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2026-08-15block: introduce bio_iov_iter_set()Pavel Begunkov1-1/+1
In preparation to supporting dma-buf backed iterators and bios, introduce bio_iov_iter_set() which attempts to set up the bio directly from the given iterator. For now, it only supports bvec and expects users to check the result and fall back to other means if fails, but later we'll add more types. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/4686a0e47fc14f3f888967a80d45a6f66044f1e0.1785596451.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-07-31block: add task-context bio completion infrastructureTal Zussman1-0/+24
Some bio completion handlers need to run from preemptible task context, but bio_endio() may be called from IRQ context (e.g., buffer_head writeback). Callers need a way to ensure their callback eventually runs from a sleepable context. Add infrastructure for that, in two forms: 1. BIO_COMPLETE_IN_TASK, a bio flag the submitter sets when it knows in advance that its callback needs task context (e.g., dropbehind writeback). bio_endio() sees the flag and offloads completion to a worker automatically. 2. bio_complete_in_task(), a helper that completion callbacks can invoke from within bi_end_io() when the deferral decision is dynamic (e.g., fserror reporting). Both share a per-CPU list drained by a work item on a WQ_PERCPU workqueue. Producers push the bio onto the local CPU's list and schedule the work item, which then dispatches each bio's bi_end_io() from task context. Both methods are gated on bio_in_atomic(), which returns true in any context where a sleeping bi_end_io() is unsafe, including non-preemptible task context. Two CPU hotplug callbacks are used to drain remaining bios from the departing CPU's batch, while maintaining the per-CPU behavior. The CPUHP_AP_ONLINE_DYN callback disables the per-CPU work item while the CPU is still online, preventing it from running on an unbound worker later. CPUHP_BP_PREPARE_DYN then drains any bios added between disabling the work item and CPU offline. Link: https://lore.kernel.org/all/20260409160243.1008358-1-hch@lst.de/ Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tal Zussman <tz2294@columbia.edu> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260730-blk-dontcache-v7-2-3e8e6850068d@columbia.edu Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-07-31block: introduce bio_in_atomic()Tal Zussman1-0/+15
Move the atomic context detection logic from erofs's z_erofs_in_atomic() into the block layer as bio_in_atomic(). This helper returns true when the current context is unsafe for sleeping bio completion handlers (e.g., hard/soft IRQ, preempt-disabled). The logic was originally added to erofs in commit c99fab6e80b7 ("erofs: fix atomic context detection when !CONFIG_DEBUG_LOCK_ALLOC"). A subsequent patch will use it in the block layer's bio completion infrastructure, so move it to include/linux/bio.h where both subsystems can share it. Convert erofs to call the new bio_in_atomic() directly. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Tal Zussman <tz2294@columbia.edu> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260730-blk-dontcache-v7-1-3e8e6850068d@columbia.edu Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-07-31block: validate user space vectors during extractionKeith Busch1-1/+1
The bio-based drivers don't necessarily check the alignment split, and stacking block drivers don't always handle a misalignment detected after submitting the bio. Validate user vectors against the device's dma_alignment as the bio is built from the iov_iter, rejecting misaligned early with -EINVAL. Cc: stable@vger.kernel.org Fixes: 5ff3f74e145a ("block: simplify direct io validity check") Fixes: 7eac33186957 ("iomap: simplify direct io validity check") Reviewed-by: Hannes Reinecke <hare@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Link: https://patch.msgid.link/20260720201057.1862857-6-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-06-16Merge tag 'for-7.2/block-20260615' of ↵Linus Torvalds1-15/+17
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block updates from Jens Axboe: - NVMe pull request via Keith: - Per-controller admin and IO timeout sysfs attributes, and letting the block layer set request timeouts (Maurizio, Maximilian) - Multipath passthrough iostats, and PCI P2PDMA enablement for multipath devices (Keith, Kiran) - A new diag sysfs attribute group exporting per-controller counters (retries, multipath failover, error counters, requeue and failure counts, reset and reconnect events) (Nilay) - FDP configuration validation and bounds check fixes (liuxixin) - Various nvmet fixes, including a pre-auth out-of-bounds read in the Discovery Get Log Page handler, auth payload bounds validation, and tcp error-path leak fixes (Bryam, Tianchu, Geliang) - nvme-tcp lockdep and workqueue fixes (Shin'ichiro, Kuniyuki, Eric) - Assorted other fixes and cleanups (John, Yao, Chao, Mateusz, Achkinazi, Wentao) - MD pull request via Yu Kuai: - raid1/raid10 fixes for a deadlock in the read error recovery path, error-path detection and bio accounting with cloned bios, and an nr_pending leak in the REQ_ATOMIC bad-block error path (Abd-Alrhman) - PCI P2PDMA propagation from member devices to the RAID device (Kiran) - dm-raid bio requeue fix, and various smaller fixes and cleanups (Benjamin, Chen, Li, Thorsten) - Enable Clang lock context analysis for the block layer, with the accompanying annotations across queue limits, the blk_holder_ops callbacks, crypto, cgroup, iocost, kyber and mq-deadline (Bart) - Block status code infrastructure work: a tagged status table, a str_to_blk_op() helper, a bio_endio_status() helper, and on top of that a new configurable block-layer error injection facility (Christoph) - DRBD netlink rework, replacing the genl_magic machinery with explicit netlink serialization and moving the DRBD UAPI headers to include/uapi/linux/ (Christoph Böhmwalder) - bvec improvements: a bvec_folio() helper and making the bvec_iter helpers proper inline functions (Willy, Christoph) - ublk cleanups and a canceling-flag fix for the disk-not-allocated case (Caleb, Ming) - Partition handling fixes: bound the AIX pp_count scan, fix an of_node refcount leak, and replace __get_free_page() with kmalloc() (Bryam, Wentao, Mike) - Convert numa_node to int in blk_mq_hw_ctx and ->init_request, and add WQ_PERCPU to the block workqueue users (Mateusz, Marco) - Block statistics and tracing: propagate in-flight to the whole disk on partition IO, export passthrough stats, and a new block_rq_tag_wait tracepoint (Tang, Keith, Aaron) - A round of removals, unexports and cleanups across bio, direct-io and the bvec helpers (Christoph) - Various driver fixes (mtip32xx use-after-free, rbd snap_count validation and strscpy conversion, nbd socket lockdep reclassify, virtio-blk zone report clamp, floppy) and a batch of MAINTAINERS email/list updates (Coly, Li, Yu, Christoph Böhmwalder) - Other little fixes and cleanups all over * tag 'for-7.2/block-20260615' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (117 commits) MAINTAINERS: Update Coly Li's email address block: check bio split for unaligned bvec nbd: Reclassify sockets to avoid lockdep circular dependency block: add configurable error injection block: add a str_to_blk_op helper block: add a "tag" for block status codes block: add a macro to initialize the status table floppy: Drop unused pnp driver data block: propagate in_flight to whole disk on partition I/O virtio-blk: clamp zone report to the report buffer capacity block: optimize I/O merge hot path with unlikely() hints drivers/block/rbd: Use strscpy() to copy strings into arrays partitions: aix: bound the pp_count scan to the ppe array block: Enable lock context analysis block/mq-deadline: Make the lock context annotations compatible with Clang block/Kyber: Make the lock context annotations compatible with Clang block/blk-mq-debugfs: Improve lock context annotations block/blk-iocost: Inline iocg_lock() and iocg_unlock() block/blk-iocost: Split ioc_rqos_throttle() block/crypto: Annotate the crypto functions ...
