Merge branch 'for-6.12/block' into for-6.12/io_uring-discard

* for-6.12/block: (115 commits)
block: unpin user pages belonging to a folio at once
mm: release number of pages of a folio
block: introduce folio awareness and add a bigger size from folio
block: Added folio-ized version of bio_add_hw_page()
block, bfq: factor out a helper to split bfqq in bfq_init_rq()
block, bfq: remove local variable 'bfqq_already_existing' in bfq_init_rq()
block, bfq: remove local variable 'split' in bfq_init_rq()
block, bfq: remove bfq_log_bfqg()
block, bfq: merge bfq_release_process_ref() into bfq_put_cooperator()
block, bfq: fix procress reference leakage for bfqq in merge chain
block, bfq: fix uaf for accessing waker_bfqq after splitting
blk-throttle: support prioritized processing of metadata
blk-throttle: remove last_low_overflow_time
drbd: Add NULL check for net_conf to prevent dereference in state validation
blk-mq: add missing unplug trace event
mtip32xx: Remove redundant null pointer checks in mtip_hw_debugfs_init()
md: Add new_level sysfs interface
zram: Shrink zram_table_entry::flags.
zram: Remove ZRAM_LOCK
zram: Replace bit spinlocks with a spinlock_t.
...

MAINTAINERS

···
 F:	fs/befs/
 
 BFQ I/O SCHEDULER
-M:	Paolo Valente <[e-mail]>
-M:	Jens Axboe <[e-mail]>
+M:	Yu Kuai <[e-mail]>
 L:	[e-mail]
-S:	Maintained
+S:	Odd Fixes
 F:	Documentation/block/bfq-iosched.rst
 F:	block/bfq-*
 

block/bfq-cgroup.c

···
 		bfq_put_idle_entity(bfq_entity_service_tree(entity), entity);
 	bfqg_and_blkg_put(old_parent);
 
-	if (entity->parent &&
-	    entity->parent->last_bfqq_created == bfqq)
-		entity->parent->last_bfqq_created = NULL;
-	else if (bfqd->last_bfqq_created == bfqq)
-		bfqd->last_bfqq_created = NULL;
-
+	bfq_reassign_last_bfqq(bfqq, NULL);
 	entity->parent = bfqg->my_entity;
 	entity->sched_data = &bfqg->sched_data;
 	/* pin down bfqg and its associated blkg  */
···
 		 */
 		bfq_put_cooperator(sync_bfqq);
 		bic_set_bfqq(bic, NULL, true, act_idx);
-		bfq_release_process_ref(bfqd, sync_bfqq);
 	}
 }
 

block/bfq-iosched.c

···
 	struct bfq_iocq_bfqq_data *bfqq_data = &bic->bfqq_data[a_idx];
 
 	/* if a merge has already been setup, then proceed with that first */
-	if (bfqq->new_bfqq)
-		return bfqq->new_bfqq;
+	new_bfqq = bfqq->new_bfqq;
+	if (new_bfqq) {
+		while (new_bfqq->new_bfqq)
+			new_bfqq = new_bfqq->new_bfqq;
+		return new_bfqq;
+	}
 
 	/*
 	 * Check delayed stable merge for rotational or non-queueing
···
 }
 
 
-static void
-bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq, struct bfq_queue *new_bfqq)
+void bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq,
+			    struct bfq_queue *new_bfqq)
 {
 	if (cur_bfqq->entity.parent &&
 	    cur_bfqq->entity.parent->last_bfqq_created == cur_bfqq)
···
 	bfq_put_queue(bfqq);
 }
 
-static void
-bfq_merge_bfqqs(struct bfq_data *bfqd, struct bfq_io_cq *bic,
-		struct bfq_queue *bfqq, struct bfq_queue *new_bfqq)
+static struct bfq_queue *bfq_merge_bfqqs(struct bfq_data *bfqd,
+					 struct bfq_io_cq *bic,
+					 struct bfq_queue *bfqq)
 {
+	struct bfq_queue *new_bfqq = bfqq->new_bfqq;
+
 	bfq_log_bfqq(bfqd, bfqq, "merging with queue %lu",
 		(unsigned long)new_bfqq->pid);
 	/* Save weight raising and idle window of the merged queues */
···
 	bfq_reassign_last_bfqq(bfqq, new_bfqq);
 
 	bfq_release_process_ref(bfqd, bfqq);
+
+	return new_bfqq;
 }
 
 static bool bfq_allow_bio_merge(struct request_queue *q, struct request *rq,
···
 		 * fulfilled, i.e., bic can be redirected to new_bfqq
 		 * and bfqq can be put.
 		 */
-		bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq,
-				new_bfqq);
-		/*
-		 * If we get here, bio will be queued into new_queue,
-		 * so use new_bfqq to decide whether bio and rq can be
-		 * merged.
-		 */
-		bfqq = new_bfqq;
+		while (bfqq != new_bfqq)
+			bfqq = bfq_merge_bfqqs(bfqd, bfqd->bio_bic, bfqq);
 
 		/*
 		 * Change also bqfd->bio_bfqq, as
···
 		bfq_put_queue(__bfqq);
 		__bfqq = next;
 	}
+
+	bfq_release_process_ref(bfqq->bfqd, bfqq);
 }
 
 static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
···
 	bfq_log_bfqq(bfqd, bfqq, "exit_bfqq: %p, %d", bfqq, bfqq->ref);
 
 	bfq_put_cooperator(bfqq);
-
-	bfq_release_process_ref(bfqd, bfqq);
 }
 
 static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync,
···
 	 * state before killing it.
 	 */
 	bfqq->bic = bic;
-	bfq_merge_bfqqs(bfqd, bic, bfqq, new_bfqq);
-
-	return new_bfqq;
+	return bfq_merge_bfqqs(bfqd, bic, bfqq);
 }
 
 /*
···
 	bool waiting, idle_timer_disabled = false;
 
 	if (new_bfqq) {
+		struct bfq_queue *old_bfqq = bfqq;
 		/*
 		 * Release the request's reference to the old bfqq
 		 * and make sure one is taken to the shared queue.
···
 		 * new_bfqq.
 		 */
 		if (bic_to_bfqq(RQ_BIC(rq), true,
-				bfq_actuator_index(bfqd, rq->bio)) == bfqq)
-			bfq_merge_bfqqs(bfqd, RQ_BIC(rq),
-					bfqq, new_bfqq);
+				bfq_actuator_index(bfqd, rq->bio)) == bfqq) {
+			while (bfqq != new_bfqq)
+				bfqq = bfq_merge_bfqqs(bfqd, RQ_BIC(rq), bfqq);
+		}
 
-		bfq_clear_bfqq_just_created(bfqq);
+		bfq_clear_bfqq_just_created(old_bfqq);
 		/*
 		 * rq is about to be enqueued into new_bfqq,
 		 * release rq reference on bfqq
 		 */
-		bfq_put_queue(bfqq);
+		bfq_put_queue(old_bfqq);
 		rq->elv.priv[1] = new_bfqq;
-		bfqq = new_bfqq;
 	}
 
 	bfq_update_io_thinktime(bfqd, bfqq);
···
 {
 	bfq_log_bfqq(bfqq->bfqd, bfqq, "splitting queue");
 
-	if (bfqq_process_refs(bfqq) == 1) {
+	if (bfqq_process_refs(bfqq) == 1 && !bfqq->new_bfqq) {
 		bfqq->pid = current->pid;
 		bfq_clear_bfqq_coop(bfqq);
 		bfq_clear_bfqq_split_coop(bfqq);
···
 	bic_set_bfqq(bic, NULL, true, bfqq->actuator_idx);
 
 	bfq_put_cooperator(bfqq);
-
-	bfq_release_process_ref(bfqq->bfqd, bfqq);
 	return NULL;
 }
 
-static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd,
-						   struct bfq_io_cq *bic,
-						   struct bio *bio,
-						   bool split, bool is_sync,
-						   bool *new_queue)
+static struct bfq_queue *
+__bfq_get_bfqq_handle_split(struct bfq_data *bfqd, struct bfq_io_cq *bic,
+			    struct bio *bio, bool split, bool is_sync,
+			    bool *new_queue)
 {
 	unsigned int act_idx = bfq_actuator_index(bfqd, bio);
 	struct bfq_queue *bfqq = bic_to_bfqq(bic, is_sync, act_idx);
···
 	rq->elv.priv[0] = rq->elv.priv[1] = NULL;
 }
 
+static struct bfq_queue *bfq_waker_bfqq(struct bfq_queue *bfqq)
+{
+	struct bfq_queue *new_bfqq = bfqq->new_bfqq;
+	struct bfq_queue *waker_bfqq = bfqq->waker_bfqq;
+
+	if (!waker_bfqq)
+		return NULL;
+
+	while (new_bfqq) {
+		if (new_bfqq == waker_bfqq) {
+			/*
+			 * If waker_bfqq is in the merge chain, and current
+			 * is the only procress.
+			 */
+			if (bfqq_process_refs(waker_bfqq) == 1)
+				return NULL;
+			break;
+		}
+
+		new_bfqq = new_bfqq->new_bfqq;
+	}
+
+	return waker_bfqq;
+}
+
+static struct bfq_queue *bfq_get_bfqq_handle_split(struct bfq_data *bfqd,
+						   struct bfq_io_cq *bic,
+						   struct bio *bio,
+						   unsigned int idx,
+						   bool is_sync)
+{
+	struct bfq_queue *waker_bfqq;
+	struct bfq_queue *bfqq;
+	bool new_queue = false;
+
+	bfqq = __bfq_get_bfqq_handle_split(bfqd, bic, bio, false, is_sync,
+					   &new_queue);
+	if (unlikely(new_queue))
+		return bfqq;
+
+	/* If the queue was seeky for too long, break it apart. */
+	if (!bfq_bfqq_coop(bfqq) || !bfq_bfqq_split_coop(bfqq) ||
+	    bic->bfqq_data[idx].stably_merged)
+		return bfqq;
+
+	waker_bfqq = bfq_waker_bfqq(bfqq);
+
+	/* Update bic before losing reference to bfqq */
+	if (bfq_bfqq_in_large_burst(bfqq))
+		bic->bfqq_data[idx].saved_in_large_burst = true;
+
+	bfqq = bfq_split_bfqq(bic, bfqq);
+	if (bfqq) {
+		bfq_bfqq_resume_state(bfqq, bfqd, bic, true);
+		return bfqq;
+	}
+
+	bfqq = __bfq_get_bfqq_handle_split(bfqd, bic, bio, true, is_sync, NULL);
+	if (unlikely(bfqq == &bfqd->oom_bfqq))
+		return bfqq;
+
+	bfq_bfqq_resume_state(bfqq, bfqd, bic, false);
+	bfqq->waker_bfqq = waker_bfqq;
+	bfqq->tentative_waker_bfqq = NULL;
+
+	/*
+	 * If the waker queue disappears, then new_bfqq->waker_bfqq must be
+	 * reset. So insert new_bfqq into the
+	 * woken_list of the waker. See
+	 * bfq_check_waker for details.
+	 */
+	if (waker_bfqq)
+		hlist_add_head(&bfqq->woken_list_node,
+			       &bfqq->waker_bfqq->woken_list);
+
+	return bfqq;
+}
+
 /*
  * If needed, init rq, allocate bfq data structures associated with
  * rq, and increment reference counters in the destination bfq_queue
···
 	struct bfq_io_cq *bic;
 	const int is_sync = rq_is_sync(rq);
 	struct bfq_queue *bfqq;
-	bool new_queue = false;
-	bool bfqq_already_existing = false, split = false;
 	unsigned int a_idx = bfq_actuator_index(bfqd, bio);
 
 	if (unlikely(!rq->elv.icq))
···
 		return RQ_BFQQ(rq);
 
 	bic = icq_to_bic(rq->elv.icq);
-
 	bfq_check_ioprio_change(bic, bio);
-
 	bfq_bic_update_cgroup(bic, bio);
-
-	bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio, false, is_sync,
-					 &new_queue);
-
-	if (likely(!new_queue)) {
-		/* If the queue was seeky for too long, break it apart. */
-		if (bfq_bfqq_coop(bfqq) && bfq_bfqq_split_coop(bfqq) &&
-			!bic->bfqq_data[a_idx].stably_merged) {
-			struct bfq_queue *old_bfqq = bfqq;
-
-			/* Update bic before losing reference to bfqq */
-			if (bfq_bfqq_in_large_burst(bfqq))
-				bic->bfqq_data[a_idx].saved_in_large_burst =
-					true;
-
-			bfqq = bfq_split_bfqq(bic, bfqq);
-			split = true;
-
-			if (!bfqq) {
-				bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio,
-								 true, is_sync,
-								 NULL);
-				if (unlikely(bfqq == &bfqd->oom_bfqq))
-					bfqq_already_existing = true;
-			} else
-				bfqq_already_existing = true;
-
-			if (!bfqq_already_existing) {
-				bfqq->waker_bfqq = old_bfqq->waker_bfqq;
-				bfqq->tentative_waker_bfqq = NULL;
-
-				/*
-				 * If the waker queue disappears, then
-				 * new_bfqq->waker_bfqq must be
-				 * reset. So insert new_bfqq into the
-				 * woken_list of the waker. See
-				 * bfq_check_waker for details.
-				 */
-				if (bfqq->waker_bfqq)
-					hlist_add_head(&bfqq->woken_list_node,
-						       &bfqq->waker_bfqq->woken_list);
-			}
-		}
-	}
+	bfqq = bfq_get_bfqq_handle_split(bfqd, bic, bio, a_idx, is_sync);
 
 	bfqq_request_allocated(bfqq);
 	bfqq->ref++;
···
 	 * addition, if the queue has also just been split, we have to
 	 * resume its state.
 	 */
-	if (likely(bfqq != &bfqd->oom_bfqq) && bfqq_process_refs(bfqq) == 1) {
+	if (likely(bfqq != &bfqd->oom_bfqq) && !bfqq->new_bfqq &&
+	    bfqq_process_refs(bfqq) == 1)
 		bfqq->bic = bic;
-		if (split) {
-			/*
-			 * The queue has just been split from a shared
-			 * queue: restore the idle window and the
-			 * possible weight raising period.
-			 */
-			bfq_bfqq_resume_state(bfqq, bfqd, bic,
-					      bfqq_already_existing);
-		}
-	}
 
 	/*
 	 * Consider bfqq as possibly belonging to a burst of newly

block/bfq-iosched.h

···
 void bfq_add_bfqq_busy(struct bfq_queue *bfqq);
 void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
 void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
+void bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq,
+			    struct bfq_queue *new_bfqq);
 
 /* --------------- end of interface of B-WF2Q+ ---------------- */
 
···
 			"%s " fmt, pid_str, ##args);			\
 } while (0)
 
-#define bfq_log_bfqg(bfqd, bfqg, fmt, args...)	do {			\
-	blk_add_cgroup_trace_msg((bfqd)->queue,				\
-		&bfqg_to_blkg(bfqg)->blkcg->css, fmt, ##args);		\
-} while (0)
-
 #else /* CONFIG_BFQ_GROUP_IOSCHED */
 
 #define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do {	\
···
 	bfq_bfqq_name((bfqq), pid_str, MAX_BFQQ_NAME_LENGTH);		\
 	blk_add_trace_msg((bfqd)->queue, "%s " fmt, pid_str, ##args);	\
 } while (0)
-#define bfq_log_bfqg(bfqd, bfqg, fmt, args...)		do {} while (0)
 
 #endif /* CONFIG_BFQ_GROUP_IOSCHED */
 

block/bio.c

···
 	if (!zone_device_pages_have_same_pgmap(bv->bv_page, page))
 		return false;
 
-	*same_page = ((vec_end_addr & PAGE_MASK) == page_addr);
+	*same_page = ((vec_end_addr & PAGE_MASK) == ((page_addr + off) &
+		     PAGE_MASK));
 	if (!*same_page) {
 		if (IS_ENABLED(CONFIG_KMSAN))
 			return false;
···
 	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);
 }
 
 /**
···
 	struct folio_iter fi;
 
 	bio_for_each_folio_all(fi, bio) {
-		struct page *page;
 		size_t nr_pages;
 
 		if (mark_dirty) {
···
 			folio_mark_dirty(fi.folio);
 			folio_unlock(fi.folio);
 		}
-		page = folio_page(fi.folio, fi.offset / PAGE_SIZE);
 		nr_pages = (fi.offset + fi.length - 1) / PAGE_SIZE -
 			   fi.offset / PAGE_SIZE + 1;
-		do {
-			bio_release_page(bio, page++);
-		} while (--nr_pages != 0);
+		unpin_user_folio(fi.folio, nr_pages);
 	}
 }
 EXPORT_SYMBOL_GPL(__bio_release_pages);
···
 	bio_set_flag(bio, BIO_CLONED);
 }
 
-static int bio_iov_add_page(struct bio *bio, struct page *page,
-		unsigned int len, unsigned int offset)
+static int bio_iov_add_folio(struct bio *bio, struct folio *folio, size_t len,
+			     size_t offset)
 {
 	bool same_page = false;
 
···
 
 	if (bio->bi_vcnt > 0 &&
 	    bvec_try_merge_page(&bio->bi_io_vec[bio->bi_vcnt - 1],
-				page, len, offset, &same_page)) {
+				folio_page(folio, 0), len, offset,
+				&same_page)) {
 		bio->bi_iter.bi_size += len;
-		if (same_page)
-			bio_release_page(bio, page);
+		if (same_page && bio_flagged(bio, BIO_PAGE_PINNED))
+			unpin_user_folio(folio, 1);
 		return 0;
 	}
-	__bio_add_page(bio, page, len, offset);
+	bio_add_folio_nofail(bio, folio, len, offset);
 	return 0;
 }
 
-static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page,
-		unsigned int len, unsigned int offset)
+static int bio_iov_add_zone_append_folio(struct bio *bio, struct folio *folio,
+					 size_t len, size_t offset)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	bool same_page = false;
 
-	if (bio_add_hw_page(q, bio, page, len, offset,
+	if (bio_add_hw_folio(q, bio, folio, len, offset,
 			queue_max_zone_append_sectors(q), &same_page) != len)
 		return -EINVAL;
-	if (same_page)
-		bio_release_page(bio, page);
+	if (same_page && bio_flagged(bio, BIO_PAGE_PINNED))
+		unpin_user_folio(folio, 1);
 	return 0;
+}
+
+static unsigned int get_contig_folio_len(unsigned int *num_pages,
+					 struct page **pages, unsigned int i,
+					 struct folio *folio, size_t left,
+					 size_t offset)
+{
+	size_t bytes = left;
+	size_t contig_sz = min_t(size_t, PAGE_SIZE - offset, bytes);
+	unsigned int j;
+
+	/*
+	 * We might COW a single page in the middle of
+	 * a large folio, so we have to check that all
+	 * pages belong to the same folio.
+	 */
+	bytes -= contig_sz;
+	for (j = i + 1; j < i + *num_pages; j++) {
+		size_t next = min_t(size_t, PAGE_SIZE, bytes);
+
+		if (page_folio(pages[j]) != folio ||
+		    pages[j] != pages[j - 1] + 1) {
+			break;
+		}
+		contig_sz += next;
+		bytes -= next;
+	}
+	*num_pages = j - i;
+
+	return contig_sz;
 }
 
 #define PAGE_PTRS_PER_BVEC     (sizeof(struct bio_vec) / sizeof(struct page *))
···
 	unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
 	struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
 	struct page **pages = (struct page **)bv;
-	ssize_t size, left;
-	unsigned len, i = 0;
-	size_t offset;
+	ssize_t size;
+	unsigned int num_pages, i = 0;
+	size_t offset, folio_offset, left, len;
 	int ret = 0;
 
 	/*
···
 		goto out;
 	}
 
-	for (left = size, i = 0; left > 0; left -= len, i++) {
+	for (left = size, i = 0; left > 0; left -= len, i += num_pages) {
 		struct page *page = pages[i];
+		struct folio *folio = page_folio(page);
 
-		len = min_t(size_t, PAGE_SIZE - offset, left);
+		folio_offset = ((size_t)folio_page_idx(folio, page) <<
+			       PAGE_SHIFT) + offset;
+
+		len = min(folio_size(folio) - folio_offset, left);
+
+		num_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+
+		if (num_pages > 1)
+			len = get_contig_folio_len(&num_pages, pages, i,
+						   folio, left, offset);
+
 		if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
-			ret = bio_iov_add_zone_append_page(bio, page, len,
-					offset);
+			ret = bio_iov_add_zone_append_folio(bio, folio, len,
+					folio_offset);
 			if (ret)
 				break;
 		} else
-			bio_iov_add_page(bio, page, len, offset);
+			bio_iov_add_folio(bio, folio, len, folio_offset);
 
 		offset = 0;
 	}

block/blk-cgroup.c

···
 	struct request_queue *q = disk->queue;
 	struct blkcg_gq *new_blkg, *blkg;
 	bool preloaded;
-	int ret;
 
 	new_blkg = blkg_alloc(&blkcg_root, disk, GFP_KERNEL);
 	if (!new_blkg)
···
 	if (preloaded)
 		radix_tree_preload_end();
 
-	ret = blk_ioprio_init(disk);
-	if (ret)
-		goto err_destroy_all;
-
 	return 0;
 
-err_destroy_all:
-	blkg_destroy_all(disk);
-	return ret;
 err_unlock:
 	spin_unlock_irq(&q->queue_lock);
 	if (preloaded)
···
 
 	if (blkcg_policy_enabled(q, pol))
 		return 0;
+
+	/*
+	 * Policy is allowed to be registered without pd_alloc_fn/pd_free_fn,
+	 * for example, ioprio. Such policy will work on blkcg level, not disk
+	 * level, and don't need to be activated.
+	 */
+	if (WARN_ON_ONCE(!pol->pd_alloc_fn || !pol->pd_free_fn))
+		return -EINVAL;
 
 	if (queue_is_mq(q))
 		blk_mq_freeze_queue(q);
···
 		goto err_unlock;
 	}
 
-	/* Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs */
+	/*
+	 * Make sure cpd/pd_alloc_fn and cpd/pd_free_fn in pairs, and policy
+	 * without pd_alloc_fn/pd_free_fn can't be activated.
+	 */
 	if ((!pol->cpd_alloc_fn ^ !pol->cpd_free_fn) ||
-		(!pol->pd_alloc_fn ^ !pol->pd_free_fn))
+	    (!pol->pd_alloc_fn ^ !pol->pd_free_fn))
 		goto err_unlock;
 
 	/* register @pol */

block/blk-cgroup.h

···
 static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
 						  struct blkcg_policy *pol) { return NULL; }
 static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
-static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
 static inline void blkg_get(struct blkcg_gq *blkg) { }
 static inline void blkg_put(struct blkcg_gq *blkg) { }
 static inline void blkcg_bio_issue_init(struct bio *bio) { }

block/blk-iocost.c

···
 			      struct ioc_now *now)
 {
 	struct ioc_gq *iocg;
-	u64 dur, usage_pct, nr_cycles;
+	u64 dur, usage_pct, nr_cycles, nr_cycles_shift;
 
 	/* if no debtor, reset the cycle */
 	if (!nr_debtors) {
···
 		old_debt = iocg->abs_vdebt;
 		old_delay = iocg->delay;
 
+		nr_cycles_shift = min_t(u64, nr_cycles, BITS_PER_LONG - 1);
 		if (iocg->abs_vdebt)
-			iocg->abs_vdebt = iocg->abs_vdebt >> nr_cycles ?: 1;
+			iocg->abs_vdebt = iocg->abs_vdebt >> nr_cycles_shift ?: 1;
+
 		if (iocg->delay)
-			iocg->delay = iocg->delay >> nr_cycles ?: 1;
+			iocg->delay = iocg->delay >> nr_cycles_shift ?: 1;
 
 		iocg_kick_waitq(iocg, true, now);
 

block/blk-ioprio.c

···
 static struct blkcg_policy ioprio_policy;
 
 /**
- * struct ioprio_blkg - Per (cgroup, request queue) data.
- * @pd: blkg_policy_data structure.
- */
-struct ioprio_blkg {
-	struct blkg_policy_data pd;
-};
-
-/**
  * struct ioprio_blkcg - Per cgroup data.
  * @cpd: blkcg_policy_data structure.
  * @prio_policy: One of the IOPRIO_CLASS_* values. See also <linux/ioprio.h>.
···
 	struct blkcg_policy_data cpd;
 	enum prio_policy	 prio_policy;
 };
-
-static inline struct ioprio_blkg *pd_to_ioprio(struct blkg_policy_data *pd)
-{
-	return pd ? container_of(pd, struct ioprio_blkg, pd) : NULL;
-}
 
 static struct ioprio_blkcg *blkcg_to_ioprio_blkcg(struct blkcg *blkcg)
 {
···
 ioprio_blkcg_from_css(struct cgroup_subsys_state *css)
 {
 	return blkcg_to_ioprio_blkcg(css_to_blkcg(css));
-}
-
-static struct ioprio_blkcg *ioprio_blkcg_from_bio(struct bio *bio)
-{
-	struct blkg_policy_data *pd = blkg_to_pd(bio->bi_blkg, &ioprio_policy);
-
-	if (!pd)
-		return NULL;
-
-	return blkcg_to_ioprio_blkcg(pd->blkg->blkcg);
 }
 
 static int ioprio_show_prio_policy(struct seq_file *sf, void *v)
···
 		return ret;
 	blkcg->prio_policy = ret;
 	return nbytes;
-}
-
-static struct blkg_policy_data *
-ioprio_alloc_pd(struct gendisk *disk, struct blkcg *blkcg, gfp_t gfp)
-{
-	struct ioprio_blkg *ioprio_blkg;
-
-	ioprio_blkg = kzalloc(sizeof(*ioprio_blkg), gfp);
-	if (!ioprio_blkg)
-		return NULL;
-
-	return &ioprio_blkg->pd;
-}
-
-static void ioprio_free_pd(struct blkg_policy_data *pd)
-{
-	struct ioprio_blkg *ioprio_blkg = pd_to_ioprio(pd);
-
-	kfree(ioprio_blkg);
 }
 
 static struct blkcg_policy_data *ioprio_alloc_cpd(gfp_t gfp)
···
 
 	.cpd_alloc_fn	= ioprio_alloc_cpd,
 	.cpd_free_fn	= ioprio_free_cpd,
-
-	.pd_alloc_fn	= ioprio_alloc_pd,
-	.pd_free_fn	= ioprio_free_pd,
 };
 
 void blkcg_set_ioprio(struct bio *bio)
 {
-	struct ioprio_blkcg *blkcg = ioprio_blkcg_from_bio(bio);
+	struct ioprio_blkcg *blkcg = blkcg_to_ioprio_blkcg(bio->bi_blkg->blkcg);
 	u16 prio;
 
 	if (!blkcg || blkcg->prio_policy == POLICY_NO_CHANGE)
···
 			IOPRIO_PRIO_VALUE(blkcg->prio_policy, 0));
 	if (prio > bio->bi_ioprio)
 		bio->bi_ioprio = prio;
-}
-
-void blk_ioprio_exit(struct gendisk *disk)
-{
-	blkcg_deactivate_policy(disk, &ioprio_policy);
-}
-
-int blk_ioprio_init(struct gendisk *disk)
-{
-	return blkcg_activate_policy(disk, &ioprio_policy);
 }
 
 static int __init ioprio_init(void)

block/blk-ioprio.h

···
 struct bio;
 
 #ifdef CONFIG_BLK_CGROUP_IOPRIO
-int blk_ioprio_init(struct gendisk *disk);
-void blk_ioprio_exit(struct gendisk *disk);
 void blkcg_set_ioprio(struct bio *bio);
 #else
-static inline int blk_ioprio_init(struct gendisk *disk)
-{
-	return 0;
-}
-static inline void blk_ioprio_exit(struct gendisk *disk)
-{
-}
 static inline void blkcg_set_ioprio(struct bio *bio)
 {
 }

block/blk-merge.c

···
 	return round_down(UINT_MAX, lim->logical_block_size) >> SECTOR_SHIFT;
 }
 
-static struct bio *bio_split_discard(struct bio *bio,
-				     const struct queue_limits *lim,
-				     unsigned *nsegs, struct bio_set *bs)
+static struct bio *bio_submit_split(struct bio *bio, int split_sectors)
+{
+	if (unlikely(split_sectors < 0)) {
+		bio->bi_status = errno_to_blk_status(split_sectors);
+		bio_endio(bio);
+		return NULL;
+	}
+
+	if (split_sectors) {
+		struct bio *split;
+
+		split = bio_split(bio, split_sectors, GFP_NOIO,
+				&bio->bi_bdev->bd_disk->bio_split);
+		split->bi_opf |= REQ_NOMERGE;
+		blkcg_bio_issue_init(split);
+		bio_chain(split, bio);
+		trace_block_split(split, bio->bi_iter.bi_sector);
+		WARN_ON_ONCE(bio_zone_write_plugging(bio));
+		submit_bio_noacct(bio);
+		return split;
+	}
+
+	return bio;
+}
+
+struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
+		unsigned *nsegs)
 {
 	unsigned int max_discard_sectors, granularity;
 	sector_t tmp;
···
 		min(lim->max_discard_sectors, bio_allowed_max_sectors(lim));
 	max_discard_sectors -= max_discard_sectors % granularity;
 	if (unlikely(!max_discard_sectors))
-		return NULL;
+		return bio;
 
 	if (bio_sectors(bio) <= max_discard_sectors)
-		return NULL;
+		return bio;
 
 	split_sectors = max_discard_sectors;
 
···
 	if (split_sectors > tmp)
 		split_sectors -= tmp;
 
-	return bio_split(bio, split_sectors, GFP_NOIO, bs);
+	return bio_submit_split(bio, split_sectors);
 }
 
-static struct bio *bio_split_write_zeroes(struct bio *bio,
-					  const struct queue_limits *lim,
-					  unsigned *nsegs, struct bio_set *bs)
+struct bio *bio_split_write_zeroes(struct bio *bio,
+		const struct queue_limits *lim, unsigned *nsegs)
 {
 	*nsegs = 0;
 	if (!lim->max_write_zeroes_sectors)
-		return NULL;
+		return bio;
 	if (bio_sectors(bio) <= lim->max_write_zeroes_sectors)
-		return NULL;
-	return bio_split(bio, lim->max_write_zeroes_sectors, GFP_NOIO, bs);
+		return bio;
+	return bio_submit_split(bio, lim->max_write_zeroes_sectors);
 }
 
 static inline unsigned int blk_boundary_sectors(const struct queue_limits *lim,
···
 }
 
 /**
- * bio_split_rw - split a bio in two bios
+ * bio_split_rw_at - check if and where to split a read/write bio
  * @bio:  [in] bio to be split
  * @lim:  [in] queue limits to split based on
  * @segs: [out] number of segments in the bio with the first half of the sectors
- * @bs:	  [in] bio set to allocate the clone from
  * @max_bytes: [in] maximum number of bytes per bio
  *
- * Clone @bio, update the bi_iter of the clone to represent the first sectors
- * of @bio and update @bio->bi_iter to represent the remaining sectors. The
- * following is guaranteed for the cloned bio:
- * - That it has at most @max_bytes worth of data
- * - That it has at most queue_max_segments(@q) segments.
- *
- * Except for discard requests the cloned bio will point at the bi_io_vec of
- * the original bio. It is the responsibility of the caller to ensure that the
- * original bio is not freed before the cloned bio. The caller is also
- * responsible for ensuring that @bs is only destroyed after processing of the
- * split bio has finished.
+ * Find out if @bio needs to be split to fit the queue limits in @lim and a
+ * maximum size of @max_bytes.  Returns a negative error number if @bio can't be
+ * split, 0 if the bio doesn't have to be split, or a positive sector offset if
+ * @bio needs to be split.
  */
-struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
-		unsigned *segs, struct bio_set *bs, unsigned max_bytes)
+int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
+		unsigned *segs, unsigned max_bytes)
 {
 	struct bio_vec bv, bvprv, *bvprvp = NULL;
 	struct bvec_iter iter;
···
 	}
 
 	*segs = nsegs;
-	return NULL;
+	return 0;
 split:
-	if (bio->bi_opf & REQ_ATOMIC) {
-		bio->bi_status = BLK_STS_INVAL;
-		bio_endio(bio);
-		return ERR_PTR(-EINVAL);
-	}
+	if (bio->bi_opf & REQ_ATOMIC)
+		return -EINVAL;
+
 	/*
 	 * We can't sanely support splitting for a REQ_NOWAIT bio. End it
 	 * with EAGAIN if splitting is required and return an error pointer.
 	 */
-	if (bio->bi_opf & REQ_NOWAIT) {
-		bio->bi_status = BLK_STS_AGAIN;
-		bio_endio(bio);
-		return ERR_PTR(-EAGAIN);
-	}
+	if (bio->bi_opf & REQ_NOWAIT)
+		return -EAGAIN;
 
 	*segs = nsegs;
 
···
 	 * big IO can be trival, disable iopoll when split needed.
 	 */
 	bio_clear_polled(bio);
-	return bio_split(bio, bytes >> SECTOR_SHIFT, GFP_NOIO, bs);
+	return bytes >> SECTOR_SHIFT;
 }
-EXPORT_SYMBOL_GPL(bio_split_rw);
+EXPORT_SYMBOL_GPL(bio_split_rw_at);
 
-/**
- * __bio_split_to_limits - split a bio to fit the queue limits
- * @bio:     bio to be split
- * @lim:     queue limits to split based on
- * @nr_segs: returns the number of segments in the returned bio
- *
- * Check if @bio needs splitting based on the queue limits, and if so split off
- * a bio fitting the limits from the beginning of @bio and return it.  @bio is
- * shortened to the remainder and re-submitted.
- *
- * The split bio is allocated from @q->bio_split, which is provided by the
- * block layer.
- */
-struct bio *__bio_split_to_limits(struct bio *bio,
-				  const struct queue_limits *lim,
-				  unsigned int *nr_segs)
+struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
+		unsigned *nr_segs)
 {
-	struct bio_set *bs = &bio->bi_bdev->bd_disk->bio_split;
-	struct bio *split;
+	return bio_submit_split(bio,
+		bio_split_rw_at(bio, lim, nr_segs,
+			get_max_io_size(bio, lim) << SECTOR_SHIFT));
+}
 
-	switch (bio_op(bio)) {
-	case REQ_OP_DISCARD:
-	case REQ_OP_SECURE_ERASE:
-		split = bio_split_discard(bio, lim, nr_segs, bs);
-		break;
-	case REQ_OP_WRITE_ZEROES:
-		split = bio_split_write_zeroes(bio, lim, nr_segs, bs);
-		break;
-	default:
-		split = bio_split_rw(bio, lim, nr_segs, bs,
-				get_max_io_size(bio, lim) << SECTOR_SHIFT);
-		if (IS_ERR(split))
-			return NULL;
-		break;
-	}
+/*
+ * REQ_OP_ZONE_APPEND bios must never be split by the block layer.
+ *
+ * But we want the nr_segs calculation provided by bio_split_rw_at, and having
+ * a good sanity check that the submitter built the bio correctly is nice to
+ * have as well.
+ */
+struct bio *bio_split_zone_append(struct bio *bio,
+		const struct queue_limits *lim, unsigned *nr_segs)
+{
+	unsigned int max_sectors = queue_limits_max_zone_append_sectors(lim);
+	int split_sectors;
 
-	if (split) {
-		/* there isn't chance to merge the split bio */
-		split->bi_opf |= REQ_NOMERGE;
-
-		blkcg_bio_issue_init(split);
-		bio_chain(split, bio);
-		trace_block_split(split, bio->bi_iter.bi_sector);
-		WARN_ON_ONCE(bio_zone_write_plugging(bio));
-		submit_bio_noacct(bio);
-		return split;
-	}
-	return bio;
+	split_sectors = bio_split_rw_at(bio, lim, nr_segs,
+			max_sectors << SECTOR_SHIFT);
+	if (WARN_ON_ONCE(split_sectors > 0))
+		split_sectors = -EINVAL;
+	return bio_submit_split(bio, split_sectors);
 }
 
 /**
···
 	const struct queue_limits *lim = &bdev_get_queue(bio->bi_bdev)->limits;
 	unsigned int nr_segs;
 
-	if (bio_may_exceed_limits(bio, lim))
-		return __bio_split_to_limits(bio, lim, &nr_segs);
-	return bio;
+	return __bio_split_to_limits(bio, lim, &nr_segs);
 }
 EXPORT_SYMBOL(bio_split_to_limits);
 

block/blk-mq.c

···
 void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
 	struct request *rq;
+	unsigned int depth;
 
 	/*
 	 * We may have been called recursively midway through handling
···
 	 */
 	if (plug->rq_count == 0)
 		return;
+	depth = plug->rq_count;
 	plug->rq_count = 0;
 
 	if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
···
 
 		rq = rq_list_peek(&plug->mq_list);
 		q = rq->q;
+		trace_block_unplug(q, depth, true);
 
 		/*
 		 * Peek first request and see if we have a ->queue_rqs() hook.
···
 	struct blk_plug *plug = current->plug;
 	const int is_sync = op_is_sync(bio->bi_opf);
 	struct blk_mq_hw_ctx *hctx;
-	unsigned int nr_segs = 1;
+	unsigned int nr_segs;
 	struct request *rq;
 	blk_status_t ret;
 
···
 		goto queue_exit;
 	}
 
-	if (unlikely(bio_may_exceed_limits(bio, &q->limits))) {
-		bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
-		if (!bio)
-			goto queue_exit;
-	}
+	bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
+	if (!bio)
+		goto queue_exit;
+
 	if (!bio_integrity_prep(bio))
 		goto queue_exit;
 

block/blk-rq-qos.c

···
 	has_sleeper = !prepare_to_wait_exclusive(&rqw->wait, &data.wq,
 						 TASK_UNINTERRUPTIBLE);
 	do {
-		/* The memory barrier in set_task_state saves us here. */
+		/* The memory barrier in set_current_state saves us here. */
 		if (data.got_token)
 			break;
 		if (!has_sleeper && acquire_inflight_cb(rqw, private_data)) {

block/blk-throttle.c

···
 	spin_unlock_irq(&q->queue_lock);
 }
 
+static bool tg_within_limit(struct throtl_grp *tg, struct bio *bio, bool rw)
+{
+	/* throtl is FIFO - if bios are already queued, should queue */
+	if (tg->service_queue.nr_queued[rw])
+		return false;
+
+	return tg_may_dispatch(tg, bio, NULL);
+}
+
+static void tg_dispatch_in_debt(struct throtl_grp *tg, struct bio *bio, bool rw)
+{
+	if (!bio_flagged(bio, BIO_BPS_THROTTLED))
+		tg->carryover_bytes[rw] -= throtl_bio_data_size(bio);
+	tg->carryover_ios[rw]--;
+}
+
 bool __blk_throtl_bio(struct bio *bio)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
···
 	sq = &tg->service_queue;
 
 	while (true) {
-		if (tg->last_low_overflow_time[rw] == 0)
-			tg->last_low_overflow_time[rw] = jiffies;
-		/* throtl is FIFO - if bios are already queued, should queue */
-		if (sq->nr_queued[rw])
-			break;
+		if (tg_within_limit(tg, bio, rw)) {
+			/* within limits, let's charge and dispatch directly */
+			throtl_charge_bio(tg, bio);
 
-		/* if above limits, break to queue */
-		if (!tg_may_dispatch(tg, bio, NULL)) {
-			tg->last_low_overflow_time[rw] = jiffies;
+			/*
+			 * We need to trim slice even when bios are not being
+			 * queued otherwise it might happen that a bio is not
+			 * queued for a long time and slice keeps on extending
+			 * and trim is not called for a long time. Now if limits
+			 * are reduced suddenly we take into account all the IO
+			 * dispatched so far at new low rate and * newly queued
+			 * IO gets a really long dispatch time.
+			 *
+			 * So keep on trimming slice even if bio is not queued.
+			 */
+			throtl_trim_slice(tg, rw);
+		} else if (bio_issue_as_root_blkg(bio)) {
+			/*
+			 * IOs which may cause priority inversions are
+			 * dispatched directly, even if they're over limit.
+			 * Debts are handled by carryover_bytes/ios while
+			 * calculating wait time.
+			 */
+			tg_dispatch_in_debt(tg, bio, rw);
+		} else {
+			/* if above limits, break to queue */
 			break;
 		}
-
-		/* within limits, let's charge and dispatch directly */
-		throtl_charge_bio(tg, bio);
-
-		/*
-		 * We need to trim slice even when bios are not being queued
-		 * otherwise it might happen that a bio is not queued for
-		 * a long time and slice keeps on extending and trim is not
-		 * called for a long time. Now if limits are reduced suddenly
-		 * we take into account all the IO dispatched so far at new
-		 * low rate and * newly queued IO gets a really long dispatch
-		 * time.
-		 *
-		 * So keep on trimming slice even if bio is not queued.
-		 */
-		throtl_trim_slice(tg, rw);
 
 		/*
 		 * @bio passed through this layer without being throttled.
···
 		   tg_bps_limit(tg, rw),
 		   tg->io_disp[rw], tg_iops_limit(tg, rw),
 		   sq->nr_queued[READ], sq->nr_queued[WRITE]);
-
-	tg->last_low_overflow_time[rw] = jiffies;
 
 	td->nr_queued[rw]++;
 	throtl_add_bio_tg(bio, qn, tg);

block/blk-throttle.h

···
 	/* Number of bio's dispatched in current slice */
 	unsigned int io_disp[2];
 
-	unsigned long last_low_overflow_time[2];
-
 	uint64_t last_bytes_disp[2];
 	unsigned int last_io_disp[2];
 

block/blk.h

···
 ssize_t part_timeout_store(struct device *, struct device_attribute *,
 				const char *, size_t);
 
-static inline bool bio_may_exceed_limits(struct bio *bio,
-					 const struct queue_limits *lim)
-{
-	switch (bio_op(bio)) {
-	case REQ_OP_DISCARD:
-	case REQ_OP_SECURE_ERASE:
-	case REQ_OP_WRITE_ZEROES:
-		return true; /* non-trivial splitting decisions */
-	default:
-		break;
-	}
+struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
+		unsigned *nsegs);
+struct bio *bio_split_write_zeroes(struct bio *bio,
+		const struct queue_limits *lim, unsigned *nsegs);
+struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
+		unsigned *nr_segs);
+struct bio *bio_split_zone_append(struct bio *bio,
+		const struct queue_limits *lim, unsigned *nr_segs);
 
-	/*
-	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
-	 * This is a quick and dirty check that relies on the fact that
-	 * bi_io_vec[0] is always valid if a bio has data.  The check might
-	 * lead to occasional false negatives when bios are cloned, but compared
-	 * to the performance impact of cloned bios themselves the loop below
-	 * doesn't matter anyway.
-	 */
+/*
+ * All drivers must accept single-segments bios that are smaller than PAGE_SIZE.
+ *
+ * This is a quick and dirty check that relies on the fact that bi_io_vec[0] is
+ * always valid if a bio has data.  The check might lead to occasional false
+ * positives when bios are cloned, but compared to the performance impact of
+ * cloned bios themselves the loop below doesn't matter anyway.
+ */
+static inline bool bio_may_need_split(struct bio *bio,
+		const struct queue_limits *lim)
+{
 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
 }
 
-struct bio *__bio_split_to_limits(struct bio *bio,
-				  const struct queue_limits *lim,
-				  unsigned int *nr_segs);
+/**
+ * __bio_split_to_limits - split a bio to fit the queue limits
+ * @bio:     bio to be split
+ * @lim:     queue limits to split based on
+ * @nr_segs: returns the number of segments in the returned bio
+ *
+ * Check if @bio needs splitting based on the queue limits, and if so split off
+ * a bio fitting the limits from the beginning of @bio and return it.  @bio is
+ * shortened to the remainder and re-submitted.
+ *
+ * The split bio is allocated from @q->bio_split, which is provided by the
+ * block layer.
+ */
+static inline struct bio *__bio_split_to_limits(struct bio *bio,
+		const struct queue_limits *lim, unsigned int *nr_segs)
+{
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
+	case REQ_OP_WRITE:
+		if (bio_may_need_split(bio, lim))
+			return bio_split_rw(bio, lim, nr_segs);
+		*nr_segs = 1;
+		return bio;
+	case REQ_OP_ZONE_APPEND:
+		return bio_split_zone_append(bio, lim, nr_segs);
+	case REQ_OP_DISCARD:
+	case REQ_OP_SECURE_ERASE:
+		return bio_split_discard(bio, lim, nr_segs);
+	case REQ_OP_WRITE_ZEROES:
+		return bio_split_write_zeroes(bio, lim, nr_segs);
+	default:
+		/* other operations can't be split */
+		*nr_segs = 0;
+		return bio;
+	}
+}
+
 int ll_back_merge_fn(struct request *req, struct bio *bio,
 		unsigned int nr_segs);
 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
···
 
 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);
 
 /*

block/ioctl.c

···
 		return -EINVAL;
 
 	filemap_invalidate_lock(bdev->bd_mapping);
-	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
+	err = truncate_bdev_range(bdev, mode, start, end - 1);
 	if (err)
 		goto fail;
 
···
 static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode,
 		void __user *argp)
 {
-	uint64_t start, len;
+	uint64_t start, len, end;
 	uint64_t range[2];
 	int err;
 
···
 	len = range[1];
 	if ((start & 511) || (len & 511))
 		return -EINVAL;
-	if (start + len > bdev_nr_bytes(bdev))
+	if (check_add_overflow(start, len, &end) ||
+	    end > bdev_nr_bytes(bdev))
 		return -EINVAL;
 
 	filemap_invalidate_lock(bdev->bd_mapping);
-	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
+	err = truncate_bdev_range(bdev, mode, start, end - 1);
 	if (!err)
 		err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9,
 						GFP_KERNEL);

block/t10-pi.c

···
 #include <linux/blk-integrity.h>
 #include <linux/crc-t10dif.h>
 #include <linux/crc64.h>
-#include <linux/module.h>
 #include <net/checksum.h>
 #include <asm/unaligned.h>
 #include "blk.h"
···
 	}
 }
 
-static bool ext_pi_ref_escape(u8 *ref_tag)
+static bool ext_pi_ref_escape(const u8 ref_tag[6])
 {
-	static u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+	static const u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
 	return memcmp(ref_tag, ref_escape, sizeof(ref_escape)) == 0;
 }
···
 	else
 		t10_pi_type1_complete(rq, nr_bytes);
 }
-
-MODULE_DESCRIPTION("T10 Protection Information module");
-MODULE_LICENSE("GPL");

drivers/block/drbd/drbd_int.h

···
 	unsigned long flags;
 };
 
-/* Prototype declaration of function defined in drbd_receiver.c */
-int drbdd_init(struct drbd_thread *);
-int drbd_asender(struct drbd_thread *);
-
 /* drbd_epoch flag bits */
 enum {
 	DE_HAVE_BARRIER_NUMBER,
···
 	struct list_head read_ee;   /* [RS]P_DATA_REQUEST being read */
 	struct list_head net_ee;    /* zero-copy network send in progress */
 
-	int next_barrier_nr;
 	struct list_head resync_reads;
 	atomic_t pp_in_use;		/* allocated from page pool */
 	atomic_t pp_in_use_by_net;	/* sendpage()d, still referenced by tcp */
···
 extern void do_submit(struct work_struct *ws);
 extern void __drbd_make_request(struct drbd_device *, struct bio *);
 void drbd_submit_bio(struct bio *bio);
-extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);
-extern int is_valid_ar_handle(struct drbd_request *, sector_t);
-
 
 /* drbd_nl.c */
 
···
 extern int w_send_write_hint(struct drbd_work *, int);
 extern int w_send_dblock(struct drbd_work *, int);
 extern int w_send_read_req(struct drbd_work *, int);
-extern int w_e_reissue(struct drbd_work *, int);
 extern int w_restart_disk_io(struct drbd_work *, int);
 extern int w_send_out_of_sync(struct drbd_work *, int);
 
···
 		sector_t start, unsigned int nr_sectors, int flags);
 extern int drbd_receiver(struct drbd_thread *thi);
 extern int drbd_ack_receiver(struct drbd_thread *thi);
-extern void drbd_send_ping_wf(struct work_struct *ws);
 extern void drbd_send_acks_wf(struct work_struct *ws);
 extern bool drbd_rs_c_min_rate_throttle(struct drbd_device *device);
 extern bool drbd_rs_should_slow_down(struct drbd_peer_device *peer_device, sector_t sector,
···
 #define drbd_free_peer_req(m,e) __drbd_free_peer_req(m, e, 0)
 #define drbd_free_net_peer_req(m,e) __drbd_free_peer_req(m, e, 1)
 extern struct page *drbd_alloc_pages(struct drbd_peer_device *, unsigned int, bool);
-extern void drbd_set_recv_tcq(struct drbd_device *device, int tcq_enabled);
 extern void _drbd_clear_done_ee(struct drbd_device *device, struct list_head *to_be_freed);
 extern int drbd_connected(struct drbd_peer_device *);
 

drivers/block/drbd/drbd_main.c

···
 	 * put_page(); and would cause either a VM_BUG directly, or
 	 * __page_cache_release a page that would actually still be referenced
 	 * by someone, leading to some obscure delayed Oops somewhere else. */
-	if (!drbd_disable_sendpage && sendpage_ok(page))
+	if (!drbd_disable_sendpage && sendpages_ok(page, len, offset))
 		msg.msg_flags |= MSG_NOSIGNAL | MSG_SPLICE_PAGES;
 
 	drbd_update_congested(peer_device->connection);

drivers/block/drbd/drbd_state.c

···
 		  ns.disk == D_OUTDATED)
 		rv = SS_CONNECTED_OUTDATES;
 
-	else if ((ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
+	else if (nc && (ns.conn == C_VERIFY_S || ns.conn == C_VERIFY_T) &&
 		 (nc->verify_alg[0] == 0))
 		rv = SS_NO_VERIFY_ALG;
 

drivers/block/mtip32xx/mtip32xx.c

···
 	.llseek = no_llseek,
 };
 
-static int mtip_hw_debugfs_init(struct driver_data *dd)
+static void mtip_hw_debugfs_init(struct driver_data *dd)
 {
-	if (!dfs_parent)
-		return -1;
-
 	dd->dfs_node = debugfs_create_dir(dd->disk->disk_name, dfs_parent);
-	if (IS_ERR_OR_NULL(dd->dfs_node)) {
-		dev_warn(&dd->pdev->dev,
-			"Error creating node %s under debugfs\n",
-						dd->disk->disk_name);
-		dd->dfs_node = NULL;
-		return -1;
-	}
-
 	debugfs_create_file("flags", 0444, dd->dfs_node, dd, &mtip_flags_fops);
 	debugfs_create_file("registers", 0444, dd->dfs_node, dd,
 			    &mtip_regs_fops);
-
-	return 0;
 }
 
 static void mtip_hw_debugfs_exit(struct driver_data *dd)
···
 	mtip_major = error;
 
 	dfs_parent = debugfs_create_dir("rssd", NULL);
-	if (IS_ERR_OR_NULL(dfs_parent)) {
-		pr_warn("Error creating debugfs parent\n");
-		dfs_parent = NULL;
-	}
 
 	/* Register our PCI operations. */
 	error = pci_register_driver(&mtip_pci_driver);

drivers/block/nbd.c

···
 {
 	struct request *req = blk_mq_rq_from_pdu(cmd);
 
+	lockdep_assert_held(&cmd->lock);
+
+	/*
+	 * Clear INFLIGHT flag so that this cmd won't be completed in
+	 * normal completion path
+	 *
+	 * INFLIGHT flag will be set when the cmd is queued to nbd next
+	 * time.
+	 */
+	__clear_bit(NBD_CMD_INFLIGHT, &cmd->flags);
+
 	if (!test_and_set_bit(NBD_CMD_REQUEUED, &cmd->flags))
 		blk_mq_requeue_request(req, true);
 }
···
 
 	lim = queue_limits_start_update(nbd->disk->queue);
 	if (nbd->config->flags & NBD_FLAG_SEND_TRIM)
-		lim.max_hw_discard_sectors = UINT_MAX;
+		lim.max_hw_discard_sectors = UINT_MAX >> SECTOR_SHIFT;
 	else
 		lim.max_hw_discard_sectors = 0;
 	if (!(nbd->config->flags & NBD_FLAG_SEND_FLUSH)) {
···
 		lim.features |= BLK_FEAT_WRITE_CACHE;
 		lim.features &= ~BLK_FEAT_FUA;
 	}
+	if (nbd->config->flags & NBD_FLAG_ROTATIONAL)
+		lim.features |= BLK_FEAT_ROTATIONAL;
+	if (nbd->config->flags & NBD_FLAG_SEND_WRITE_ZEROES)
+		lim.max_write_zeroes_sectors = UINT_MAX >> SECTOR_SHIFT;
+
 	lim.logical_block_size = blksize;
 	lim.physical_block_size = blksize;
 	error = queue_limits_commit_update(nbd->disk->queue, &lim);
···
 		return NBD_CMD_WRITE;
 	case REQ_OP_READ:
 		return NBD_CMD_READ;
+	case REQ_OP_WRITE_ZEROES:
+		return NBD_CMD_WRITE_ZEROES;
 	default:
 		return U32_MAX;
 	}
···
 					nbd_mark_nsock_dead(nbd, nsock, 1);
 				mutex_unlock(&nsock->tx_lock);
 			}
-			mutex_unlock(&cmd->lock);
 			nbd_requeue_cmd(cmd);
+			mutex_unlock(&cmd->lock);
 			nbd_config_put(nbd);
 			return BLK_EH_DONE;
 		}
···
 
 	if (req->cmd_flags & REQ_FUA)
 		nbd_cmd_flags |= NBD_CMD_FLAG_FUA;
+	if ((req->cmd_flags & REQ_NOUNMAP) && (type == NBD_CMD_WRITE_ZEROES))
+		nbd_cmd_flags |= NBD_CMD_FLAG_NO_HOLE;
 
 	/* We did a partial send previously, and we at least sent the whole
 	 * request struct, so just go and send the rest of the pages in the
···
 		seq_puts(s, "NBD_FLAG_SEND_FUA\n");
 	if (flags & NBD_FLAG_SEND_TRIM)
 		seq_puts(s, "NBD_FLAG_SEND_TRIM\n");
+	if (flags & NBD_FLAG_SEND_WRITE_ZEROES)
+		seq_puts(s, "NBD_FLAG_SEND_WRITE_ZEROES\n");
+	if (flags & NBD_FLAG_ROTATIONAL)
+		seq_puts(s, "NBD_FLAG_ROTATIONAL\n");
 
 	return 0;
 }

drivers/block/pktcdvd.c

···
 	if (!pkt_debugfs_root)
 		return;
 	pd->dfs_d_root = debugfs_create_dir(pd->disk->disk_name, pkt_debugfs_root);
-	if (!pd->dfs_d_root)
-		return;
 
 	pd->dfs_f_info = debugfs_create_file("info", 0444, pd->dfs_d_root,
 					     pd, &pkt_seq_fops);

drivers/block/rnbd/rnbd-srv.c

···
 			rnbd_to_bio_flags(le32_to_cpu(msg->rw)), GFP_KERNEL);
 	if (bio_add_page(bio, virt_to_page(data), datalen,
 			offset_in_page(data)) != datalen) {
-		rnbd_srv_err(sess_dev, "Failed to map data to bio\n");
+		rnbd_srv_err_rl(sess_dev, "Failed to map data to bio\n");
 		err = -EINVAL;
 		goto bio_put;
 	}
 
+	bio->bi_opf = rnbd_to_bio_flags(le32_to_cpu(msg->rw));
+	if (bio_has_data(bio) &&
+	    bio->bi_iter.bi_size != le32_to_cpu(msg->bi_size)) {
+		rnbd_srv_err_rl(sess_dev, "Datalen mismatch:  bio bi_size (%u), bi_size (%u)\n",
+				bio->bi_iter.bi_size, msg->bi_size);
+		err = -EINVAL;
+		goto bio_put;
+	}
 	bio->bi_end_io = rnbd_dev_bi_end_io;
 	bio->bi_private = priv;
 	bio->bi_iter.bi_sector = le64_to_cpu(msg->sector);
-	bio->bi_iter.bi_size = le32_to_cpu(msg->bi_size);
 	prio = srv_sess->ver < RNBD_PROTO_VER_MAJOR ||
 	       usrlen < sizeof(*msg) ? 0 : le16_to_cpu(msg->prio);
 	bio_set_prio(bio, prio);

drivers/block/ublk_drv.c

···
 	struct llist_node node;
 
 	struct kref ref;
-	__u64 sector;
-	__u32 operation;
-	__u32 nr_zones;
 };
 
 struct ublk_uring_cmd_pdu {
···
 
 #ifdef CONFIG_BLK_DEV_ZONED
 
+struct ublk_zoned_report_desc {
+	__u64 sector;
+	__u32 operation;
+	__u32 nr_zones;
+};
+
+static DEFINE_XARRAY(ublk_zoned_report_descs);
+
+static int ublk_zoned_insert_report_desc(const struct request *req,
+		struct ublk_zoned_report_desc *desc)
+{
+	return xa_insert(&ublk_zoned_report_descs, (unsigned long)req,
+			    desc, GFP_KERNEL);
+}
+
+static struct ublk_zoned_report_desc *ublk_zoned_erase_report_desc(
+		const struct request *req)
+{
+	return xa_erase(&ublk_zoned_report_descs, (unsigned long)req);
+}
+
+static struct ublk_zoned_report_desc *ublk_zoned_get_report_desc(
+		const struct request *req)
+{
+	return xa_load(&ublk_zoned_report_descs, (unsigned long)req);
+}
+
 static int ublk_get_nr_zones(const struct ublk_device *ub)
 {
 	const struct ublk_param_basic *p = &ub->params.basic;
···
 		unsigned int zones_in_request =
 			min_t(unsigned int, remaining_zones, max_zones_per_request);
 		struct request *req;
-		struct ublk_rq_data *pdu;
+		struct ublk_zoned_report_desc desc;
 		blk_status_t status;
 
 		memset(buffer, 0, buffer_length);
···
 			goto out;
 		}
 
-		pdu = blk_mq_rq_to_pdu(req);
-		pdu->operation = UBLK_IO_OP_REPORT_ZONES;
-		pdu->sector = sector;
-		pdu->nr_zones = zones_in_request;
+		desc.operation = UBLK_IO_OP_REPORT_ZONES;
+		desc.sector = sector;
+		desc.nr_zones = zones_in_request;
+		ret = ublk_zoned_insert_report_desc(req, &desc);
+		if (ret)
+			goto free_req;
 
 		ret = blk_rq_map_kern(disk->queue, req, buffer, buffer_length,
 					GFP_KERNEL);
-		if (ret) {
-			blk_mq_free_request(req);
-			goto out;
-		}
+		if (ret)
+			goto erase_desc;
 
 		status = blk_execute_rq(req, 0);
 		ret = blk_status_to_errno(status);
+erase_desc:
+		ublk_zoned_erase_report_desc(req);
+free_req:
 		blk_mq_free_request(req);
 		if (ret)
 			goto out;
···
 {
 	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
 	struct ublk_io *io = &ubq->ios[req->tag];
-	struct ublk_rq_data *pdu = blk_mq_rq_to_pdu(req);
+	struct ublk_zoned_report_desc *desc;
 	u32 ublk_op;
 
 	switch (req_op(req)) {
···
 		ublk_op = UBLK_IO_OP_ZONE_RESET_ALL;
 		break;
 	case REQ_OP_DRV_IN:
-		ublk_op = pdu->operation;
+		desc = ublk_zoned_get_report_desc(req);
+		if (!desc)
+			return BLK_STS_IOERR;
+		ublk_op = desc->operation;
 		switch (ublk_op) {
 		case UBLK_IO_OP_REPORT_ZONES:
 			iod->op_flags = ublk_op | ublk_req_build_flags(req);
-			iod->nr_zones = pdu->nr_zones;
-			iod->start_sector = pdu->sector;
+			iod->nr_zones = desc->nr_zones;
+			iod->start_sector = desc->sector;
 			return BLK_STS_OK;
 		default:
 			return BLK_STS_IOERR;

drivers/block/zram/zram_drv.c

···
 
 static int zram_slot_trylock(struct zram *zram, u32 index)
 {
-	return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags);
+	return spin_trylock(&zram->table[index].lock);
 }
 
 static void zram_slot_lock(struct zram *zram, u32 index)
 {
-	bit_spin_lock(ZRAM_LOCK, &zram->table[index].flags);
+	spin_lock(&zram->table[index].lock);
 }
 
 static void zram_slot_unlock(struct zram *zram, u32 index)
 {
-	bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags);
+	spin_unlock(&zram->table[index].lock);
 }
 
 static inline bool init_done(struct zram *zram)
···
 
 static bool zram_meta_alloc(struct zram *zram, u64 disksize)
 {
-	size_t num_pages;
+	size_t num_pages, index;
 
 	num_pages = disksize >> PAGE_SHIFT;
 	zram->table = vzalloc(array_size(num_pages, sizeof(*zram->table)));
···
 
 	if (!huge_class_size)
 		huge_class_size = zs_huge_class_size(zram->mem_pool);
+
+	for (index = 0; index < num_pages; index++)
+		spin_lock_init(&zram->table[index].lock);
 	return true;
 }
 
···
 	zram_set_handle(zram, index, 0);
 	zram_set_obj_size(zram, index, 0);
 	WARN_ON_ONCE(zram->table[index].flags &
-		~(1UL << ZRAM_LOCK | 1UL << ZRAM_UNDER_WB));
+		~(1UL << ZRAM_UNDER_WB));
 }
 
 /*
···
 
 static int __init zram_init(void)
 {
+	struct zram_table_entry zram_te;
 	int ret;
 
-	BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > BITS_PER_LONG);
+	BUILD_BUG_ON(__NR_ZRAM_PAGEFLAGS > sizeof(zram_te.flags) * 8);
 
 	ret = cpuhp_setup_state_multi(CPUHP_ZCOMP_PREPARE, "block/zram:prepare",
 				      zcomp_cpu_up_prepare, zcomp_cpu_dead);

drivers/block/zram/zram_drv.h

···
 
 /* Flags for zram pages (table[page_no].flags) */
 enum zram_pageflags {
-	/* zram slot is locked */
-	ZRAM_LOCK = ZRAM_FLAG_SHIFT,
-	ZRAM_SAME,	/* Page consists the same element */
+	ZRAM_SAME = ZRAM_FLAG_SHIFT,	/* Page consists the same element */
 	ZRAM_WB,	/* page is stored on backing_device */
 	ZRAM_UNDER_WB,	/* page is under writeback */
 	ZRAM_HUGE,	/* Incompressible page */
···
 		unsigned long handle;
 		unsigned long element;
 	};
-	unsigned long flags;
+	unsigned int flags;
+	spinlock_t lock;
 #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
 	ktime_t ac_time;
 #endif

drivers/md/dm-raid.c

···
 	/* Try loading the bitmap unless "raid0", which does not have one */
 	if (!rs_is_raid0(rs) &&
 	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
-		r = md_bitmap_load(&rs->md);
+		struct mddev *mddev = &rs->md;
+
+		r = mddev->bitmap_ops->load(mddev);
 		if (r)
 			DMERR("Failed to load bitmap");
 	}
···
 	       mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
 		int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
 
-		r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
+		r = mddev->bitmap_ops->resize(mddev, mddev->dev_sectors,
+					      chunksize, false);
 		if (r)
 			DMERR("Failed to resize bitmap");
 	}

drivers/md/md-bitmap.c

···
 #include "md.h"
 #include "md-bitmap.h"
 
+#define BITMAP_MAJOR_LO 3
+/* version 4 insists the bitmap is in little-endian order
+ * with version 3, it is host-endian which is non-portable
+ * Version 5 is currently set only for clustered devices
+ */
+#define BITMAP_MAJOR_HI 4
+#define BITMAP_MAJOR_CLUSTERED 5
+#define	BITMAP_MAJOR_HOSTENDIAN 3
+
+/*
+ * in-memory bitmap:
+ *
+ * Use 16 bit block counters to track pending writes to each "chunk".
+ * The 2 high order bits are special-purpose, the first is a flag indicating
+ * whether a resync is needed.  The second is a flag indicating whether a
+ * resync is active.
+ * This means that the counter is actually 14 bits:
+ *
+ * +--------+--------+------------------------------------------------+
+ * | resync | resync |               counter                          |
+ * | needed | active |                                                |
+ * |  (0-1) |  (0-1) |              (0-16383)                         |
+ * +--------+--------+------------------------------------------------+
+ *
+ * The "resync needed" bit is set when:
+ *    a '1' bit is read from storage at startup.
+ *    a write request fails on some drives
+ *    a resync is aborted on a chunk with 'resync active' set
+ * It is cleared (and resync-active set) when a resync starts across all drives
+ * of the chunk.
+ *
+ *
+ * The "resync active" bit is set when:
+ *    a resync is started on all drives, and resync_needed is set.
+ *       resync_needed will be cleared (as long as resync_active wasn't already set).
+ * It is cleared when a resync completes.
+ *
+ * The counter counts pending write requests, plus the on-disk bit.
+ * When the counter is '1' and the resync bits are clear, the on-disk
+ * bit can be cleared as well, thus setting the counter to 0.
+ * When we set a bit, or in the counter (to start a write), if the fields is
+ * 0, we first set the disk bit and set the counter to 1.
+ *
+ * If the counter is 0, the on-disk bit is clear and the stripe is clean
+ * Anything that dirties the stripe pushes the counter to 2 (at least)
+ * and sets the on-disk bit (lazily).
+ * If a periodic sweep find the counter at 2, it is decremented to 1.
+ * If the sweep find the counter at 1, the on-disk bit is cleared and the
+ * counter goes to zero.
+ *
+ * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
+ * counters as a fallback when "page" memory cannot be allocated:
+ *
+ * Normal case (page memory allocated):
+ *
+ *     page pointer (32-bit)
+ *
+ *     [ ] ------+
+ *               |
+ *               +-------> [   ][   ]..[   ] (4096 byte page == 2048 counters)
+ *                          c1   c2    c2048
+ *
+ * Hijacked case (page memory allocation failed):
+ *
+ *     hijacked page pointer (32-bit)
+ *
+ *     [		  ][		  ] (no page memory allocated)
+ *      counter #1 (16-bit) counter #2 (16-bit)
+ *
+ */
+
+#define PAGE_BITS (PAGE_SIZE << 3)
+#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
+
+#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
+#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
+#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
+
+/* how many counters per page? */
+#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
+/* same, except a shift value for more efficient bitops */
+#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
+/* same, except a mask value for more efficient bitops */
+#define PAGE_COUNTER_MASK  (PAGE_COUNTER_RATIO - 1)
+
+#define BITMAP_BLOCK_SHIFT 9
+
+/*
+ * bitmap structures:
+ */
+
+/* the in-memory bitmap is represented by bitmap_pages */
+struct bitmap_page {
+	/*
+	 * map points to the actual memory page
+	 */
+	char *map;
+	/*
+	 * in emergencies (when map cannot be alloced), hijack the map
+	 * pointer and use it as two counters itself
+	 */
+	unsigned int hijacked:1;
+	/*
+	 * If any counter in this page is '1' or '2' - and so could be
+	 * cleared then that page is marked as 'pending'
+	 */
+	unsigned int pending:1;
+	/*
+	 * count of dirty bits on the page
+	 */
+	unsigned int  count:30;
+};
+
+/* the main bitmap structure - one per mddev */
+struct bitmap {
+
+	struct bitmap_counts {
+		spinlock_t lock;
+		struct bitmap_page *bp;
+		/* total number of pages in the bitmap */
+		unsigned long pages;
+		/* number of pages not yet allocated */
+		unsigned long missing_pages;
+		/* chunksize = 2^chunkshift (for bitops) */
+		unsigned long chunkshift;
+		/* total number of data chunks for the array */
+		unsigned long chunks;
+	} counts;
+
+	struct mddev *mddev; /* the md device that the bitmap is for */
+
+	__u64	events_cleared;
+	int need_sync;
+
+	struct bitmap_storage {
+		/* backing disk file */
+		struct file *file;
+		/* cached copy of the bitmap file superblock */
+		struct page *sb_page;
+		unsigned long sb_index;
+		/* list of cache pages for the file */
+		struct page **filemap;
+		/* attributes associated filemap pages */
+		unsigned long *filemap_attr;
+		/* number of pages in the file */
+		unsigned long file_pages;
+		/* total bytes in the bitmap */
+		unsigned long bytes;
+	} storage;
+
+	unsigned long flags;
+
+	int allclean;
+
+	atomic_t behind_writes;
+	/* highest actual value at runtime */
+	unsigned long behind_writes_used;
+
+	/*
+	 * the bitmap daemon - periodically wakes up and sweeps the bitmap
+	 * file, cleaning up bits and flushing out pages to disk as necessary
+	 */
+	unsigned long daemon_lastrun; /* jiffies of last run */
+	/*
+	 * when we lasted called end_sync to update bitmap with resync
+	 * progress.
+	 */
+	unsigned long last_end_sync;
+
+	/* pending writes to the bitmap file */
+	atomic_t pending_writes;
+	wait_queue_head_t write_wait;
+	wait_queue_head_t overflow_wait;
+	wait_queue_head_t behind_wait;
+
+	struct kernfs_node *sysfs_can_clear;
+	/* slot offset for clustered env */
+	int cluster_slot;
+};
+
+static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
+			   int chunksize, bool init);
+
 static inline char *bmname(struct bitmap *bitmap)
 {
 	return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
+}
+
+static bool __bitmap_enabled(struct bitmap *bitmap)
+{
+	return bitmap->storage.filemap &&
+	       !test_bit(BITMAP_STALE, &bitmap->flags);
+}
+
+static bool bitmap_enabled(struct mddev *mddev)
+{
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
+		return false;
+
+	return __bitmap_enabled(bitmap);
 }
 
 /*
···
 
 
 /* update the event counter and sync the superblock to disk */
-void md_bitmap_update_sb(struct bitmap *bitmap)
+static void bitmap_update_sb(void *data)
 {
 	bitmap_super_t *sb;
+	struct bitmap *bitmap = data;
 
 	if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
 		return;
···
 		write_sb_page(bitmap, bitmap->storage.sb_index,
 			      bitmap->storage.sb_page, 1);
 }
-EXPORT_SYMBOL(md_bitmap_update_sb);
 
-/* print out the bitmap file superblock */
-void md_bitmap_print_sb(struct bitmap *bitmap)
+static void bitmap_print_sb(struct bitmap *bitmap)
 {
 	bitmap_super_t *sb;
 
···
 			bitmap->mddev->bitmap_info.space > sectors_reserved)
 			bitmap->mddev->bitmap_info.space = sectors_reserved;
 	} else {
-		md_bitmap_print_sb(bitmap);
+		bitmap_print_sb(bitmap);
 		if (bitmap->cluster_slot < 0)
 			md_cluster_stop(bitmap->mddev);
 	}
···
 static void md_bitmap_file_kick(struct bitmap *bitmap)
 {
 	if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
-		md_bitmap_update_sb(bitmap);
+		bitmap_update_sb(bitmap);
 
 		if (bitmap->storage.file) {
 			pr_warn("%s: kicking failed bitmap file %pD4 from array!\n",
···
 /* this gets called when the md device is ready to unplug its underlying
  * (slave) device queues -- before we let any writes go down, we need to
  * sync the dirty pages of the bitmap file to disk */
-void md_bitmap_unplug(struct bitmap *bitmap)
+static void __bitmap_unplug(struct bitmap *bitmap)
 {
 	unsigned long i;
 	int dirty, need_write;
 	int writing = 0;
 
-	if (!md_bitmap_enabled(bitmap))
+	if (!__bitmap_enabled(bitmap))
 		return;
 
 	/* look at each page to see if there are any set bits that need to be
···
 	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
 		md_bitmap_file_kick(bitmap);
 }
-EXPORT_SYMBOL(md_bitmap_unplug);
 
 struct bitmap_unplug_work {
 	struct work_struct work;
···
 	struct bitmap_unplug_work *unplug_work =
 		container_of(work, struct bitmap_unplug_work, work);
 
-	md_bitmap_unplug(unplug_work->bitmap);
+	__bitmap_unplug(unplug_work->bitmap);
 	complete(unplug_work->done);
 }
 
-void md_bitmap_unplug_async(struct bitmap *bitmap)
+static void bitmap_unplug_async(struct bitmap *bitmap)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
 	struct bitmap_unplug_work unplug_work;
···
 	queue_work(md_bitmap_wq, &unplug_work.work);
 	wait_for_completion(&done);
 }
-EXPORT_SYMBOL(md_bitmap_unplug_async);
+
+static void bitmap_unplug(struct mddev *mddev, bool sync)
+{
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
+		return;
+
+	if (sync)
+		__bitmap_unplug(bitmap);
+	else
+		bitmap_unplug_async(bitmap);
+}
 
 static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
 
···
 	return ret;
 }
 
-void md_bitmap_write_all(struct bitmap *bitmap)
+/* just flag bitmap pages as needing to be written. */
+static void bitmap_write_all(struct mddev *mddev)
 {
-	/* We don't actually write all bitmap blocks here,
-	 * just flag them as needing to be written
-	 */
 	int i;
+	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap || !bitmap->storage.filemap)
 		return;
+
+	/* Only one copy, so nothing needed */
 	if (bitmap->storage.file)
-		/* Only one copy, so nothing needed */
 		return;
 
 	for (i = 0; i < bitmap->storage.file_pages; i++)
-		set_page_attr(bitmap, i,
-			      BITMAP_PAGE_NEEDWRITE);
+		set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
 	bitmap->allclean = 0;
 }
 
···
  * bitmap daemon -- periodically wakes up to clean bits and flush pages
  *			out to disk
  */
-void md_bitmap_daemon_work(struct mddev *mddev)
+static void bitmap_daemon_work(struct mddev *mddev)
 {
 	struct bitmap *bitmap;
 	unsigned long j;
···
 			&(bitmap->bp[page].map[pageoff]);
 }
 
-int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
+static int bitmap_startwrite(struct mddev *mddev, sector_t offset,
+			     unsigned long sectors, bool behind)
 {
+	struct bitmap *bitmap = mddev->bitmap;
+
 	if (!bitmap)
 		return 0;
 
···
 	}
 	return 0;
 }
-EXPORT_SYMBOL(md_bitmap_startwrite);
 
-void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
-			unsigned long sectors, int success, int behind)
+static void bitmap_endwrite(struct mddev *mddev, sector_t offset,
+			    unsigned long sectors, bool success, bool behind)
 {
+	struct bitmap *bitmap = mddev->bitmap;
+
 	if (!bitmap)
 		return;
+
 	if (behind) {
 		if (atomic_dec_and_test(&bitmap->behind_writes))
 			wake_up(&bitmap->behind_wait);
···
 			sectors = 0;
 	}
 }
-EXPORT_SYMBOL(md_bitmap_endwrite);
 
-static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
-			       int degraded)
+static bool __bitmap_start_sync(struct bitmap *bitmap, sector_t offset,
+				sector_t *blocks, bool degraded)
 {
 	bitmap_counter_t *bmc;
-	int rv;
+	bool rv;
+
 	if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
 		*blocks = 1024;
-		return 1; /* always resync if no bitmap */
+		return true; /* always resync if no bitmap */
 	}
 	spin_lock_irq(&bitmap->counts.lock);
+
+	rv = false;
 	bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
-	rv = 0;
 	if (bmc) {
 		/* locked */
-		if (RESYNC(*bmc))
-			rv = 1;
-		else if (NEEDED(*bmc)) {
-			rv = 1;
+		if (RESYNC(*bmc)) {
+			rv = true;
+		} else if (NEEDED(*bmc)) {
+			rv = true;
 			if (!degraded) { /* don't set/clear bits if degraded */
 				*bmc |= RESYNC_MASK;
 				*bmc &= ~NEEDED_MASK;
···
 		}
 	}
 	spin_unlock_irq(&bitmap->counts.lock);
+
 	return rv;
 }
 
