Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "This branch also contains core changes.  I've come to the conclusion
  that from 4.9 and forward, I'll be doing just a single branch.  We
  often have dependencies between core and drivers, and it's hard to
  always split them up appropriately without pulling core into drivers
  when that happens.

  That said, this contains:

   - separate secure erase type for the core block layer, from
     Christoph.

   - set of discard fixes, from Christoph.

   - bio shrinking fixes from Christoph, as a followup up to the
     op/flags change in the core branch.

   - map and append request fixes from Christoph.

   - NVMeF (NVMe over Fabrics) code from Christoph.  This is pretty
     exciting!

   - nvme-loop fixes from Arnd.

   - removal of ->driverfs_dev from Dan, after providing a
     device_add_disk() helper.

   - bcache fixes from Bhaktipriya and Yijing.

   - cdrom subchannel read fix from Vchannaiah.

   - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.

   - set of drbd updates and fixes from Fabian, Lars, and Philipp.

   - mg_disk error path fix from Bart.

   - user notification for failed device add for loop, from Minfei.

   - NVMe in general:
        + NVMe delay quirk from Guilherme.
        + SR-IOV support and command retry limits from Keith.
        + fix for memory-less NUMA node from Masayoshi.
        + use UINT_MAX for discard sectors, from Minfei.
        + cancel IO fixes from Ming.
        + don't allocate unused major, from Neil.
        + error code fixup from Dan.
        + use constants for PSDT/FUSE from James.
        + variable init fix from Jay.
        + fabrics fixes from Ming, Sagi, and Wei.
        + various fixes"

* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
  nvme/pci: Provide SR-IOV support
  nvme: initialize variable before logical OR'ing it
  block: unexport various bio mapping helpers
  scsi/osd: open code blk_make_request
  target: stop using blk_make_request
  block: simplify and export blk_rq_append_bio
  block: ensure bios return from blk_get_request are properly initialized
  virtio_blk: use blk_rq_map_kern
  memstick: don't allow REQ_TYPE_BLOCK_PC requests
  block: shrink bio size again
  block: simplify and cleanup bvec pool handling
  block: get rid of bio_rw and READA
  block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
  block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
  NVMe: don't allocate unused nvme_major
  nvme: avoid crashes when node 0 is memoryless node.
  nvme: Limit command retries
  loop: Make user notify for adding loop device failed
  nvme-loop: fix nvme-loop Kconfig dependencies
  nvmet: fix return value check in nvmet_subsys_alloc()
  ...

10 files changed, 168 insertions, 137 deletions

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 15d37b1..f70cc3b 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -54,7 +54,6 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 {
 	struct bio_integrity_payload *bip;
 	struct bio_set *bs = bio->bi_pool;
-	unsigned long idx = BIO_POOL_NONE;
 	unsigned inline_vecs;
 
 	if (!bs || !bs->bio_integrity_pool) {
@@ -72,17 +71,19 @@ struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 	memset(bip, 0, sizeof(*bip));
 
 	if (nr_vecs > inline_vecs) {
+		unsigned long idx = 0;
+
 		bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
 					  bs->bvec_integrity_pool);
 		if (!bip->bip_vec)
 			goto err;
 		bip->bip_max_vcnt = bvec_nr_vecs(idx);
+		bip->bip_slab = idx;
 	} else {
 		bip->bip_vec = bip->bip_inline_vecs;
 		bip->bip_max_vcnt = inline_vecs;
 	}
 
-	bip->bip_slab = idx;
 	bip->bip_bio = bio;
 	bio->bi_integrity = bip;
 	bio->bi_rw |= REQ_INTEGRITY;
@@ -111,9 +112,7 @@ void bio_integrity_free(struct bio *bio)
 		      bip->bip_vec->bv_offset);
 
 	if (bs && bs->bio_integrity_pool) {
-		if (bip->bip_slab != BIO_POOL_NONE)
-			bvec_free(bs->bvec_integrity_pool, bip->bip_vec,
-				  bip->bip_slab);
+		bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);
 
 		mempool_free(bip, bs->bio_integrity_pool);
 	} else {
diff --git a/block/bio.c b/block/bio.c
index 848cd35..54ee384 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -43,7 +43,7 @@
  * unsigned short
  */
 #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
-static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
+static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {
 	BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
 };
 #undef BV
@@ -160,11 +160,15 @@ unsigned int bvec_nr_vecs(unsigned short idx)
 
