Re: [PATCH 01/12] dm-integrity: use the nop integrity profile

[Milan Broz <gmazyland@gmail.com>]

On 6/5/24 8:28 AM, Christoph Hellwig wrote:
> Use the block layer built-in nop profile instead of reinventing it.

As this is my "invention", I am pretty sure that "nop" profile was
not available at the time I was prototyping AEAD dmcrypt extension.
(It was months before we submitted it upstream - and then nobody
apparently fixed it.)

So, I am quite happy this hack can go away!

I run full cryptsetup testuite with this patch and everything
works, nice cleanup.

Reviewed-by: Milan Broz <gmazyland@gmail.com>

Thanks,
Milan

> 
> Tested by:
> 
> $ dd if=/dev/urandom of=key.bin bs=512 count=1
> 
> $ cryptsetup luksFormat -q --type luks2 --integrity hmac-sha256 \
>   	--integrity-no-wipe /dev/nvme0n1 key.bin
> $ cryptsetup luksOpen /dev/nvme0n1 luks-integrity --key-file key.bin
> 
> and then doing mkfs.xfs and simple I/O on the mount file system.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   drivers/md/dm-crypt.c     |  4 ++--
>   drivers/md/dm-integrity.c | 20 --------------------
>   2 files changed, 2 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
> index 1b7a97cc377943..1dfc462f29cd6f 100644
> --- a/drivers/md/dm-crypt.c
> +++ b/drivers/md/dm-crypt.c
> @@ -1176,8 +1176,8 @@ static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
>   	struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
>   	struct mapped_device *md = dm_table_get_md(ti->table);
>   
> -	/* From now we require underlying device with our integrity profile */
> -	if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
> +	/* We require an underlying device with non-PI metadata */
> +	if (!bi || strcmp(bi->profile->name, "nop")) {
>   		ti->error = "Integrity profile not supported.";
>   		return -EINVAL;
>   	}
> diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
> index 417fddebe367a2..c1cc27541673c7 100644
> --- a/drivers/md/dm-integrity.c
> +++ b/drivers/md/dm-integrity.c
> @@ -350,25 +350,6 @@ static struct kmem_cache *journal_io_cache;
>   #define DEBUG_bytes(bytes, len, msg, ...)	do { } while (0)
>   #endif
>   
> -static void dm_integrity_prepare(struct request *rq)
> -{
> -}
> -
> -static void dm_integrity_complete(struct request *rq, unsigned int nr_bytes)
> -{
> -}
> -
> -/*
> - * DM Integrity profile, protection is performed layer above (dm-crypt)
> - */
> -static const struct blk_integrity_profile dm_integrity_profile = {
> -	.name			= "DM-DIF-EXT-TAG",
> -	.generate_fn		= NULL,
> -	.verify_fn		= NULL,
> -	.prepare_fn		= dm_integrity_prepare,
> -	.complete_fn		= dm_integrity_complete,
> -};
> -
>   static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map);
>   static void integrity_bio_wait(struct work_struct *w);
>   static void dm_integrity_dtr(struct dm_target *ti);
> @@ -3656,7 +3637,6 @@ static void dm_integrity_set(struct dm_target *ti, struct dm_integrity_c *ic)
>   	struct blk_integrity bi;
>   
>   	memset(&bi, 0, sizeof(bi));
> -	bi.profile = &dm_integrity_profile;
>   	bi.tuple_size = ic->tag_size;
>   	bi.tag_size = bi.tuple_size;
>   	bi.interval_exp = ic->sb->log2_sectors_per_block + SECTOR_SHIFT;