Re: [PATCH 06/15] block: add fs_bio_integrity helpers

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Jan 21, 2026 at 07:43:14AM +0100, Christoph Hellwig wrote:
> Add a set of helpers for file system initiated integrity information.
> These include mempool backed allocations and verifying based on a passed
> in sector and size which is often available from file system completion
> routines.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/Makefile                |  2 +-
>  block/bio-integrity-fs.c      | 81 +++++++++++++++++++++++++++++++++++
>  include/linux/bio-integrity.h |  6 +++
>  3 files changed, 88 insertions(+), 1 deletion(-)
>  create mode 100644 block/bio-integrity-fs.c
> 
> diff --git a/block/Makefile b/block/Makefile
> index c65f4da93702..7dce2e44276c 100644
> --- a/block/Makefile
> +++ b/block/Makefile
> @@ -26,7 +26,7 @@ bfq-y				:= bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
>  obj-$(CONFIG_IOSCHED_BFQ)	+= bfq.o
>  
>  obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o \
> -				   bio-integrity-auto.o
> +				   bio-integrity-auto.o bio-integrity-fs.o
>  obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
>  obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
>  obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
> diff --git a/block/bio-integrity-fs.c b/block/bio-integrity-fs.c
> new file mode 100644
> index 000000000000..c8b3c753965d
> --- /dev/null
> +++ b/block/bio-integrity-fs.c
> @@ -0,0 +1,81 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2025 Christoph Hellwig.
> + */
> +#include <linux/blk-integrity.h>
> +#include <linux/bio-integrity.h>
> +#include "blk.h"
> +
> +struct fs_bio_integrity_buf {
> +	struct bio_integrity_payload	bip;
> +	struct bio_vec			bvec;
> +};
> +
> +static struct kmem_cache *fs_bio_integrity_cache;
> +static mempool_t fs_bio_integrity_pool;
> +
> +void fs_bio_integrity_alloc(struct bio *bio)
> +{
> +	struct fs_bio_integrity_buf *iib;
> +	unsigned int action;
> +
> +	action = bio_integrity_action(bio);
> +	if (!action)
> +		return;
> +
> +	iib = mempool_alloc(&fs_bio_integrity_pool, GFP_NOIO);
> +	bio_integrity_init(bio, &iib->bip, &iib->bvec, 1);
> +
> +	bio_integrity_alloc_buf(bio, action & BI_ACT_ZERO);
> +	if (action & BI_ACT_CHECK)
> +		bio_integrity_setup_default(bio);
> +}
> +
> +void fs_bio_integrity_free(struct bio *bio)
> +{
> +	struct bio_integrity_payload *bip = bio_integrity(bio);
> +
> +	bio_integrity_free_buf(bip);
> +	mempool_free(container_of(bip, struct fs_bio_integrity_buf, bip),
> +			&fs_bio_integrity_pool);
> +
> +	bio->bi_integrity = NULL;
> +	bio->bi_opf &= ~REQ_INTEGRITY;
> +}
> +
> +void fs_bio_integrity_generate(struct bio *bio)
> +{
> +	fs_bio_integrity_alloc(bio);
> +	bio_integrity_generate(bio);
> +}
> +EXPORT_SYMBOL_GPL(fs_bio_integrity_generate);
> +
> +int fs_bio_integrity_verify(struct bio *bio, sector_t sector, unsigned int size)
> +{
> +	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
> +	struct bio_integrity_payload *bip = bio_integrity(bio);
> +
> +	/*
> +	 * Reinitialize bip->bit_iter.

s/bit_iter/bip_iter/ ?

With that fixed, this looks fine to me;
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> +	 *
> +	 * This is for use in the submitter after the driver is done with the
> +	 * bio. Requires the submitter to remember the sector and the size.
> +	 */
> +
> +	memset(&bip->bip_iter, 0, sizeof(bip->bip_iter));
> +	bip->bip_iter.bi_sector = sector;
> +	bip->bip_iter.bi_size = bio_integrity_bytes(bi, size >> SECTOR_SHIFT);
> +	return blk_status_to_errno(bio_integrity_verify(bio, &bip->bip_iter));
> +}
> +
> +static int __init fs_bio_integrity_init(void)
> +{
> +	fs_bio_integrity_cache = kmem_cache_create("fs_bio_integrity",
> +			sizeof(struct fs_bio_integrity_buf), 0,
> +			SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
> +	if (mempool_init_slab_pool(&fs_bio_integrity_pool, BIO_POOL_SIZE,
> +			fs_bio_integrity_cache))
> +		panic("fs_bio_integrity: can't create pool\n");
> +	return 0;
> +}
> +fs_initcall(fs_bio_integrity_init);
> diff --git a/include/linux/bio-integrity.h b/include/linux/bio-integrity.h
> index 232b86b9bbcb..503dc9bc655d 100644
> --- a/include/linux/bio-integrity.h
> +++ b/include/linux/bio-integrity.h
> @@ -145,4 +145,10 @@ void bio_integrity_alloc_buf(struct bio *bio, bool zero_buffer);
>  void bio_integrity_free_buf(struct bio_integrity_payload *bip);
>  void bio_integrity_setup_default(struct bio *bio);
>  
> +void fs_bio_integrity_alloc(struct bio *bio);
> +void fs_bio_integrity_free(struct bio *bio);
> +void fs_bio_integrity_generate(struct bio *bio);
> +int fs_bio_integrity_verify(struct bio *bio, sector_t sector,
> +		unsigned int size);
> +
>  #endif /* _LINUX_BIO_INTEGRITY_H */
> -- 
> 2.47.3
> 
>