Merge tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe pull requests via Keith:
      - Target support for PCI-Endpoint transport (Damien)
      - TCP IO queue spreading fixes (Sagi, Chaitanya)
      - Target handling for "limited retry" flags (Guixen)
      - Poll type fix (Yongsoo)
      - Xarray storage error handling (Keisuke)
      - Host memory buffer free size fix on error (Francis)

 - MD pull requests via Song:
      - Reintroduce md-linear (Yu Kuai)
      - md-bitmap refactor and fix (Yu Kuai)
      - Replace kmap_atomic with kmap_local_page (David Reaver)

 - Quite a few queue freeze and debugfs deadlock fixes

   Ming introduced lockdep support for this in the 6.13 kernel, and it
   has (unsurprisingly) uncovered quite a few issues

 - Use const attributes for IO schedulers

 - Remove bio ioprio wrappers

 - Fixes for stacked device atomic write support

 - Refactor queue affinity helpers, in preparation for better supporting
   isolated CPUs

 - Cleanups of loop O_DIRECT handling

 - Cleanup of BLK_MQ_F_* flags

 - Add rotational support for null_blk

 - Various fixes and cleanups

* tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux: (106 commits)
  block: Don't trim an atomic write
  block: Add common atomic writes enable flag
  md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add()
  block: limit disk max sectors to (LLONG_MAX >> 9)
  block: Change blk_stack_atomic_writes_limits() unit_min check
  block: Ensure start sector is aligned for stacking atomic writes
  blk-mq: Move more error handling into blk_mq_submit_bio()
  block: Reorder the request allocation code in blk_mq_submit_bio()
  nvme: fix bogus kzalloc() return check in nvme_init_effects_log()
  md/md-bitmap: move bitmap_{start, end}write to md upper layer
  md/raid5: implement pers->bitmap_sector()
  md: add a new callback pers->bitmap_sector()
  md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()
  md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()
  md: Replace deprecated kmap_atomic() with kmap_local_page()
  md: reintroduce md-linear
  partitions: ldm: remove the initial kernel-doc notation
  blk-cgroup: rwstat: fix kernel-doc warnings in header file
  blk-cgroup: fix kernel-doc warnings in header file
  nbd: fix partial sending
  ...

28 files changed, 442 insertions, 688 deletions

diff --git a/block/Makefile b/block/Makefile
index ddfd21c1a9ff..33748123710b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -27,8 +27,6 @@ bfq-y				:= bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
 obj-$(CONFIG_IOSCHED_BFQ)	+= bfq.o
 
 obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
-obj-$(CONFIG_BLK_MQ_PCI)	+= blk-mq-pci.o
-obj-$(CONFIG_BLK_MQ_VIRTIO)	+= blk-mq-virtio.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index cad16c163611..167542201603 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7622,7 +7622,7 @@ static ssize_t bfq_low_latency_store(struct elevator_queue *e,
 #define BFQ_ATTR(name) \
 	__ATTR(name, 0644, bfq_##name##_show, bfq_##name##_store)
 
-static struct elv_fs_entry bfq_attrs[] = {
+static const struct elv_fs_entry bfq_attrs[] = {
 	BFQ_ATTR(fifo_expire_sync),
 	BFQ_ATTR(fifo_expire_async),
 	BFQ_ATTR(back_seek_max),
diff --git a/block/bio.c b/block/bio.c
index d5bdc31d88d3..f0c416e5931d 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -946,8 +946,11 @@ static bool bvec_try_merge_page(struct bio_vec *bv, struct page *page,
 
 /*
  * Try to merge a page into a segment, while obeying the hardware segment
- * size limit.  This is not for normal read/write bios, but for passthrough
- * or Zone Append operations that we can't split.
+ * size limit.
+ *
+ * This is kept around for the integrity metadata, which is still tries
+ * to build the initial bio to the hardware limit and doesn't have proper
+ * helpers to split.  Hopefully this will go away soon.
  */
 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
 		struct page *page, unsigned len, unsigned offset,
@@ -965,106 +968,6 @@ bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
 }
 
 /**
- * bio_add_hw_page - attempt to add a page to a bio with hw constraints
- * @q: the target queue
- * @bio: destination bio
- * @page: page to add
- * @len: vec entry length
- * @offset: vec entry offset
- * @max_sectors: maximum number of sectors that can be added
- * @same_page: return if the segment has been merged inside the same page
- *
- * Add a page to a bio while respecting the hardware max_sectors, max_segment
- * and gap limitations.
- */
-int bio_add_hw_page(struct request_queue *q, struct bio *bio,
-		struct page *page, unsigned int len, unsigned int offset,
-		unsigned int max_sectors, bool *same_page)
-{
-	unsigned int max_size = max_sectors << SECTOR_SHIFT;
-
-	if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
-		return 0;
-
-	len = min3(len, max_size, queue_max_segment_size(q));
-	if (len > max_size - bio->bi_iter.bi_size)
-		return 0;
-
-	if (bio->bi_vcnt > 0) {
-		struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
-
-		if (bvec_try_merge_hw_page(q, bv, page, len, offset,
-				same_page)) {
-			bio->bi_iter.bi_size += len;
-			return len;
-		}
-
-		if (bio->bi_vcnt >=
-		    min(bio->bi_max_vecs, queue_max_segments(q)))
-			return 0;
-
-		/*
-		 * If the queue doesn't support SG gaps and adding this segment
-		 * would create a gap, disallow it.
-		 */
-		if (bvec_gap_to_prev(&q->limits, bv, offset))
-			return 0;
-	}
-
-	bvec_set_page(&bio->bi_io_vec[bio->bi_vcnt], page, len, offset);
-	bio->bi_vcnt++;
-	bio->bi_iter.bi_size += len;
-	return len;
-}
-
-/**
- * bio_add_hw_folio - attempt to add a folio to a bio with hw constraints
- * @q: the target queue
- * @bio: destination bio
- * @folio: folio to add
- * @len: vec entry length
- * @offset: vec entry offset in the folio
- * @max_sectors: maximum number of sectors that can be added
- * @same_page: return if the segment has been merged inside the same folio
- *
- * Add a folio to a bio while respecting the hardware max_sectors, max_segment
- * and gap limitations.
- */
-int bio_add_hw_folio(struct request_queue *q, struct bio *bio,
-		struct folio *folio, size_t len, size_t offset,
-		unsigned int max_sectors, bool *same_page)
-{
-	if (len > UINT_MAX || offset > UINT_MAX)
-		return 0;
-	return bio_add_hw_page(q, bio, folio_page(folio, 0), len, offset,
-			       max_sectors, same_page);
-}
-
-/**
- * bio_add_pc_page	- attempt to add page to passthrough bio
- * @q: the target queue
- * @bio: destination bio
- * @page: page to add
- * @len: vec entry length
- * @offset: vec entry offset
- *
- * Attempt to add a page to the bio_vec maplist. This can fail for a
- * number of reasons, such as the bio being full or target block device
- * limitations. The target block device must allow bio's up to PAGE_SIZE,
- * so it is always possible to add a single page to an empty bio.
- *
- * This should only be used by passthrough bios.
- */
-int bio_add_pc_page(struct request_queue *q, struct bio *bio,
-		struct page *page, unsigned int len, unsigned int offset)
-{
-	bool same_page = false;
-	return bio_add_hw_page(q, bio, page, len, offset,
-			queue_max_hw_sectors(q), &same_page);
-}
-EXPORT_SYMBOL(bio_add_pc_page);
-
-/**
  * __bio_add_page - add page(s) to a bio in a new segment
  * @bio: destination bio
  * @page: start page to add
@@ -1707,6 +1610,10 @@ EXPORT_SYMBOL(bio_split);
  */
 void bio_trim(struct bio *bio, sector_t offset, sector_t size)
 {
+	/* We should never trim an atomic write */
+	if (WARN_ON_ONCE(bio->bi_opf & REQ_ATOMIC && size))
+		return;
+
 	if (WARN_ON_ONCE(offset > BIO_MAX_SECTORS || size > BIO_MAX_SECTORS ||
 			 offset + size > bio_sectors(bio)))
 		return;
diff --git a/block/blk-cgroup-rwstat.h b/block/blk-cgroup-rwstat.h
index 022527b0b043..703a16fe1404 100644
--- a/block/blk-cgroup-rwstat.h
+++ b/block/blk-cgroup-rwstat.h
@@ -52,7 +52,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
 /**
  * blkg_rwstat_add - add a value to a blkg_rwstat
  * @rwstat: target blkg_rwstat
- * @op: REQ_OP and flags
+ * @opf: REQ_OP and flags
  * @val: value to add
  *
  * Add @val to @rwstat.  The counters are chosen according to @rw.  The
@@ -83,8 +83,9 @@ static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
 /**
  * blkg_rwstat_read - read the current values of a blkg_rwstat
  * @rwstat: blkg_rwstat to read
+ * @result: where to put the current values
  *
- * Read the current snapshot of @rwstat and return it in the aux counts.
+ * Read the current snapshot of @rwstat and return it in the @result counts.
  */
 static inline void blkg_rwstat_read(struct blkg_rwstat *rwstat,
 		struct blkg_rwstat_sample *result)
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index b9e3265c1eb3..2c4663bd993a 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -225,7 +225,9 @@ void blkg_conf_exit(struct blkg_conf_ctx *ctx);
 
 /**
  * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg
- * @return: true if this bio needs to be submitted with the root blkg context.
+ * @bio: the target &bio
+ *
+ * Return: true if this bio needs to be submitted with the root blkg context.
  *
  * In order to avoid priority inversions we sometimes need to issue a bio as if
  * it were attached to the root blkg, and then backcharge to the actual owning
@@ -245,7 +247,7 @@ static inline bool bio_issue_as_root_blkg(struct bio *bio)
  * @q: request_queue of interest
  *
  * Lookup blkg for the @blkcg - @q pair.
-
+ *
  * Must be called in a RCU critical section.
  */
 static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
@@ -268,7 +270,7 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
 }
 
