[PATCH v2 09/10] block: add support to pass user meta buffer

[Anuj Gupta <anuj20.g@samsung.com>]

From: Kanchan Joshi <joshi.k@samsung.com>

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@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
---
 block/bio-integrity.c | 44 +++++++++++++++++++++++++++++++++++++++++++
 block/fops.c          | 28 ++++++++++++++++++++++++++-
 block/t10-pi.c        |  6 ++++++
 include/linux/bio.h   | 10 ++++++++++
 4 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 38418be07139..599f39999174 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 <uapi/linux/io_uring.h>
 #include "blk.h"
 
 static struct kmem_cache *bip_slab;
@@ -337,6 +338,49 @@ static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
 	return nr_bvecs;
 }
 
+static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta)
+{
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+	u16 bip_flags = 0;
+
+	if (meta->flags & INTEGRITY_CHK_GUARD)
+		bip_flags |= BIP_USER_CHK_GUARD;
+	if (meta->flags & INTEGRITY_CHK_APPTAG)
+		bip_flags |= BIP_USER_CHK_APPTAG;
+	if (meta->flags & INTEGRITY_CHK_REFTAG)
+		bip_flags |= BIP_USER_CHK_REFTAG;
+
+	bip->bip_flags |= bip_flags;
+	bip->apptag = meta->apptag;
+}
+
+int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	unsigned int integrity_bytes;
+	int ret;
+	struct iov_iter it;
+
+	if (!bi)
+		return -EINVAL;
+	/*
+	 * original meta iterator can be bigger.
+	 * process integrity info corresponding to current data buffer only.
+	 */
+	it = meta->iter;
+	integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio));
+	if (it.count < integrity_bytes)
+		return -EINVAL;
+
+	it.count = integrity_bytes;
+	ret = bio_integrity_map_user(bio, &it, 0);
+	if (!ret) {
+		bio_uio_meta_to_bip(bio, meta);
+		iov_iter_advance(&meta->iter, integrity_bytes);
+	}
+	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 be36c9fbd500..6477424b4ebc 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -126,12 +126,13 @@ static void blkdev_bio_end_io(struct bio *bio)
 {
 	struct blkdev_dio *dio = bio->bi_private;
 	bool should_dirty = dio->flags & DIO_SHOULD_DIRTY;
+	bool is_async = !(dio->flags & DIO_IS_SYNC);
 
 	if (bio->bi_status && !dio->bio.bi_status)
 		dio->bio.bi_status = bio->bi_status;
 
 	if (atomic_dec_and_test(&dio->ref)) {
-		if (!(dio->flags & DIO_IS_SYNC)) {
+		if (is_async) {
 			struct kiocb *iocb = dio->iocb;
 			ssize_t ret;
 
@@ -154,6 +155,9 @@ static void blkdev_bio_end_io(struct bio *bio)
 		}
 	}
 
+	if (is_async && (dio->iocb->ki_flags & IOCB_HAS_META))
+		bio_integrity_unmap_free_user(bio);
+
 	if (should_dirty) {
 		bio_check_pages_dirty(bio);
 	} else {
@@ -231,6 +235,16 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 			}
 			bio->bi_opf |= REQ_NOWAIT;
 		}
+		if (!is_sync && unlikely(iocb->ki_flags & IOCB_HAS_META)) {
+			ret = bio_integrity_map_iter(bio, iocb->private);
+			if (unlikely(ret)) {
+				bio_release_pages(bio, false);
+				bio_clear_flag(bio, BIO_REFFED);
+				bio_put(bio);
+				blk_finish_plug(&plug);
+				return ret;
+			}
+		}
 
 		if (is_read) {
 			if (dio->flags & DIO_SHOULD_DIRTY)
@@ -288,6 +302,9 @@ static void blkdev_bio_end_io_async(struct bio *bio)
 		ret = blk_status_to_errno(bio->bi_status);
 	}
 
+	if (unlikely(iocb->ki_flags & IOCB_HAS_META))
+		bio_integrity_unmap_free_user(bio);
+
 	iocb->ki_complete(iocb, ret);
 
 	if (dio->flags & DIO_SHOULD_DIRTY) {
@@ -348,6 +365,15 @@ 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_HAS_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_ATOMIC)
 		bio->bi_opf |= REQ_ATOMIC;
 
diff --git a/block/t10-pi.c b/block/t10-pi.c
index cd7fa60d63ff..38c3da245b11 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -131,6 +131,8 @@ 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;
@@ -180,6 +182,8 @@ 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;
@@ -305,6 +309,8 @@ 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 966e22a04996..ff22b627906d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -330,6 +330,9 @@ enum bip_flags {
 	BIP_INTEGRITY_USER	= 1 << 5, /* Integrity payload is user address */
 	BIP_COPY_USER		= 1 << 6, /* Kernel bounce buffer in use */
 	BIP_CLONED		= 1 << 7, /* Indicates that bip is cloned */
+	BIP_USER_CHK_GUARD	= 1 << 8,
+	BIP_USER_CHK_APPTAG	= 1 << 9,
+	BIP_USER_CHK_REFTAG	= 1 << 10,
 };
 
 struct uio_meta {
@@ -349,6 +352,7 @@ 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 */
 
@@ -738,6 +742,7 @@ static inline bool bioset_initialized(struct bio_set *bs)
 		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
 
 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter, u32 seed);
+int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta);
 void bio_integrity_unmap_free_user(struct bio *bio);
 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);
@@ -817,6 +822,11 @@ 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;
+}
+
 static inline void bio_integrity_unmap_free_user(struct bio *bio)
 {
 }
-- 
2.25.1