On Wed, Feb 26, 2020 at 04:37:17PM +0800, Bob Liu wrote:
> Introduce two funcs handle protect information passthrough from
> user space.
>
> iter_slice_protect_info() will slice the last segment as protect
> information.
>
> bio_integrity_prep_from_iovec() attach the protect information to
> a bio.
>
> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>
> ---
> block/bio-integrity.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/bio.h | 14 ++++++++++
> 2 files changed, 91 insertions(+)
>
> diff --git a/block/bio-integrity.c b/block/bio-integrity.c
> index 575df98..0b22c5d 100644
> --- a/block/bio-integrity.c
> +++ b/block/bio-integrity.c
> @@ -12,6 +12,7 @@
> #include <linux/bio.h>
> #include <linux/workqueue.h>
> #include <linux/slab.h>
> +#include <linux/uio.h>
> #include "blk.h"
>
> #define BIP_INLINE_VECS 4
> @@ -305,6 +306,53 @@ bool bio_integrity_prep(struct bio *bio)
> }
> EXPORT_SYMBOL(bio_integrity_prep);
>
> +int bio_integrity_prep_from_iovec(struct bio *bio, struct iovec *pi_iov)
> +{
> + struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
> + struct bio_integrity_payload *bip;
> + struct page *user_pi_page;
> + int nr_vec_page = 0;
> + int ret = 0, interval = 0;
> +
> + if (!pi_iov || !pi_iov->iov_base)
> + return 1;
> +
> + nr_vec_page = (pi_iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
> + if (nr_vec_page > 1) {
> + printk("Now only support 1 page containing integrity "
> + "metadata, while requires %d pages.\n", nr_vec_page);
> + return 1;
I would've thought this would be -EINVAL or something given the -ENOMEM
below...?
> + }
> +
> + interval = bio_integrity_intervals(bi, bio_sectors(bio));
> + if ((interval * bi->tuple_size) != pi_iov->iov_len)
> + return 1;
> +
> + bip = bio_integrity_alloc(bio, GFP_NOIO, nr_vec_page);
> + if (IS_ERR(bip))
> + return PTR_ERR(bip);
> +
> + bip->bip_iter.bi_size = pi_iov->iov_len;
> + bip->bio_iter = bio->bi_iter;
> + bip_set_seed(bip, bio->bi_iter.bi_sector);
> +
> + if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
> + bip->bip_flags |= BIP_IP_CHECKSUM;
> +
> + ret = get_user_pages_fast((unsigned long)(pi_iov->iov_base), nr_vec_page,
> + op_is_write(bio_op(bio)) ? FOLL_WRITE : 0,
> + &user_pi_page);
> + if (unlikely(ret < 0))
> + return 1;
> +
> + ret = bio_integrity_add_page(bio, user_pi_page, pi_iov->iov_len, 0);
> + if (unlikely(ret != pi_iov->iov_len))
> + return -ENOMEM;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(bio_integrity_prep_from_iovec);
> +
> /**
> * bio_integrity_verify_fn - Integrity I/O completion worker
> * @work: Work struct stored in bio to be verified
> @@ -378,6 +426,35 @@ void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
> }
>
> /**
> + * iter_slice_protect_info
> + *
> + * Description: slice protection information from iter.
> + * The last iovec contains protection information pass from user space.
What do the return values here mean?
Also kinda wondering about the slice & dice of the iovec here, but
<shrug> I guess this is RFC. :)
--D
> + */
> +int iter_slice_protect_info(struct iov_iter *iter, int nr_pages,
> + struct iovec **pi_iov)
> +{
> + size_t len = 0;
> +
> + /* TBD: now only support one bio. */
> + if (!iter_is_iovec(iter) || nr_pages >= BIO_MAX_PAGES - 1)
> + return 1;
> +
> + /* Last iovec contains protection information. */
> + iter->nr_segs--;
> + *pi_iov = (struct iovec *)(iter->iov + iter->nr_segs);
> +
> + len = (*pi_iov)->iov_len;
> + if (len > 0 && len < iter->count) {
> + iter->count -= len;
> + return 0;
> + }
> +
> + return 1;
> +}
> +EXPORT_SYMBOL(iter_slice_protect_info);
> +
> +/**
> * bio_integrity_trim - Trim integrity vector
> * @bio: bio whose integrity vector to update
> *
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 3cdb84c..6172b13 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -749,6 +749,8 @@ static inline bool bioset_initialized(struct bio_set *bs)
> extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
> extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
> extern bool bio_integrity_prep(struct bio *);
> +extern int bio_integrity_prep_from_iovec(struct bio *bio, struct iovec *pi_iov);
> +extern int iter_slice_protect_info(struct iov_iter *iter, int nr_pages, struct iovec **pi_iov);
> extern void bio_integrity_advance(struct bio *, unsigned int);
> extern void bio_integrity_trim(struct bio *);
> extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
> @@ -778,6 +780,18 @@ static inline bool bio_integrity_prep(struct bio *bio)
> return true;
> }
>
> +static inline int bio_integrity_prep_from_iovec(struct bio *bio,
> + struct iovec *pi_iov)
> +{
> + return 0;
> +}
> +
> +static inline int iter_slice_protect_info(struct iov_iter *iter, int nr_pages,
> + struct iovec **pi_iov)
> +{
> + return 0;
> +}
> +
> static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
> gfp_t gfp_mask)
> {
> --
> 2.9.5
>