 /**
- * blkg_to_pdata - get policy private data
+ * blkg_to_pd - get policy private data
  * @blkg: blkg of interest
  * @pol: policy of interest
  *
@@ -287,7 +289,7 @@ static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
 }
 
 /**
- * pdata_to_blkg - get blkg associated with policy private data
+ * pd_to_blkg - get blkg associated with policy private data
  * @pd: policy private data of interest
  *
  * @pd is policy private data.  Determine the blkg it's associated with.
diff --git a/block/blk-core.c b/block/blk-core.c
index 666efe8fa202..32fb28a6372c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -629,8 +629,14 @@ static void __submit_bio(struct bio *bio)
 		blk_mq_submit_bio(bio);
 	} else if (likely(bio_queue_enter(bio) == 0)) {
 		struct gendisk *disk = bio->bi_bdev->bd_disk;
-
-		disk->fops->submit_bio(bio);
+	
+		if ((bio->bi_opf & REQ_POLLED) &&
+		    !(disk->queue->limits.features & BLK_FEAT_POLL)) {
+			bio->bi_status = BLK_STS_NOTSUPP;
+			bio_endio(bio);
+		} else {
+			disk->fops->submit_bio(bio);
+		}
 		blk_queue_exit(disk->queue);
 	}
 
@@ -805,12 +811,6 @@ void submit_bio_noacct(struct bio *bio)
 		}
 	}
 
-	if (!(q->limits.features & BLK_FEAT_POLL) &&
-			(bio->bi_opf & REQ_POLLED)) {
-		bio_clear_polled(bio);
-		goto not_supported;
-	}
-
 	switch (bio_op(bio)) {
 	case REQ_OP_READ:
 		break;
@@ -935,7 +935,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 		return 0;
 
 	q = bdev_get_queue(bdev);
-	if (cookie == BLK_QC_T_NONE || !(q->limits.features & BLK_FEAT_POLL))
+	if (cookie == BLK_QC_T_NONE)
 		return 0;
 
 	blk_flush_plug(current->plug, false);
@@ -956,7 +956,8 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 	} else {
 		struct gendisk *disk = q->disk;
 
-		if (disk && disk->fops->poll_bio)
+		if ((q->limits.features & BLK_FEAT_POLL) && disk &&
+		    disk->fops->poll_bio)
 			ret = disk->fops->poll_bio(bio, iob, flags);
 	}
 	blk_queue_exit(q);
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index b180cac61a9d..013469faa5e7 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -218,9 +218,7 @@ static ssize_t flag_store(struct device *dev, const char *page, size_t count,
 	else
 		lim.integrity.flags |= flag;
 
-	blk_mq_freeze_queue(q);
-	err = queue_limits_commit_update(q, &lim);
-	blk_mq_unfreeze_queue(q);
+	err = queue_limits_commit_update_frozen(q, &lim);
 	if (err)
 		return err;
 	return count;
diff --git a/block/blk-map.c b/block/blk-map.c
index 894009b2d881..d2f22744b3d1 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -189,7 +189,7 @@ static int bio_copy_user_iov(struct request *rq, struct rq_map_data *map_data,
 			}
 		}
 
-		if (bio_add_pc_page(rq->q, bio, page, bytes, offset) < bytes) {
+		if (bio_add_page(bio, page, bytes, offset) < bytes) {
 			if (!map_data)
 				__free_page(page);
 			break;
@@ -272,86 +272,27 @@ static struct bio *blk_rq_map_bio_alloc(struct request *rq,
 static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
 		gfp_t gfp_mask)
 {
-	iov_iter_extraction_t extraction_flags = 0;
-	unsigned int max_sectors = queue_max_hw_sectors(rq->q);
 	unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
 	struct bio *bio;
 	int ret;
-	int j;
 
 	if (!iov_iter_count(iter))
 		return -EINVAL;
 
 	bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
-	if (bio == NULL)
+	if (!bio)
 		return -ENOMEM;
-
-	if (blk_queue_pci_p2pdma(rq->q))
-		extraction_flags |= ITER_ALLOW_P2PDMA;
-	if (iov_iter_extract_will_pin(iter))
-		bio_set_flag(bio, BIO_PAGE_PINNED);
-
-	while (iov_iter_count(iter)) {
-		struct page *stack_pages[UIO_FASTIOV];
-		struct page **pages = stack_pages;
-		ssize_t bytes;
-		size_t offs;
-		int npages;
-
-		if (nr_vecs > ARRAY_SIZE(stack_pages))
-			pages = NULL;
-
-		bytes = iov_iter_extract_pages(iter, &pages, LONG_MAX,
-					       nr_vecs, extraction_flags, &offs);
-		if (unlikely(bytes <= 0)) {
-			ret = bytes ? bytes : -EFAULT;
-			goto out_unmap;
-		}
-
-		npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
-
-		if (unlikely(offs & queue_dma_alignment(rq->q)))
-			j = 0;
-		else {
-			for (j = 0; j < npages; j++) {
-				struct page *page = pages[j];
-				unsigned int n = PAGE_SIZE - offs;
-				bool same_page = false;
-
-				if (n > bytes)
-					n = bytes;
-
-				if (!bio_add_hw_page(rq->q, bio, page, n, offs,
-						     max_sectors, &same_page))
-					break;
-
-				if (same_page)
-					bio_release_page(bio, page);
-				bytes -= n;
-				offs = 0;
-			}
-		}
-		/*
-		 * release the pages we didn't map into the bio, if any
-		 */
-		while (j < npages)
-			bio_release_page(bio, pages[j++]);
-		if (pages != stack_pages)
-			kvfree(pages);
-		/* couldn't stuff something into bio? */
-		if (bytes) {
-			iov_iter_revert(iter, bytes);
-			break;
-		}
-	}
-
+	ret = bio_iov_iter_get_pages(bio, iter);
+	if (ret)
+		goto out_put;
 	ret = blk_rq_append_bio(rq, bio);
 	if (ret)
-		goto out_unmap;
+		goto out_release;
 	return 0;
 
- out_unmap:
+out_release:
 	bio_release_pages(bio, false);
+out_put:
 	blk_mq_map_bio_put(bio);
 	return ret;
 }
@@ -422,8 +363,7 @@ static struct bio *bio_map_kern(struct request_queue *q, void *data,
 			page = virt_to_page(data);
 		else
 			page = vmalloc_to_page(data);
-		if (bio_add_pc_page(q, bio, page, bytes,
-				    offset) < bytes) {
+		if (bio_add_page(bio, page, bytes, offset) < bytes) {
 			/* we don't support partial mappings */
 			bio_uninit(bio);
 			kfree(bio);
@@ -507,7 +447,7 @@ static struct bio *bio_copy_kern(struct request_queue *q, void *data,
 		if (!reading)
 			memcpy(page_address(page), p, bytes);
 
-		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
+		if (bio_add_page(bio, page, bytes, 0) < bytes)
 			break;
 
 		len -= bytes;
@@ -536,24 +476,33 @@ cleanup:
  */
 int blk_rq_append_bio(struct request *rq, struct bio *bio)
 {
-	struct bvec_iter iter;
-	struct bio_vec bv;
+	const struct queue_limits *lim = &rq->q->limits;
+	unsigned int max_bytes = lim->max_hw_sectors << SECTOR_SHIFT;
 	unsigned int nr_segs = 0;
+	int ret;
 
-	bio_for_each_bvec(bv, bio, iter)
-		nr_segs++;
+	/* check that the data layout matches the hardware restrictions */
+	ret = bio_split_rw_at(bio, lim, &nr_segs, max_bytes);
+	if (ret) {
+		/* if we would have to split the bio, copy instead */
+		if (ret > 0)
+			ret = -EREMOTEIO;
+		return ret;
+	}
 
-	if (!rq->bio) {
-		blk_rq_bio_prep(rq, bio, nr_segs);
-	} else {
+	if (rq->bio) {
 		if (!ll_back_merge_fn(rq, bio, nr_segs))
 			return -EINVAL;
 		rq->biotail->bi_next = bio;
 		rq->biotail = bio;
-		rq->__data_len += (bio)->bi_iter.bi_size;
+		rq->__data_len += bio->bi_iter.bi_size;
 		bio_crypt_free_ctx(bio);
+		return 0;
 	}
 
+	rq->nr_phys_segments = nr_segs;
+	rq->bio = rq->biotail = bio;
+	rq->__data_len = bio->bi_iter.bi_size;
 	return 0;
 }
 EXPORT_SYMBOL(blk_rq_append_bio);
@@ -561,9 +510,7 @@ EXPORT_SYMBOL(blk_rq_append_bio);
 /* Prepare bio for passthrough IO given ITER_BVEC iter */
 static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
 {
-	const struct queue_limits *lim = &rq->q->limits;
-	unsigned int max_bytes = lim->max_hw_sectors << SECTOR_SHIFT;
-	unsigned int nsegs;
+	unsigned int max_bytes = rq->q->limits.max_hw_sectors << SECTOR_SHIFT;
 	struct bio *bio;
 	int ret;
 
@@ -576,18 +523,10 @@ static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter)
 		return -ENOMEM;
 	bio_iov_bvec_set(bio, iter);
 
-	/* check that the data layout matches the hardware restrictions */
-	ret = bio_split_rw_at(bio, lim, &nsegs, max_bytes);
-	if (ret) {
-		/* if we would have to split the bio, copy instead */
-		if (ret > 0)
-			ret = -EREMOTEIO;
+	ret = blk_rq_append_bio(rq, bio);
+	if (ret)
 		blk_mq_map_bio_put(bio);
-		return ret;
-	}
-
-	blk_rq_bio_prep(rq, bio, nsegs);
-	return 0;
+	return ret;
 }
 
 /**
@@ -644,8 +583,11 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 			ret = bio_copy_user_iov(rq, map_data, &i, gfp_mask);
 		else
 			ret = bio_map_user_iov(rq, &i, gfp_mask);
-		if (ret)
+		if (ret) {
+			if (ret == -EREMOTEIO)
+				ret = -EINVAL;
 			goto unmap_rq;
+		}
 		if (!bio)
 			bio = rq->bio;
 	} while (iov_iter_count(&i));
diff --git a/block/blk-merge.c b/block/blk-merge.c
index e01383c6e534..15cd231d560c 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -473,137 +473,100 @@ unsigned int blk_recalc_rq_segments(struct request *rq)
 	return nr_phys_segs;
 }
 
