Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block

Pull core block IO changes from Jens Axboe:
 "The major piece in here is the immutable bio_ve series from Kent, the
  rest is fairly minor.  It was supposed to go in last round, but
  various issues pushed it to this release instead.  The pull request
  contains:

   - Various smaller blk-mq fixes from different folks.  Nothing major
     here, just minor fixes and cleanups.

   - Fix for a memory leak in the error path in the block ioctl code
     from Christian Engelmayer.

   - Header export fix from CaiZhiyong.

   - Finally the immutable biovec changes from Kent Overstreet.  This
     enables some nice future work on making arbitrarily sized bios
     possible, and splitting more efficient.  Related fixes to immutable
     bio_vecs:

        - dm-cache immutable fixup from Mike Snitzer.
        - btrfs immutable fixup from Muthu Kumar.

  - bio-integrity fix from Nic Bellinger, which is also going to stable"

* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
  xtensa: fixup simdisk driver to work with immutable bio_vecs
  block/blk-mq-cpu.c: use hotcpu_notifier()
  blk-mq: for_each_* macro correctness
  block: Fix memory leak in rw_copy_check_uvector() handling
  bio-integrity: Fix bio_integrity_verify segment start bug
  block: remove unrelated header files and export symbol
  blk-mq: uses page->list incorrectly
  blk-mq: use __smp_call_function_single directly
  btrfs: fix missing increment of bi_remaining
  Revert "block: Warn and free bio if bi_end_io is not set"
  block: Warn and free bio if bi_end_io is not set
  blk-mq: fix initializing request's start time
  block: blk-mq: don't export blk_mq_free_queue()
  block: blk-mq: make blk_sync_queue support mq
  block: blk-mq: support draining mq queue
  dm cache: increment bi_remaining when bi_end_io is restored
  block: fixup for generic bio chaining
  block: Really silence spurious compiler warnings
  block: Silence spurious compiler warnings
  block: Kill bio_pair_split()
  ...

27 files changed, 456 insertions, 619 deletions

diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index fc60b31..0bad24d 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -134,8 +134,7 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
 		return 0;
 	}
 
-	iv = bip_vec_idx(bip, bip->bip_vcnt);
-	BUG_ON(iv == NULL);
+	iv = bip->bip_vec + bip->bip_vcnt;
 
 	iv->bv_page = page;
 	iv->bv_len = len;
@@ -203,6 +202,12 @@ static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
 	return sectors;
 }
 
+static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
+					       unsigned int sectors)
+{
+	return bio_integrity_hw_sectors(bi, sectors) * bi->tuple_size;
+}
+
 /**
  * bio_integrity_tag_size - Retrieve integrity tag space
  * @bio:	bio to inspect
@@ -215,9 +220,9 @@ unsigned int bio_integrity_tag_size(struct bio *bio)
 {
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 
-	BUG_ON(bio->bi_size == 0);
+	BUG_ON(bio->bi_iter.bi_size == 0);
 
-	return bi->tag_size * (bio->bi_size / bi->sector_size);
+	return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size);
 }
 EXPORT_SYMBOL(bio_integrity_tag_size);
 
@@ -235,9 +240,9 @@ int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
 	nr_sectors = bio_integrity_hw_sectors(bi,
 					DIV_ROUND_UP(len, bi->tag_size));
 
-	if (nr_sectors * bi->tuple_size > bip->bip_size) {
-		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
-		       __func__, nr_sectors * bi->tuple_size, bip->bip_size);
+	if (nr_sectors * bi->tuple_size > bip->bip_iter.bi_size) {
+		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__,
+		       nr_sectors * bi->tuple_size, bip->bip_iter.bi_size);
 		return -1;
 	}
 
@@ -299,29 +304,30 @@ static void bio_integrity_generate(struct bio *bio)
 {
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 	struct blk_integrity_exchg bix;
-	struct bio_vec *bv;
-	sector_t sector = bio->bi_sector;
-	unsigned int i, sectors, total;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+	sector_t sector = bio->bi_iter.bi_sector;
+	unsigned int sectors, total;
 	void *prot_buf = bio->bi_integrity->bip_buf;
 
 	total = 0;
 	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 	bix.sector_size = bi->sector_size;
 
-	bio_for_each_segment(bv, bio, i) {
-		void *kaddr = kmap_atomic(bv->bv_page);
-		bix.data_buf = kaddr + bv->bv_offset;
-		bix.data_size = bv->bv_len;
+	bio_for_each_segment(bv, bio, iter) {
+		void *kaddr = kmap_atomic(bv.bv_page);
+		bix.data_buf = kaddr + bv.bv_offset;
+		bix.data_size = bv.bv_len;
 		bix.prot_buf = prot_buf;
 		bix.sector = sector;
 
 		bi->generate_fn(&bix);
 
-		sectors = bv->bv_len / bi->sector_size;
+		sectors = bv.bv_len / bi->sector_size;
 		sector += sectors;
 		prot_buf += sectors * bi->tuple_size;
 		total += sectors * bi->tuple_size;
-		BUG_ON(total > bio->bi_integrity->bip_size);
+		BUG_ON(total > bio->bi_integrity->bip_iter.bi_size);
 
 		kunmap_atomic(kaddr);
 	}
@@ -386,8 +392,8 @@ int bio_integrity_prep(struct bio *bio)
 
 	bip->bip_owns_buf = 1;
 	bip->bip_buf = buf;
-	bip->bip_size = len;
-	bip->bip_sector = bio->bi_sector;
+	bip->bip_iter.bi_size = len;
+	bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 
 	/* Map it */
 	offset = offset_in_page(buf);
@@ -442,16 +448,18 @@ static int bio_integrity_verify(struct bio *bio)
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
 	struct blk_integrity_exchg bix;
 	struct bio_vec *bv;
-	sector_t sector = bio->bi_integrity->bip_sector;
-	unsigned int i, sectors, total, ret;
+	sector_t sector = bio->bi_integrity->bip_iter.bi_sector;
+	unsigned int sectors, total, ret;
 	void *prot_buf = bio->bi_integrity->bip_buf;
+	int i;
 
 	ret = total = 0;
 	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
 	bix.sector_size = bi->sector_size;
 
-	bio_for_each_segment(bv, bio, i) {
+	bio_for_each_segment_all(bv, bio, i) {
 		void *kaddr = kmap_atomic(bv->bv_page);
+
 		bix.data_buf = kaddr + bv->bv_offset;
 		bix.data_size = bv->bv_len;
 		bix.prot_buf = prot_buf;
@@ -468,7 +476,7 @@ static int bio_integrity_verify(struct bio *bio)
 		sector += sectors;
 		prot_buf += sectors * bi->tuple_size;
 		total += sectors * bi->tuple_size;
-		BUG_ON(total > bio->bi_integrity->bip_size);
+		BUG_ON(total > bio->bi_integrity->bip_iter.bi_size);
 
 		kunmap_atomic(kaddr);
 	}
@@ -495,7 +503,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
 
 	/* Restore original bio completion handler */
 	bio->bi_end_io = bip->bip_end_io;
-	bio_endio(bio, error);
+	bio_endio_nodec(bio, error);
 }
 
 /**
@@ -533,56 +541,6 @@ void bio_integrity_endio(struct bio *bio, int error)
 EXPORT_SYMBOL(bio_integrity_endio);
 
 /**
- * bio_integrity_mark_head - Advance bip_vec skip bytes
- * @bip:	Integrity vector to advance
- * @skip:	Number of bytes to advance it
- */
-void bio_integrity_mark_head(struct bio_integrity_payload *bip,
-			     unsigned int skip)
-{
-	struct bio_vec *iv;
-	unsigned int i;
-
-	bip_for_each_vec(iv, bip, i) {
-		if (skip == 0) {
-			bip->bip_idx = i;
-			return;
-		} else if (skip >= iv->bv_len) {
-			skip -= iv->bv_len;
-		} else { /* skip < iv->bv_len) */
-			iv->bv_offset += skip;
-			iv->bv_len -= skip;
-			bip->bip_idx = i;
-			return;
-		}
-	}
-}
-
-/**
- * bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
- * @bip:	Integrity vector to truncate
- * @len:	New length of integrity vector
- */
-void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
-			     unsigned int len)
-{
-	struct bio_vec *iv;
-	unsigned int i;
-
-	bip_for_each_vec(iv, bip, i) {
-		if (len == 0) {
-			bip->bip_vcnt = i;
-			return;
-		} else if (len >= iv->bv_len) {
-			len -= iv->bv_len;
-		} else { /* len < iv->bv_len) */
-			iv->bv_len = len;
-			len = 0;
-		}
-	}
-}
-
-/**
  * bio_integrity_advance - Advance integrity vector
  * @bio:	bio whose integrity vector to update
  * @bytes_done:	number of data bytes that have been completed
@@ -595,13 +553,9 @@ void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 {
 	struct bio_integrity_payload *bip = bio->bi_integrity;
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-	unsigned int nr_sectors;
+	unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
 
-	BUG_ON(bip == NULL);
-	BUG_ON(bi == NULL);
-
-	nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
-	bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
+	bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
 }
 EXPORT_SYMBOL(bio_integrity_advance);
 
@@ -621,64 +575,13 @@ void bio_integrity_trim(struct bio *bio, unsigned int offset,
 {
 	struct bio_integrity_payload *bip = bio->bi_integrity;
 	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-	unsigned int nr_sectors;
-
-	BUG_ON(bip == NULL);
-	BUG_ON(bi == NULL);
-	BUG_ON(!bio_flagged(bio, BIO_CLONED));
 
-	nr_sectors = bio_integrity_hw_sectors(bi, sectors);
-	bip->bip_sector = bip->bip_sector + offset;
-	bio_integrity_mark_head(bip, offset * bi->tuple_size);
-	bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
+	bio_integrity_advance(bio, offset << 9);
+	bip->bip_iter.bi_size = bio_integrity_bytes(bi, sectors);
 }
 EXPORT_SYMBOL(bio_integrity_trim);
 