 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
 {
-	BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
+	if (!idx)
+		return;
+	idx--;
+
+	BIO_BUG_ON(idx >= BVEC_POOL_NR);
 
-	if (idx == BIOVEC_MAX_IDX)
+	if (idx == BVEC_POOL_MAX) {
 		mempool_free(bv, pool);
-	else {
+	} else {
 		struct biovec_slab *bvs = bvec_slabs + idx;
 
 		kmem_cache_free(bvs->slab, bv);
@@ -206,7 +210,7 @@ struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
 	 * idx now points to the pool we want to allocate from. only the
 	 * 1-vec entry pool is mempool backed.
 	 */
-	if (*idx == BIOVEC_MAX_IDX) {
+	if (*idx == BVEC_POOL_MAX) {
 fallback:
 		bvl = mempool_alloc(pool, gfp_mask);
 	} else {
@@ -226,11 +230,12 @@ fallback:
 		 */
 		bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
 		if (unlikely(!bvl && (gfp_mask & __GFP_DIRECT_RECLAIM))) {
-			*idx = BIOVEC_MAX_IDX;
+			*idx = BVEC_POOL_MAX;
 			goto fallback;
 		}
 	}
 
+	(*idx)++;
 	return bvl;
 }
 
@@ -250,8 +255,7 @@ static void bio_free(struct bio *bio)
 	__bio_free(bio);
 
 	if (bs) {
-		if (bio_flagged(bio, BIO_OWNS_VEC))
-			bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio));
+		bvec_free(bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));
 
 		/*
 		 * If we have front padding, adjust the bio pointer before freeing
@@ -420,7 +424,6 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 	gfp_t saved_gfp = gfp_mask;
 	unsigned front_pad;
 	unsigned inline_vecs;
-	unsigned long idx = BIO_POOL_NONE;
 	struct bio_vec *bvl = NULL;
 	struct bio *bio;
 	void *p;
@@ -480,6 +483,8 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 	bio_init(bio);
 
 	if (nr_iovecs > inline_vecs) {
+		unsigned long idx = 0;
+
 		bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
 		if (!bvl && gfp_mask != saved_gfp) {
 			punt_bios_to_rescuer(bs);
@@ -490,13 +495,12 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 		if (unlikely(!bvl))
 			goto err_free;
 
-		bio_set_flag(bio, BIO_OWNS_VEC);
+		bio->bi_flags |= idx << BVEC_POOL_OFFSET;
 	} else if (nr_iovecs) {
 		bvl = bio->bi_inline_vecs;
 	}
 
 	bio->bi_pool = bs;
-	bio->bi_flags |= idx << BIO_POOL_OFFSET;
 	bio->bi_max_vecs = nr_iovecs;
 	bio->bi_io_vec = bvl;
 	return bio;
@@ -568,7 +572,7 @@ EXPORT_SYMBOL(bio_phys_segments);
  */
 void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
 {
-	BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE);
+	BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
 
 	/*
 	 * most users will be overriding ->bi_bdev with a new target,
@@ -1097,7 +1101,6 @@ int bio_uncopy_user(struct bio *bio)
 	bio_put(bio);
 	return ret;
 }
-EXPORT_SYMBOL(bio_uncopy_user);
 
 /**
  *	bio_copy_user_iov	-	copy user data to bio
@@ -1392,7 +1395,6 @@ void bio_unmap_user(struct bio *bio)
 	__bio_unmap_user(bio);
 	bio_put(bio);
 }
-EXPORT_SYMBOL(bio_unmap_user);
 
 static void bio_map_kern_endio(struct bio *bio)
 {
@@ -1538,7 +1540,6 @@ cleanup:
 	bio_put(bio);
 	return ERR_PTR(-ENOMEM);
 }
-EXPORT_SYMBOL(bio_copy_kern);
 
 /*
  * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
@@ -1832,7 +1833,7 @@ EXPORT_SYMBOL_GPL(bio_trim);
  */
 mempool_t *biovec_create_pool(int pool_entries)
 {
-	struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
+	struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;
 
 	return mempool_create_slab_pool(pool_entries, bp->slab);
 }
@@ -2009,7 +2010,7 @@ static void __init biovec_init_slabs(void)
 {
 	int i;
 