-static inline struct scatterlist *blk_next_sg(struct scatterlist **sg,
-		struct scatterlist *sglist)
-{
-	if (!*sg)
-		return sglist;
+struct phys_vec {
+	phys_addr_t	paddr;
+	u32		len;
+};
 
-	/*
-	 * If the driver previously mapped a shorter list, we could see a
-	 * termination bit prematurely unless it fully inits the sg table
-	 * on each mapping. We KNOW that there must be more entries here
-	 * or the driver would be buggy, so force clear the termination bit
-	 * to avoid doing a full sg_init_table() in drivers for each command.
-	 */
-	sg_unmark_end(*sg);
-	return sg_next(*sg);
-}
-
-static unsigned blk_bvec_map_sg(struct request_queue *q,
-		struct bio_vec *bvec, struct scatterlist *sglist,
-		struct scatterlist **sg)
+static bool blk_map_iter_next(struct request *req,
+		struct req_iterator *iter, struct phys_vec *vec)
 {
-	unsigned nbytes = bvec->bv_len;
-	unsigned nsegs = 0, total = 0;
-
-	while (nbytes > 0) {
-		unsigned offset = bvec->bv_offset + total;
-		unsigned len = get_max_segment_size(&q->limits,
-				bvec_phys(bvec) + total, nbytes);
-		struct page *page = bvec->bv_page;
-
-		/*
-		 * Unfortunately a fair number of drivers barf on scatterlists
-		 * that have an offset larger than PAGE_SIZE, despite other
-		 * subsystems dealing with that invariant just fine.  For now
-		 * stick to the legacy format where we never present those from
-		 * the block layer, but the code below should be removed once
-		 * these offenders (mostly MMC/SD drivers) are fixed.
-		 */
-		page += (offset >> PAGE_SHIFT);
-		offset &= ~PAGE_MASK;
-
-		*sg = blk_next_sg(sg, sglist);
-		sg_set_page(*sg, page, len, offset);
+	unsigned int max_size;
+	struct bio_vec bv;
 
-		total += len;
-		nbytes -= len;
-		nsegs++;
+	if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
+		if (!iter->bio)
+			return false;
+		vec->paddr = bvec_phys(&req->special_vec);
+		vec->len = req->special_vec.bv_len;
+		iter->bio = NULL;
+		return true;
 	}
 
-	return nsegs;
-}
-
-static inline int __blk_bvec_map_sg(struct bio_vec bv,
-		struct scatterlist *sglist, struct scatterlist **sg)
-{
-	*sg = blk_next_sg(sg, sglist);
-	sg_set_page(*sg, bv.bv_page, bv.bv_len, bv.bv_offset);
-	return 1;
-}
-
-/* only try to merge bvecs into one sg if they are from two bios */
-static inline bool
-__blk_segment_map_sg_merge(struct request_queue *q, struct bio_vec *bvec,
-			   struct bio_vec *bvprv, struct scatterlist **sg)
-{
-
-	int nbytes = bvec->bv_len;
-
-	if (!*sg)
+	if (!iter->iter.bi_size)
 		return false;
 
-	if ((*sg)->length + nbytes > queue_max_segment_size(q))
-		return false;
+	bv = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
+	vec->paddr = bvec_phys(&bv);
+	max_size = get_max_segment_size(&req->q->limits, vec->paddr, UINT_MAX);
+	bv.bv_len = min(bv.bv_len, max_size);
+	bio_advance_iter_single(iter->bio, &iter->iter, bv.bv_len);
 
-	if (!biovec_phys_mergeable(q, bvprv, bvec))
-		return false;
+	/*
+	 * If we are entirely done with this bi_io_vec entry, check if the next
+	 * one could be merged into it.  This typically happens when moving to
+	 * the next bio, but some callers also don't pack bvecs tight.
+	 */
+	while (!iter->iter.bi_size || !iter->iter.bi_bvec_done) {
+		struct bio_vec next;
+
+		if (!iter->iter.bi_size) {
+			if (!iter->bio->bi_next)
+				break;
+			iter->bio = iter->bio->bi_next;
+			iter->iter = iter->bio->bi_iter;
+		}
 
-	(*sg)->length += nbytes;
+		next = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
+		if (bv.bv_len + next.bv_len > max_size ||
+		    !biovec_phys_mergeable(req->q, &bv, &next))
+			break;
+
+		bv.bv_len += next.bv_len;
+		bio_advance_iter_single(iter->bio, &iter->iter, next.bv_len);
+	}
 
+	vec->len = bv.bv_len;
 	return true;
 }
 
-static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio,
-			     struct scatterlist *sglist,
-			     struct scatterlist **sg)
+static inline struct scatterlist *blk_next_sg(struct scatterlist **sg,
+		struct scatterlist *sglist)
 {
-	struct bio_vec bvec, bvprv = { NULL };
-	struct bvec_iter iter;
-	int nsegs = 0;
-	bool new_bio = false;
-
-	for_each_bio(bio) {
-		bio_for_each_bvec(bvec, bio, iter) {
-			/*
-			 * Only try to merge bvecs from two bios given we
-			 * have done bio internal merge when adding pages
-			 * to bio
-			 */
-			if (new_bio &&
-			    __blk_segment_map_sg_merge(q, &bvec, &bvprv, sg))
-				goto next_bvec;
-
-			if (bvec.bv_offset + bvec.bv_len <= PAGE_SIZE)
-				nsegs += __blk_bvec_map_sg(bvec, sglist, sg);
-			else
-				nsegs += blk_bvec_map_sg(q, &bvec, sglist, sg);
- next_bvec:
-			new_bio = false;
-		}
-		if (likely(bio->bi_iter.bi_size)) {
-			bvprv = bvec;
-			new_bio = true;
-		}
-	}
+	if (!*sg)
+		return sglist;
 
-	return nsegs;
+	/*
+	 * If the driver previously mapped a shorter list, we could see a
+	 * termination bit prematurely unless it fully inits the sg table
+	 * on each mapping. We KNOW that there must be more entries here
+	 * or the driver would be buggy, so force clear the termination bit
+	 * to avoid doing a full sg_init_table() in drivers for each command.
+	 */
+	sg_unmark_end(*sg);
+	return sg_next(*sg);
 }
 
 /*
- * map a request to scatterlist, return number of sg entries setup. Caller
- * must make sure sg can hold rq->nr_phys_segments entries
+ * Map a request to scatterlist, return number of sg entries setup. Caller
+ * must make sure sg can hold rq->nr_phys_segments entries.
  */
 int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
 		struct scatterlist *sglist, struct scatterlist **last_sg)
 {
+	struct req_iterator iter = {
+		.bio	= rq->bio,
+		.iter	= rq->bio->bi_iter,
+	};
+	struct phys_vec vec;
 	int nsegs = 0;
 
-	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
-		nsegs = __blk_bvec_map_sg(rq->special_vec, sglist, last_sg);
-	else if (rq->bio)
-		nsegs = __blk_bios_map_sg(q, rq->bio, sglist, last_sg);
+	while (blk_map_iter_next(rq, &iter, &vec)) {
+		*last_sg = blk_next_sg(last_sg, sglist);
+		sg_set_page(*last_sg, phys_to_page(vec.paddr), vec.len,
+				offset_in_page(vec.paddr));
+		nsegs++;
+	}
 
 	if (*last_sg)
 		sg_mark_end(*last_sg);
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c
index 9638b25fd521..ad8d6a363f24 100644
--- a/block/blk-mq-cpumap.c
+++ b/block/blk-mq-cpumap.c
@@ -11,6 +11,7 @@
 #include <linux/smp.h>
 #include <linux/cpu.h>
 #include <linux/group_cpus.h>
+#include <linux/device/bus.h>
 
 #include "blk.h"
 #include "blk-mq.h"
@@ -54,3 +55,39 @@ int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)
 
 	return NUMA_NO_NODE;
 }
+
+/**
+ * blk_mq_map_hw_queues - Create CPU to hardware queue mapping
+ * @qmap:	CPU to hardware queue map
+ * @dev:	The device to map queues
+ * @offset:	Queue offset to use for the device
+ *
+ * Create a CPU to hardware queue mapping in @qmap. The struct bus_type
+ * irq_get_affinity callback will be used to retrieve the affinity.
+ */
+void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap,
+			  struct device *dev, unsigned int offset)
+
+{
+	const struct cpumask *mask;
+	unsigned int queue, cpu;
+
+	if (!dev->bus->irq_get_affinity)
+		goto fallback;
+
+	for (queue = 0; queue < qmap->nr_queues; queue++) {
+		mask = dev->bus->irq_get_affinity(dev, queue + offset);
+		if (!mask)
+			goto fallback;
+
+		for_each_cpu(cpu, mask)
+			qmap->mq_map[cpu] = qmap->queue_offset + queue;
+	}
+
+	return;
+
+fallback:
+	WARN_ON_ONCE(qmap->nr_queues > 1);
+	blk_mq_clear_mq_map(qmap);
+}
+EXPORT_SYMBOL_GPL(blk_mq_map_hw_queues);
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 5463697a8442..adf5f0697b6b 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -172,21 +172,13 @@ static int hctx_state_show(void *data, struct seq_file *m)
 	return 0;
 }
 