 /**
- * bio_integrity_split - Split integrity metadata
- * @bio:	Protected bio
- * @bp:		Resulting bio_pair
- * @sectors:	Offset
- *
- * Description: Splits an integrity page into a bio_pair.
- */
-void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
-{
-	struct blk_integrity *bi;
-	struct bio_integrity_payload *bip = bio->bi_integrity;
-	unsigned int nr_sectors;
-
-	if (bio_integrity(bio) == 0)
-		return;
-
-	bi = bdev_get_integrity(bio->bi_bdev);
-	BUG_ON(bi == NULL);
-	BUG_ON(bip->bip_vcnt != 1);
-
-	nr_sectors = bio_integrity_hw_sectors(bi, sectors);
-
-	bp->bio1.bi_integrity = &bp->bip1;
-	bp->bio2.bi_integrity = &bp->bip2;
-
-	bp->iv1 = bip->bip_vec[bip->bip_idx];
-	bp->iv2 = bip->bip_vec[bip->bip_idx];
-
-	bp->bip1.bip_vec = &bp->iv1;
-	bp->bip2.bip_vec = &bp->iv2;
-
-	bp->iv1.bv_len = sectors * bi->tuple_size;
-	bp->iv2.bv_offset += sectors * bi->tuple_size;
-	bp->iv2.bv_len -= sectors * bi->tuple_size;
-
-	bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
-	bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
-
-	bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
-	bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
-}
-EXPORT_SYMBOL(bio_integrity_split);
-
-/**
  * bio_integrity_clone - Callback for cloning bios with integrity metadata
  * @bio:	New bio
  * @bio_src:	Original bio
@@ -702,9 +605,8 @@ int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 	memcpy(bip->bip_vec, bip_src->bip_vec,
 	       bip_src->bip_vcnt * sizeof(struct bio_vec));
 
-	bip->bip_sector = bip_src->bip_sector;
 	bip->bip_vcnt = bip_src->bip_vcnt;
-	bip->bip_idx = bip_src->bip_idx;
+	bip->bip_iter = bip_src->bip_iter;
 
 	return 0;
 }
diff --git a/fs/bio.c b/fs/bio.c
index 33d79a4..75c49a3 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -38,8 +38,6 @@
  */
 #define BIO_INLINE_VECS		4
 
-static mempool_t *bio_split_pool __read_mostly;
-
 /*
  * if you change this list, also change bvec_alloc or things will
  * break badly! cannot be bigger than what you can fit into an
@@ -273,6 +271,7 @@ void bio_init(struct bio *bio)
 {
 	memset(bio, 0, sizeof(*bio));
 	bio->bi_flags = 1 << BIO_UPTODATE;
+	atomic_set(&bio->bi_remaining, 1);
 	atomic_set(&bio->bi_cnt, 1);
 }
 EXPORT_SYMBOL(bio_init);
@@ -295,9 +294,35 @@ void bio_reset(struct bio *bio)
 
 	memset(bio, 0, BIO_RESET_BYTES);
 	bio->bi_flags = flags|(1 << BIO_UPTODATE);
+	atomic_set(&bio->bi_remaining, 1);
 }
 EXPORT_SYMBOL(bio_reset);
 
+static void bio_chain_endio(struct bio *bio, int error)
+{
+	bio_endio(bio->bi_private, error);
+	bio_put(bio);
+}
+
+/**
+ * bio_chain - chain bio completions
+ *
+ * The caller won't have a bi_end_io called when @bio completes - instead,
+ * @parent's bi_end_io won't be called until both @parent and @bio have
+ * completed; the chained bio will also be freed when it completes.
+ *
+ * The caller must not set bi_private or bi_end_io in @bio.
+ */
+void bio_chain(struct bio *bio, struct bio *parent)
+{
+	BUG_ON(bio->bi_private || bio->bi_end_io);
+
+	bio->bi_private = parent;
+	bio->bi_end_io	= bio_chain_endio;
+	atomic_inc(&parent->bi_remaining);
+}
+EXPORT_SYMBOL(bio_chain);
+
 static void bio_alloc_rescue(struct work_struct *work)
 {
 	struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
@@ -473,13 +498,13 @@ EXPORT_SYMBOL(bio_alloc_bioset);
 void zero_fill_bio(struct bio *bio)
 {
 	unsigned long flags;
-	struct bio_vec *bv;
-	int i;
+	struct bio_vec bv;
+	struct bvec_iter iter;
 
-	bio_for_each_segment(bv, bio, i) {
-		char *data = bvec_kmap_irq(bv, &flags);
-		memset(data, 0, bv->bv_len);
-		flush_dcache_page(bv->bv_page);
+	bio_for_each_segment(bv, bio, iter) {
+		char *data = bvec_kmap_irq(&bv, &flags);
+		memset(data, 0, bv.bv_len);
+		flush_dcache_page(bv.bv_page);
 		bvec_kunmap_irq(data, &flags);
 	}
 }
@@ -515,51 +540,49 @@ inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
 EXPORT_SYMBOL(bio_phys_segments);
 
 /**
- * 	__bio_clone	-	clone a bio
+ * 	__bio_clone_fast - clone a bio that shares the original bio's biovec
  * 	@bio: destination bio
  * 	@bio_src: bio to clone
  *
  *	Clone a &bio. Caller will own the returned bio, but not
  *	the actual data it points to. Reference count of returned
  * 	bio will be one.
+ *
+ * 	Caller must ensure that @bio_src is not freed before @bio.
  */
-void __bio_clone(struct bio *bio, struct bio *bio_src)
+void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
 {
-	memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
-		bio_src->bi_max_vecs * sizeof(struct bio_vec));
+	BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE);
 
 	/*
 	 * most users will be overriding ->bi_bdev with a new target,
 	 * so we don't set nor calculate new physical/hw segment counts here
 	 */
-	bio->bi_sector = bio_src->bi_sector;
 	bio->bi_bdev = bio_src->bi_bdev;
 	bio->bi_flags |= 1 << BIO_CLONED;
 	bio->bi_rw = bio_src->bi_rw;
-	bio->bi_vcnt = bio_src->bi_vcnt;
-	bio->bi_size = bio_src->bi_size;
-	bio->bi_idx = bio_src->bi_idx;
+	bio->bi_iter = bio_src->bi_iter;
+	bio->bi_io_vec = bio_src->bi_io_vec;
 }
-EXPORT_SYMBOL(__bio_clone);
+EXPORT_SYMBOL(__bio_clone_fast);
 
 /**
- *	bio_clone_bioset -	clone a bio
+ *	bio_clone_fast - clone a bio that shares the original bio's biovec
  *	@bio: bio to clone
  *	@gfp_mask: allocation priority
  *	@bs: bio_set to allocate from
  *
- * 	Like __bio_clone, only also allocates the returned bio
+ * 	Like __bio_clone_fast, only also allocates the returned bio
  */
-struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask,
-			     struct bio_set *bs)
+struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
 {
 	struct bio *b;
 
-	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, bs);
+	b = bio_alloc_bioset(gfp_mask, 0, bs);
 	if (!b)
 		return NULL;
 
-	__bio_clone(b, bio);
+	__bio_clone_fast(b, bio);
 
 	if (bio_integrity(bio)) {
 		int ret;
@@ -574,6 +597,74 @@ struct bio *bio_clone_bioset(struct bio *bio, gfp_t gfp_mask,
 
 	return b;
 }
+EXPORT_SYMBOL(bio_clone_fast);
+
+/**
+ * 	bio_clone_bioset - clone a bio
+ * 	@bio_src: bio to clone
+ *	@gfp_mask: allocation priority
+ *	@bs: bio_set to allocate from
+ *
+ *	Clone bio. Caller will own the returned bio, but not the actual data it
+ *	points to. Reference count of returned bio will be one.
+ */
+struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
+			     struct bio_set *bs)
+{
+	unsigned nr_iovecs = 0;
+	struct bvec_iter iter;
+	struct bio_vec bv;
+	struct bio *bio;
+
+	/*
+	 * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
+	 * bio_src->bi_io_vec to bio->bi_io_vec.
+	 *
+	 * We can't do that anymore, because:
+	 *
+	 *  - The point of cloning the biovec is to produce a bio with a biovec
+	 *    the caller can modify: bi_idx and bi_bvec_done should be 0.
+	 *
+	 *  - The original bio could've had more than BIO_MAX_PAGES biovecs; if
+	 *    we tried to clone the whole thing bio_alloc_bioset() would fail.
+	 *    But the clone should succeed as long as the number of biovecs we
+	 *    actually need to allocate is fewer than BIO_MAX_PAGES.
+	 *
+	 *  - Lastly, bi_vcnt should not be looked at or relied upon by code
+	 *    that does not own the bio - reason being drivers don't use it for
+	 *    iterating over the biovec anymore, so expecting it to be kept up
+	 *    to date (i.e. for clones that share the parent biovec) is just
+	 *    asking for trouble and would force extra work on
+	 *    __bio_clone_fast() anyways.
+	 */
+
+	bio_for_each_segment(bv, bio_src, iter)
+		nr_iovecs++;
+
+	bio = bio_alloc_bioset(gfp_mask, nr_iovecs, bs);
+	if (!bio)
+		return NULL;
+
+	bio->bi_bdev		= bio_src->bi_bdev;
+	bio->bi_rw		= bio_src->bi_rw;
+	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
+	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
+
+	bio_for_each_segment(bv, bio_src, iter)
+		bio->bi_io_vec[bio->bi_vcnt++] = bv;
+
+	if (bio_integrity(bio_src)) {
+		int ret;
+
+		ret = bio_integrity_clone(bio, bio_src, gfp_mask);
+		if (ret < 0) {
+			bio_put(bio);
+			return NULL;
+		}
+	}
+
+	return bio;
+}
 EXPORT_SYMBOL(bio_clone_bioset);
 
 /**
@@ -612,7 +703,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	if (unlikely(bio_flagged(bio, BIO_CLONED)))
 		return 0;
 
-	if (((bio->bi_size + len) >> 9) > max_sectors)
+	if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
 		return 0;
 
 	/*
@@ -635,8 +726,9 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 					   simulate merging updated prev_bvec
 					   as new bvec. */
 					.bi_bdev = bio->bi_bdev,
-					.bi_sector = bio->bi_sector,
-					.bi_size = bio->bi_size - prev_bv_len,
+					.bi_sector = bio->bi_iter.bi_sector,
+					.bi_size = bio->bi_iter.bi_size -
+						prev_bv_len,
 					.bi_rw = bio->bi_rw,
 				};
 
@@ -684,8 +776,8 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	if (q->merge_bvec_fn) {
 		struct bvec_merge_data bvm = {
 			.bi_bdev = bio->bi_bdev,
-			.bi_sector = bio->bi_sector,
-			.bi_size = bio->bi_size,
+			.bi_sector = bio->bi_iter.bi_sector,
+			.bi_size = bio->bi_iter.bi_size,
 			.bi_rw = bio->bi_rw,
 		};
 
@@ -708,7 +800,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	bio->bi_vcnt++;
 	bio->bi_phys_segments++;
  done:
-	bio->bi_size += len;
+	bio->bi_iter.bi_size += len;
 	return len;
 }
 
@@ -807,28 +899,7 @@ void bio_advance(struct bio *bio, unsigned bytes)
 	if (bio_integrity(bio))
 		bio_integrity_advance(bio, bytes);
 