-	for (i = 0; i < BIOVEC_NR_POOLS; i++) {
+	for (i = 0; i < BVEC_POOL_NR; i++) {
 		int size;
 		struct biovec_slab *bvs = bvec_slabs + i;
 
diff --git a/block/blk-core.c b/block/blk-core.c
index 3cfd67d..a687e9c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1294,10 +1294,15 @@ static struct request *blk_old_get_request(struct request_queue *q, int rw,
 
 	spin_lock_irq(q->queue_lock);
 	rq = get_request(q, rw, 0, NULL, gfp_mask);
-	if (IS_ERR(rq))
+	if (IS_ERR(rq)) {
 		spin_unlock_irq(q->queue_lock);
-	/* q->queue_lock is unlocked at this point */
+		return rq;
+	}
 
+	/* q->queue_lock is unlocked at this point */
+	rq->__data_len = 0;
+	rq->__sector = (sector_t) -1;
+	rq->bio = rq->biotail = NULL;
 	return rq;
 }
 
@@ -1313,63 +1318,6 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
 EXPORT_SYMBOL(blk_get_request);
 
 /**
- * blk_make_request - given a bio, allocate a corresponding struct request.
- * @q: target request queue
- * @bio:  The bio describing the memory mappings that will be submitted for IO.
- *        It may be a chained-bio properly constructed by block/bio layer.
- * @gfp_mask: gfp flags to be used for memory allocation
- *
- * blk_make_request is the parallel of generic_make_request for BLOCK_PC
- * type commands. Where the struct request needs to be farther initialized by
- * the caller. It is passed a &struct bio, which describes the memory info of
- * the I/O transfer.
- *
- * The caller of blk_make_request must make sure that bi_io_vec
- * are set to describe the memory buffers. That bio_data_dir() will return
- * the needed direction of the request. (And all bio's in the passed bio-chain
- * are properly set accordingly)
- *
- * If called under none-sleepable conditions, mapped bio buffers must not
- * need bouncing, by calling the appropriate masked or flagged allocator,
- * suitable for the target device. Otherwise the call to blk_queue_bounce will
- * BUG.
- *
- * WARNING: When allocating/cloning a bio-chain, careful consideration should be
- * given to how you allocate bios. In particular, you cannot use
- * __GFP_DIRECT_RECLAIM for anything but the first bio in the chain. Otherwise
- * you risk waiting for IO completion of a bio that hasn't been submitted yet,
- * thus resulting in a deadlock. Alternatively bios should be allocated using
- * bio_kmalloc() instead of bio_alloc(), as that avoids the mempool deadlock.
- * If possible a big IO should be split into smaller parts when allocation
- * fails. Partial allocation should not be an error, or you risk a live-lock.
- */
-struct request *blk_make_request(struct request_queue *q, struct bio *bio,
-				 gfp_t gfp_mask)
-{
-	struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
-
-	if (IS_ERR(rq))
-		return rq;
-
-	blk_rq_set_block_pc(rq);
-
-	for_each_bio(bio) {
-		struct bio *bounce_bio = bio;
-		int ret;
-
-		blk_queue_bounce(q, &bounce_bio);
-		ret = blk_rq_append_bio(q, rq, bounce_bio);
-		if (unlikely(ret)) {
-			blk_put_request(rq);
-			return ERR_PTR(ret);
-		}
-	}
-
-	return rq;
-}
-EXPORT_SYMBOL(blk_make_request);
-
-/**
  * blk_rq_set_block_pc - initialize a request to type BLOCK_PC
  * @rq:		request to be initialized
  *
@@ -1377,9 +1325,6 @@ EXPORT_SYMBOL(blk_make_request);
 void blk_rq_set_block_pc(struct request *rq)
 {
 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
-	rq->__data_len = 0;
-	rq->__sector = (sector_t) -1;
-	rq->bio = rq->biotail = NULL;
 	memset(rq->__cmd, 0, sizeof(rq->__cmd));
 }
 EXPORT_SYMBOL(blk_rq_set_block_pc);
@@ -1982,16 +1927,21 @@ generic_make_request_checks(struct bio *bio)
 		}
 	}
 