-#define BLK_TAG_ALLOC_NAME(name) [BLK_TAG_ALLOC_##name] = #name
-static const char *const alloc_policy_name[] = {
-	BLK_TAG_ALLOC_NAME(FIFO),
-	BLK_TAG_ALLOC_NAME(RR),
-};
-#undef BLK_TAG_ALLOC_NAME
-
 #define HCTX_FLAG_NAME(name) [ilog2(BLK_MQ_F_##name)] = #name
 static const char *const hctx_flag_name[] = {
-	HCTX_FLAG_NAME(SHOULD_MERGE),
 	HCTX_FLAG_NAME(TAG_QUEUE_SHARED),
 	HCTX_FLAG_NAME(STACKING),
 	HCTX_FLAG_NAME(TAG_HCTX_SHARED),
 	HCTX_FLAG_NAME(BLOCKING),
-	HCTX_FLAG_NAME(NO_SCHED),
+	HCTX_FLAG_NAME(TAG_RR),
 	HCTX_FLAG_NAME(NO_SCHED_BY_DEFAULT),
 };
 #undef HCTX_FLAG_NAME
@@ -194,22 +186,11 @@ static const char *const hctx_flag_name[] = {
 static int hctx_flags_show(void *data, struct seq_file *m)
 {
 	struct blk_mq_hw_ctx *hctx = data;
-	const int alloc_policy = BLK_MQ_FLAG_TO_ALLOC_POLICY(hctx->flags);
 
-	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) !=
-			BLK_MQ_F_ALLOC_POLICY_START_BIT);
-	BUILD_BUG_ON(ARRAY_SIZE(alloc_policy_name) != BLK_TAG_ALLOC_MAX);
+	BUILD_BUG_ON(ARRAY_SIZE(hctx_flag_name) != ilog2(BLK_MQ_F_MAX));
 
-	seq_puts(m, "alloc_policy=");
-	if (alloc_policy < ARRAY_SIZE(alloc_policy_name) &&
-	    alloc_policy_name[alloc_policy])
-		seq_puts(m, alloc_policy_name[alloc_policy]);
-	else
-		seq_printf(m, "%d", alloc_policy);
-	seq_puts(m, " ");
-	blk_flags_show(m,
-		       hctx->flags ^ BLK_ALLOC_POLICY_TO_MQ_FLAG(alloc_policy),
-		       hctx_flag_name, ARRAY_SIZE(hctx_flag_name));
+	blk_flags_show(m, hctx->flags, hctx_flag_name,
+			ARRAY_SIZE(hctx_flag_name));
 	seq_puts(m, "\n");
 	return 0;
 }
diff --git a/block/blk-mq-pci.c b/block/blk-mq-pci.c
deleted file mode 100644
index d47b5c73c9eb..000000000000
--- a/block/blk-mq-pci.c
+++ /dev/null
@@ -1,46 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2016 Christoph Hellwig.
- */
-#include <linux/kobject.h>
-#include <linux/blkdev.h>
-#include <linux/blk-mq-pci.h>
-#include <linux/pci.h>
-#include <linux/module.h>
-
-#include "blk-mq.h"
-
-/**
- * blk_mq_pci_map_queues - provide a default queue mapping for PCI device
- * @qmap:	CPU to hardware queue map.
- * @pdev:	PCI device associated with @set.
- * @offset:	Offset to use for the pci irq vector
- *
- * This function assumes the PCI device @pdev has at least as many available
- * interrupt vectors as @set has queues.  It will then query the vector
- * corresponding to each queue for it's affinity mask and built queue mapping
- * that maps a queue to the CPUs that have irq affinity for the corresponding
- * vector.
- */
-void blk_mq_pci_map_queues(struct blk_mq_queue_map *qmap, struct pci_dev *pdev,
-			   int offset)
-{
-	const struct cpumask *mask;
-	unsigned int queue, cpu;
-
-	for (queue = 0; queue < qmap->nr_queues; queue++) {
-		mask = pci_irq_get_affinity(pdev, queue + offset);
-		if (!mask)
-			goto fallback;
-
-		for_each_cpu(cpu, mask)
-			qmap->mq_map[cpu] = qmap->queue_offset + queue;
-	}
-
-	return;
-
-fallback:
-	WARN_ON_ONCE(qmap->nr_queues > 1);
-	blk_mq_clear_mq_map(qmap);
-}
-EXPORT_SYMBOL_GPL(blk_mq_pci_map_queues);
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 451a2c1f1f32..7442ca27c2bf 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -351,8 +351,7 @@ bool blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
 	ctx = blk_mq_get_ctx(q);
 	hctx = blk_mq_map_queue(q, bio->bi_opf, ctx);
 	type = hctx->type;
-	if (!(hctx->flags & BLK_MQ_F_SHOULD_MERGE) ||
-	    list_empty_careful(&ctx->rq_lists[type]))
+	if (list_empty_careful(&ctx->rq_lists[type]))
 		goto out_put;
 
 	/* default per sw-queue merge */
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 2cafcf11ee8b..b9f417d980b4 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -544,30 +544,11 @@ static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
 				       node);
 }
 
-int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
-			struct sbitmap_queue *breserved_tags,
-			unsigned int queue_depth, unsigned int reserved,
-			int node, int alloc_policy)
-{
-	unsigned int depth = queue_depth - reserved;
-	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
-
-	if (bt_alloc(bitmap_tags, depth, round_robin, node))
-		return -ENOMEM;
-	if (bt_alloc(breserved_tags, reserved, round_robin, node))
-		goto free_bitmap_tags;
-
-	return 0;
-
-free_bitmap_tags:
-	sbitmap_queue_free(bitmap_tags);
-	return -ENOMEM;
-}
-
 struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
-				     unsigned int reserved_tags,
-				     int node, int alloc_policy)
+		unsigned int reserved_tags, unsigned int flags, int node)
 {
+	unsigned int depth = total_tags - reserved_tags;
+	bool round_robin = flags & BLK_MQ_F_TAG_RR;
 	struct blk_mq_tags *tags;
 
 	if (total_tags > BLK_MQ_TAG_MAX) {
@@ -582,14 +563,18 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
 	tags->nr_tags = total_tags;
 	tags->nr_reserved_tags = reserved_tags;
 	spin_lock_init(&tags->lock);
+	if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
+		goto out_free_tags;
+	if (bt_alloc(&tags->breserved_tags, reserved_tags, round_robin, node))
+		goto out_free_bitmap_tags;
 
-	if (blk_mq_init_bitmaps(&tags->bitmap_tags, &tags->breserved_tags,
-				total_tags, reserved_tags, node,
-				alloc_policy) < 0) {
-		kfree(tags);
-		return NULL;
-	}
 	return tags;
+
+out_free_bitmap_tags:
+	sbitmap_queue_free(&tags->bitmap_tags);
+out_free_tags:
+	kfree(tags);
+	return NULL;
 }
 
 void blk_mq_free_tags(struct blk_mq_tags *tags)
diff --git a/block/blk-mq-virtio.c b/block/blk-mq-virtio.c
deleted file mode 100644
index 68d0945c0b08..000000000000
--- a/block/blk-mq-virtio.c
+++ /dev/null
@@ -1,46 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (c) 2016 Christoph Hellwig.
- */
-#include <linux/device.h>
-#include <linux/blk-mq-virtio.h>
-#include <linux/virtio_config.h>
-#include <linux/module.h>
-#include "blk-mq.h"
-
-/**
- * blk_mq_virtio_map_queues - provide a default queue mapping for virtio device
- * @qmap:	CPU to hardware queue map.
- * @vdev:	virtio device to provide a mapping for.
- * @first_vec:	first interrupt vectors to use for queues (usually 0)
- *
- * This function assumes the virtio device @vdev has at least as many available
- * interrupt vectors as @set has queues.  It will then query the vector
- * corresponding to each queue for it's affinity mask and built queue mapping
- * that maps a queue to the CPUs that have irq affinity for the corresponding
- * vector.
- */
-void blk_mq_virtio_map_queues(struct blk_mq_queue_map *qmap,
-		struct virtio_device *vdev, int first_vec)
-{
-	const struct cpumask *mask;
-	unsigned int queue, cpu;
-
-	if (!vdev->config->get_vq_affinity)
-		goto fallback;
-
-	for (queue = 0; queue < qmap->nr_queues; queue++) {
-		mask = vdev->config->get_vq_affinity(vdev, first_vec + queue);
-		if (!mask)
-			goto fallback;
-
-		for_each_cpu(cpu, mask)
-			qmap->mq_map[cpu] = qmap->queue_offset + queue;
-	}
-
-	return;
-
-fallback:
-	blk_mq_map_queues(qmap);
-}
-EXPORT_SYMBOL_GPL(blk_mq_virtio_map_queues);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8ac19d4ae3c0..da39a1cac702 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -131,6 +131,10 @@ static bool blk_freeze_set_owner(struct request_queue *q,
 	if (!q->mq_freeze_depth) {
 		q->mq_freeze_owner = owner;
 		q->mq_freeze_owner_depth = 1;
+		q->mq_freeze_disk_dead = !q->disk ||
+			test_bit(GD_DEAD, &q->disk->state) ||
+			!blk_queue_registered(q);
+		q->mq_freeze_queue_dying = blk_queue_dying(q);
 		return true;
 	}
 
@@ -142,8 +146,6 @@ static bool blk_freeze_set_owner(struct request_queue *q,
 /* verify the last unfreeze in owner context */
 static bool blk_unfreeze_check_owner(struct request_queue *q)
 {
-	if (!q->mq_freeze_owner)
-		return false;
 	if (q->mq_freeze_owner != current)
 		return false;
 	if (--q->mq_freeze_owner_depth == 0) {
@@ -189,7 +191,7 @@ bool __blk_freeze_queue_start(struct request_queue *q,
 void blk_freeze_queue_start(struct request_queue *q)
 {
 	if (__blk_freeze_queue_start(q, current))
-		blk_freeze_acquire_lock(q, false, false);
+		blk_freeze_acquire_lock(q);
 }
 EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
 
@@ -237,7 +239,7 @@ bool __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic)
 void blk_mq_unfreeze_queue(struct request_queue *q)
 {
 	if (__blk_mq_unfreeze_queue(q, false))
-		blk_unfreeze_release_lock(q, false, false);
+		blk_unfreeze_release_lock(q);
 }
 EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
 
@@ -2656,8 +2658,10 @@ static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 	if (bio->bi_opf & REQ_RAHEAD)
 		rq->cmd_flags |= REQ_FAILFAST_MASK;
 
