kernel/linux.git/block/blk.h, branch v6.12.92

block: add pgmap check to biovec_phys_mergeable

2026-05-14T13:29:22+00:00

commit 13920e4b7b784b40cf4519ff1f0f3e513476a499 upstream. biovec_phys_mergeable() is used by the request merge, DMA mapping, and integrity merge paths to decide if two physically contiguous bvec segments can be coalesced into one. It currently has no check for whether the segments belong to different dev_pagemaps. When zone device memory is registered in multiple chunks, each chunk gets its own dev_pagemap. A single bio can legitimately contain bvecs from different pgmaps -- iov_iter_extract_bvecs() breaks at pgmap boundaries but the outer loop in bio_iov_iter_get_pages() continues filling the same bio. If such bvecs are physically contiguous, biovec_phys_mergeable() will coalesce them, making it impossible to recover the correct pgmap for the merged segment via page_pgmap(). Add a zone_device_pages_have_same_pgmap() check to prevent merging bvec segments that span different pgmaps. Fixes: 49580e690755 ("block: add check when merging zone device pages") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Naman Jain Link: https://patch.msgid.link/20260410153414.4159050-2-namjain@linux.microsoft.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

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

2026-05-07T04:09:45+00:00

[ Upstream commit 41c665aae2b5dbecddddcc8ace344caf630cc7a4 ] 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 [ restructured combined `if` into explicit `bv` block ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

block: decouple secure erase size limit from discard size limit

2026-03-04T12:20:56+00:00

[ Upstream commit ee81212f74a57c5d2b56cf504f40d528dac6faaf ] Secure erase should use max_secure_erase_sectors instead of being limited by max_discard_sectors. Separate the handling of REQ_OP_SECURE_ERASE from REQ_OP_DISCARD to allow each operation to use its own size limit. Signed-off-by: Luke Wang Reviewed-by: Ulf Hansson Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: handle zone management operations completions

2026-01-08T09:15:04+00:00

[ Upstream commit efae226c2ef19528ffd81d29ba0eecf1b0896ca2 ] The functions blk_zone_wplug_handle_reset_or_finish() and blk_zone_wplug_handle_reset_all() both modify the zone write pointer offset of zone write plugs that are the target of a reset, reset all or finish zone management operation. However, these functions do this modification before the BIO is executed. So if the zone operation fails, the modified zone write pointer offsets become invalid. Avoid this by modifying the zone write pointer offset of a zone write plug that is the target of a zone management operation when the operation completes. To do so, modify blk_zone_bio_endio() to call the new function blk_zone_mgmt_bio_endio() which in turn calls the functions blk_zone_reset_all_bio_endio(), blk_zone_reset_bio_endio() or blk_zone_finish_bio_endio() depending on the operation of the completed BIO, to modify a zone write plug write pointer offset accordingly. These functions are called only if the BIO execution was successful. Fixes: dd291d77cc90 ("block: Introduce zone write plugging") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe [ adapted bdev_zone_is_seq() check to disk_zone_is_conv() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

block: only update request sector if needed

2025-05-29T09:03:12+00:00

[ Upstream commit db492e24f9b05547ba12b4783f09c9d943cf42fe ] In case of a ZONE APPEND write, regardless of native ZONE APPEND or the emulation layer in the zone write plugging code, the sector the data got written to by the device needs to be updated in the bio. At the moment, this is done for every native ZONE APPEND write and every request that is flagged with 'BIO_ZONE_WRITE_PLUGGING'. But thus superfluously updates the sector for regular writes to a zoned block device. Check if a bio is a native ZONE APPEND write or if the bio is flagged as 'BIO_EMULATES_ZONE_APPEND', meaning the block layer's zone write plugging code handles the ZONE APPEND and translates it into a regular write and back. Only if one of these two criterion is met, update the sector in the bio upon completion. Signed-off-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/dea089581cb6b777c1cd1500b38ac0b61df4b2d1.1746530748.git.jth@kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: lift bio_is_zone_append to bio.h