-	bio->bi_sector += bytes >> 9;
-	bio->bi_size -= bytes;
-
-	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
-		return;
-
-	while (bytes) {
-		if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
-			WARN_ONCE(1, "bio idx %d >= vcnt %d\n",
-				  bio->bi_idx, bio->bi_vcnt);
-			break;
-		}
-
-		if (bytes >= bio_iovec(bio)->bv_len) {
-			bytes -= bio_iovec(bio)->bv_len;
-			bio->bi_idx++;
-		} else {
-			bio_iovec(bio)->bv_len -= bytes;
-			bio_iovec(bio)->bv_offset += bytes;
-			bytes = 0;
-		}
-	}
+	bio_advance_iter(bio, &bio->bi_iter, bytes);
 }
 EXPORT_SYMBOL(bio_advance);
 
@@ -874,117 +945,80 @@ EXPORT_SYMBOL(bio_alloc_pages);
  */
 void bio_copy_data(struct bio *dst, struct bio *src)
 {
-	struct bio_vec *src_bv, *dst_bv;
-	unsigned src_offset, dst_offset, bytes;
+	struct bvec_iter src_iter, dst_iter;
+	struct bio_vec src_bv, dst_bv;
 	void *src_p, *dst_p;
+	unsigned bytes;
 
-	src_bv = bio_iovec(src);
-	dst_bv = bio_iovec(dst);
-
-	src_offset = src_bv->bv_offset;
-	dst_offset = dst_bv->bv_offset;
+	src_iter = src->bi_iter;
+	dst_iter = dst->bi_iter;
 
 	while (1) {
-		if (src_offset == src_bv->bv_offset + src_bv->bv_len) {
-			src_bv++;
-			if (src_bv == bio_iovec_idx(src, src->bi_vcnt)) {
-				src = src->bi_next;
-				if (!src)
-					break;
-
-				src_bv = bio_iovec(src);
-			}
+		if (!src_iter.bi_size) {
+			src = src->bi_next;
+			if (!src)
+				break;
 
-			src_offset = src_bv->bv_offset;
+			src_iter = src->bi_iter;
 		}
 
-		if (dst_offset == dst_bv->bv_offset + dst_bv->bv_len) {
-			dst_bv++;
-			if (dst_bv == bio_iovec_idx(dst, dst->bi_vcnt)) {
-				dst = dst->bi_next;
-				if (!dst)
-					break;
-
-				dst_bv = bio_iovec(dst);
-			}
+		if (!dst_iter.bi_size) {
+			dst = dst->bi_next;
+			if (!dst)
+				break;
 
-			dst_offset = dst_bv->bv_offset;
+			dst_iter = dst->bi_iter;
 		}
 
-		bytes = min(dst_bv->bv_offset + dst_bv->bv_len - dst_offset,
-			    src_bv->bv_offset + src_bv->bv_len - src_offset);
+		src_bv = bio_iter_iovec(src, src_iter);
+		dst_bv = bio_iter_iovec(dst, dst_iter);
+
+		bytes = min(src_bv.bv_len, dst_bv.bv_len);
 
-		src_p = kmap_atomic(src_bv->bv_page);
-		dst_p = kmap_atomic(dst_bv->bv_page);
+		src_p = kmap_atomic(src_bv.bv_page);
+		dst_p = kmap_atomic(dst_bv.bv_page);
 
-		memcpy(dst_p + dst_offset,
-		       src_p + src_offset,
+		memcpy(dst_p + dst_bv.bv_offset,
+		       src_p + src_bv.bv_offset,
 		       bytes);
 
 		kunmap_atomic(dst_p);
 		kunmap_atomic(src_p);
 
-		src_offset += bytes;
-		dst_offset += bytes;
+		bio_advance_iter(src, &src_iter, bytes);
+		bio_advance_iter(dst, &dst_iter, bytes);
 	}
 }
 EXPORT_SYMBOL(bio_copy_data);
 
 struct bio_map_data {
-	struct bio_vec *iovecs;
-	struct sg_iovec *sgvecs;
 	int nr_sgvecs;
 	int is_our_pages;
+	struct sg_iovec sgvecs[];
 };
 
 static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
 			     struct sg_iovec *iov, int iov_count,
 			     int is_our_pages)
 {
-	memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
 	memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
 	bmd->nr_sgvecs = iov_count;
 	bmd->is_our_pages = is_our_pages;
 	bio->bi_private = bmd;
 }
 
-static void bio_free_map_data(struct bio_map_data *bmd)
-{
-	kfree(bmd->iovecs);
-	kfree(bmd->sgvecs);
-	kfree(bmd);
-}
-
 static struct bio_map_data *bio_alloc_map_data(int nr_segs,
 					       unsigned int iov_count,
 					       gfp_t gfp_mask)
 {
-	struct bio_map_data *bmd;
-
 	if (iov_count > UIO_MAXIOV)
 		return NULL;
 
-	bmd = kmalloc(sizeof(*bmd), gfp_mask);
-	if (!bmd)
-		return NULL;
-
-	bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
-	if (!bmd->iovecs) {
-		kfree(bmd);
-		return NULL;
-	}
-
-	bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
-	if (bmd->sgvecs)
-		return bmd;
-
-	kfree(bmd->iovecs);
-	kfree(bmd);
-	return NULL;
+	return kmalloc(sizeof(struct bio_map_data) +
+		       sizeof(struct sg_iovec) * iov_count, gfp_mask);
 }
 
-static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
-			  struct sg_iovec *iov, int iov_count,
+static int __bio_copy_iov(struct bio *bio, struct sg_iovec *iov, int iov_count,
 			  int to_user, int from_user, int do_free_page)
 {
 	int ret = 0, i;
@@ -994,7 +1028,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
 
 	bio_for_each_segment_all(bvec, bio, i) {
 		char *bv_addr = page_address(bvec->bv_page);
-		unsigned int bv_len = iovecs[i].bv_len;
+		unsigned int bv_len = bvec->bv_len;
 
 		while (bv_len && iov_idx < iov_count) {
 			unsigned int bytes;
@@ -1054,14 +1088,14 @@ int bio_uncopy_user(struct bio *bio)
 		 * don't copy into a random user address space, just free.
 		 */
 		if (current->mm)
-			ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
-					     bmd->nr_sgvecs, bio_data_dir(bio) == READ,
+			ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs,
+					     bio_data_dir(bio) == READ,
 					     0, bmd->is_our_pages);
 		else if (bmd->is_our_pages)
 			bio_for_each_segment_all(bvec, bio, i)
 				__free_page(bvec->bv_page);
 	}
-	bio_free_map_data(bmd);
+	kfree(bmd);
 	bio_put(bio);
 	return ret;
 }
@@ -1175,7 +1209,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 	 */
 	if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||
 	    (map_data && map_data->from_user)) {
-		ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 1, 0);
+		ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0);
 		if (ret)
 			goto cleanup;
 	}
@@ -1189,7 +1223,7 @@ cleanup:
 
 	bio_put(bio);
 out_bmd:
-	bio_free_map_data(bmd);
+	kfree(bmd);
 	return ERR_PTR(ret);
 }
 
@@ -1485,7 +1519,7 @@ struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
 	if (IS_ERR(bio))
 		return bio;
 
-	if (bio->bi_size == len)
+	if (bio->bi_iter.bi_size == len)
 		return bio;
 
 	/*
@@ -1506,16 +1540,15 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
 
 	bio_for_each_segment_all(bvec, bio, i) {
 		char *addr = page_address(bvec->bv_page);
-		int len = bmd->iovecs[i].bv_len;
 
 		if (read)
-			memcpy(p, addr, len);
+			memcpy(p, addr, bvec->bv_len);
 
 		__free_page(bvec->bv_page);
-		p += len;
+		p += bvec->bv_len;
 	}
 
-	bio_free_map_data(bmd);
+	kfree(bmd);
 	bio_put(bio);
 }
 
@@ -1686,11 +1719,11 @@ void bio_check_pages_dirty(struct bio *bio)
 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 void bio_flush_dcache_pages(struct bio *bi)
 {
-	int i;
-	struct bio_vec *bvec;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
 
-	bio_for_each_segment(bvec, bi, i)
-		flush_dcache_page(bvec->bv_page);
+	bio_for_each_segment(bvec, bi, iter)
+		flush_dcache_page(bvec.bv_page);
 }
 EXPORT_SYMBOL(bio_flush_dcache_pages);
 #endif
@@ -1711,96 +1744,86 @@ EXPORT_SYMBOL(bio_flush_dcache_pages);
  **/
 void bio_endio(struct bio *bio, int error)
 {
-	if (error)
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
-	else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
-		error = -EIO;
+	while (bio) {
+		BUG_ON(atomic_read(&bio->bi_remaining) <= 0);
 
-	if (bio->bi_end_io)
-		bio->bi_end_io(bio, error);
-}
-EXPORT_SYMBOL(bio_endio);
+		if (error)
+			clear_bit(BIO_UPTODATE, &bio->bi_flags);
+		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
+			error = -EIO;
 
-void bio_pair_release(struct bio_pair *bp)
-{
-	if (atomic_dec_and_test(&bp->cnt)) {
-		struct bio *master = bp->bio1.bi_private;
+		if (!atomic_dec_and_test(&bio->bi_remaining))
+			return;
 
-		bio_endio(master, bp->error);
-		mempool_free(bp, bp->bio2.bi_private);
+		/*
+		 * Need to have a real endio function for chained bios,
+		 * otherwise various corner cases will break (like stacking
+		 * block devices that save/restore bi_end_io) - however, we want
+		 * to avoid unbounded recursion and blowing the stack. Tail call
+		 * optimization would handle this, but compiling with frame
+		 * pointers also disables gcc's sibling call optimization.
+		 */
+		if (bio->bi_end_io == bio_chain_endio) {
+			struct bio *parent = bio->bi_private;
+			bio_put(bio);
+			bio = parent;
+		} else {
+			if (bio->bi_end_io)
+				bio->bi_end_io(bio, error);
+			bio = NULL;
+		}
 	}
 }
-EXPORT_SYMBOL(bio_pair_release);
+EXPORT_SYMBOL(bio_endio);
 
-static void bio_pair_end_1(struct bio *bi, int err)
+/**
+ * bio_endio_nodec - end I/O on a bio, without decrementing bi_remaining
+ * @bio:	bio
+ * @error:	error, if any
+ *
+ * For code that has saved and restored bi_end_io; thing hard before using this
+ * function, probably you should've cloned the entire bio.
+ **/
+void bio_endio_nodec(struct bio *bio, int error)
 {
-	struct bio_pair *bp = container_of(bi, struct bio_pair, bio1);
-
-	if (err)
-		bp->error = err;
-
-	bio_pair_release(bp);
+	atomic_inc(&bio->bi_remaining);
+	bio_endio(bio, error);
 }
+EXPORT_SYMBOL(bio_endio_nodec);
 