+	rq->bio = rq->biotail = bio;
 	rq->__sector = bio->bi_iter.bi_sector;
-	blk_rq_bio_prep(rq, bio, nr_segs);
+	rq->__data_len = bio->bi_iter.bi_size;
+	rq->nr_phys_segments = nr_segs;
 	if (bio_integrity(bio))
 		rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q,
 								      bio);
@@ -2980,12 +2984,9 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
 	}
 
 	rq = __blk_mq_alloc_requests(&data);
-	if (rq)
-		return rq;
-	rq_qos_cleanup(q, bio);
-	if (bio->bi_opf & REQ_NOWAIT)
-		bio_wouldblock_error(bio);
-	return NULL;
+	if (unlikely(!rq))
+		rq_qos_cleanup(q, bio);
+	return rq;
 }
 
 /*
@@ -3092,14 +3093,21 @@ void blk_mq_submit_bio(struct bio *bio)
 	}
 
 	/*
-	 * Device reconfiguration may change logical block size, so alignment
-	 * check has to be done with queue usage counter held
+	 * Device reconfiguration may change logical block size or reduce the
+	 * number of poll queues, so the checks for alignment and poll support
+	 * have to be done with queue usage counter held.
 	 */
 	if (unlikely(bio_unaligned(bio, q))) {
 		bio_io_error(bio);
 		goto queue_exit;
 	}
 
+	if ((bio->bi_opf & REQ_POLLED) && !blk_mq_can_poll(q)) {
+		bio->bi_status = BLK_STS_NOTSUPP;
+		bio_endio(bio);
+		goto queue_exit;
+	}
+
 	bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
 	if (!bio)
 		goto queue_exit;
@@ -3114,12 +3122,15 @@ void blk_mq_submit_bio(struct bio *bio)
 		goto queue_exit;
 
 new_request:
-	if (!rq) {
+	if (rq) {
+		blk_mq_use_cached_rq(rq, plug, bio);
+	} else {
 		rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
-		if (unlikely(!rq))
+		if (unlikely(!rq)) {
+			if (bio->bi_opf & REQ_NOWAIT)
+				bio_wouldblock_error(bio);
 			goto queue_exit;
-	} else {
-		blk_mq_use_cached_rq(rq, plug, bio);
+		}
 	}
 
 	trace_block_getrq(bio);
@@ -3472,8 +3483,7 @@ static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
 	if (node == NUMA_NO_NODE)
 		node = set->numa_node;
 
-	tags = blk_mq_init_tags(nr_tags, reserved_tags, node,
-				BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
+	tags = blk_mq_init_tags(nr_tags, reserved_tags, set->flags, node);
 	if (!tags)
 		return NULL;
 
@@ -4317,12 +4327,6 @@ void blk_mq_release(struct request_queue *q)
 	blk_mq_sysfs_deinit(q);
 }
 
-static bool blk_mq_can_poll(struct blk_mq_tag_set *set)
-{
-	return set->nr_maps > HCTX_TYPE_POLL &&
-		set->map[HCTX_TYPE_POLL].nr_queues;
-}
-
 struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,
 		struct queue_limits *lim, void *queuedata)
 {
@@ -4333,7 +4337,7 @@ struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,
 	if (!lim)
 		lim = &default_lim;
 	lim->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT;
-	if (blk_mq_can_poll(set))
+	if (set->nr_maps > HCTX_TYPE_POLL)
 		lim->features |= BLK_FEAT_POLL;
 
 	q = blk_alloc_queue(lim, set->numa_node);
@@ -5021,8 +5025,6 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
 fallback:
 	blk_mq_update_queue_map(set);
 	list_for_each_entry(q, &set->tag_list, tag_set_list) {
-		struct queue_limits lim;
-
 		blk_mq_realloc_hw_ctxs(set, q);
 
 		if (q->nr_hw_queues != set->nr_hw_queues) {
@@ -5036,13 +5038,6 @@ fallback:
 			set->nr_hw_queues = prev_nr_hw_queues;
 			goto fallback;
 		}
-		lim = queue_limits_start_update(q);
-		if (blk_mq_can_poll(set))
-			lim.features |= BLK_FEAT_POLL;
-		else
-			lim.features &= ~BLK_FEAT_POLL;
-		if (queue_limits_commit_update(q, &lim) < 0)
-			pr_warn("updating the poll flag failed\n");
 		blk_mq_map_swqueue(q);
 	}
 
@@ -5102,9 +5097,9 @@ static int blk_hctx_poll(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
 int blk_mq_poll(struct request_queue *q, blk_qc_t cookie,
 		struct io_comp_batch *iob, unsigned int flags)
 {
-	struct blk_mq_hw_ctx *hctx = xa_load(&q->hctx_table, cookie);
-
-	return blk_hctx_poll(q, hctx, iob, flags);
+	if (!blk_mq_can_poll(q))
+		return 0;
+	return blk_hctx_poll(q, xa_load(&q->hctx_table, cookie), iob, flags);
 }
 
 int blk_rq_poll(struct request *rq, struct io_comp_batch *iob,
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 89a20fffa4b1..44979e92b79f 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -163,11 +163,8 @@ struct blk_mq_alloc_data {
 };
 
 struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags,
-		unsigned int reserved_tags, int node, int alloc_policy);
+		unsigned int reserved_tags, unsigned int flags, int node);
 void blk_mq_free_tags(struct blk_mq_tags *tags);
-int blk_mq_init_bitmaps(struct sbitmap_queue *bitmap_tags,
-		struct sbitmap_queue *breserved_tags, unsigned int queue_depth,
-		unsigned int reserved, int node, int alloc_policy);
 
 unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
 unsigned long blk_mq_get_tags(struct blk_mq_alloc_data *data, int nr_tags,
@@ -451,4 +448,10 @@ do {								\
 #define blk_mq_run_dispatch_ops(q, dispatch_ops)		\
 	__blk_mq_run_dispatch_ops(q, true, dispatch_ops)	\
 
+static inline bool blk_mq_can_poll(struct request_queue *q)
+{
+	return (q->limits.features & BLK_FEAT_POLL) &&
+		q->tag_set->map[HCTX_TYPE_POLL].nr_queues;
+}
+
 #endif
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 8f09e33f41f6..db12396ff5c7 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -175,6 +175,9 @@ static void blk_validate_atomic_write_limits(struct queue_limits *lim)
 {
 	unsigned int boundary_sectors;
 
+	if (!(lim->features & BLK_FEAT_ATOMIC_WRITES))
+		goto unsupported;
+
 	if (!lim->atomic_write_hw_max)
 		goto unsupported;
 
@@ -413,7 +416,8 @@ int blk_set_default_limits(struct queue_limits *lim)
  * @lim:	limits to apply
  *
  * Apply the limits in @lim that were obtained from queue_limits_start_update()
- * and updated by the caller to @q.
+ * and updated by the caller to @q.  The caller must have frozen the queue or
+ * ensure that there are no outstanding I/Os by other means.
  *
  * Returns 0 if successful, else a negative error code.
  */
@@ -444,6 +448,30 @@ out_unlock:
 EXPORT_SYMBOL_GPL(queue_limits_commit_update);
 
 /**
+ * queue_limits_commit_update_frozen - commit an atomic update of queue limits
+ * @q:		queue to update
+ * @lim:	limits to apply
+ *
+ * Apply the limits in @lim that were obtained from queue_limits_start_update()
+ * and updated with the new values by the caller to @q.  Freezes the queue
+ * before the update and unfreezes it after.
+ *
+ * Returns 0 if successful, else a negative error code.
+ */
+int queue_limits_commit_update_frozen(struct request_queue *q,
+		struct queue_limits *lim)
+{
+	int ret;
+
+	blk_mq_freeze_queue(q);
+	ret = queue_limits_commit_update(q, lim);
+	blk_mq_unfreeze_queue(q);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(queue_limits_commit_update_frozen);
+
+/**
  * queue_limits_set - apply queue limits to queue
  * @q:		queue to update
  * @lim:	limits to apply
@@ -584,12 +612,15 @@ static bool blk_stack_atomic_writes_head(struct queue_limits *t,
 }
 
 static void blk_stack_atomic_writes_limits(struct queue_limits *t,
-				struct queue_limits *b)
+				struct queue_limits *b, sector_t start)
 {
-	if (!(t->features & BLK_FEAT_ATOMIC_WRITES_STACKED))
+	if (!(b->features & BLK_FEAT_ATOMIC_WRITES))
+		goto unsupported;
+
+	if (!b->atomic_write_hw_unit_min)
 		goto unsupported;
 
-	if (!b->atomic_write_unit_min)
+	if (!blk_atomic_write_start_sect_aligned(start, b))
 		goto unsupported;
 
 	/*
@@ -611,7 +642,6 @@ unsupported:
 	t->atomic_write_hw_unit_max = 0;
 	t->atomic_write_hw_unit_min = 0;
 	t->atomic_write_hw_boundary = 0;
-	t->features &= ~BLK_FEAT_ATOMIC_WRITES_STACKED;
 }
 
 /**
@@ -774,7 +804,7 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
 		t->zone_write_granularity = 0;
 		t->max_zone_append_sectors = 0;
 	}
-	blk_stack_atomic_writes_limits(t, b);
+	blk_stack_atomic_writes_limits(t, b, start);
 
 	return ret;
 }
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 767598e719ab..e09b455874bf 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -24,6 +24,8 @@ struct queue_sysfs_entry {
 	struct attribute attr;
 	ssize_t (*show)(struct gendisk *disk, char *page);
 	ssize_t (*store)(struct gendisk *disk, const char *page, size_t count);
+	int (*store_limit)(struct gendisk *disk, const char *page,
+			size_t count, struct queue_limits *lim);
 	void (*load_module)(struct gendisk *disk, const char *page, size_t count);
 };
 
@@ -153,13 +155,11 @@ QUEUE_SYSFS_SHOW_CONST(discard_zeroes_data, 0)
 QUEUE_SYSFS_SHOW_CONST(write_same_max, 0)
 QUEUE_SYSFS_SHOW_CONST(poll_delay, -1)
 
