kernel/git/stable/linux.git/block/bio.c, branch linux-rolling-lts

block: save page offset gaps in cloned bio

2026-09-14T11:36:18+00:00

[ Upstream commit 96c8ea3c5add7920b3c43840d1ea76b3354c8d2d ] The cloned bio needs to inherit the accumulated gaps between vectors so that we can know if this bio can subscribe to the iova coalescing optimization. When cloning for a split, the gap only applies to the front bio since that's as far as has been processed. The remaining bio can reset its gaps to 0 since it advanced past the checked vectors, and will start its accounting from there on the next split check. Fixes: 2f6b2565d43c ("block: accumulate memory segment gaps per bio") Reported-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Keith Busch Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260819154937.3903312-1-kbusch@meta.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: accumulate memory segment gaps per bio

2026-09-14T11:35:51+00:00

[ Upstream commit 2f6b2565d43cdb5087cac23d530cca84aa3d897e ] 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 Stable-dep-of: ea2160c7b781 ("nvme-apple: Require page aligned buffers on the admin queue") Signed-off-by: Sasha Levin

block: relax pgmap check in bio_add_page for compatible zone device pages

2026-05-07T04:11:42+00:00

commit 41c665aae2b5dbecddddcc8ace344caf630cc7a4 upstream. bio_add_page() and bio_integrity_add_page() reject pages from different dev_pagemaps entirely, returning 0 even when those pages have compatible DMA mapping requirements. This forces callers to start a new bio when buffers span pgmap boundaries, even though the pages could safely coexist as separate bvec entries. This matters for guests where memory is registered through devm_memremap_pages() with MEMORY_DEVICE_GENERIC in multiple calls, creating separate dev_pagemaps for each chunk. When a direct I/O buffer spans two such chunks, bio_add_page() rejects the second page, forcing an unnecessary bio split or I/O failure. Introduce zone_device_pages_compatible() in blk.h to check whether two pages can coexist in the same bio as separate bvec entries. The block DMA iterator (blk_dma_map_iter_start) caches the P2PDMA mapping state from the first segment and applies it to all others, so P2PDMA pages from different pgmaps must not be mixed, and neither must P2PDMA and non-P2PDMA pages. All other combinations (MEMORY_DEVICE_GENERIC pages from different pgmaps, or MEMORY_DEVICE_GENERIC with normal RAM) use the same dma_map_phys path and are safe. Replace the blanket zone_device_pages_have_same_pgmap() rejection with zone_device_pages_compatible(), while keeping zone_device_pages_have_same_pgmap() as a merge guard. Pages from different pgmaps can be added as separate bvec entries but must not be coalesced into the same segment, as that would make it impossible to recover the correct pgmap via page_pgmap(). Fixes: 49580e690755 ("block: add check when merging zone device pages") Cc: stable@vger.kernel.org Signed-off-by: Naman Jain Reviewed-by: Christoph Hellwig Link: https://patch.msgid.link/20260410153414.4159050-3-namjain@linux.microsoft.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: rename bio_iov_iter_get_pages_aligned to bio_iov_iter_get_pages

2025-10-07T14:05:44+00:00

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 Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Reviewed-by: Keith Busch Reviewed-by: Qu Wenruo Signed-off-by: Jens Axboe

block: cleanup bio_issue

2025-09-10T11:23:45+00:00

Now that bio->bi_issue is only used by blk-iolatency to get bio issue time, replace bio_issue with u64 time directly and remove bio_issue to make code cleaner. Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: align the bio after building it

2025-09-09T16:27:01+00:00

Instead of ensuring each vector is block size aligned while constructing the bio, just ensure the entire size is aligned after it's built. This makes getting bio pages more flexible to accepting device valid io vectors that would otherwise get rejected by alignment checks. Signed-off-by: Keith Busch Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe

block: add size alignment to bio_iov_iter_get_pages

2025-09-09T16:27:01+00:00

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

block: remove the bi_inline_vecs variable sized array from struct bio

2025-09-09T13:31:59+00:00

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 Reviewed-by: John Garry Signed-off-by: Jens Axboe

block: add a bio_init_inline helper

2025-09-09T13:31:59+00:00

Just a simpler wrapper around bio_init for callers that want to initialize a bio with inline bvecs. Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Reviewed-by: Yu Kuai Signed-off-by: Jens Axboe

blk-mq: remove REQ_P2PDMA flag

2025-08-25T13:44:39+00:00

It's not serving any particular purpose. pci_p2pdma_state() already has all the appropriate checks, so the config and flag checks are not guarding anything. Signed-off-by: Keith Busch Reviewed-by: Kanchan Joshi Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Link: https://lore.kernel.org/r/20250813153153.3260897-5-kbusch@meta.com Signed-off-by: Jens Axboe