-static void bio_pair_end_2(struct bio *bi, int err)
-{
-	struct bio_pair *bp = container_of(bi, struct bio_pair, bio2);
-
-	if (err)
-		bp->error = err;
-
-	bio_pair_release(bp);
-}
-
-/*
- * split a bio - only worry about a bio with a single page in its iovec
+/**
+ * bio_split - split a bio
+ * @bio:	bio to split
+ * @sectors:	number of sectors to split from the front of @bio
+ * @gfp:	gfp mask
+ * @bs:		bio set to allocate from
+ *
+ * Allocates and returns a new bio which represents @sectors from the start of
+ * @bio, and updates @bio to represent the remaining sectors.
+ *
+ * The newly allocated bio will point to @bio's bi_io_vec; it is the caller's
+ * responsibility to ensure that @bio is not freed before the split.
  */
-struct bio_pair *bio_split(struct bio *bi, int first_sectors)
+struct bio *bio_split(struct bio *bio, int sectors,
+		      gfp_t gfp, struct bio_set *bs)
 {
-	struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
-
-	if (!bp)
-		return bp;
-
-	trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
-				bi->bi_sector + first_sectors);
-
-	BUG_ON(bio_segments(bi) > 1);
-	atomic_set(&bp->cnt, 3);
-	bp->error = 0;
-	bp->bio1 = *bi;
-	bp->bio2 = *bi;
-	bp->bio2.bi_sector += first_sectors;
-	bp->bio2.bi_size -= first_sectors << 9;
-	bp->bio1.bi_size = first_sectors << 9;
-
-	if (bi->bi_vcnt != 0) {
-		bp->bv1 = *bio_iovec(bi);
-		bp->bv2 = *bio_iovec(bi);
-
-		if (bio_is_rw(bi)) {
-			bp->bv2.bv_offset += first_sectors << 9;
-			bp->bv2.bv_len -= first_sectors << 9;
-			bp->bv1.bv_len = first_sectors << 9;
-		}
+	struct bio *split = NULL;
 
-		bp->bio1.bi_io_vec = &bp->bv1;
-		bp->bio2.bi_io_vec = &bp->bv2;
+	BUG_ON(sectors <= 0);
+	BUG_ON(sectors >= bio_sectors(bio));
 
-		bp->bio1.bi_max_vecs = 1;
-		bp->bio2.bi_max_vecs = 1;
-	}
+	split = bio_clone_fast(bio, gfp, bs);
+	if (!split)
+		return NULL;
 
-	bp->bio1.bi_end_io = bio_pair_end_1;
-	bp->bio2.bi_end_io = bio_pair_end_2;
+	split->bi_iter.bi_size = sectors << 9;
 
-	bp->bio1.bi_private = bi;
-	bp->bio2.bi_private = bio_split_pool;
+	if (bio_integrity(split))
+		bio_integrity_trim(split, 0, sectors);
 
-	if (bio_integrity(bi))
-		bio_integrity_split(bi, bp, first_sectors);
+	bio_advance(bio, split->bi_iter.bi_size);
 
-	return bp;
+	return split;
 }
 EXPORT_SYMBOL(bio_split);
 
@@ -1814,80 +1837,20 @@ void bio_trim(struct bio *bio, int offset, int size)
 {
 	/* 'bio' is a cloned bio which we need to trim to match
 	 * the given offset and size.
-	 * This requires adjusting bi_sector, bi_size, and bi_io_vec
 	 */
-	int i;
-	struct bio_vec *bvec;
-	int sofar = 0;
 
 	size <<= 9;
-	if (offset == 0 && size == bio->bi_size)
+	if (offset == 0 && size == bio->bi_iter.bi_size)
 		return;
 
 	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
 
 	bio_advance(bio, offset << 9);
 
-	bio->bi_size = size;
-
-	/* avoid any complications with bi_idx being non-zero*/
-	if (bio->bi_idx) {
-		memmove(bio->bi_io_vec, bio->bi_io_vec+bio->bi_idx,
-			(bio->bi_vcnt - bio->bi_idx) * sizeof(struct bio_vec));
-		bio->bi_vcnt -= bio->bi_idx;
-		bio->bi_idx = 0;
-	}
-	/* Make sure vcnt and last bv are not too big */
-	bio_for_each_segment(bvec, bio, i) {
-		if (sofar + bvec->bv_len > size)
-			bvec->bv_len = size - sofar;
-		if (bvec->bv_len == 0) {
-			bio->bi_vcnt = i;
-			break;
-		}
-		sofar += bvec->bv_len;
-	}
+	bio->bi_iter.bi_size = size;
 }
 EXPORT_SYMBOL_GPL(bio_trim);
 
-/**
- *      bio_sector_offset - Find hardware sector offset in bio
- *      @bio:           bio to inspect
- *      @index:         bio_vec index
- *      @offset:        offset in bv_page
- *
- *      Return the number of hardware sectors between beginning of bio
- *      and an end point indicated by a bio_vec index and an offset
- *      within that vector's page.
- */
-sector_t bio_sector_offset(struct bio *bio, unsigned short index,
-			   unsigned int offset)
-{
-	unsigned int sector_sz;
-	struct bio_vec *bv;
-	sector_t sectors;
-	int i;
-
-	sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue);
-	sectors = 0;
-
-	if (index >= bio->bi_idx)
-		index = bio->bi_vcnt - 1;
-
-	bio_for_each_segment_all(bv, bio, i) {
-		if (i == index) {
-			if (offset > bv->bv_offset)
-				sectors += (offset - bv->bv_offset) / sector_sz;
-			break;
-		}
-
-		sectors += bv->bv_len / sector_sz;
-	}
-
-	return sectors;
-}
-EXPORT_SYMBOL(bio_sector_offset);
-
 /*
  * create memory pools for biovec's in a bio_set.
  * use the global biovec slabs created for general use.
@@ -2065,11 +2028,6 @@ static int __init init_bio(void)
 	if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE))
 		panic("bio: can't create integrity pool\n");
 
-	bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES,
-						     sizeof(struct bio_pair));
-	if (!bio_split_pool)
-		panic("bio: can't create split pool\n");
-
 	return 0;
 }
 subsys_initcall(init_bio);
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 131d828..cb05e1c 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -1695,7 +1695,7 @@ static int btrfsic_read_block(struct btrfsic_state *state,
 			return -1;
 		}
 		bio->bi_bdev = block_ctx->dev->bdev;
-		bio->bi_sector = dev_bytenr >> 9;
+		bio->bi_iter.bi_sector = dev_bytenr >> 9;
 
 		for (j = i; j < num_pages; j++) {
 			ret = bio_add_page(bio, block_ctx->pagev[j],
@@ -3013,7 +3013,7 @@ static void __btrfsic_submit_bio(int rw, struct bio *bio)
 		int bio_is_patched;
 		char **mapped_datav;
 
-		dev_bytenr = 512 * bio->bi_sector;
+		dev_bytenr = 512 * bio->bi_iter.bi_sector;
 		bio_is_patched = 0;
 		if (dev_state->state->print_mask &
 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
@@ -3021,8 +3021,8 @@ static void __btrfsic_submit_bio(int rw, struct bio *bio)
 			       "submit_bio(rw=0x%x, bi_vcnt=%u,"
 			       " bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
 			       rw, bio->bi_vcnt,
-			       (unsigned long long)bio->bi_sector, dev_bytenr,
-			       bio->bi_bdev);
+			       (unsigned long long)bio->bi_iter.bi_sector,
+			       dev_bytenr, bio->bi_bdev);
 
 		mapped_datav = kmalloc(sizeof(*mapped_datav) * bio->bi_vcnt,
 				       GFP_NOFS);
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 1499b27..f5cdeb4 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -172,7 +172,8 @@ static void end_compressed_bio_read(struct bio *bio, int err)
 		goto out;
 
 	inode = cb->inode;
-	ret = check_compressed_csum(inode, cb, (u64)bio->bi_sector << 9);
+	ret = check_compressed_csum(inode, cb,
+				    (u64)bio->bi_iter.bi_sector << 9);
 	if (ret)
 		goto csum_failed;
 
@@ -201,18 +202,16 @@ csum_failed:
 	if (cb->errors) {
 		bio_io_error(cb->orig_bio);
 	} else {
-		int bio_index = 0;
-		struct bio_vec *bvec = cb->orig_bio->bi_io_vec;
+		int i;
+		struct bio_vec *bvec;
 
 		/*
 		 * we have verified the checksum already, set page
 		 * checked so the end_io handlers know about it
 		 */
-		while (bio_index < cb->orig_bio->bi_vcnt) {
+		bio_for_each_segment_all(bvec, cb->orig_bio, i)
 			SetPageChecked(bvec->bv_page);
-			bvec++;
-			bio_index++;
-		}
+
 		bio_endio(cb->orig_bio, 0);
 	}
 
@@ -372,7 +371,7 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start,
 	for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
 		page = compressed_pages[pg_index];
 		page->mapping = inode->i_mapping;
-		if (bio->bi_size)
+		if (bio->bi_iter.bi_size)
 			ret = io_tree->ops->merge_bio_hook(WRITE, page, 0,
 							   PAGE_CACHE_SIZE,
 							   bio, 0);
@@ -506,7 +505,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 
 		if (!em || last_offset < em->start ||
 		    (last_offset + PAGE_CACHE_SIZE > extent_map_end(em)) ||
-		    (em->block_start >> 9) != cb->orig_bio->bi_sector) {
+		    (em->block_start >> 9) != cb->orig_bio->bi_iter.bi_sector) {
 			free_extent_map(em);
 			unlock_extent(tree, last_offset, end);
 			unlock_page(page);
@@ -552,7 +551,7 @@ next:
  * in it.  We don't actually do IO on those pages but allocate new ones
  * to hold the compressed pages on disk.
  *
- * bio->bi_sector points to the compressed extent on disk
+ * bio->bi_iter.bi_sector points to the compressed extent on disk
  * bio->bi_io_vec points to all of the inode pages
  * bio->bi_vcnt is a count of pages
  *
@@ -573,7 +572,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	struct page *page;
 	struct block_device *bdev;
 	struct bio *comp_bio;
-	u64 cur_disk_byte = (u64)bio->bi_sector << 9;
+	u64 cur_disk_byte = (u64)bio->bi_iter.bi_sector << 9;
 	u64 em_len;
 	u64 em_start;
 	struct extent_map *em;
@@ -659,7 +658,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 		page->mapping = inode->i_mapping;
 		page->index = em_start >> PAGE_CACHE_SHIFT;
 