-static ssize_t queue_max_discard_sectors_store(struct gendisk *disk,
-		const char *page, size_t count)
+static int queue_max_discard_sectors_store(struct gendisk *disk,
+		const char *page, size_t count, struct queue_limits *lim)
 {
 	unsigned long max_discard_bytes;
-	struct queue_limits lim;
 	ssize_t ret;
-	int err;
 
 	ret = queue_var_store(&max_discard_bytes, page, count);
 	if (ret < 0)
@@ -171,38 +171,28 @@ static ssize_t queue_max_discard_sectors_store(struct gendisk *disk,
 	if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
 		return -EINVAL;
 
-	lim = queue_limits_start_update(disk->queue);
-	lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
-	err = queue_limits_commit_update(disk->queue, &lim);
-	if (err)
-		return err;
-	return ret;
+	lim->max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
+	return 0;
 }
 
-static ssize_t
-queue_max_sectors_store(struct gendisk *disk, const char *page, size_t count)
+static int
+queue_max_sectors_store(struct gendisk *disk, const char *page, size_t count,
+		struct queue_limits *lim)
 {
 	unsigned long max_sectors_kb;
-	struct queue_limits lim;
 	ssize_t ret;
-	int err;
 
 	ret = queue_var_store(&max_sectors_kb, page, count);
 	if (ret < 0)
 		return ret;
 
-	lim = queue_limits_start_update(disk->queue);
-	lim.max_user_sectors = max_sectors_kb << 1;
-	err = queue_limits_commit_update(disk->queue, &lim);
-	if (err)
-		return err;
-	return ret;
+	lim->max_user_sectors = max_sectors_kb << 1;
+	return 0;
 }
 
 static ssize_t queue_feature_store(struct gendisk *disk, const char *page,
-		size_t count, blk_features_t feature)
+		size_t count, struct queue_limits *lim, blk_features_t feature)
 {
-	struct queue_limits lim;
 	unsigned long val;
 	ssize_t ret;
 
@@ -210,15 +200,11 @@ static ssize_t queue_feature_store(struct gendisk *disk, const char *page,
 	if (ret < 0)
 		return ret;
 
-	lim = queue_limits_start_update(disk->queue);
 	if (val)
-		lim.features |= feature;
+		lim->features |= feature;
 	else
-		lim.features &= ~feature;
-	ret = queue_limits_commit_update(disk->queue, &lim);
-	if (ret)
-		return ret;
-	return count;
+		lim->features &= ~feature;
+	return 0;
 }
 
 #define QUEUE_SYSFS_FEATURE(_name, _feature)				\
@@ -227,10 +213,10 @@ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page)	\
 	return sysfs_emit(page, "%u\n",					\
 		!!(disk->queue->limits.features & _feature));		\
 }									\
-static ssize_t queue_##_name##_store(struct gendisk *disk,		\
-		const char *page, size_t count)				\
+static int queue_##_name##_store(struct gendisk *disk,			\
+		const char *page, size_t count, struct queue_limits *lim) \
 {									\
-	return queue_feature_store(disk, page, count, _feature);	\
+	return queue_feature_store(disk, page, count, lim, _feature);	\
 }
 
 QUEUE_SYSFS_FEATURE(rotational, BLK_FEAT_ROTATIONAL)
@@ -245,10 +231,17 @@ static ssize_t queue_##_name##_show(struct gendisk *disk, char *page)	\
 		!!(disk->queue->limits.features & _feature));		\
 }
 
-QUEUE_SYSFS_FEATURE_SHOW(poll, BLK_FEAT_POLL);
 QUEUE_SYSFS_FEATURE_SHOW(fua, BLK_FEAT_FUA);
 QUEUE_SYSFS_FEATURE_SHOW(dax, BLK_FEAT_DAX);
 
+static ssize_t queue_poll_show(struct gendisk *disk, char *page)
+{
+	if (queue_is_mq(disk->queue))
+		return sysfs_emit(page, "%u\n", blk_mq_can_poll(disk->queue));
+	return sysfs_emit(page, "%u\n",
+		!!(disk->queue->limits.features & BLK_FEAT_POLL));
+}
+
 static ssize_t queue_zoned_show(struct gendisk *disk, char *page)
 {
 	if (blk_queue_is_zoned(disk->queue))
@@ -266,10 +259,9 @@ static ssize_t queue_iostats_passthrough_show(struct gendisk *disk, char *page)
 	return queue_var_show(!!blk_queue_passthrough_stat(disk->queue), page);
 }
 
-static ssize_t queue_iostats_passthrough_store(struct gendisk *disk,
-					       const char *page, size_t count)
+static int queue_iostats_passthrough_store(struct gendisk *disk,
+		const char *page, size_t count, struct queue_limits *lim)
 {
-	struct queue_limits lim;
 	unsigned long ios;
 	ssize_t ret;
 
@@ -277,18 +269,13 @@ static ssize_t queue_iostats_passthrough_store(struct gendisk *disk,
 	if (ret < 0)
 		return ret;
 
-	lim = queue_limits_start_update(disk->queue);
 	if (ios)
-		lim.flags |= BLK_FLAG_IOSTATS_PASSTHROUGH;
+		lim->flags |= BLK_FLAG_IOSTATS_PASSTHROUGH;
 	else
-		lim.flags &= ~BLK_FLAG_IOSTATS_PASSTHROUGH;
-
-	ret = queue_limits_commit_update(disk->queue, &lim);
-	if (ret)
-		return ret;
-
-	return count;
+		lim->flags &= ~BLK_FLAG_IOSTATS_PASSTHROUGH;
+	return 0;
 }
+
 static ssize_t queue_nomerges_show(struct gendisk *disk, char *page)
 {
 	return queue_var_show((blk_queue_nomerges(disk->queue) << 1) |
@@ -391,12 +378,10 @@ static ssize_t queue_wc_show(struct gendisk *disk, char *page)
 	return sysfs_emit(page, "write through\n");
 }
 
-static ssize_t queue_wc_store(struct gendisk *disk, const char *page,
-			      size_t count)
+static int queue_wc_store(struct gendisk *disk, const char *page,
+		size_t count, struct queue_limits *lim)
 {
-	struct queue_limits lim;
 	bool disable;
-	int err;
 
 	if (!strncmp(page, "write back", 10)) {
 		disable = false;
@@ -407,15 +392,11 @@ static ssize_t queue_wc_store(struct gendisk *disk, const char *page,
 		return -EINVAL;
 	}
 
-	lim = queue_limits_start_update(disk->queue);
 	if (disable)
-		lim.flags |= BLK_FLAG_WRITE_CACHE_DISABLED;
+		lim->flags |= BLK_FLAG_WRITE_CACHE_DISABLED;
 	else
-		lim.flags &= ~BLK_FLAG_WRITE_CACHE_DISABLED;
-	err = queue_limits_commit_update(disk->queue, &lim);
-	if (err)
-		return err;
-	return count;
+		lim->flags &= ~BLK_FLAG_WRITE_CACHE_DISABLED;
+	return 0;
 }
 
 #define QUEUE_RO_ENTRY(_prefix, _name)			\
@@ -431,6 +412,13 @@ static struct queue_sysfs_entry _prefix##_entry = {	\
 	.store	= _prefix##_store,			\
 };
 
+#define QUEUE_LIM_RW_ENTRY(_prefix, _name)			\
+static struct queue_sysfs_entry _prefix##_entry = {	\
+	.attr		= { .name = _name, .mode = 0644 },	\
+	.show		= _prefix##_show,			\
+	.store_limit	= _prefix##_store,			\
+}
+
 #define QUEUE_RW_LOAD_MODULE_ENTRY(_prefix, _name)		\
 static struct queue_sysfs_entry _prefix##_entry = {		\
 	.attr		= { .name = _name, .mode = 0644 },	\
@@ -441,7 +429,7 @@ static struct queue_sysfs_entry _prefix##_entry = {		\
 
 QUEUE_RW_ENTRY(queue_requests, "nr_requests");
 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
-QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
+QUEUE_LIM_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
 QUEUE_RO_ENTRY(queue_max_segments, "max_segments");
 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
@@ -457,7 +445,7 @@ QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size");
 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity");
 QUEUE_RO_ENTRY(queue_max_hw_discard_sectors, "discard_max_hw_bytes");
-QUEUE_RW_ENTRY(queue_max_discard_sectors, "discard_max_bytes");
+QUEUE_LIM_RW_ENTRY(queue_max_discard_sectors, "discard_max_bytes");
 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
 
 QUEUE_RO_ENTRY(queue_atomic_write_max_sectors, "atomic_write_max_bytes");
@@ -477,11 +465,11 @@ QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones");
 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones");
 
 QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
-QUEUE_RW_ENTRY(queue_iostats_passthrough, "iostats_passthrough");
+QUEUE_LIM_RW_ENTRY(queue_iostats_passthrough, "iostats_passthrough");
 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
 QUEUE_RW_ENTRY(queue_poll, "io_poll");
 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
-QUEUE_RW_ENTRY(queue_wc, "write_cache");
+QUEUE_LIM_RW_ENTRY(queue_wc, "write_cache");
 QUEUE_RO_ENTRY(queue_fua, "fua");
 QUEUE_RO_ENTRY(queue_dax, "dax");
 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
@@ -494,10 +482,10 @@ static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 	.show = queue_logical_block_size_show,
 };
 
-QUEUE_RW_ENTRY(queue_rotational, "rotational");
-QUEUE_RW_ENTRY(queue_iostats, "iostats");
-QUEUE_RW_ENTRY(queue_add_random, "add_random");
-QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
+QUEUE_LIM_RW_ENTRY(queue_rotational, "rotational");
+QUEUE_LIM_RW_ENTRY(queue_iostats, "iostats");
+QUEUE_LIM_RW_ENTRY(queue_add_random, "add_random");
+QUEUE_LIM_RW_ENTRY(queue_stable_writes, "stable_writes");
 
