[PATCH 09/10] block: add support to send meta buffer

[Kanchan Joshi]

If iocb contains the meta, extract that and prepare the bip.
Extend bip so that can it can carry three new integrity-check flags
and application tag.

Make sure that ->prepare_fn and ->complete_fn are skipped for
user-owned meta buffer.

Signed-off-by: Anuj Gupta <anuj20.g at samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
---
 block/bio-integrity.c | 31 ++++++++++++++++++++++++++++++-
 block/fops.c          |  9 +++++++++
 block/t10-pi.c        |  6 ++++++
 include/linux/bio.h   | 10 ++++++++++
 4 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 1085cf45f51e..dab76fd73813 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -11,7 +11,7 @@
 #include <linux/export.h>
 #include <linux/bio.h>
 #include <linux/workqueue.h>
-#include <linux/slab.h>
+#include <uapi/linux/io_uring.h>
 #include "blk.h"
 
 static struct kmem_cache *bip_slab;
@@ -318,6 +318,35 @@ static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
 	return nr_bvecs;
 }
 
+int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	u16 bip_flags = 0;
+	int ret;
+
+	if (!bi)
+		return -EINVAL;
+
+	if (meta->iter.count < bio_integrity_bytes(bi, bio_sectors(bio)))
+		return -EINVAL;
+
+	ret = bio_integrity_map_user(bio, &meta->iter, 0);
+	if (!ret) {
+		struct bio_integrity_payload *bip = bio_integrity(bio);
+
+		if (meta->flags & META_CHK_GUARD)
+			bip_flags |= BIP_USER_CHK_GUARD;
+		if (meta->flags & META_CHK_APPTAG)
+			bip_flags |= BIP_USER_CHK_APPTAG;
+		if (meta->flags & META_CHK_REFTAG)
+			bip_flags |= BIP_USER_CHK_REFTAG;
+
+		bip->bip_flags |= bip_flags;
+		bip->apptag = meta->apptag;
+	}
+	return ret;
+}
+
 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter,
 			  u32 seed)
 {
diff --git a/block/fops.c b/block/fops.c
index 679d9b752fe8..e488fa66dd60 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -353,6 +353,15 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 		task_io_account_write(bio->bi_iter.bi_size);
 	}
 
+	if (unlikely(iocb->ki_flags & IOCB_USE_META)) {
+		ret = bio_integrity_map_iter(bio, iocb->private);
+		WRITE_ONCE(iocb->private, NULL);
+		if (unlikely(ret)) {
+			bio_put(bio);
+			return ret;
+		}
+	}
+
 	if (iocb->ki_flags & IOCB_NOWAIT)
 		bio->bi_opf |= REQ_NOWAIT;
 
diff --git a/block/t10-pi.c b/block/t10-pi.c
index d90892fd6f2a..72d1522417a1 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -156,6 +156,8 @@ static void t10_pi_type1_prepare(struct request *rq)
 		/* Already remapped? */
 		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
 			break;
+		if (bip->bip_flags & BIP_INTEGRITY_USER)
+			break;
 
 		bip_for_each_vec(iv, bip, iter) {
 			unsigned int j;
@@ -205,6 +207,8 @@ static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
 		struct bio_vec iv;
 		struct bvec_iter iter;
 
+		if (bip->bip_flags & BIP_INTEGRITY_USER)
+			break;
 		bip_for_each_vec(iv, bip, iter) {
 			unsigned int j;
 			void *p;
@@ -408,6 +412,8 @@ static void ext_pi_type1_prepare(struct request *rq)
 		/* Already remapped? */
 		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
 			break;
+		if (bip->bip_flags & BIP_INTEGRITY_USER)
+			break;
 
 		bip_for_each_vec(iv, bip, iter) {
 			unsigned int j;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 0281b356935a..8724305bce62 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -329,6 +329,9 @@ enum bip_flags {
 	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
 	BIP_INTEGRITY_USER	= 1 << 5, /* Integrity payload is user address */
 	BIP_COPY_USER		= 1 << 6, /* Kernel bounce buffer in use */
+	BIP_USER_CHK_GUARD	= 1 << 7,
+	BIP_USER_CHK_APPTAG	= 1 << 8,
+	BIP_USER_CHK_REFTAG	= 1 << 9,
 };
 
 struct uio_meta {
@@ -348,6 +351,7 @@ struct bio_integrity_payload {
 	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
 	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
 	unsigned short		bip_flags;	/* control flags */
+	u16			apptag;		/* apptag */
 
 	struct bvec_iter	bio_iter;	/* for rewinding parent bio */
 
@@ -729,6 +733,7 @@ static inline bool bioset_initialized(struct bio_set *bs)
 	for_each_bio(_bio)						\
 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
 
+int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta);
 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter, u32 seed);
 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);
@@ -808,6 +813,11 @@ static inline int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter,
 	return -EINVAL;
 }
 
+static inline int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
+{
+	return -EINVAL;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 /*
-- 
2.25.1