-		if (comp_bio->bi_size)
+		if (comp_bio->bi_iter.bi_size)
 			ret = tree->ops->merge_bio_hook(READ, page, 0,
 							PAGE_CACHE_SIZE,
 							comp_bio, 0);
@@ -687,8 +686,8 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 							comp_bio, sums);
 				BUG_ON(ret); /* -ENOMEM */
 			}
-			sums += (comp_bio->bi_size + root->sectorsize - 1) /
-				root->sectorsize;
+			sums += (comp_bio->bi_iter.bi_size +
+				 root->sectorsize - 1) / root->sectorsize;
 
 			ret = btrfs_map_bio(root, READ, comp_bio,
 					    mirror_num, 0);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8072cfa..e71039e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -842,20 +842,17 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 
 static int btree_csum_one_bio(struct bio *bio)
 {
-	struct bio_vec *bvec = bio->bi_io_vec;
-	int bio_index = 0;
+	struct bio_vec *bvec;
 	struct btrfs_root *root;
-	int ret = 0;
+	int i, ret = 0;
 
-	WARN_ON(bio->bi_vcnt <= 0);
-	while (bio_index < bio->bi_vcnt) {
+	bio_for_each_segment_all(bvec, bio, i) {
 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 		ret = csum_dirty_buffer(root, bvec->bv_page);
 		if (ret)
 			break;
-		bio_index++;
-		bvec++;
 	}
+
 	return ret;
 }
 
@@ -1695,7 +1692,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
 	bio->bi_private = end_io_wq->private;
 	bio->bi_end_io = end_io_wq->end_io;
 	kfree(end_io_wq);
-	bio_endio(bio, error);
+	bio_endio_nodec(bio, error);
 }
 
 static int cleaner_kthread(void *arg)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index ff43802..bcb6f1b 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1984,7 +1984,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
 	bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
 	if (!bio)
 		return -EIO;
-	bio->bi_size = 0;
+	bio->bi_iter.bi_size = 0;
 	map_length = length;
 
 	ret = btrfs_map_block(fs_info, WRITE, logical,
@@ -1995,7 +1995,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
 	}
 	BUG_ON(mirror_num != bbio->mirror_num);
 	sector = bbio->stripes[mirror_num-1].physical >> 9;
-	bio->bi_sector = sector;
+	bio->bi_iter.bi_sector = sector;
 	dev = bbio->stripes[mirror_num-1].dev;
 	kfree(bbio);
 	if (!dev || !dev->bdev || !dev->writeable) {
@@ -2268,9 +2268,9 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
 		return -EIO;
 	}
 	bio->bi_end_io = failed_bio->bi_end_io;
-	bio->bi_sector = failrec->logical >> 9;
+	bio->bi_iter.bi_sector = failrec->logical >> 9;
 	bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
-	bio->bi_size = 0;
+	bio->bi_iter.bi_size = 0;
 
 	btrfs_failed_bio = btrfs_io_bio(failed_bio);
 	if (btrfs_failed_bio->csum) {
@@ -2332,12 +2332,13 @@ int end_extent_writepage(struct page *page, int err, u64 start, u64 end)
  */
 static void end_bio_extent_writepage(struct bio *bio, int err)
 {
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
 	struct extent_io_tree *tree;
 	u64 start;
 	u64 end;
+	int i;
 
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 		tree = &BTRFS_I(page->mapping->host)->io_tree;
 
@@ -2355,14 +2356,11 @@ static void end_bio_extent_writepage(struct bio *bio, int err)
 		start = page_offset(page);
 		end = start + bvec->bv_offset + bvec->bv_len - 1;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-
 		if (end_extent_writepage(page, err, start, end))
 			continue;
 
 		end_page_writeback(page);
-	} while (bvec >= bio->bi_io_vec);
+	}
 
 	bio_put(bio);
 }
@@ -2392,9 +2390,8 @@ endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len,
  */
 static void end_bio_extent_readpage(struct bio *bio, int err)
 {
+	struct bio_vec *bvec;
 	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct bio_vec *bvec = bio->bi_io_vec;
 	struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
 	struct extent_io_tree *tree;
 	u64 offset = 0;
@@ -2405,16 +2402,17 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
 	u64 extent_len = 0;
 	int mirror;
 	int ret;
+	int i;
 
 	if (err)
 		uptodate = 0;
 
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 		struct inode *inode = page->mapping->host;
 
 		pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, "
-			 "mirror=%lu\n", (u64)bio->bi_sector, err,
+			 "mirror=%lu\n", (u64)bio->bi_iter.bi_sector, err,
 			 io_bio->mirror_num);
 		tree = &BTRFS_I(inode)->io_tree;
 
@@ -2433,9 +2431,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err)
 		end = start + bvec->bv_offset + bvec->bv_len - 1;
 		len = bvec->bv_len;
 
-		if (++bvec <= bvec_end)
-			prefetchw(&bvec->bv_page->flags);
-
 		mirror = io_bio->mirror_num;
 		if (likely(uptodate && tree->ops &&
 			   tree->ops->readpage_end_io_hook)) {
@@ -2516,7 +2511,7 @@ readpage_ok:
 			extent_start = start;
 			extent_len = end + 1 - start;
 		}
-	} while (bvec <= bvec_end);
+	}
 
 	if (extent_len)
 		endio_readpage_release_extent(tree, extent_start, extent_len,
@@ -2547,9 +2542,8 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs,
 	}
 
 	if (bio) {
-		bio->bi_size = 0;
 		bio->bi_bdev = bdev;
-		bio->bi_sector = first_sector;
+		bio->bi_iter.bi_sector = first_sector;
 		btrfs_bio = btrfs_io_bio(bio);
 		btrfs_bio->csum = NULL;
 		btrfs_bio->csum_allocated = NULL;
@@ -2643,7 +2637,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
 	if (bio_ret && *bio_ret) {
 		bio = *bio_ret;
 		if (old_compressed)
-			contig = bio->bi_sector == sector;
+			contig = bio->bi_iter.bi_sector == sector;
 		else
 			contig = bio_end_sector(bio) == sector;
 
@@ -3410,20 +3404,18 @@ static void end_extent_buffer_writeback(struct extent_buffer *eb)
 
 static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
 {
-	int uptodate = err == 0;
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
 	struct extent_buffer *eb;
-	int done;
+	int i, done;
 
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 
-		bvec--;
 		eb = (struct extent_buffer *)page->private;
 		BUG_ON(!eb);
 		done = atomic_dec_and_test(&eb->io_pages);
 
-		if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
+		if (err || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) {
 			set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
 			ClearPageUptodate(page);
 			SetPageError(page);
@@ -3435,10 +3427,9 @@ static void end_bio_extent_buffer_writepage(struct bio *bio, int err)
 			continue;
 
 		end_extent_buffer_writeback(eb);
-	} while (bvec >= bio->bi_io_vec);
+	}
 
 	bio_put(bio);
-
 }
 
 static int write_one_eb(struct extent_buffer *eb,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 6f38488..84a46a4 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -182,7 +182,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 	if (!path)
 		return -ENOMEM;
 
-	nblocks = bio->bi_size >> inode->i_sb->s_blocksize_bits;
+	nblocks = bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits;
 	if (!dst) {
 		if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
 			btrfs_bio->csum_allocated = kmalloc(nblocks * csum_size,
@@ -201,7 +201,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 		csum = (u8 *)dst;
 	}
 
-	if (bio->bi_size > PAGE_CACHE_SIZE * 8)
+	if (bio->bi_iter.bi_size > PAGE_CACHE_SIZE * 8)
 		path->reada = 2;
 
 	WARN_ON(bio->bi_vcnt <= 0);
@@ -217,7 +217,7 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 		path->skip_locking = 1;
 	}
 
-	disk_bytenr = (u64)bio->bi_sector << 9;
+	disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
 	if (dio)
 		offset = logical_offset;
 	while (bio_index < bio->bi_vcnt) {
@@ -302,7 +302,7 @@ int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
 			      struct btrfs_dio_private *dip, struct bio *bio,
 			      u64 offset)
 {
-	int len = (bio->bi_sector << 9) - dip->disk_bytenr;
+	int len = (bio->bi_iter.bi_sector << 9) - dip->disk_bytenr;
 	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 	int ret;
 
@@ -447,11 +447,12 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 	u64 offset;
 
 	WARN_ON(bio->bi_vcnt <= 0);
-	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
+	sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_iter.bi_size),
+		       GFP_NOFS);
 	if (!sums)
 		return -ENOMEM;
 
-	sums->len = bio->bi_size;
+	sums->len = bio->bi_iter.bi_size;
 	INIT_LIST_HEAD(&sums->list);
 
 	if (contig)
@@ -461,7 +462,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 
 	ordered = btrfs_lookup_ordered_extent(inode, offset);
 	BUG_ON(!ordered); /* Logic error */
-	sums->bytenr = (u64)bio->bi_sector << 9;
+	sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
 	index = 0;
 
 	while (bio_index < bio->bi_vcnt) {
@@ -476,7 +477,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 			btrfs_add_ordered_sum(inode, ordered, sums);
 			btrfs_put_ordered_extent(ordered);
 
-			bytes_left = bio->bi_size - total_bytes;
+			bytes_left = bio->bi_iter.bi_size - total_bytes;
 
 			sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
 				       GFP_NOFS);
@@ -484,7 +485,7 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
 			sums->len = bytes_left;
 			ordered = btrfs_lookup_ordered_extent(inode, offset);
 			BUG_ON(!ordered); /* Logic error */
-			sums->bytenr = ((u64)bio->bi_sector << 9) +
+			sums->bytenr = ((u64)bio->bi_iter.bi_sector << 9) +
 				       total_bytes;
 			index = 0;
 		}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 514b291..d546d8c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1577,7 +1577,7 @@ int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
 			 unsigned long bio_flags)
 {
 	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
-	u64 logical = (u64)bio->bi_sector << 9;
+	u64 logical = (u64)bio->bi_iter.bi_sector << 9;
 	u64 length = 0;
 	u64 map_length;
 	int ret;
@@ -1585,7 +1585,7 @@ int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
 	if (bio_flags & EXTENT_BIO_COMPRESSED)
 		return 0;
 
-	length = bio->bi_size;
+	length = bio->bi_iter.bi_size;
 	map_length = length;
 	ret = btrfs_map_block(root->fs_info, rw, logical,
 			      &map_length, NULL, 0);
@@ -6783,17 +6783,16 @@ unlock_err:
 static void btrfs_endio_direct_read(struct bio *bio, int err)
 {
 	struct btrfs_dio_private *dip = bio->bi_private;
-	struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct bio_vec *bvec = bio->bi_io_vec;
+	struct bio_vec *bvec;
 	struct inode *inode = dip->inode;
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct bio *dio_bio;
 	u32 *csums = (u32 *)dip->csum;
-	int index = 0;
 	u64 start;
+	int i;
 
 	start = dip->logical_offset;
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
 			struct page *page = bvec->bv_page;
 			char *kaddr;
@@ -6809,18 +6808,16 @@ static void btrfs_endio_direct_read(struct bio *bio, int err)
 			local_irq_restore(flags);
 
 			flush_dcache_page(bvec->bv_page);
-			if (csum != csums[index]) {
+			if (csum != csums[i]) {
 				btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
 					  btrfs_ino(inode), start, csum,
-					  csums[index]);
+					  csums[i]);
 				err = -EIO;
 			}
 		}
 
 		start += bvec->bv_len;
-		bvec++;
-		index++;
-	} while (bvec <= bvec_end);
+	}
 
 	unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
 		      dip->logical_offset + dip->bytes - 1);
@@ -6901,7 +6898,8 @@ static void btrfs_end_dio_bio(struct bio *bio, int err)
 		printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
 		      "sector %#Lx len %u err no %d\n",
 		      btrfs_ino(dip->inode), bio->bi_rw,
-		      (unsigned long long)bio->bi_sector, bio->bi_size, err);
+		      (unsigned long long)bio->bi_iter.bi_sector,
+		      bio->bi_iter.bi_size, err);
 		dip->errors = 1;
 
