off-by: Jens Axboe

block: make max_integrity_io_size public

2026-03-09T13:47:02+00:00

File systems that generate integrity will need this, so move it out of the block private or blk-mq specific headers. Signed-off-by: Christoph Hellwig Reviewed-by: Anuj Gupta Reviewed-by: Kanchan Joshi Reviewed-by: Martin K. Petersen Reviewed-by: Darrick J. Wong Tested-by: Anuj Gupta Signed-off-by: Jens Axboe

block: validate interval_exp integrity limit

2025-12-18T16:51:49+00:00

Various code assumes that the integrity interval is at least 1 sector and evenly divides the logical block size. Add these checks to blk_validate_integrity_limits(). This guards against block drivers that report invalid interval_exp values. Signed-off-by: Caleb Sander Mateos Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: validate pi_offset integrity limit

2025-12-18T16:51:49+00:00

The PI tuple must be contained within the metadata value, so validate that pi_offset + pi_tuple_size <= metadata_size. This guards against block drivers that report invalid pi_offset values. Signed-off-by: Caleb Sander Mateos Reviewed-by: Christoph Hellwig 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: add lockdep to queue_limits_commit_update()

2025-11-11T14:51:08+00:00

queue_limits_commit_update() expects q->limits_lock to be held by the caller (via queue_limits_start_update()). The API pattern is: lim = queue_limits_start_update(q); /* acquires lock */ /* modify lim */ queue_limits_commit_update(q, &lim); /* releases lock */ OR queue_limits_commit_update_frozen(q, &lim); lim = queue_limits_start_update(q); /* acquires lock */ queue_limits_commit_update(q, &lim); /* releases lock */ Add lockdep_assert_held() to report incorrect API usage. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: make bio auto-integrity deadlock safe

2025-11-04T19:41:50+00:00

The current block layer automatic integrity protection allocates the actual integrity buffer, which has three problems: - because it happens at the bottom of the I/O stack and doesn't use a mempool it can deadlock under load - because the data size in a bio is almost unbounded when using lage folios it can relatively easily exceed the maximum kmalloc size - even when it does not exceed the maximum kmalloc size, it could exceed the maximum segment size of the device Fix this by limiting the I/O size so that we can allocate at least a 2MiB integrity buffer, i.e. 128MiB for 8 byte PI and 512 byte integrity intervals, and create a mempool as a last resort for this maximum size, mirroring the scheme used for bvecs. As a nice upside none of this can fail now, so we remove the error handling and open code the trivial addition of the bip vec. The new allocation helpers sit outside of bio-integrity-auto.c because I plan to reuse them for file system based PI in the near future. Fixes: 7ba1ba12eeef ("block: Block layer data integrity support") Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Reviewed-by: Anuj Gupta Reviewed-by: Kanchan Joshi Signed-off-by: Jens Axboe

block: require LBA dma_alignment when using PI

2025-10-22T16:02:54+00:00

The block layer PI generation / verification code expects the bio_vecs to have at least LBA size (or more correctly integrity internal) granularity. With the direct I/O alignment relaxation in 2022, user space can now feed bios with less alignment than that, leading to scribbling outside the PI buffers. Apparently this wasn't noticed so far because none of the tests generate such buffers, but since 851c4c96db00 ("xfs: implement XFS_IOC_DIOINFO in terms of vfs_getattr"), xfstests generic/013 by default generates such I/O now that the relaxed alignment is advertised by the XFS_IOC_DIOINFO ioctl. Fix this by increasing the required alignment when using PI, although handling arbitrary alignment in the long run would be even nicer. Fixes: bf8d08532bc1 ("iomap: add support for dma aligned direct-io") Fixes: b1a000d3b8ec ("block: relax direct io memory alignment") Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Keith Busch Signed-off-by: Jens Axboe

block: rename min_segment_size

2025-10-22T13:39:39+00:00

Despite its name, the block layer is fine with segments smaller that the "min_segment_size" limit. The value is an optimization limit indicating the largest segment that can be used without considering boundary limits. Smaller segments can take a fast path, so give it a name that reflects that: max_fast_segment_size. Signed-off-by: Keith Busch Reviewed-by: Christoph Hellwig Reviewed-by: Ming Lei Reviewed-by: Chaitanya Kulkarni Signed-off-by: Jens Axboe

block: relax atomic write boundary vs chunk size check

2025-09-16T18:29:10+00:00

blk_validate_atomic_write_limits() ensures that any boundary fits into and is aligned to any chunk size. However, it should also be possible to fit the chunk size into any boundary. That check is already made in blk_stack_atomic_writes_boundary_head(). Relax the check in blk_validate_atomic_write_limits() by reusing (and renaming) blk_stack_atomic_writes_boundary_head(). Signed-off-by: John Garry Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe