kernel/linux.git/block/bio.c, branch v7.2-rc5

block: fix aligning of bounced dio read bios

2026-07-16T12:11:37+00:00

bio_iov_iter_align_down expects the "normal" biovec layout from vector 0, while bio_iov_iter_bounce_read abuses vector 0 for a bounce buffer allocation. Pass an explicit bvec to bio_iov_iter_align_down to deal with this case to avoid a double unpin. Additionally we need to free the folio if no bio_vec could be added, and adjust the size of the first bio_vec that contains the bounce buffer when the I/O size is aligned down. Fixes: e7b8b3c5b2a6 ("block: align down bounces bios") Reported-by: 0wnerD1ed Signed-off-by: Christoph Hellwig Tested-by: 0wnerD1ed Reviewed-by: Keith Busch Link: https://patch.msgid.link/20260716091306.316625-3-hch@lst.de Signed-off-by: Jens Axboe

block: handle huge zero folios in bio_free_folios

2026-07-16T12:11:37+00:00

When CONFIG_PERSISTENT_HUGE_ZERO_FOLIO is enabled, iomap_dio_zero() can add a huge zero folio to a zeroing bio, which needs special treatment in bio_free_folios by also checking is_huge_zero_folio() in addition to is_zero_folio(). Fixes: 8dd5e7c75d7b ("block: add helpers to bounce buffer an iov_iter into bios") Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Link: https://patch.msgid.link/20260716091306.316625-2-hch@lst.de Signed-off-by: Jens Axboe

block: try slab allocation in bio_alloc_bioset() before mempool

2026-07-16T12:10:44+00:00

When the per-CPU bio cache is enabled but empty, bio_alloc_percpu_cache() returns NULL and bio_alloc_bioset() falls straight through to the mempool fallback: if (unlikely(!bio)) { if (!(saved_gfp & __GFP_DIRECT_RECLAIM)) return NULL; ... } For non-sleeping allocations (no __GFP_DIRECT_RECLAIM) this returns NULL without ever attempting a slab allocation, even when there is plenty of free memory. Commit b520c4eef83d ("block: split bio_alloc_bioset more clearly into a fast and slowpath") introduced this. Before it, a percpu cache miss fell through to mempool_alloc(), which attempted the underlying slab allocation first and only failed when that slab allocation failed. The restructuring dropped the slab attempt that non-sleeping callers of a cache-enabled bioset (such as the default fs_bio_set used by bio_alloc()) relied on. Try a slab allocation with optimistic GFP_ flags before falling back to the mempool whenever the bio is still NULL, so both the cache-empty and non-cache paths share the same slab attempt. This restores the previous behavior for non-sleeping allocations. Fixes: b520c4eef83d ("block: split bio_alloc_bioset more clearly into a fast and slowpath") Suggested-by: Christoph Hellwig Signed-off-by: Joseph Qi Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260709020145.4011533-1-joseph.qi@linux.alibaba.com Signed-off-by: Jens Axboe

block: do not warn when doing greedy allocation in folio_alloc_greedy()

2026-07-15T22:33:29+00:00

During one of my local btrfs fstests runs, folio_alloc() inside folio_alloc_greedy() triggered an allocation failure report when trying to allocate an order-4 folio. The kernel is from the latest development branch, which is utilizing the IOMAP_DIO_BOUNCE flag for direct writes when the inode requires checksum. Unfortunately I didn't save the full log, only the function and the order. When the IOMAP_DIO_BOUNCE flag is utilized, we will hit the following call chain: bio_iov_iter_bounce_write() |- folio_alloc_greedy() |- folio_alloc(gfp | __GFP_NORETRY, get_order(*size)); However __GFP_NORETRY will still emit an allocation failure report when it fails. And folio_alloc_greedy() will retry with a smaller order anyway, there is no point in emitting that allocation failure report. Append the __GFP_NOWARN flag to folio_alloc() for the larger-order folio attempts. Fixes: 8dd5e7c75d7b ("block: add helpers to bounce buffer an iov_iter into bios") Signed-off-by: Qu Wenruo Link: https://patch.msgid.link/d10571445ee505d95ba6eaad7558fc1f556d2921.1784020005.git.wqu@suse.com Signed-off-by: Jens Axboe

block: respect iov_iter::nofault flag in bio_iov_iter_bounce_write()

2026-06-16T20:48:35+00:00

For the incoming usage of IOMAP_DIO_BOUNCE in btrfs, btrfs has set iov_iter::nofault to prevent deadlock when a page fault is needed to read out the buffer. However bio_iov_iter_bounce_write() doesn't respect iov_iter::nofault flag, and just call a plain copy_from_iter() so it can still trigger page fault and cause deadlock in btrfs. Fix it by utilizing copy_folio_from_iter_atomic() if nofault flag is set, otherwise use copy_folio_from_iter(). Signed-off-by: Qu Wenruo Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/9c165a314022b61566eb247852eb773ca6c70889.1781597506.git.wqu@suse.com Signed-off-by: Jens Axboe

block: revert the iov_iter after a short copy in bio_iov_iter_bounce_write()

2026-06-16T20:48:35+00:00

For the incoming IOMAP_DIO_BOUNCE flag usage inside btrfs, it's pretty easy to hit short copy inside bio_iov_iter_bounce_write(). This is because btrfs has disabled page fault to avoid certain deadlock during direct writes, and instead btrfs manually fault in the pages then retry. And inside bio_iov_iter_bounce_write(), if we hit a short write, we didn't revert the iov_iter, which can cause problems like unexpected garbage for the next retry. Revert the iov_iter after a short copy. One thing to note is that, the folio is allocated then immediately queued into the bio, so the proper revert size should be (bi_size - this_len + copied). Fixes: 8dd5e7c75d7b ("block: add helpers to bounce buffer an iov_iter into bios") Signed-off-by: Qu Wenruo Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/c400989f227343b134110773d5acaaacf7024574.1781597506.git.wqu@suse.com Signed-off-by: Jens Axboe

Merge tag 'for-7.2/block-20260615' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

2026-06-16T07:32:47+00:00

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 ...

block: Add bvec_folio()

2026-05-29T11:34:24+00:00

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) Cc: Leon Romanovsky Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Reviewed-by: William Kucharski Link: https://patch.msgid.link/20260528175905.1102280-2-willy@infradead.org Signed-off-by: Jens Axboe

block: mark biovec_init_pool static

2026-05-28T13:57:50+00:00

Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: Bart Van Assche Link: https://patch.msgid.link/20260527150646.2349405-1-hch@lst.de Signed-off-by: Jens Axboe

block: unexport bio_{set,check}_pages_dirty

2026-05-15T14:46:45+00:00

Only used in built-in code. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260515045547.3790129-6-hch@lst.de Signed-off-by: Jens Axboe