 		/*
@@ -6992,7 +6990,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 	struct bio *bio;
 	struct bio *orig_bio = dip->orig_bio;
 	struct bio_vec *bvec = orig_bio->bi_io_vec;
-	u64 start_sector = orig_bio->bi_sector;
+	u64 start_sector = orig_bio->bi_iter.bi_sector;
 	u64 file_offset = dip->logical_offset;
 	u64 submit_len = 0;
 	u64 map_length;
@@ -7000,7 +6998,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 	int ret = 0;
 	int async_submit = 0;
 
-	map_length = orig_bio->bi_size;
+	map_length = orig_bio->bi_iter.bi_size;
 	ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
 			      &map_length, NULL, 0);
 	if (ret) {
@@ -7008,7 +7006,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 		return -EIO;
 	}
 
-	if (map_length >= orig_bio->bi_size) {
+	if (map_length >= orig_bio->bi_iter.bi_size) {
 		bio = orig_bio;
 		goto submit;
 	}
@@ -7060,7 +7058,7 @@ static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
 			bio->bi_private = dip;
 			bio->bi_end_io = btrfs_end_dio_bio;
 
-			map_length = orig_bio->bi_size;
+			map_length = orig_bio->bi_iter.bi_size;
 			ret = btrfs_map_block(root->fs_info, rw,
 					      start_sector << 9,
 					      &map_length, NULL, 0);
@@ -7118,7 +7116,8 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio,
 
 	if (!skip_sum && !write) {
 		csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
-		sum_len = dio_bio->bi_size >> inode->i_sb->s_blocksize_bits;
+		sum_len = dio_bio->bi_iter.bi_size >>
+			inode->i_sb->s_blocksize_bits;
 		sum_len *= csum_size;
 	} else {
 		sum_len = 0;
@@ -7133,8 +7132,8 @@ static void btrfs_submit_direct(int rw, struct bio *dio_bio,
 	dip->private = dio_bio->bi_private;
 	dip->inode = inode;
 	dip->logical_offset = file_offset;
-	dip->bytes = dio_bio->bi_size;
-	dip->disk_bytenr = (u64)dio_bio->bi_sector << 9;
+	dip->bytes = dio_bio->bi_iter.bi_size;
+	dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
 	io_bio->bi_private = dip;
 	dip->errors = 0;
 	dip->orig_bio = io_bio;
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 24ac218..9af0b25 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1032,8 +1032,8 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
 
 	/* see if we can add this page onto our existing bio */
 	if (last) {
-		last_end = (u64)last->bi_sector << 9;
-		last_end += last->bi_size;
+		last_end = (u64)last->bi_iter.bi_sector << 9;
+		last_end += last->bi_iter.bi_size;
 
 		/*
 		 * we can't merge these if they are from different
@@ -1053,9 +1053,9 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
 	if (!bio)
 		return -ENOMEM;
 
-	bio->bi_size = 0;
+	bio->bi_iter.bi_size = 0;
 	bio->bi_bdev = stripe->dev->bdev;
-	bio->bi_sector = disk_start >> 9;
+	bio->bi_iter.bi_sector = disk_start >> 9;
 	set_bit(BIO_UPTODATE, &bio->bi_flags);
 
 	bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
@@ -1111,7 +1111,7 @@ static void index_rbio_pages(struct btrfs_raid_bio *rbio)
 
 	spin_lock_irq(&rbio->bio_list_lock);
 	bio_list_for_each(bio, &rbio->bio_list) {
-		start = (u64)bio->bi_sector << 9;
+		start = (u64)bio->bi_iter.bi_sector << 9;
 		stripe_offset = start - rbio->raid_map[0];
 		page_index = stripe_offset >> PAGE_CACHE_SHIFT;
 
@@ -1272,7 +1272,7 @@ cleanup:
 static int find_bio_stripe(struct btrfs_raid_bio *rbio,
 			   struct bio *bio)
 {
-	u64 physical = bio->bi_sector;
+	u64 physical = bio->bi_iter.bi_sector;
 	u64 stripe_start;
 	int i;
 	struct btrfs_bio_stripe *stripe;
@@ -1298,7 +1298,7 @@ static int find_bio_stripe(struct btrfs_raid_bio *rbio,
 static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
 				   struct bio *bio)
 {
-	u64 logical = bio->bi_sector;
+	u64 logical = bio->bi_iter.bi_sector;
 	u64 stripe_start;
 	int i;
 
@@ -1602,8 +1602,8 @@ static int plug_cmp(void *priv, struct list_head *a, struct list_head *b)
 						 plug_list);
 	struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
 						 plug_list);
-	u64 a_sector = ra->bio_list.head->bi_sector;
-	u64 b_sector = rb->bio_list.head->bi_sector;
+	u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
+	u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
 
 	if (a_sector < b_sector)
 		return -1;
@@ -1691,7 +1691,7 @@ int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
 	if (IS_ERR(rbio))
 		return PTR_ERR(rbio);
 	bio_list_add(&rbio->bio_list, bio);
-	rbio->bio_list_bytes = bio->bi_size;
+	rbio->bio_list_bytes = bio->bi_iter.bi_size;
 
 	/*
 	 * don't plug on full rbios, just get them out the door
@@ -2044,7 +2044,7 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
 
 	rbio->read_rebuild = 1;
 	bio_list_add(&rbio->bio_list, bio);
-	rbio->bio_list_bytes = bio->bi_size;
+	rbio->bio_list_bytes = bio->bi_iter.bi_size;
 
 	rbio->faila = find_logical_bio_stripe(rbio, bio);
 	if (rbio->faila == -1) {
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 1fd3f33..bb9a928 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1308,7 +1308,7 @@ static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
 			continue;
 		}
 		bio->bi_bdev = page->dev->bdev;
-		bio->bi_sector = page->physical >> 9;
+		bio->bi_iter.bi_sector = page->physical >> 9;
 
 		bio_add_page(bio, page->page, PAGE_SIZE, 0);
 		if (btrfsic_submit_bio_wait(READ, bio))
@@ -1427,7 +1427,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 		if (!bio)
 			return -EIO;
 		bio->bi_bdev = page_bad->dev->bdev;
-		bio->bi_sector = page_bad->physical >> 9;
+		bio->bi_iter.bi_sector = page_bad->physical >> 9;
 
 		ret = bio_add_page(bio, page_good->page, PAGE_SIZE, 0);
 		if (PAGE_SIZE != ret) {
@@ -1520,7 +1520,7 @@ again:
 		bio->bi_private = sbio;
 		bio->bi_end_io = scrub_wr_bio_end_io;
 		bio->bi_bdev = sbio->dev->bdev;
-		bio->bi_sector = sbio->physical >> 9;
+		bio->bi_iter.bi_sector = sbio->physical >> 9;
 		sbio->err = 0;
 	} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
 		   spage->physical_for_dev_replace ||
@@ -1926,7 +1926,7 @@ again:
 		bio->bi_private = sbio;
 		bio->bi_end_io = scrub_bio_end_io;
 		bio->bi_bdev = sbio->dev->bdev;
-		bio->bi_sector = sbio->physical >> 9;
+		bio->bi_iter.bi_sector = sbio->physical >> 9;
 		sbio->err = 0;
 	} else if (sbio->physical + sbio->page_count * PAGE_SIZE !=
 		   spage->physical ||
@@ -3371,8 +3371,8 @@ static int write_page_nocow(struct scrub_ctx *sctx,
 		spin_unlock(&sctx->stat_lock);
 		return -ENOMEM;
 	}
-	bio->bi_size = 0;
-	bio->bi_sector = physical_for_dev_replace >> 9;
+	bio->bi_iter.bi_size = 0;
+	bio->bi_iter.bi_sector = physical_for_dev_replace >> 9;
 	bio->bi_bdev = dev->bdev;
 	ret = bio_add_page(bio, page, PAGE_CACHE_SIZE, 0);
 	if (ret != PAGE_CACHE_SIZE) {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 92303f4..54d2685 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5298,6 +5298,13 @@ static void btrfs_end_bio(struct bio *bio, int err)
 			bio_put(bio);
 			bio = bbio->orig_bio;
 		}
+
+ 		/*
+		 * We have original bio now. So increment bi_remaining to
+		 * account for it in endio
+		 */
+		atomic_inc(&bio->bi_remaining);
+
 		bio->bi_private = bbio->private;
 		bio->bi_end_io = bbio->end_io;
 		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
@@ -5411,7 +5418,7 @@ static int bio_size_ok(struct block_device *bdev, struct bio *bio,
 	if (!q->merge_bvec_fn)
 		return 1;
 
-	bvm.bi_size = bio->bi_size - prev->bv_len;
+	bvm.bi_size = bio->bi_iter.bi_size - prev->bv_len;
 	if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
 		return 0;
 	return 1;
@@ -5426,7 +5433,7 @@ static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
 	bio->bi_private = bbio;
 	btrfs_io_bio(bio)->stripe_index = dev_nr;
 	bio->bi_end_io = btrfs_end_bio;
-	bio->bi_sector = physical >> 9;
+	bio->bi_iter.bi_sector = physical >> 9;
 #ifdef DEBUG
 	{
 		struct rcu_string *name;
@@ -5464,7 +5471,7 @@ again:
 	while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
 		if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
 				 bvec->bv_offset) < bvec->bv_len) {
-			u64 len = bio->bi_size;
+			u64 len = bio->bi_iter.bi_size;
 
 			atomic_inc(&bbio->stripes_pending);
 			submit_stripe_bio(root, bbio, bio, physical, dev_nr,
@@ -5486,7 +5493,7 @@ static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
 		bio->bi_private = bbio->private;
 		bio->bi_end_io = bbio->end_io;
 		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
-		bio->bi_sector = logical >> 9;
+		bio->bi_iter.bi_sector = logical >> 9;
 		kfree(bbio);
 		bio_endio(bio, -EIO);
 	}
@@ -5497,7 +5504,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 {
 	struct btrfs_device *dev;
 	struct bio *first_bio = bio;
-	u64 logical = (u64)bio->bi_sector << 9;
+	u64 logical = (u64)bio->bi_iter.bi_sector << 9;
 	u64 length = 0;
 	u64 map_length;
 	u64 *raid_map = NULL;
@@ -5506,7 +5513,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 	int total_devs = 1;
 	struct btrfs_bio *bbio = NULL;
 