2026-06-15Merge tag 'vfs-7.2-rc1.iomap' of ↵Linus Torvalds1-14/+0
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull iomap updates from Christian Brauner: - Add the vfs infrastructure required to implement fs-verity support for XFS with a post-EOF merkle tree: fsverity generates and stores a zero-block hash, and iomap learns to verify data on buffered reads, to handle fsverity during writeback via the new IOMAP_F_FSVERITY flag, and to write fsverity metadata through iomap_fsverity_write(). - Skip the memset of the iomap in iomap_iter() once the iteration is done. In high-IOPS scenarios (4k randread NVMe polling via io_uring) the pointless memset wasted memory write bandwidth; this improves IOPS by about 5% on ext4 and xfs. - Add balance_dirty_pages_ratelimited() to iomap_zero_iter(), aligning it with iomap_write_iter(). This prepares for the exFAT iomap conversion where zeroing beyond valid_size can trigger large-scale zeroing operations that caused memory pressure without throttling. - Remove the over-strict inline data boundary check. If a filesystem provides a valid inline_data pointer and length there is no reason to require that inline data must not cross a page boundary. - Don't make REQ_POLLED imply REQ_NOWAIT, matching the earlier equivalent block layer fix: there are valid cases to poll for I/O completion without REQ_NOWAIT, and REQ_NOWAIT for file system writes is currently not supported as writes aren't idempotent. - Introduce IOMAP_F_ZERO_TAIL for filesystems that maintain a separate valid data length (exFAT, NTFS). For a write starting at or beyond valid_size, __iomap_write_begin() now zeroes only the tail portion of the block while preserving valid data before it, instead of leaving stale data in the page cache. The flag is also added to the iomap trace event strings. * tag 'vfs-7.2-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iomap: Add IOMAP_F_ZERO_TAIL flag to trace event strings iomap: introduce iomap_fsverity_write() for writing fsverity metadata iomap: teach iomap to read files with fsverity iomap: introduce IOMAP_F_FSVERITY and teach writeback to handle fsverity fsverity: generate and store zero-block hash iomap: introduce IOMAP_F_ZERO_TAIL flag iomap: don't make REQ_POLLED imply REQ_NOWAIT iomap: remove over-strict inline data boundary check iomap: add dirty page control to iomap_zero_iter iomap: avoid memset iomap when iter is done
2026-05-29block: Add bvec_folio()Matthew Wilcox (Oracle)1-1/+1
This is a simple helper which replaces page_folio(bvec->bv_page). Minor improvement in readability, but the real motivation is to reduce the number of references to bvec->bv_page so that it can be changed with less work. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Leon Romanovsky <leon@kernel.org> Reviewed-by: Hannes Reinecke <hare@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: William Kucharski <william.kucharski@linux.dev> Link: https://patch.msgid.link/20260528175905.1102280-2-willy@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-28block: add a bio_endio_status helperChristoph Hellwig1-4/+15
Add a helper that sets bi_status and call bio_endio() as that is a very common pattern and convert the core block code over to it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Md Haris Iqbal <haris.iqbal@linux.dev> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@kernel.org> Link: https://patch.msgid.link/20260528084632.2505277-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-28block: mark biovec_init_pool staticChristoph Hellwig1-1/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://patch.msgid.link/20260527150646.2349405-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-26block: don't set BIO_QUIET for BLK_STS_AGAINChristoph Hellwig1-1/+0
Commit abb30460bda2 ("block: mark bio_wouldblock_error() bio with BIO_QUIET") added this to suppress buffer_head warnings, but neither when this commit was added nor now any buffer_head using code actually ever sets REQ_NOWAIT which can lead to BLK_STS_AGAIN. Remove the special handling for now. If we ever plan to use REQ_NOWAIT for buffer_head based I/O we're better off handling BLK_STS_AGAIN in the completion handler as it actually needs to retry the I/O as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260518063336.507369-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-18iomap: don't make REQ_POLLED imply REQ_NOWAITChristoph Hellwig1-14/+0
As described in commit 2bc057692599 ("block: don't make REQ_POLLED imply REQ_NOWAIT"), which fixed the same issue for the block device node, there are valid cases to poll for I/O completion without REQ_NOWAIT. Additionally, sing REQ_NOWAIT for file system writes is currently not supported as file systems writes are not idempotent and would need a retry of just the bio and not the entire operation to be fully supported. Switch iomap to set REQ_POLLED and remove the now unused bio_set_polled helper. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260518062917.506483-1-hch@lst.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-05-15block: remove bio_copy_data_iterChristoph Hellwig1-2/+0
Only used by bio_copy_data, so implement that directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260515045547.3790129-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-15block: remove zero_fill_bio_iterChristoph Hellwig1-6/+1
Only used to implement zero_fill_bio, so directly implement that. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260515045547.3790129-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-05-13block: pass a minsize argument to bio_iov_iter_bounceChristoph Hellwig1-1/+2
When bouncing for block size > PAGE_SIZE file systems that require file system block size alignment (e.g. zoned XFS), the bio needs to be big enough to fit an entire block. Fixes: 8dd5e7c75d7b ("block: add helpers to bounce buffer an iov_iter into bios") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@kernel.org> Link: https://patch.msgid.link/20260507050153.1298375-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-04-07block: factor out a bio_await helperChristoph Hellwig1-0/+2
Add a new helper to wait for a bio and anything chained off it to complete synchronously after submitting it. This factors common code out of submit_bio_wait and bio_await_chain and will also be useful for file system code and thus is exported. Note that this will now set REQ_SYNC also for the bio_await case for consistency. Nothing should look at the flag in the end_io handler, but if something does having the flag set makes more sense. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://patch.msgid.link/20260407140538.633364-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-17block: split bio_alloc_bioset more clearly into a fast and slowpathChristoph Hellwig1-2/+1
bio_alloc_bioset tries non-waiting slab allocations first for the bio and bvec array, but does so in a somewhat convoluted way. Restructure the function so that it first open codes these slab allocations, and then falls back to the mempools with the original gfp mask. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> -ck Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://patch.msgid.link/20260316161144.1607877-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-09block: pass a maxlen argument to bio_iov_iter_bounceChristoph Hellwig1-1/+1
Allow the file system to limit the size processed in a single bounce operation. This is needed when generating integrity data so that the size of a single integrity segment can't overflow. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Tested-by: Anuj Gupta <anuj20.g@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-02-09Merge tag 'for-7.0/block-stable-pages-20260206' of ↵Linus Torvalds1-0/+26
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull bounce buffer dio for stable pages from Jens Axboe: "This adds support for bounce buffering of dio for stable pages. This was all done by Christoph. In his words: This series tries to address the problem that under I/O pages can be modified during direct I/O, even when the device or file system require stable pages during I/O to calculate checksums, parity or data operations. It does so by adding block layer helpers to bounce buffer an iov_iter into a bio, then wires that up in iomap and ultimately XFS. The reason that the file system even needs to know about it, is because reads need a user context to copy the data back, and the infrastructure to defer ioends to a workqueue currently sits in XFS. I'm going to look into moving that into ioend and enabling it for other file systems. Additionally btrfs already has it's own infrastructure for this, and actually an urgent need to bounce buffer, so this should be useful there and could be wire up easily. In fact the idea comes from patches by Qu that did this in btrfs. This patch fixes all but one xfstests failures on T10 PI capable devices (generic/095 seems to have issues with a mix of mmap and splice still, I'm looking into that separately), and make qemu VMs running Windows, or Linux with swap enabled fine on an XFS file on a device using PI. Performance numbers on my (not exactly state of the art) NVMe PI test setup: Sequential reads using io_uring, QD=16. Bandwidth and CPU usage (usr/sys): | size | zero copy | bounce | +------+--------------------------+--------------------------+ | 4k | 1316MiB/s (12.65/55.40%) | 1081MiB/s (11.76/49.78%) | | 64K | 3370MiB/s ( 5.46/18.20%) | 3365MiB/s ( 4.47/15.68%) | | 1M | 3401MiB/s ( 0.76/23.05%) | 3400MiB/s ( 0.80/09.06%) | +------+--------------------------+--------------------------+ Sequential writes using io_uring, QD=16. Bandwidth and CPU usage (usr/sys): | size | zero copy | bounce | +------+--------------------------+--------------------------+ | 4k | 882MiB/s (11.83/33.88%) | 750MiB/s (10.53/34.08%) | | 64K | 2009MiB/s ( 7.33/15.80%) | 2007MiB/s ( 7.47/24.71%) | | 1M | 1992MiB/s ( 7.26/ 9.13%) | 1992MiB/s ( 9.21/19.11%) | +------+--------------------------+--------------------------+ Note that the 64k read numbers look really odd to me for the baseline zero copy case, but are reproducible over many repeated runs. The bounce read numbers should further improve when moving the PI validation to the file system and removing the double context switch, which I have patches for that will sent out soon" * tag 'for-7.0/block-stable-pages-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: xfs: use bounce buffering direct I/O when the device requires stable pages iomap: add a flag to bounce buffer direct I/O iomap: support ioends for direct reads iomap: rename IOMAP_DIO_DIRTY to IOMAP_DIO_USER_BACKED iomap: free the bio before completing the dio iomap: share code between iomap_dio_bio_end_io and iomap_finish_ioend_direct iomap: split out the per-bio logic from iomap_dio_bio_iter iomap: simplify iomap_dio_bio_iter iomap: fix submission side handling of completion side errors block: add helpers to bounce buffer an iov_iter into bios block: remove bio_release_page iov_iter: extract a iov_iter_extract_bvecs helper from bio code block: open code bio_add_page and fix handling of mismatching P2P ranges block: refactor get_contig_folio_len block: add a BIO_MAX_SIZE constant and use it
2026-02-09Merge tag 'for-7.0/block-20260206' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block updates from Jens Axboe: - Support for batch request processing for ublk, improving the efficiency of the kernel/ublk server communication. This can yield nice 7-12% performance improvements - Support for integrity data for ublk - Various other ublk improvements and additions, including a ton of selftests additions and updated - Move the handling of blk-crypto software fallback from below the block layer to above it. This reduces the complexity of dealing with bio splitting - Series fixing a number of potential deadlocks in blk-mq related to the queue usage counter and writeback throttling and rq-qos debugfs handling - Add an async_depth queue attribute, to resolve a performance regression that's been around for a qhilw related to the scheduler depth handling - Only use task_work for IOPOLL completions on NVMe, if it is necessary to do so. An earlier fix for an issue resulted in all these completions being punted to task_work, to guarantee that completions were only run for a given io_uring ring when it was local to that ring. With the new changes, we can detect if it's necessary to use task_work or not, and avoid it if possible. - rnbd fixes: - Fix refcount underflow in device unmap path - Handle PREFLUSH and NOUNMAP flags properly in protocol - Fix server-side bi_size for special IOs - Zero response buffer before use - Fix trace format for flags - Add .release to rnbd_dev_ktype - MD pull requests via Yu Kuai - Fix raid5_run() to return error when log_init() fails - Fix IO hang with degraded array with llbitmap - Fix percpu_ref not resurrected on suspend timeout in llbitmap - Fix GPF in write_page caused by resize race - Fix NULL pointer dereference in process_metadata_update - Fix hang when stopping arrays with metadata through dm-raid - Fix any_working flag handling in raid10_sync_request - Refactor sync/recovery code path, improve error handling for badblocks, and remove unused recovery_disabled field - Consolidate mddev boolean fields into mddev_flags - Use mempool to allocate stripe_request_ctx and make sure max_sectors is not less than io_opt in raid5 - Fix return value of mddev_trylock - Fix memory leak in raid1_run() - Add Li Nan as mdraid reviewer - Move phys_vec definitions to the kernel types, mostly in preparation for some VFIO and RDMA changes - Improve the speed for secure erase for some devices - Various little rust updates - Various other minor fixes, improvements, and cleanups * tag 'for-7.0/block-20260206' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (162 commits) blk-mq: ABI/sysfs-block: fix docs build warnings selftests: ublk: organize test directories by test ID block: decouple secure erase size limit from discard size limit block: remove redundant kill_bdev() call in set_blocksize() blk-mq: add documentation for new queue attribute async_dpeth block, bfq: convert to use request_queue->async_depth mq-deadline: covert to use request_queue->async_depth kyber: covert to use request_queue->async_depth blk-mq: add a new queue sysfs attribute async_depth blk-mq: factor out a helper blk_mq_limit_depth() blk-mq-sched: unify elevators checking for async requests block: convert nr_requests to unsigned int block: don't use strcpy to copy blockdev name blk-mq-debugfs: warn about possible deadlock blk-mq-debugfs: add missing debugfs_mutex in blk_mq_debugfs_register_hctxs() blk-mq-debugfs: remove blk_mq_debugfs_unregister_rqos() blk-mq-debugfs: make blk_mq_debugfs_register_rqos() static blk-rq-qos: fix possible debugfs_mutex deadlock blk-mq-debugfs: factor out a helper to register debugfs for all rq_qos blk-wbt: fix possible deadlock to nest pcpu_alloc_mutex under q_usage_counter ...
2026-01-28block: add helpers to bounce buffer an iov_iter into biosChristoph Hellwig1-0/+26
Add helpers to implement bounce buffering of data into a bio to implement direct I/O for cases where direct user access is not possible because stable in-flight data is required. These are intended to be used as easily as bio_iov_iter_get_pages for the zero-copy path. The write side is trivial and just copies data into the bounce buffer. The read side is a lot more complex because it needs to perform the copy from the completion context, and without preserving the iov_iter through the call chain. It steals a trick from the integrity data user interface and uses the first vector in the bio for the bounce buffer data that is fed to the block I/O stack, and uses the others to record the user buffer fragments. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Tested-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-26block: remove bio_last_bvec_allKeith Busch1-6/+0
There are no more callers of this function after commit f6b2d8b134b2413 ("btrfs: track the next file offset in struct btrfs_bio_ctrl"), so remove the function. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-01-21block: add a bio_reuse helperChristoph Hellwig1-0/+1
Add a helper to allow an existing bio to be resubmitted without having to re-add the payload. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2025-12-12block: move around bio flagging helpersPavel Begunkov1-15/+15
We'll need bio_flagged() earlier in bio.h for later patches, move it together with all related helpers, and mark the bio_flagged()'s bio argument as const. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-06block: accumulate memory segment gaps per bioKeith Busch1-0/+2
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 <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-10-07block: rename bio_iov_iter_get_pages_aligned to bio_iov_iter_get_pagesChristoph Hellwig1-1/+1
Now that the bio_iov_iter_get_pages is free again, use it instead of the more complicated now. Also drop the unused export. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-10-07block: remove bio_iov_iter_get_pagesChristoph Hellwig1-5/+0
Switch the only caller to bio_iov_iter_get_pages, and explain why it does not have any alignment requirements. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-09block: add size alignment to bio_iov_iter_get_pagesKeith Busch1-1/+8
The block layer tries to align bio vectors to the block device's logical block size. Some cases don't have a block device, or we may need to align to something larger, which we can't derive it from the queue limits. Have the caller specify what they want, or allow any length alignment if nothing was specified. Since the most common use case relies on the block device's limits, a helper function is provided. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-09block: check for valid bio while splittingKeith Busch1-2/+2
We're already iterating every segment, so check these for a valid IO lengths at the same time. Individual segment lengths will not be checked on passthrough commands. The read/write command segments must be sized to the dma alignment. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-09block: remove the bi_inline_vecs variable sized array from struct bioChristoph Hellwig1-1/+1
Bios are embedded into other structures, and at least spare is unhappy about embedding structures with variable sized arrays. There's no real need to the array anyway, we can replace it with a helper pointing to the memory just behind the bio, and with the previous cleanups there is very few site doing anything special with it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-09-09block: add a bio_init_inline helperChristoph Hellwig1-0/+5
Just a simpler wrapper around bio_init for callers that want to initialize a bio with inline bvecs. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-06-13bio: Fix bio_first_folio() for SPARSEMEM without VMEMMAPMatthew Wilcox (Oracle)1-1/+1
It is possible for physically contiguous folios to have discontiguous struct pages if SPARSEMEM is enabled and SPARSEMEM_VMEMMAP is not. This is correctly handled by folio_page_idx(), so remove this open-coded implementation. Fixes: 640d1930bef4 (block: Add bio_for_each_folio_all()) Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Link: https://lore.kernel.org/r/20250612144126.2849931-1-willy@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-26Merge tag 'for-6.16/block-20250523' of git://git.kernel.dk/linuxLinus Torvalds1-1/+24
Pull block updates from Jens Axboe: - ublk updates: - Add support for updating the size of a ublk instance - Zero-copy improvements - Auto-registering of buffers for zero-copy - Series simplifying and improving GET_DATA and request lookup - Series adding quiesce support - Lots of selftests additions - Various cleanups - NVMe updates via Christoph: - add per-node DMA pools and use them for PRP/SGL allocations (Caleb Sander Mateos, Keith Busch) - nvme-fcloop refcounting fixes (Daniel Wagner) - support delayed removal of the multipath node and optionally support the multipath node for private namespaces (Nilay Shroff) - support shared CQs in the PCI endpoint target code (Wilfred Mallawa) - support admin-queue only authentication (Hannes Reinecke) - use the crc32c library instead of the crypto API (Eric Biggers) - misc cleanups (Christoph Hellwig, Marcelo Moreira, Hannes Reinecke, Leon Romanovsky, Gustavo A. R. Silva) - MD updates via Yu: - Fix that normal IO can be starved by sync IO, found by mkfs on newly created large raid5, with some clean up patches for bdev inflight counters - Clean up brd, getting rid of atomic kmaps and bvec poking - Add loop driver specifically for zoned IO testing - Eliminate blk-rq-qos calls with a static key, if not enabled - Improve hctx locking for when a plug has IO for multiple queues pending - Remove block layer bouncing support, which in turn means we can remove the per-node bounce stat as well - Improve blk-throttle support - Improve delay support for blk-throttle - Improve brd discard support - Unify IO scheduler switching. This should also fix a bunch of lockdep warnings we've been seeing, after enabling lockdep support for queue freezing/unfreezeing - Add support for block write streams via FDP (flexible data placement) on NVMe - Add a bunch of block helpers, facilitating the removal of a bunch of duplicated boilerplate code - Remove obsolete BLK_MQ pci and virtio Kconfig options - Add atomic/untorn write support to blktrace - Various little cleanups and fixes * tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux: (186 commits) selftests: ublk: add test for UBLK_F_QUIESCE ublk: add feature UBLK_F_QUIESCE selftests: ublk: add test case for UBLK_U_CMD_UPDATE_SIZE traceevent/block: Add REQ_ATOMIC flag to block trace events ublk: run auto buf unregisgering in same io_ring_ctx with registering io_uring: add helper io_uring_cmd_ctx_handle() ublk: remove io argument from ublk_auto_buf_reg_fallback() ublk: handle ublk_set_auto_buf_reg() failure correctly in ublk_fetch() selftests: ublk: add test for covering UBLK_AUTO_BUF_REG_FALLBACK selftests: ublk: support UBLK_F_AUTO_BUF_REG ublk: support UBLK_AUTO_BUF_REG_FALLBACK ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG ublk: prepare for supporting to register request buffer automatically ublk: convert to refcount_t selftests: ublk: make IO & device removal test more stressful nvme: rename nvme_mpath_shutdown_disk to nvme_mpath_remove_disk nvme: introduce multipath_always_on module param nvme-multipath: introduce delayed removal of the multipath head node nvme-pci: derive and better document max segments limits nvme-pci: use struct_size for allocation struct nvme_dev ...
2025-05-12scsi: sd_zbc: block: Respect bio vector limits for REPORT ZONES bufferSteve Siwinski1-0/+1
The REPORT ZONES buffer size is currently limited by the HBA's maximum segment count to ensure the buffer can be mapped. However, the block layer further limits the number of iovec entries to 1024 when allocating a bio. To avoid allocation of buffers too large to be mapped, further restrict the maximum buffer size to BIO_MAX_INLINE_VECS. Replace the UIO_MAXIOV symbolic name with the more contextually appropriate BIO_MAX_INLINE_VECS. Fixes: b091ac616846 ("sd_zbc: Fix report zones buffer allocation") Cc: stable@vger.kernel.org Signed-off-by: Steve Siwinski <ssiwinski@atto.com> Link: https://lore.kernel.org/r/20250508200122.243129-1-ssiwinski@atto.com Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2025-05-07block: add a bio_add_vmalloc helpersChristoph Hellwig1-0/+3
Add a helper to add a vmalloc region to a bio, abstracting away the vmalloc addresses from the underlying pages and another one wrapping it for the simple case where all data fits into a single bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250507120451.4000627-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-07block: add a bio_add_max_vecs helperChristoph Hellwig1-0/+15
Add a helper to check how many bio_vecs are needed to add a kernel virtual address range to a bio, accounting for the always contiguous direct mapping and vmalloc mappings that usually need a bio_vec per page sized chunk. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250507120451.4000627-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-07block: add a bdev_rw_virt helperChristoph Hellwig1-1/+4
Add a helper to perform synchronous I/O on a kernel direct map range. Currently this is implemented in various places in usually not very efficient ways, so provide a generic helper instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250507120451.4000627-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-05-07block: add a bio_add_virt_nofail helperChristoph Hellwig1-0/+2
Add a helper to add a directly mapped kernel virtual address to a bio so that callers don't have to convert to pages or folios. For now only the _nofail variant is provided as that is what all the obvious callers want. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20250507120451.4000627-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-03block: split struct bio_integrity_payloadChristoph Hellwig1-4/+0
Many of the fields in struct bio_integrity_payload are only needed for the default integrity buffer in the block layer, and the variable sized array at the end of the structure makes it very hard to embed into caller allocated structures. Reduce struct bio_integrity_payload to the minimal structure needed in common code and create two separate containing structures for the automatically generated payload and the caller allocated payload. The latter is a simple wrapper for struct bio_integrity_payload and the bvecs, while the former contains the additional fields moved out of struct bio_integrity_payload. Always use a dedicated mempool for automatic integrity metadata instead of depending on bio_set that is submitter controlled and thus often doesn't have the mempool initialized and stop using mempools for the submitter buffers as they aren't in the NOIO I/O submission path where we need to guarantee forward progress. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Tested-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20250225154449.422989-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-01-04block: remove bio_add_pc_pageChristoph Hellwig1-2/+0
Lift bio_split_rw_at into blk_rq_append_bio so that it validates the hardware limits. With this all passthrough callers can simply add bio_add_page to build the bio and delay checking for exceeding of limits to this point instead of doing it for each page. While this looks like adding a new expensive loop over all bio_vecs, blk_rq_append_bio is already doing that just to counter the number of segments. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Link: https://lore.kernel.org/r/20250103073417.459715-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23block: Delete bio_set_prio()John Garry1-2/+0
Since commit 43b62ce3ff0a ("block: move bio io prio to a new field"), macro bio_set_prio() does nothing but set bio->bi_ioprio. All other places just set bio->bi_ioprio directly, so replace bio_set_prio() remaining callsites with setting bio->bi_ioprio directly and delete that macro. Signed-off-by: John Garry <john.g.garry@oracle.com> Acked-by: Jack Wang <jinpu.wang@ionos.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20241202111957.2311683-3-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-23block: Delete bio_prio()John Garry1-1/+0
Since commit 43b62ce3ff0a ("block: move bio io prio to a new field"), macro bio_prio() does nothing but return the value in bio->bi_ioprio. Most other places just read bio->bi_ioprio directly, so replace bi_ioprio() callsites with reading bio->bi_ioprio directly and delete that macro. Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20241202111957.2311683-2-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-12-12block: Make bio_iov_bvec_set() accept pointer to const iov_iterJohn Garry1-1/+1
Make bio_iov_bvec_set() accept a pointer to const iov_iter, which means that we can drop the undesirable casting to struct iov_iter pointer in blk_rq_map_user_bvec(). Signed-off-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241202115727.2320401-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-11block: lift bio_is_zone_append to bio.hChristoph Hellwig1-0/+17
Make bio_is_zone_append globally available, because file systems need to use to check for a zone append bio in their end_io handlers to deal with the block layer emulation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241104062647.91160-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-31block: remove bio_add_zone_append_pageChristoph Hellwig1-2/+0
This is only used by the nvmet zns passthrough code, which can trivially just use bio_add_pc_page and do the sanity check for the max zone append limit itself. All future zoned file systems should follow the btrfs lead and let the upper layers fill up bios unlimited by hardware constraints and split them to the limits in the I/O submission handler. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20241030051859.280923-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-08-29block: rework bio splittingChristoph Hellwig1-2/+2
The current setup with bio_may_exceed_limit and __bio_split_to_limits is a bit of a mess. Change it so that __bio_split_to_limits does all the work and is just a variant of bio_split_to_limits that returns nr_segs. This is done by inlining it and instead have the various bio_split_* helpers directly submit the potentially split bios. To support btrfs, the rw version has a lower level helper split out that just returns the offset to split. This turns out to nicely clean up the btrfs flow as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Tested-by: Hans Holmberg <hans.holmberg@wdc.com> Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com> Link: https://lore.kernel.org/r/20240826173820.1690925-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-03block: split integrity support out of bio.hChristoph Hellwig1-156/+0
Split struct bio_integrity_payload and the related prototypes out of bio.h into a separate bio-integrity.h header so that it is only pulled in by the few places that need it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20240702151047.1746127-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12block: unmap and free user mapped integrity via submitterAnuj Gupta1-0/+4
The user mapped intergity is copied back and unpinned by bio_integrity_free which is a low-level routine. Do it via the submitter rather than doing it in the low-level block layer code, to split the submitter side from the consumer side of the bio. Signed-off-by: Anuj Gupta <anuj20.g@samsung.com> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20240610111144.14647-1-anuj20.g@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-07block: add a blk_alloc_discard_bio helperChristoph Hellwig1-0/+3
Factor out a helper from __blkdev_issue_discard that chews off as much as possible from a discard range and allocates a bio for it. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240506042027.2289826-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-07block: add a bio_chain_and_submit helperChristoph Hellwig1-0/+1
This is basically blk_next_bio just with the bio allocation moved to the caller to allow for more flexible bio handling in the caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20240506042027.2289826-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-01block: add a bio_list_merge_init helperChristoph Hellwig1-0/+7
This is a simple combination of bio_list_merge + bio_list_init similar to list_splice_init. While it only saves a single line in a callers, it makes the move all bios from one list to another and reinitialize the original pattern a lot more obvious in the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Matthew Sakai <msakai@redhat.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Link: https://lore.kernel.org/r/20240328084147.2954434-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>