 #ifdef CONFIG_BLK_WBT
 static ssize_t queue_var_store64(s64 *var, const char *page)
@@ -693,9 +681,10 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr,
 	struct queue_sysfs_entry *entry = to_queue(attr);
 	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
 	struct request_queue *q = disk->queue;
+	unsigned int noio_flag;
 	ssize_t res;
 
-	if (!entry->store)
+	if (!entry->store_limit && !entry->store)
 		return -EIO;
 
 	/*
@@ -706,11 +695,28 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr,
 	if (entry->load_module)
 		entry->load_module(disk, page, length);
 
-	blk_mq_freeze_queue(q);
+	if (entry->store_limit) {
+		struct queue_limits lim = queue_limits_start_update(q);
+
+		res = entry->store_limit(disk, page, length, &lim);
+		if (res < 0) {
+			queue_limits_cancel_update(q);
+			return res;
+		}
+
+		res = queue_limits_commit_update_frozen(q, &lim);
+		if (res)
+			return res;
+		return length;
+	}
+
 	mutex_lock(&q->sysfs_lock);
+	blk_mq_freeze_queue(q);
+	noio_flag = memalloc_noio_save();
 	res = entry->store(disk, page, length);
-	mutex_unlock(&q->sysfs_lock);
+	memalloc_noio_restore(noio_flag);
 	blk_mq_unfreeze_queue(q);
+	mutex_unlock(&q->sysfs_lock);
 	return res;
 }
 
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 84da1eadff64..9d08a54c201e 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -11,12 +11,8 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/blk-mq.h>
-#include <linux/mm.h>
-#include <linux/vmalloc.h>
-#include <linux/sched/mm.h>
 #include <linux/spinlock.h>
 #include <linux/refcount.h>
 #include <linux/mempool.h>
@@ -463,6 +459,8 @@ static inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug)
 static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
 						 struct blk_zone_wplug *zwplug)
 {
+	lockdep_assert_held(&zwplug->lock);
+
 	/* If the zone write plug was already removed, we are done. */
 	if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED)
 		return false;
@@ -584,6 +582,7 @@ static inline void blk_zone_wplug_bio_io_error(struct blk_zone_wplug *zwplug,
 	bio_clear_flag(bio, BIO_ZONE_WRITE_PLUGGING);
 	bio_io_error(bio);
 	disk_put_zone_wplug(zwplug);
+	/* Drop the reference taken by disk_zone_wplug_add_bio(() */
 	blk_queue_exit(q);
 }
 
@@ -895,10 +894,7 @@ void blk_zone_write_plug_init_request(struct request *req)
 			break;
 		}
 
-		/*
-		 * Drop the extra reference on the queue usage we got when
-		 * plugging the BIO and advance the write pointer offset.
-		 */
+		/* Drop the reference taken by disk_zone_wplug_add_bio(). */
 		blk_queue_exit(q);
 		zwplug->wp_offset += bio_sectors(bio);
 
@@ -917,6 +913,8 @@ static bool blk_zone_wplug_prepare_bio(struct blk_zone_wplug *zwplug,
 {
 	struct gendisk *disk = bio->bi_bdev->bd_disk;
 
+	lockdep_assert_held(&zwplug->lock);
+
 	/*
 	 * If we lost track of the zone write pointer due to a write error,
 	 * the user must either execute a report zones, reset the zone or finish
@@ -1446,7 +1444,6 @@ static int disk_update_zone_resources(struct gendisk *disk,
 	unsigned int nr_seq_zones, nr_conv_zones;
 	unsigned int pool_size;
 	struct queue_limits lim;
-	int ret;
 
 	disk->nr_zones = args->nr_zones;
 	disk->zone_capacity = args->zone_capacity;
@@ -1497,11 +1494,7 @@ static int disk_update_zone_resources(struct gendisk *disk,
 	}
 
 commit:
-	blk_mq_freeze_queue(q);
-	ret = queue_limits_commit_update(q, &lim);
-	blk_mq_unfreeze_queue(q);
-
-	return ret;
+	return queue_limits_commit_update_frozen(q, &lim);
 }
 
 static int blk_revalidate_conv_zone(struct blk_zone *zone, unsigned int idx,
@@ -1776,37 +1769,41 @@ int blk_zone_issue_zeroout(struct block_device *bdev, sector_t sector,
 EXPORT_SYMBOL_GPL(blk_zone_issue_zeroout);
 
 #ifdef CONFIG_BLK_DEBUG_FS
+static void queue_zone_wplug_show(struct blk_zone_wplug *zwplug,
+				  struct seq_file *m)
+{
+	unsigned int zwp_wp_offset, zwp_flags;
+	unsigned int zwp_zone_no, zwp_ref;
+	unsigned int zwp_bio_list_size;
+	unsigned long flags;
+
+	spin_lock_irqsave(&zwplug->lock, flags);
+	zwp_zone_no = zwplug->zone_no;
+	zwp_flags = zwplug->flags;
+	zwp_ref = refcount_read(&zwplug->ref);
+	zwp_wp_offset = zwplug->wp_offset;
+	zwp_bio_list_size = bio_list_size(&zwplug->bio_list);
+	spin_unlock_irqrestore(&zwplug->lock, flags);
+
+	seq_printf(m, "%u 0x%x %u %u %u\n", zwp_zone_no, zwp_flags, zwp_ref,
+		   zwp_wp_offset, zwp_bio_list_size);
+}
 
 int queue_zone_wplugs_show(void *data, struct seq_file *m)
 {
 	struct request_queue *q = data;
 	struct gendisk *disk = q->disk;
 	struct blk_zone_wplug *zwplug;
-	unsigned int zwp_wp_offset, zwp_flags;
-	unsigned int zwp_zone_no, zwp_ref;
-	unsigned int zwp_bio_list_size, i;
-	unsigned long flags;
+	unsigned int i;
 
 	if (!disk->zone_wplugs_hash)
 		return 0;
 
 	rcu_read_lock();
-	for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++) {
-		hlist_for_each_entry_rcu(zwplug,
-					 &disk->zone_wplugs_hash[i], node) {
-			spin_lock_irqsave(&zwplug->lock, flags);
-			zwp_zone_no = zwplug->zone_no;
-			zwp_flags = zwplug->flags;
-			zwp_ref = refcount_read(&zwplug->ref);
-			zwp_wp_offset = zwplug->wp_offset;
-			zwp_bio_list_size = bio_list_size(&zwplug->bio_list);
-			spin_unlock_irqrestore(&zwplug->lock, flags);
-
-			seq_printf(m, "%u 0x%x %u %u %u\n",
-				   zwp_zone_no, zwp_flags, zwp_ref,
-				   zwp_wp_offset, zwp_bio_list_size);
-		}
-	}
+	for (i = 0; i < disk_zone_wplugs_hash_size(disk); i++)
+		hlist_for_each_entry_rcu(zwplug, &disk->zone_wplugs_hash[i],
+					 node)
+			queue_zone_wplug_show(zwplug, m);
 	rcu_read_unlock();
 
 	return 0;
diff --git a/block/blk.h b/block/blk.h
index 2c26abf505b8..90fa5f28ccab 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -13,6 +13,8 @@
 
 struct elevator_type;
 
+#define	BLK_DEV_MAX_SECTORS	(LLONG_MAX >> 9)
+
 /* Max future timer expiry for timeouts */
 #define BLK_MAX_TIMEOUT		(5 * HZ)
 
@@ -556,14 +558,6 @@ void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 		struct lock_class_key *lkclass);
 
-int bio_add_hw_page(struct request_queue *q, struct bio *bio,
-		struct page *page, unsigned int len, unsigned int offset,
-		unsigned int max_sectors, bool *same_page);
-
-int bio_add_hw_folio(struct request_queue *q, struct bio *bio,
-		struct folio *folio, size_t len, size_t offset,
-		unsigned int max_sectors, bool *same_page);
-
 /*
  * Clean up a page appropriately, where the page may be pinned, may have a
  * ref taken on it or neither.
@@ -720,22 +714,29 @@ void blk_integrity_verify(struct bio *bio);
 void blk_integrity_prepare(struct request *rq);
 void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
 
-static inline void blk_freeze_acquire_lock(struct request_queue *q, bool
-		disk_dead, bool queue_dying)
+#ifdef CONFIG_LOCKDEP
+static inline void blk_freeze_acquire_lock(struct request_queue *q)
 {
-	if (!disk_dead)
+	if (!q->mq_freeze_disk_dead)
 		rwsem_acquire(&q->io_lockdep_map, 0, 1, _RET_IP_);
-	if (!queue_dying)
+	if (!q->mq_freeze_queue_dying)
 		rwsem_acquire(&q->q_lockdep_map, 0, 1, _RET_IP_);
 }
 
-static inline void blk_unfreeze_release_lock(struct request_queue *q, bool
-		disk_dead, bool queue_dying)
+static inline void blk_unfreeze_release_lock(struct request_queue *q)
 {
-	if (!queue_dying)
+	if (!q->mq_freeze_queue_dying)
 		rwsem_release(&q->q_lockdep_map, _RET_IP_);
-	if (!disk_dead)
+	if (!q->mq_freeze_disk_dead)
 		rwsem_release(&q->io_lockdep_map, _RET_IP_);
 }
+#else
+static inline void blk_freeze_acquire_lock(struct request_queue *q)
+{
+}
+static inline void blk_unfreeze_release_lock(struct request_queue *q)
+{
+}
+#endif
 
 #endif /* BLK_INTERNAL_H */
diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 32da4a4429ce..93523d8f8195 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -381,7 +381,7 @@ struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
 	set->queue_depth = 128;
 	set->numa_node = NUMA_NO_NODE;
 	set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
-	set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
+	set->flags = BLK_MQ_F_BLOCKING;
 	if (blk_mq_alloc_tag_set(set))
 		goto out_tag_set;
 
diff --git a/block/elevator.c b/block/elevator.c
index 7c3ba80e5ff4..b81216c48b6b 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -405,12 +405,12 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
 	return NULL;
 }
 
-#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
+#define to_elv(atr) container_of_const((atr), struct elv_fs_entry, attr)
 
 static ssize_t
 elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 {
-	struct elv_fs_entry *entry = to_elv(attr);
+	const struct elv_fs_entry *entry = to_elv(attr);
 	struct elevator_queue *e;
 	ssize_t error;
 
@@ -428,7 +428,7 @@ static ssize_t
 elv_attr_store(struct kobject *kobj, struct attribute *attr,
 	       const char *page, size_t length)
 {
-	struct elv_fs_entry *entry = to_elv(attr);
+	const struct elv_fs_entry *entry = to_elv(attr);
 	struct elevator_queue *e;
 	ssize_t error;
 
@@ -461,7 +461,7 @@ int elv_register_queue(struct request_queue *q, bool uevent)
 
 	error = kobject_add(&e->kobj, &q->disk->queue_kobj, "iosched");
 	if (!error) {
-		struct elv_fs_entry *attr = e->type->elevator_attrs;
+		const struct elv_fs_entry *attr = e->type->elevator_attrs;
 		if (attr) {
 			while (attr->attr.name) {
 				if (sysfs_create_file(&e->kobj, &attr->attr))
@@ -547,14 +547,6 @@ void elv_unregister(struct elevator_type *e)
 }
 EXPORT_SYMBOL_GPL(elv_unregister);
 
-static inline bool elv_support_iosched(struct request_queue *q)
-{
-	if (!queue_is_mq(q) ||
-	    (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
-		return false;
-	return true;
-}
-
 /*
  * For single queue devices, default to using mq-deadline. If we have multiple
  * queues or mq-deadline is not available, default to "none".
@@ -580,9 +572,6 @@ void elevator_init_mq(struct request_queue *q)
 	struct elevator_type *e;
 	int err;
 
-	if (!elv_support_iosched(q))
-		return;
-
 	WARN_ON_ONCE(blk_queue_registered(q));
 
 	if (unlikely(q->elevator))
@@ -601,16 +590,13 @@ void elevator_init_mq(struct request_queue *q)
 	 *
 	 * Disk isn't added yet, so verifying queue lock only manually.
 	 */
-	blk_freeze_queue_start_non_owner(q);
-	blk_freeze_acquire_lock(q, true, false);
-	blk_mq_freeze_queue_wait(q);
+	blk_mq_freeze_queue(q);
 
 	blk_mq_cancel_work_sync(q);
 
 	err = blk_mq_init_sched(q, e);
 
-	blk_unfreeze_release_lock(q, true, false);
-	blk_mq_unfreeze_queue_non_owner(q);
+	blk_mq_unfreeze_queue(q);
 
 	if (err) {
 		pr_warn("\"%s\" elevator initialization failed, "
@@ -717,9 +703,6 @@ void elv_iosched_load_module(struct gendisk *disk, const char *buf,
 	struct elevator_type *found;
 	const char *name;
 
-	if (!elv_support_iosched(disk->queue))
-		return;
-
 	strscpy(elevator_name, buf, sizeof(elevator_name));
 	name = strstrip(elevator_name);
 
@@ -737,9 +720,6 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf,
 	char elevator_name[ELV_NAME_MAX];
 	int ret;
 
-	if (!elv_support_iosched(disk->queue))
-		return count;
-
 	strscpy(elevator_name, buf, sizeof(elevator_name));
 	ret = elevator_change(disk->queue, strstrip(elevator_name));
 	if (!ret)
@@ -754,9 +734,6 @@ ssize_t elv_iosched_show(struct gendisk *disk, char *name)
 	struct elevator_type *cur = NULL, *e;
 	int len = 0;
 
-	if (!elv_support_iosched(q))
-		return sprintf(name, "none\n");
-
 	if (!q->elevator) {
 		len += sprintf(name+len, "[none] ");
 	} else {
diff --git a/block/elevator.h b/block/elevator.h
index dbf357ef4fab..e526662c5dbb 100644
--- a/block/elevator.h
+++ b/block/elevator.h
@@ -71,7 +71,7 @@ struct elevator_type
 
 	size_t icq_size;	/* see iocontext.h */
 	size_t icq_align;	/* ditto */
-	struct elv_fs_entry *elevator_attrs;
+	const struct elv_fs_entry *elevator_attrs;
 	const char *elevator_name;
 	const char *elevator_alias;
 	struct module *elevator_owner;
diff --git a/block/genhd.c b/block/genhd.c
index 79230c109fca..e9375e20d866 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -58,6 +58,13 @@ static DEFINE_IDA(ext_devt_ida);
 
 void set_capacity(struct gendisk *disk, sector_t sectors)
 {
+	if (sectors > BLK_DEV_MAX_SECTORS) {
+		pr_warn_once("%s: truncate capacity from %lld to %lld\n",
+				disk->disk_name, sectors,
+				BLK_DEV_MAX_SECTORS);
+		sectors = BLK_DEV_MAX_SECTORS;
+	}
+
 	bdev_set_nr_sectors(disk->part0, sectors);
 }
 EXPORT_SYMBOL(set_capacity);
@@ -400,21 +407,26 @@ int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk,
 	struct device *ddev = disk_to_dev(disk);
 	int ret;
 
-	/* Only makes sense for bio-based to set ->poll_bio */
-	if (queue_is_mq(disk->queue) && disk->fops->poll_bio)
+	if (WARN_ON_ONCE(bdev_nr_sectors(disk->part0) > BLK_DEV_MAX_SECTORS))
 		return -EINVAL;
 
-	/*
-	 * The disk queue should now be all set with enough information about
-	 * the device for the elevator code to pick an adequate default
-	 * elevator if one is needed, that is, for devices requesting queue
-	 * registration.
-	 */
-	elevator_init_mq(disk->queue);
+	if (queue_is_mq(disk->queue)) {
+		/*
+		 * ->submit_bio and ->poll_bio are bypassed for blk-mq drivers.
+		 */
+		if (disk->fops->submit_bio || disk->fops->poll_bio)
+			return -EINVAL;
 
-	/* Mark bdev as having a submit_bio, if needed */
-	if (disk->fops->submit_bio)
+		/*
+		 * Initialize the I/O scheduler code and pick a default one if
+		 * needed.
+		 */
+		elevator_init_mq(disk->queue);
+	} else {
+		if (!disk->fops->submit_bio)
+			return -EINVAL;
 		bdev_set_flag(disk->part0, BD_HAS_SUBMIT_BIO);
+	}
 
 	/*
 	 * If the driver provides an explicit major number it also must provide
@@ -661,7 +673,7 @@ void del_gendisk(struct gendisk *disk)
 	struct request_queue *q = disk->queue;
 	struct block_device *part;
 	unsigned long idx;
-	bool start_drain, queue_dying;
+	bool start_drain;
 
 	might_sleep();
 
@@ -690,9 +702,8 @@ void del_gendisk(struct gendisk *disk)
 	 */
 	mutex_lock(&disk->open_mutex);
 	start_drain = __blk_mark_disk_dead(disk);
-	queue_dying = blk_queue_dying(q);
 	if (start_drain)
-		blk_freeze_acquire_lock(q, true, queue_dying);
+		blk_freeze_acquire_lock(q);
 	xa_for_each_start(&disk->part_tbl, idx, part, 1)
 		drop_partition(part);
 	mutex_unlock(&disk->open_mutex);
@@ -748,7 +759,7 @@ void del_gendisk(struct gendisk *disk)
 		blk_mq_exit_queue(q);
 
 	if (start_drain)
-		blk_unfreeze_release_lock(q, true, queue_dying);
+		blk_unfreeze_release_lock(q);
 }
 EXPORT_SYMBOL(del_gendisk);
 
@@ -798,7 +809,7 @@ static ssize_t disk_badblocks_store(struct device *dev,
 }
 
 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
-void blk_request_module(dev_t devt)
+static bool blk_probe_dev(dev_t devt)
 {
 	unsigned int major = MAJOR(devt);
 	struct blk_major_name **n;
@@ -808,14 +819,26 @@ void blk_request_module(dev_t devt)
 		if ((*n)->major == major && (*n)->probe) {
 			(*n)->probe(devt);
 			mutex_unlock(&major_names_lock);
-			return;
+			return true;
 		}
 	}
 	mutex_unlock(&major_names_lock);
+	return false;
+}
+
+void blk_request_module(dev_t devt)
+{
+	int error;
+
+	if (blk_probe_dev(devt))
+		return;
 
-	if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
-		/* Make old-style 2.4 aliases work */
-		request_module("block-major-%d", MAJOR(devt));
+	error = request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt));
+	/* Make old-style 2.4 aliases work */
+	if (error > 0)
+		error = request_module("block-major-%d", MAJOR(devt));
+	if (!error)
+		blk_probe_dev(devt);
 }
 #endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */
 
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 4155594aefc6..dc31f2dfa414 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -889,7 +889,7 @@ KYBER_LAT_SHOW_STORE(KYBER_WRITE, write);
 #undef KYBER_LAT_SHOW_STORE
 
 #define KYBER_LAT_ATTR(op) __ATTR(op##_lat_nsec, 0644, kyber_##op##_lat_show, kyber_##op##_lat_store)
-static struct elv_fs_entry kyber_sched_attrs[] = {
+static const struct elv_fs_entry kyber_sched_attrs[] = {
 	KYBER_LAT_ATTR(read),
 	KYBER_LAT_ATTR(write),
 	__ATTR_NULL
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 5528347b5fcf..754f6b7415cd 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -834,7 +834,7 @@ STORE_INT(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX);
 #define DD_ATTR(name) \
 	__ATTR(name, 0644, deadline_##name##_show, deadline_##name##_store)
 
-static struct elv_fs_entry deadline_attrs[] = {
+static const struct elv_fs_entry deadline_attrs[] = {
 	DD_ATTR(read_expire),
 	DD_ATTR(write_expire),
 	DD_ATTR(writes_starved),
diff --git a/block/partitions/ldm.h b/block/partitions/ldm.h
index e259180c8914..aa3bd050d8cd 100644
--- a/block/partitions/ldm.h
+++ b/block/partitions/ldm.h
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/**
+/*
  * ldm - Part of the Linux-NTFS project.
  *
  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>