-	length = bio->bi_size;
+	length = bio->bi_iter.bi_size;
 	map_length = length;
 
 	ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
diff --git a/fs/buffer.c b/fs/buffer.c
index 6024877..1c04ec6 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2982,11 +2982,11 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
 	 * let it through, and the IO layer will turn it into
 	 * an EIO.
 	 */
-	if (unlikely(bio->bi_sector >= maxsector))
+	if (unlikely(bio->bi_iter.bi_sector >= maxsector))
 		return;
 
-	maxsector -= bio->bi_sector;
-	bytes = bio->bi_size;
+	maxsector -= bio->bi_iter.bi_sector;
+	bytes = bio->bi_iter.bi_size;
 	if (likely((bytes >> 9) <= maxsector))
 		return;
 
@@ -2994,7 +2994,7 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
 	bytes = maxsector << 9;
 
 	/* Truncate the bio.. */
-	bio->bi_size = bytes;
+	bio->bi_iter.bi_size = bytes;
 	bio->bi_io_vec[0].bv_len = bytes;
 
 	/* ..and clear the end of the buffer for reads */
@@ -3029,14 +3029,14 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
 	 */
 	bio = bio_alloc(GFP_NOIO, 1);
 
-	bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 	bio->bi_bdev = bh->b_bdev;
 	bio->bi_io_vec[0].bv_page = bh->b_page;
 	bio->bi_io_vec[0].bv_len = bh->b_size;
 	bio->bi_io_vec[0].bv_offset = bh_offset(bh);
 
 	bio->bi_vcnt = 1;
-	bio->bi_size = bh->b_size;
+	bio->bi_iter.bi_size = bh->b_size;
 
 	bio->bi_end_io = end_bio_bh_io_sync;
 	bio->bi_private = bh;
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 0e04142..160a548 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -375,7 +375,7 @@ dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
 	bio = bio_alloc(GFP_KERNEL, nr_vecs);
 
 	bio->bi_bdev = bdev;
-	bio->bi_sector = first_sector;
+	bio->bi_iter.bi_sector = first_sector;
 	if (dio->is_async)
 		bio->bi_end_io = dio_bio_end_aio;
 	else
@@ -719,7 +719,7 @@ static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
 	if (sdio->bio) {
 		loff_t cur_offset = sdio->cur_page_fs_offset;
 		loff_t bio_next_offset = sdio->logical_offset_in_bio +
-			sdio->bio->bi_size;
+			sdio->bio->bi_iter.bi_size;
 
 		/*
 		 * See whether this new request is contiguous with the old.
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index d488f80..ab95508 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -65,9 +65,9 @@ static void ext4_finish_bio(struct bio *bio)
 {
 	int i;
 	int error = !test_bit(BIO_UPTODATE, &bio->bi_flags);
+	struct bio_vec *bvec;
 
-	for (i = 0; i < bio->bi_vcnt; i++) {
-		struct bio_vec *bvec = &bio->bi_io_vec[i];
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 		struct buffer_head *bh, *head;
 		unsigned bio_start = bvec->bv_offset;
@@ -298,7 +298,7 @@ ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end)
 static void ext4_end_bio(struct bio *bio, int error)
 {
 	ext4_io_end_t *io_end = bio->bi_private;
-	sector_t bi_sector = bio->bi_sector;
+	sector_t bi_sector = bio->bi_iter.bi_sector;
 
 	BUG_ON(!io_end);
 	bio->bi_end_io = NULL;
@@ -366,7 +366,7 @@ static int io_submit_init_bio(struct ext4_io_submit *io,
 	bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES));
 	if (!bio)
 		return -ENOMEM;
-	bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 	bio->bi_bdev = bh->b_bdev;
 	bio->bi_end_io = ext4_end_bio;
 	bio->bi_private = ext4_get_io_end(io->io_end);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 0ae5587..2261ccd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -26,40 +26,33 @@
 
 static void f2fs_read_end_io(struct bio *bio, int err)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
+	int i;
 
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-
-		if (unlikely(!uptodate)) {
+		if (!err) {
+			SetPageUptodate(page);
+		} else {
 			ClearPageUptodate(page);
 			SetPageError(page);
-		} else {
-			SetPageUptodate(page);
 		}
 		unlock_page(page);
-	} while (bvec >= bio->bi_io_vec);
-
+	}
 	bio_put(bio);
 }
 
 static void f2fs_write_end_io(struct bio *bio, int err)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-	struct f2fs_sb_info *sbi = F2FS_SB(bvec->bv_page->mapping->host->i_sb);
+	struct f2fs_sb_info *sbi = F2FS_SB(bio->bi_io_vec->bv_page->mapping->host->i_sb);
+	struct bio_vec *bvec;
+	int i;
 
-	do {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-
-		if (unlikely(!uptodate)) {
+		if (unlikely(err)) {
 			SetPageError(page);
 			set_bit(AS_EIO, &page->mapping->flags);
 			set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
@@ -67,7 +60,7 @@ static void f2fs_write_end_io(struct bio *bio, int err)
 		}
 		end_page_writeback(page);
 		dec_page_count(sbi, F2FS_WRITEBACK);
-	} while (bvec >= bio->bi_io_vec);
+	}
 
 	if (bio->bi_private)
 		complete(bio->bi_private);
@@ -91,7 +84,7 @@ static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
 	bio = bio_alloc(GFP_NOIO, npages);
 
 	bio->bi_bdev = sbi->sb->s_bdev;
-	bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
+	bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
 	bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
 
 	return bio;
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 58f0640..7669379 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -273,7 +273,7 @@ static struct bio *gfs2_log_alloc_bio(struct gfs2_sbd *sdp, u64 blkno)
 		nrvecs = max(nrvecs/2, 1U);
 	}
 
-	bio->bi_sector = blkno * (sb->s_blocksize >> 9);
+	bio->bi_iter.bi_sector = blkno * (sb->s_blocksize >> 9);
 	bio->bi_bdev = sb->s_bdev;
 	bio->bi_end_io = gfs2_end_log_write;
 	bio->bi_private = sdp;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 1e712b5..c6872d0 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -238,7 +238,7 @@ static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
 	lock_page(page);
 
 	bio = bio_alloc(GFP_NOFS, 1);
-	bio->bi_sector = sector * (sb->s_blocksize >> 9);
+	bio->bi_iter.bi_sector = sector * (sb->s_blocksize >> 9);
 	bio->bi_bdev = sb->s_bdev;
 	bio_add_page(bio, page, PAGE_SIZE, 0);
 
diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
index e9a97a0..3f99964 100644
--- a/fs/hfsplus/wrapper.c
+++ b/fs/hfsplus/wrapper.c
@@ -63,7 +63,7 @@ int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
 	sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1);
 
 	bio = bio_alloc(GFP_NOIO, 1);
-	bio->bi_sector = sector;
+	bio->bi_iter.bi_sector = sector;
 	bio->bi_bdev = sb->s_bdev;
 
 	if (!(rw & WRITE) && data)
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 360d27c..8d811e0 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -1998,20 +1998,20 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
 
 	bio = bio_alloc(GFP_NOFS, 1);
 
-	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
+	bio->bi_iter.bi_sector = bp->l_blkno << (log->l2bsize - 9);
 	bio->bi_bdev = log->bdev;
 	bio->bi_io_vec[0].bv_page = bp->l_page;
 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
 
 	bio->bi_vcnt = 1;
-	bio->bi_size = LOGPSIZE;
+	bio->bi_iter.bi_size = LOGPSIZE;
 
 	bio->bi_end_io = lbmIODone;
 	bio->bi_private = bp;
 	/*check if journaling to disk has been disabled*/
 	if (log->no_integrity) {
-		bio->bi_size = 0;
+		bio->bi_iter.bi_size = 0;
 		lbmIODone(bio, 0);
 	} else {
 		submit_bio(READ_SYNC, bio);
@@ -2144,21 +2144,21 @@ static void lbmStartIO(struct lbuf * bp)
 	jfs_info("lbmStartIO\n");
 
 	bio = bio_alloc(GFP_NOFS, 1);
-	bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
+	bio->bi_iter.bi_sector = bp->l_blkno << (log->l2bsize - 9);
 	bio->bi_bdev = log->bdev;
 	bio->bi_io_vec[0].bv_page = bp->l_page;
 	bio->bi_io_vec[0].bv_len = LOGPSIZE;
 	bio->bi_io_vec[0].bv_offset = bp->l_offset;
 
 	bio->bi_vcnt = 1;
-	bio->bi_size = LOGPSIZE;
+	bio->bi_iter.bi_size = LOGPSIZE;
 
 	bio->bi_end_io = lbmIODone;
 	bio->bi_private = bp;
 
 	/* check if journaling to disk has been disabled */
 	if (log->no_integrity) {
-		bio->bi_size = 0;
+		bio->bi_iter.bi_size = 0;
 		lbmIODone(bio, 0);
 	} else {
 		submit_bio(WRITE_SYNC, bio);
diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index d165cde..49ba7ff 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -416,7 +416,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
 			 * count from hitting zero before we're through
 			 */
 			inc_io(page);
-			if (!bio->bi_size)
+			if (!bio->bi_iter.bi_size)
 				goto dump_bio;
 			submit_bio(WRITE, bio);
 			nr_underway++;
@@ -438,7 +438,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
 
 		bio = bio_alloc(GFP_NOFS, 1);
 		bio->bi_bdev = inode->i_sb->s_bdev;
-		bio->bi_sector = pblock << (inode->i_blkbits - 9);
+		bio->bi_iter.bi_sector = pblock << (inode->i_blkbits - 9);
 		bio->bi_end_io = metapage_write_end_io;
 		bio->bi_private = page;
 