-	if ((bio_op(bio) == REQ_OP_DISCARD) &&
-	    (!blk_queue_discard(q) ||
-	     ((bio->bi_rw & REQ_SECURE) && !blk_queue_secdiscard(q)))) {
-		err = -EOPNOTSUPP;
-		goto end_io;
-	}
-
-	if (bio_op(bio) == REQ_OP_WRITE_SAME && !bdev_write_same(bio->bi_bdev)) {
-		err = -EOPNOTSUPP;
-		goto end_io;
+	switch (bio_op(bio)) {
+	case REQ_OP_DISCARD:
+		if (!blk_queue_discard(q))
+			goto not_supported;
+		break;
+	case REQ_OP_SECURE_ERASE:
+		if (!blk_queue_secure_erase(q))
+			goto not_supported;
+		break;
+	case REQ_OP_WRITE_SAME:
+		if (!bdev_write_same(bio->bi_bdev))
+			goto not_supported;
+		break;
+	default:
+		break;
 	}
 
 	/*
@@ -2008,6 +1958,8 @@ generic_make_request_checks(struct bio *bio)
 	trace_block_bio_queue(q, bio);
 	return true;
 
+not_supported:
+	err = -EOPNOTSUPP;
 end_io:
 	bio->bi_error = err;
 	bio_endio(bio);
@@ -3383,6 +3335,7 @@ bool blk_poll(struct request_queue *q, blk_qc_t cookie)
 
 	return false;
 }
+EXPORT_SYMBOL_GPL(blk_poll);
 
 #ifdef CONFIG_PM
 /**
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9031d2a..083e56f 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -23,20 +23,32 @@ static struct bio *next_bio(struct bio *bio, unsigned int nr_pages,
 }
 
 int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
-		sector_t nr_sects, gfp_t gfp_mask, int op_flags,
+		sector_t nr_sects, gfp_t gfp_mask, int flags,
 		struct bio **biop)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
 	struct bio *bio = *biop;
 	unsigned int granularity;
+	enum req_op op;
 	int alignment;
 
 	if (!q)
 		return -ENXIO;
-	if (!blk_queue_discard(q))
-		return -EOPNOTSUPP;
-	if ((op_flags & REQ_SECURE) && !blk_queue_secdiscard(q))
-		return -EOPNOTSUPP;
+
+	if (flags & BLKDEV_DISCARD_SECURE) {
+		if (flags & BLKDEV_DISCARD_ZERO)
+			return -EOPNOTSUPP;
+		if (!blk_queue_secure_erase(q))
+			return -EOPNOTSUPP;
+		op = REQ_OP_SECURE_ERASE;
+	} else {
+		if (!blk_queue_discard(q))
+			return -EOPNOTSUPP;
+		if ((flags & BLKDEV_DISCARD_ZERO) &&
+		    !q->limits.discard_zeroes_data)
+			return -EOPNOTSUPP;
+		op = REQ_OP_DISCARD;
+	}
 
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
@@ -66,7 +78,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		bio = next_bio(bio, 1, gfp_mask);
 		bio->bi_iter.bi_sector = sector;
 		bio->bi_bdev = bdev;
-		bio_set_op_attrs(bio, REQ_OP_DISCARD, op_flags);
+		bio_set_op_attrs(bio, op, 0);
 
 		bio->bi_iter.bi_size = req_sects << 9;
 		nr_sects -= req_sects;
@@ -100,20 +112,16 @@ EXPORT_SYMBOL(__blkdev_issue_discard);
 int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags)
 {
-	int op_flags = 0;
 	struct bio *bio = NULL;
 	struct blk_plug plug;
 	int ret;
 
-	if (flags & BLKDEV_DISCARD_SECURE)
-		op_flags |= REQ_SECURE;
-
 	blk_start_plug(&plug);
-	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, op_flags,
+	ret = __blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, flags,
 			&bio);
 	if (!ret && bio) {
 		ret = submit_bio_wait(bio);
-		if (ret == -EOPNOTSUPP)
+		if (ret == -EOPNOTSUPP && !(flags & BLKDEV_DISCARD_ZERO))
 			ret = 0;
 		bio_put(bio);
 	}
@@ -173,7 +181,7 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 		ret = submit_bio_wait(bio);
 		bio_put(bio);
 	}
-	return ret != -EOPNOTSUPP ? ret : 0;
+	return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_write_same);
 
