kernel/linux.git/include/linux/bio-integrity.h, branch v6.19.11

block-dma: properly take MMIO path

2025-11-14T12:09:56+00:00

In commit eadaa8b255f3 ("dma-mapping: introduce new DMA attribute to indicate MMIO memory"), DMA_ATTR_MMIO attribute was added to describe MMIO addresses, which require to avoid any memory cache flushing, as an outcome of the discussion pointed in Link tag below. In case of PCI_P2PDMA_MAP_THRU_HOST_BRIDGE transfer, blk-mq-dm logic treated this as regular page and relied on "struct page" DMA flow. That flow performs CPU cache flushing, which shouldn't be done here, and doesn't set IOMMU_MMIO flag in DMA-IOMMU case. As a solution, let's encode peer-to-peer transaction type in NVMe IOD flags variable and provide it to blk-mq-dma API. Link: https://lore.kernel.org/all/f912c446-1ae9-4390-9c11-00dce7bf0fd3@arm.com/ Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Reviewed-by: Keith Busch Signed-off-by: Leon Romanovsky 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

blk-mq-dma: bring back p2p request flags

2025-09-09T16:33:35+00:00

We only need to consider data and metadata dma mapping types separately. The request and bio integrity payload have enough flag bits to internally track the mapping type for each. Use these so the caller doesn't need to track them, and provide separete request and integrity helpers to the common code. This will make it easier to scale new mappings, like the proposed MMIO attribute, without burdening the caller to track such things. Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Leon Romanovsky Signed-off-by: Keith Busch Signed-off-by: Jens Axboe

block: split struct bio_integrity_payload

2025-03-03T18:17:52+00:00

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 Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Tested-by: Anuj Gupta Reviewed-by: Anuj Gupta Reviewed-by: Kanchan Joshi Link: https://lore.kernel.org/r/20250225154449.422989-4-hch@lst.de Signed-off-by: Jens Axboe

block: make bio_integrity_map_user() static inline

2024-12-23T15:19:09+00:00

If CONFIG_BLK_DEV_INTEGRITY isn't set, then the dummy helper must be static inline to avoid complaints about the function being unused. Fixes: fe8f4ca7107e ("block: modify bio_integrity_map_user to accept iov_iter as argument") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202411300229.y7h60mDg-lkp@intel.com/ Signed-off-by: Jens Axboe

block: add support to pass user meta buffer

2024-12-23T15:17:17+00:00

If an iocb contains metadata, extract that and prepare the bip. Based on flags specified by the user, set corresponding guard/app/ref tags to be checked in bip. Reviewed-by: Christoph Hellwig Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20241128112240.8867-11-anuj20.g@samsung.com Signed-off-by: Jens Axboe

scsi: add support for user-meta interface

2024-12-23T15:17:17+00:00

Add support for sending user-meta buffer. Set tags to be checked using flags specified by user/block-layer. With this change, BIP_CTRL_NOCHECK becomes unused. Remove it. Signed-off-by: Anuj Gupta Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20241128112240.8867-10-anuj20.g@samsung.com Signed-off-by: Jens Axboe

block: introduce BIP_CHECK_GUARD/REFTAG/APPTAG bip_flags

2024-12-23T15:17:16+00:00

This patch introduces BIP_CHECK_GUARD/REFTAG/APPTAG bip_flags which indicate how the hardware should check the integrity payload. BIP_CHECK_GUARD/REFTAG are conversion of existing semantics, while BIP_CHECK_APPTAG is a new flag. The driver can now just rely on block layer flags, and doesn't need to know the integrity source. Submitter of PI decides which tags to check. This would also give us a unified interface for user and kernel generated integrity. Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Reviewed-by: Christoph Hellwig Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20241128112240.8867-8-anuj20.g@samsung.com Signed-off-by: Jens Axboe

block: modify bio_integrity_map_user to accept iov_iter as argument

2024-12-23T15:17:16+00:00

This patch refactors bio_integrity_map_user to accept iov_iter as argument. This is a prep patch. Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Reviewed-by: Christoph Hellwig Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20241128112240.8867-4-anuj20.g@samsung.com Signed-off-by: Jens Axboe

block: define set of integrity flags to be inherited by cloned bip

2024-12-23T15:17:16+00:00

Introduce BIP_CLONE_FLAGS describing integrity flags that should be inherited in the cloned bip from the parent. Suggested-by: Christoph Hellwig Signed-off-by: Anuj Gupta Reviewed-by: Christoph Hellwig Reviewed-by: Martin K. Petersen Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20241128112240.8867-2-anuj20.g@samsung.com Signed-off-by: Jens Axboe