@@ -452,7 +452,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
 	if (bio) {
 		if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
 				goto add_failed;
-		if (!bio->bi_size)
+		if (!bio->bi_iter.bi_size)
 			goto dump_bio;
 
 		submit_bio(WRITE, bio);
@@ -517,7 +517,8 @@ static int metapage_readpage(struct file *fp, struct page *page)
 
 			bio = bio_alloc(GFP_NOFS, 1);
 			bio->bi_bdev = inode->i_sb->s_bdev;
-			bio->bi_sector = pblock << (inode->i_blkbits - 9);
+			bio->bi_iter.bi_sector =
+				pblock << (inode->i_blkbits - 9);
 			bio->bi_end_io = metapage_read_end_io;
 			bio->bi_private = page;
 			len = xlen << inode->i_blkbits;
diff --git a/fs/logfs/dev_bdev.c b/fs/logfs/dev_bdev.c
index 0f95f0d..76279e1 100644
--- a/fs/logfs/dev_bdev.c
+++ b/fs/logfs/dev_bdev.c
@@ -26,9 +26,9 @@ static int sync_request(struct page *page, struct block_device *bdev, int rw)
 	bio_vec.bv_len = PAGE_SIZE;
 	bio_vec.bv_offset = 0;
 	bio.bi_vcnt = 1;
-	bio.bi_size = PAGE_SIZE;
 	bio.bi_bdev = bdev;
-	bio.bi_sector = page->index * (PAGE_SIZE >> 9);
+	bio.bi_iter.bi_sector = page->index * (PAGE_SIZE >> 9);
+	bio.bi_iter.bi_size = PAGE_SIZE;
 
 	return submit_bio_wait(rw, &bio);
 }
@@ -56,22 +56,18 @@ static DECLARE_WAIT_QUEUE_HEAD(wq);
 static void writeseg_end_io(struct bio *bio, int err)
 {
 	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
+	int i;
 	struct super_block *sb = bio->bi_private;
 	struct logfs_super *super = logfs_super(sb);
-	struct page *page;
 
 	BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */
 	BUG_ON(err);
-	BUG_ON(bio->bi_vcnt == 0);
-	do {
-		page = bvec->bv_page;
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-
-		end_page_writeback(page);
-		page_cache_release(page);
-	} while (bvec >= bio->bi_io_vec);
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		end_page_writeback(bvec->bv_page);
+		page_cache_release(bvec->bv_page);
+	}
 	bio_put(bio);
 	if (atomic_dec_and_test(&super->s_pending_writes))
 		wake_up(&wq);
@@ -96,9 +92,9 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
 		if (i >= max_pages) {
 			/* Block layer cannot split bios :( */
 			bio->bi_vcnt = i;
-			bio->bi_size = i * PAGE_SIZE;
+			bio->bi_iter.bi_size = i * PAGE_SIZE;
 			bio->bi_bdev = super->s_bdev;
-			bio->bi_sector = ofs >> 9;
+			bio->bi_iter.bi_sector = ofs >> 9;
 			bio->bi_private = sb;
 			bio->bi_end_io = writeseg_end_io;
 			atomic_inc(&super->s_pending_writes);
@@ -123,9 +119,9 @@ static int __bdev_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
 		unlock_page(page);
 	}
 	bio->bi_vcnt = nr_pages;
-	bio->bi_size = nr_pages * PAGE_SIZE;
+	bio->bi_iter.bi_size = nr_pages * PAGE_SIZE;
 	bio->bi_bdev = super->s_bdev;
-	bio->bi_sector = ofs >> 9;
+	bio->bi_iter.bi_sector = ofs >> 9;
 	bio->bi_private = sb;
 	bio->bi_end_io = writeseg_end_io;
 	atomic_inc(&super->s_pending_writes);
@@ -188,9 +184,9 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
 		if (i >= max_pages) {
 			/* Block layer cannot split bios :( */
 			bio->bi_vcnt = i;
-			bio->bi_size = i * PAGE_SIZE;
+			bio->bi_iter.bi_size = i * PAGE_SIZE;
 			bio->bi_bdev = super->s_bdev;
-			bio->bi_sector = ofs >> 9;
+			bio->bi_iter.bi_sector = ofs >> 9;
 			bio->bi_private = sb;
 			bio->bi_end_io = erase_end_io;
 			atomic_inc(&super->s_pending_writes);
@@ -209,9 +205,9 @@ static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index,
 		bio->bi_io_vec[i].bv_offset = 0;
 	}
 	bio->bi_vcnt = nr_pages;
-	bio->bi_size = nr_pages * PAGE_SIZE;
+	bio->bi_iter.bi_size = nr_pages * PAGE_SIZE;
 	bio->bi_bdev = super->s_bdev;
-	bio->bi_sector = ofs >> 9;
+	bio->bi_iter.bi_sector = ofs >> 9;
 	bio->bi_private = sb;
 	bio->bi_end_io = erase_end_io;
 	atomic_inc(&super->s_pending_writes);
diff --git a/fs/mpage.c b/fs/mpage.c
index 0face1c..4979ffa 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -43,16 +43,14 @@
  */
 static void mpage_end_io(struct bio *bio, int err)
 {
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bv;
+	int i;
 
-	do {
-		struct page *page = bvec->bv_page;
+	bio_for_each_segment_all(bv, bio, i) {
+		struct page *page = bv->bv_page;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
 		if (bio_data_dir(bio) == READ) {
-			if (uptodate) {
+			if (!err) {
 				SetPageUptodate(page);
 			} else {
 				ClearPageUptodate(page);
@@ -60,14 +58,15 @@ static void mpage_end_io(struct bio *bio, int err)
 			}
 			unlock_page(page);
 		} else { /* bio_data_dir(bio) == WRITE */
-			if (!uptodate) {
+			if (err) {
 				SetPageError(page);
 				if (page->mapping)
 					set_bit(AS_EIO, &page->mapping->flags);
 			}
 			end_page_writeback(page);
 		}
-	} while (bvec >= bio->bi_io_vec);
+	}
+
 	bio_put(bio);
 }
 
@@ -94,7 +93,7 @@ mpage_alloc(struct block_device *bdev,
 
 	if (bio) {
 		bio->bi_bdev = bdev;
-		bio->bi_sector = first_sector;
+		bio->bi_iter.bi_sector = first_sector;
 	}
 	return bio;
 }
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index e242bbf..56ff823 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -134,8 +134,8 @@ bl_submit_bio(int rw, struct bio *bio)
 	if (bio) {
 		get_parallel(bio->bi_private);
 		dprintk("%s submitting %s bio %u@%llu\n", __func__,
-			rw == READ ? "read" : "write",
-			bio->bi_size, (unsigned long long)bio->bi_sector);
+			rw == READ ? "read" : "write", bio->bi_iter.bi_size,
+			(unsigned long long)bio->bi_iter.bi_sector);
 		submit_bio(rw, bio);
 	}
 	return NULL;
@@ -156,7 +156,8 @@ static struct bio *bl_alloc_init_bio(int npg, sector_t isect,
 	}
 
 	if (bio) {
-		bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
+		bio->bi_iter.bi_sector = isect - be->be_f_offset +
+			be->be_v_offset;
 		bio->bi_bdev = be->be_mdev;
 		bio->bi_end_io = end_io;
 		bio->bi_private = par;
@@ -201,18 +202,14 @@ static struct bio *bl_add_page_to_bio(struct bio *bio, int npg, int rw,
 static void bl_end_io_read(struct bio *bio, int err)
 {
 	struct parallel_io *par = bio->bi_private;
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
+	struct bio_vec *bvec;
+	int i;
 
-	do {
-		struct page *page = bvec->bv_page;
+	if (!err)
+		bio_for_each_segment_all(bvec, bio, i)
+			SetPageUptodate(bvec->bv_page);
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
-		if (uptodate)
-			SetPageUptodate(page);
-	} while (bvec >= bio->bi_io_vec);
-	if (!uptodate) {
+	if (err) {
 		struct nfs_read_data *rdata = par->data;
 		struct nfs_pgio_header *header = rdata->header;
 
@@ -383,20 +380,16 @@ static void mark_extents_written(struct pnfs_block_layout *bl,
 static void bl_end_io_write_zero(struct bio *bio, int err)
 {
 	struct parallel_io *par = bio->bi_private;
-	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
-
-	do {
-		struct page *page = bvec->bv_page;
+	struct bio_vec *bvec;
+	int i;
 
-		if (--bvec >= bio->bi_io_vec)
-			prefetchw(&bvec->bv_page->flags);
+	bio_for_each_segment_all(bvec, bio, i) {
 		/* This is the zeroing page we added */
-		end_page_writeback(page);
-		page_cache_release(page);
-	} while (bvec >= bio->bi_io_vec);
+		end_page_writeback(bvec->bv_page);
+		page_cache_release(bvec->bv_page);
+	}
 
-	if (unlikely(!uptodate)) {
+	if (unlikely(err)) {
 		struct nfs_write_data *data = par->data;
 		struct nfs_pgio_header *header = data->header;
 
@@ -519,7 +512,7 @@ bl_do_readpage_sync(struct page *page, struct pnfs_block_extent *be,
 	isect = (page->index << PAGE_CACHE_SECTOR_SHIFT) +
 		(offset / SECTOR_SIZE);
 
-	bio->bi_sector = isect - be->be_f_offset + be->be_v_offset;
+	bio->bi_iter.bi_sector = isect - be->be_f_offset + be->be_v_offset;
 	bio->bi_bdev = be->be_mdev;
 	bio->bi_end_io = bl_read_single_end_io;
 
diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index 2d8be51..dc3a9efd 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -416,7 +416,8 @@ static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
 	}
 	if (likely(bio)) {
 		bio->bi_bdev = nilfs->ns_bdev;
-		bio->bi_sector = start << (nilfs->ns_blocksize_bits - 9);
+		bio->bi_iter.bi_sector =
+			start << (nilfs->ns_blocksize_bits - 9);
 	}
 	return bio;
 }
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 73920ff..bf482df 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -413,7 +413,7 @@ static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
 	}
 
 	/* Must put everything in 512 byte sectors for the bio... */
-	bio->bi_sector = (reg->hr_start_block + cs) << (bits - 9);
+	bio->bi_iter.bi_sector = (reg->hr_start_block + cs) << (bits - 9);
 	bio->bi_bdev = reg->hr_bdev;
 	bio->bi_private = wc;
 	bio->bi_end_io = o2hb_bio_end_io;
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index a267394..db2cfb0 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -407,7 +407,7 @@ xfs_alloc_ioend_bio(
 	struct bio		*bio = bio_alloc(GFP_NOIO, nvecs);
 
 	ASSERT(bio->bi_private == NULL);
-	bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
+	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
 	bio->bi_bdev = bh->b_bdev;
 	return bio;
 }
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 5175711..9c061ef 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1240,7 +1240,7 @@ next_chunk:
 
 	bio = bio_alloc(GFP_NOIO, nr_pages);
 	bio->bi_bdev = bp->b_target->bt_bdev;
-	bio->bi_sector = sector;
+	bio->bi_iter.bi_sector = sector;
 	bio->bi_end_io = xfs_buf_bio_end_io;
 	bio->bi_private = bp;
 
@@ -1262,7 +1262,7 @@ next_chunk:
 		total_nr_pages--;
 	}
 
-	if (likely(bio->bi_size)) {
+	if (likely(bio->bi_iter.bi_size)) {
 		if (xfs_buf_is_vmapped(bp)) {
 			flush_kernel_vmap_range(bp->b_addr,
 						xfs_buf_vmap_len(bp));