@@ -244,11 +252,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 			 sector_t nr_sects, gfp_t gfp_mask, bool discard)
 {
-	struct request_queue *q = bdev_get_queue(bdev);
-
-	if (discard && blk_queue_discard(q) && q->limits.discard_zeroes_data &&
-	    blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask, 0) == 0)
-		return 0;
+	if (discard) {
+		if (!blkdev_issue_discard(bdev, sector, nr_sects, gfp_mask,
+				BLKDEV_DISCARD_ZERO))
+			return 0;
+	}
 
 	if (bdev_write_same(bdev) &&
 	    blkdev_issue_write_same(bdev, sector, nr_sects, gfp_mask,
diff --git a/block/blk-map.c b/block/blk-map.c
index 61733a6..b8657fa 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -9,21 +9,26 @@
 
 #include "blk.h"
 
-int blk_rq_append_bio(struct request_queue *q, struct request *rq,
-		      struct bio *bio)
+/*
+ * Append a bio to a passthrough request.  Only works can be merged into
+ * the request based on the driver constraints.
+ */
+int blk_rq_append_bio(struct request *rq, struct bio *bio)
 {
-	if (!rq->bio)
-		blk_rq_bio_prep(q, rq, bio);
-	else if (!ll_back_merge_fn(q, rq, bio))
-		return -EINVAL;
-	else {
+	if (!rq->bio) {
+		blk_rq_bio_prep(rq->q, rq, bio);
+	} else {
+		if (!ll_back_merge_fn(rq->q, rq, bio))
+			return -EINVAL;
+
 		rq->biotail->bi_next = bio;
 		rq->biotail = bio;
-
 		rq->__data_len += bio->bi_iter.bi_size;
 	}
+
 	return 0;
 }
+EXPORT_SYMBOL(blk_rq_append_bio);
 
 static int __blk_rq_unmap_user(struct bio *bio)
 {
@@ -71,7 +76,7 @@ static int __blk_rq_map_user_iov(struct request *rq,
 	 */
 	bio_get(bio);
 
-	ret = blk_rq_append_bio(q, rq, bio);
+	ret = blk_rq_append_bio(rq, bio);
 	if (ret) {
 		bio_endio(bio);
 		__blk_rq_unmap_user(orig_bio);
@@ -229,7 +234,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (do_copy)
 		rq->cmd_flags |= REQ_COPY_USER;
 
-	ret = blk_rq_append_bio(q, rq, bio);
+	ret = blk_rq_append_bio(rq, bio);
 	if (unlikely(ret)) {
 		/* request is too big */
 		bio_put(bio);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 5e4d93e..41cbd48 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -649,8 +649,7 @@ static int attempt_merge(struct request_queue *q, struct request *req,
 	if (!rq_mergeable(req) || !rq_mergeable(next))
 		return 0;
 
-	if (!blk_check_merge_flags(req->cmd_flags, req_op(req), next->cmd_flags,
-				   req_op(next)))
+	if (req_op(req) != req_op(next))
 		return 0;
 
 	/*
@@ -758,8 +757,7 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (!rq_mergeable(rq) || !bio_mergeable(bio))
 		return false;
 
-	if (!blk_check_merge_flags(rq->cmd_flags, req_op(rq), bio->bi_rw,
-				   bio_op(bio)))
+	if (req_op(rq) != bio_op(bio))
 		return false;
 
 	/* different data direction or already started, don't merge */
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 56a0c37..729bac3 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -485,6 +485,32 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 }
 EXPORT_SYMBOL(blk_mq_tagset_busy_iter);
 
+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set)
+{
+	int i, j, ret = 0;
+
+	if (!set->ops->reinit_request)
+		goto out;
+
+	for (i = 0; i < set->nr_hw_queues; i++) {
+		struct blk_mq_tags *tags = set->tags[i];
+
+		for (j = 0; j < tags->nr_tags; j++) {
+			if (!tags->rqs[j])
+				continue;
+
+			ret = set->ops->reinit_request(set->driver_data,
+						tags->rqs[j]);
+			if (ret)
+				goto out;
+		}
+	}
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset);
+
 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
 		void *priv)
 {
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2a1920c..576e711 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -263,10 +263,53 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
 		blk_queue_exit(q);
 		return ERR_PTR(-EWOULDBLOCK);
 	}
+
+	rq->__data_len = 0;
+	rq->__sector = (sector_t) -1;
+	rq->bio = rq->biotail = NULL;
 	return rq;
 }
 EXPORT_SYMBOL(blk_mq_alloc_request);
 
+struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
+		unsigned int flags, unsigned int hctx_idx)
+{
+	struct blk_mq_hw_ctx *hctx;
+	struct blk_mq_ctx *ctx;
+	struct request *rq;
+	struct blk_mq_alloc_data alloc_data;
+	int ret;
+
+	/*
+	 * If the tag allocator sleeps we could get an allocation for a
+	 * different hardware context.  No need to complicate the low level
+	 * allocator for this for the rare use case of a command tied to
+	 * a specific queue.
+	 */
+	if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
+		return ERR_PTR(-EINVAL);
+
+	if (hctx_idx >= q->nr_hw_queues)
+		return ERR_PTR(-EIO);
+
+	ret = blk_queue_enter(q, true);
+	if (ret)
+		return ERR_PTR(ret);
+
+	hctx = q->queue_hw_ctx[hctx_idx];
+	ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask));
+
+	blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
+	rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
+	if (!rq) {
+		blk_queue_exit(q);
+		return ERR_PTR(-EWOULDBLOCK);
+	}
+
+	return rq;
+}
+EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
+
 static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
 				  struct blk_mq_ctx *ctx, struct request *rq)
 {
diff --git a/block/blk.h b/block/blk.h
index 70e4aee..c37492f 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -64,8 +64,6 @@ void blk_exit_rl(struct request_list *rl);
 void init_request_from_bio(struct request *req, struct bio *bio);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);
-int blk_rq_append_bio(struct request_queue *q, struct request *rq,
-		      struct bio *bio);
 void blk_queue_bypass_start(struct request_queue *q);
 void blk_queue_bypass_end(struct request_queue *q);
 void blk_dequeue_request(struct request *rq);
diff --git a/block/genhd.c b/block/genhd.c
index f06d7f3..3c9dede 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -506,7 +506,7 @@ static int exact_lock(dev_t devt, void *data)
 	return 0;
 }
 
-static void register_disk(struct gendisk *disk)
+static void register_disk(struct device *parent, struct gendisk *disk)
 {
 	struct device *ddev = disk_to_dev(disk);
 	struct block_device *bdev;
@@ -514,7 +514,7 @@ static void register_disk(struct gendisk *disk)
 	struct hd_struct *part;
 	int err;
 
-	ddev->parent = disk->driverfs_dev;
+	ddev->parent = parent;
 
 	dev_set_name(ddev, "%s", disk->disk_name);
 
@@ -573,7 +573,8 @@ exit:
 }
 
 /**
- * add_disk - add partitioning information to kernel list
+ * device_add_disk - add partitioning information to kernel list
+ * @parent: parent device for the disk
  * @disk: per-device partitioning information
  *
  * This function registers the partitioning information in @disk
@@ -581,7 +582,7 @@ exit:
  *
  * FIXME: error handling
  */
-void add_disk(struct gendisk *disk)
+void device_add_disk(struct device *parent, struct gendisk *disk)
 {
 	struct backing_dev_info *bdi;
 	dev_t devt;
@@ -617,7 +618,7 @@ void add_disk(struct gendisk *disk)
 
 	blk_register_region(disk_devt(disk), disk->minors, NULL,
 			    exact_match, exact_lock, disk);
-	register_disk(disk);
+	register_disk(parent, disk);
 	blk_register_queue(disk);
 
 	/*
@@ -633,7 +634,7 @@ void add_disk(struct gendisk *disk)
 	disk_add_events(disk);
 	blk_integrity_add(disk);
 }
-EXPORT_SYMBOL(add_disk);
+EXPORT_SYMBOL(device_add_disk);
 
 void del_gendisk(struct gendisk *disk)
 {
@@ -799,10 +800,9 @@ void __init printk_all_partitions(void)
 			       , disk_name(disk, part->partno, name_buf),
 			       part->info ? part->info->uuid : "");
 			if (is_part0) {
-				if (disk->driverfs_dev != NULL &&
-				    disk->driverfs_dev->driver != NULL)
+				if (dev->parent && dev->parent->driver)
 					printk(" driver: %s\n",
-					      disk->driverfs_dev->driver->name);
+					      dev->parent->driver->name);
 				else
 					printk(" (driver?)\n");
 			} else