2025-01-09T12:33:32+00:00

[ Upstream commit 0ef2b9e698dbf9ba78f67952a747f35eb7060470 ] 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 Reviewed-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Link: https://lore.kernel.org/r/20241104062647.91160-4-hch@lst.de Signed-off-by: Jens Axboe Stable-dep-of: 6c3864e05548 ("btrfs: use bio_is_zone_append() in the completion handler") Signed-off-by: Sasha Levin

block: always verify unfreeze lock on the owner task

2024-12-05T13:03:10+00:00

commit 6a78699838a0ddeed3620ddf50c1521f1fe1e811 upstream. commit f1be1788a32e ("block: model freeze & enter queue as lock for supporting lockdep") tries to apply lockdep for verifying freeze & unfreeze. However, the verification is only done the outmost freeze and unfreeze. This way is actually not correct because q->mq_freeze_depth still may drop to zero on other task instead of the freeze owner task. Fix this issue by always verifying the last unfreeze lock on the owner task context, and make sure both the outmost freeze & unfreeze are verified in the current task. Fixes: f1be1788a32e ("block: model freeze & enter queue as lock for supporting lockdep") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20241031133723.303835-4-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: model freeze & enter queue as lock for supporting lockdep

2024-12-05T13:03:05+00:00

[ Upstream commit f1be1788a32e8fa63416ad4518bbd1a85a825c9d ] Recently we got several deadlock report[1][2][3] caused by blk_mq_freeze_queue and blk_enter_queue(). Turns out the two are just like acquiring read/write lock, so model them as read/write lock for supporting lockdep: 1) model q->q_usage_counter as two locks(io and queue lock) - queue lock covers sync with blk_enter_queue() - io lock covers sync with bio_enter_queue() 2) make the lockdep class/key as per-queue: - different subsystem has very different lock use pattern, shared lock class causes false positive easily - freeze_queue degrades to no lock in case that disk state becomes DEAD because bio_enter_queue() won't be blocked any more - freeze_queue degrades to no lock in case that request queue becomes dying because blk_enter_queue() won't be blocked any more 3) model blk_mq_freeze_queue() as acquire_exclusive & try_lock - it is exclusive lock, so dependency with blk_enter_queue() is covered - it is trylock because blk_mq_freeze_queue() are allowed to run concurrently 4) model blk_enter_queue() & bio_enter_queue() as acquire_read() - nested blk_enter_queue() are allowed - dependency with blk_mq_freeze_queue() is covered - blk_queue_exit() is often called from other contexts(such as irq), and it can't be annotated as lock_release(), so simply do it in blk_enter_queue(), this way still covered cases as many as possible With lockdep support, such kind of reports may be reported asap and needn't wait until the real deadlock is triggered. For example, lockdep report can be triggered in the report[3] with this patch applied. [1] occasional block layer hang when setting 'echo noop > /sys/block/sda/queue/scheduler' https://bugzilla.kernel.org/show_bug.cgi?id=219166 [2] del_gendisk() vs blk_queue_enter() race condition https://lore.kernel.org/linux-block/20241003085610.GK11458@google.com/ [3] queue_freeze & queue_enter deadlock in scsi https://lore.kernel.org/linux-block/ZxG38G9BuFdBpBHZ@fedora/T/#u Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20241025003722.3630252-4-ming.lei@redhat.com Signed-off-by: Jens Axboe Stable-dep-of: 3802f73bd807 ("block: fix uaf for flush rq while iterating tags") Signed-off-by: Sasha Levin

block: implement async io_uring discard cmd

2024-09-11T16:45:28+00:00

io_uring allows implementing custom file specific asynchronous operations via the fops->uring_cmd callback, a.k.a. IORING_OP_URING_CMD requests or just io_uring commands. Use it to add support for async discards. Normally, it first tries to queue up bios in a non-blocking context, and if that fails, we'd retry from a blocking context by returning -EAGAIN to the core io_uring. We always get the result from bios asynchronously by setting a custom bi_end_io callback, at which point we drag the request into the task context to either reissue or complete it and post a completion to the user. Unlike ioctl(BLKDISCARD) with stronger guarantees against races, we only do a best effort attempt to invalidate page cache, and it can race with any writes and reads and leave page cache stale. It's the same kind of races we allow to direct writes. Also, apart from cases where discarding is not allowed at all, e.g. discards are not supported or the file/device is read only, the user should assume that the sector range on disk is not valid anymore, even when an error was returned to the user. Suggested-by: Conrad Meyer Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/2b5210443e4fa0257934f73dfafcc18a77cd0e09.1726072086.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

block: Added folio-ized version of bio_add_hw_page()

2024-09-11T13:24:00+00:00

Added new bio_add_hw_folio() function as a wrapper around bio_add_hw_page(). This is a prep patch. Signed-off-by: Kundan Kumar Tested-by: Luis Chamberlain Reviewed-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20240911064935.5630-2-kundan.kumar@samsung.com Signed-off-by: Jens Axboe