-int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
-			 int degraded)
+static bool bitmap_start_sync(struct mddev *mddev, sector_t offset,
+			      sector_t *blocks, bool degraded)
 {
 	/* bitmap_start_sync must always report on multiples of whole
 	 * pages, otherwise resync (which is very PAGE_SIZE based) will
···
 	 * At least PAGE_SIZE>>9 blocks are covered.
 	 * Return the 'or' of the result.
 	 */
-	int rv = 0;
+	bool rv = false;
 	sector_t blocks1;
 
 	*blocks = 0;
 	while (*blocks < (PAGE_SIZE>>9)) {
-		rv |= __bitmap_start_sync(bitmap, offset,
+		rv |= __bitmap_start_sync(mddev->bitmap, offset,
 					  &blocks1, degraded);
 		offset += blocks1;
 		*blocks += blocks1;
 	}
+
 	return rv;
 }
-EXPORT_SYMBOL(md_bitmap_start_sync);
 
-void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
+static void __bitmap_end_sync(struct bitmap *bitmap, sector_t offset,
+			      sector_t *blocks, bool aborted)
 {
 	bitmap_counter_t *bmc;
 	unsigned long flags;
···
  unlock:
 	spin_unlock_irqrestore(&bitmap->counts.lock, flags);
 }
-EXPORT_SYMBOL(md_bitmap_end_sync);
 
-void md_bitmap_close_sync(struct bitmap *bitmap)
+static void bitmap_end_sync(struct mddev *mddev, sector_t offset,
+			    sector_t *blocks)
+{
+	__bitmap_end_sync(mddev->bitmap, offset, blocks, true);
+}
+
+static void bitmap_close_sync(struct mddev *mddev)
 {
 	/* Sync has finished, and any bitmap chunks that weren't synced
 	 * properly have been aborted.  It remains to us to clear the
···
 	 */
 	sector_t sector = 0;
 	sector_t blocks;
+	struct bitmap *bitmap = mddev->bitmap;
+
 	if (!bitmap)
 		return;
+
 	while (sector < bitmap->mddev->resync_max_sectors) {
-		md_bitmap_end_sync(bitmap, sector, &blocks, 0);
+		__bitmap_end_sync(bitmap, sector, &blocks, false);
 		sector += blocks;
 	}
 }
-EXPORT_SYMBOL(md_bitmap_close_sync);
 
-void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
+static void bitmap_cond_end_sync(struct mddev *mddev, sector_t sector,
+				 bool force)
 {
 	sector_t s = 0;
 	sector_t blocks;
+	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap)
 		return;
···
 	sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
 	s = 0;
 	while (s < sector && s < bitmap->mddev->resync_max_sectors) {
-		md_bitmap_end_sync(bitmap, s, &blocks, 0);
+		__bitmap_end_sync(bitmap, s, &blocks, false);
 		s += blocks;
 	}
 	bitmap->last_end_sync = jiffies;
 	sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
 }
-EXPORT_SYMBOL(md_bitmap_cond_end_sync);
 
-void md_bitmap_sync_with_cluster(struct mddev *mddev,
-			      sector_t old_lo, sector_t old_hi,
-			      sector_t new_lo, sector_t new_hi)
+static void bitmap_sync_with_cluster(struct mddev *mddev,
+				     sector_t old_lo, sector_t old_hi,
+				     sector_t new_lo, sector_t new_hi)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 	sector_t sector, blocks = 0;
 
 	for (sector = old_lo; sector < new_lo; ) {
-		md_bitmap_end_sync(bitmap, sector, &blocks, 0);
+		__bitmap_end_sync(bitmap, sector, &blocks, false);
 		sector += blocks;
 	}
 	WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
 
 	for (sector = old_hi; sector < new_hi; ) {
-		md_bitmap_start_sync(bitmap, sector, &blocks, 0);
+		bitmap_start_sync(mddev, sector, &blocks, false);
 		sector += blocks;
 	}
 	WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
 }
-EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
 
 static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
 {
···
 }
 
 /* dirty the memory and file bits for bitmap chunks "s" to "e" */
-void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
+static void bitmap_dirty_bits(struct mddev *mddev, unsigned long s,
+			      unsigned long e)
 {
 	unsigned long chunk;
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
+		return;
 
 	for (chunk = s; chunk <= e; chunk++) {
 		sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
+
 		md_bitmap_set_memory_bits(bitmap, sec, 1);
 		md_bitmap_file_set_bit(bitmap, sec);
 		if (sec < bitmap->mddev->recovery_cp)
···
 	}
 }
 
-/*
- * flush out any pending updates
- */
-void md_bitmap_flush(struct mddev *mddev)
+static void bitmap_flush(struct mddev *mddev)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 	long sleep;
···
 	 */
 	sleep = mddev->bitmap_info.daemon_sleep * 2;
 	bitmap->daemon_lastrun -= sleep;
-	md_bitmap_daemon_work(mddev);
+	bitmap_daemon_work(mddev);
 	bitmap->daemon_lastrun -= sleep;
-	md_bitmap_daemon_work(mddev);
+	bitmap_daemon_work(mddev);
 	bitmap->daemon_lastrun -= sleep;
-	md_bitmap_daemon_work(mddev);
+	bitmap_daemon_work(mddev);
 	if (mddev->bitmap_info.external)
 		md_super_wait(mddev);
-	md_bitmap_update_sb(bitmap);
+	bitmap_update_sb(bitmap);
 }
 
-/*
- * free memory that was allocated
- */
-void md_bitmap_free(struct bitmap *bitmap)
+static void md_bitmap_free(void *data)
 {
 	unsigned long k, pages;
 	struct bitmap_page *bp;
+	struct bitmap *bitmap = data;
 
 	if (!bitmap) /* there was no bitmap */
 		return;
···
 	kfree(bp);
 	kfree(bitmap);
 }
-EXPORT_SYMBOL(md_bitmap_free);
 
-void md_bitmap_wait_behind_writes(struct mddev *mddev)
+static void bitmap_wait_behind_writes(struct mddev *mddev)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 
···
 	}
 }
 
-void md_bitmap_destroy(struct mddev *mddev)
+static void bitmap_destroy(struct mddev *mddev)
 {
 	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap) /* there was no bitmap */
 		return;
 
-	md_bitmap_wait_behind_writes(mddev);
+	bitmap_wait_behind_writes(mddev);
 	if (!mddev->serialize_policy)
 		mddev_destroy_serial_pool(mddev, NULL);
 
···
  * if this returns an error, bitmap_destroy must be called to do clean up
  * once mddev->bitmap is set
  */
-struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
+static struct bitmap *__bitmap_create(struct mddev *mddev, int slot)
 {
 	struct bitmap *bitmap;
 	sector_t blocks = mddev->resync_max_sectors;
···
 		goto error;
 
 	bitmap->daemon_lastrun = jiffies;
-	err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
+	err = __bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize,
+			      true);
 	if (err)
 		goto error;
 
···
 	return ERR_PTR(err);
 }
 
-int md_bitmap_load(struct mddev *mddev)
+static int bitmap_create(struct mddev *mddev, int slot)
+{
+	struct bitmap *bitmap = __bitmap_create(mddev, slot);
+
+	if (IS_ERR(bitmap))
+		return PTR_ERR(bitmap);
+
+	mddev->bitmap = bitmap;
+	return 0;
+}
+
+static int bitmap_load(struct mddev *mddev)
 {
 	int err = 0;
 	sector_t start = 0;
···
 	 */
 	while (sector < mddev->resync_max_sectors) {
 		sector_t blocks;
-		md_bitmap_start_sync(bitmap, sector, &blocks, 0);
+		bitmap_start_sync(mddev, sector, &blocks, false);
 		sector += blocks;
 	}
-	md_bitmap_close_sync(bitmap);
+	bitmap_close_sync(mddev);
 
 	if (mddev->degraded == 0
 	    || bitmap->events_cleared == mddev->events)
···
 	mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
 	md_wakeup_thread(mddev->thread);
 
-	md_bitmap_update_sb(bitmap);
+	bitmap_update_sb(bitmap);
 
 	if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
 		err = -EIO;
 out:
 	return err;
 }
-EXPORT_SYMBOL_GPL(md_bitmap_load);
 
 /* caller need to free returned bitmap with md_bitmap_free() */
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
+static void *bitmap_get_from_slot(struct mddev *mddev, int slot)
 {
 	int rv = 0;
 	struct bitmap *bitmap;
 
-	bitmap = md_bitmap_create(mddev, slot);
+	bitmap = __bitmap_create(mddev, slot);
 	if (IS_ERR(bitmap)) {
 		rv = PTR_ERR(bitmap);
 		return ERR_PTR(rv);
···
 
 	return bitmap;
 }
-EXPORT_SYMBOL(get_bitmap_from_slot);
 
 /* Loads the bitmap associated with slot and copies the resync information
  * to our bitmap
  */
-int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
-		sector_t *low, sector_t *high, bool clear_bits)
+static int bitmap_copy_from_slot(struct mddev *mddev, int slot, sector_t *low,
+				 sector_t *high, bool clear_bits)
 {
 	int rv = 0, i, j;
 	sector_t block, lo = 0, hi = 0;
 	struct bitmap_counts *counts;
 	struct bitmap *bitmap;
 
-	bitmap = get_bitmap_from_slot(mddev, slot);
+	bitmap = bitmap_get_from_slot(mddev, slot);
 	if (IS_ERR(bitmap)) {
 		pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
 		return -1;
···
 	}
 
 	if (clear_bits) {
-		md_bitmap_update_sb(bitmap);
+		bitmap_update_sb(bitmap);
 		/* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
 		 * BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
 		for (i = 0; i < bitmap->storage.file_pages; i++)
 			if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
 				set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
-		md_bitmap_unplug(bitmap);
+		__bitmap_unplug(bitmap);
 	}
-	md_bitmap_unplug(mddev->bitmap);
+	__bitmap_unplug(mddev->bitmap);
 	*low = lo;
 	*high = hi;
 	md_bitmap_free(bitmap);
 
 	return rv;
 }
-EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
 
-
-void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
+static void bitmap_set_pages(void *data, unsigned long pages)
 {
-	unsigned long chunk_kb;
-	struct bitmap_counts *counts;
+	struct bitmap *bitmap = data;
 
-	if (!bitmap)
-		return;
-
-	counts = &bitmap->counts;
-
-	chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
-	seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
-		   "%lu%s chunk",
-		   counts->pages - counts->missing_pages,
-		   counts->pages,
-		   (counts->pages - counts->missing_pages)
-		   << (PAGE_SHIFT - 10),
-		   chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
-		   chunk_kb ? "KB" : "B");
-	if (bitmap->storage.file) {
-		seq_printf(seq, ", file: ");
-		seq_file_path(seq, bitmap->storage.file, " \t\n");
-	}
-
-	seq_printf(seq, "\n");
+	bitmap->counts.pages = pages;
 }
 
-int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
-		  int chunksize, int init)
+static int bitmap_get_stats(void *data, struct md_bitmap_stats *stats)
+{
+	struct bitmap_storage *storage;
+	struct bitmap_counts *counts;
+	struct bitmap *bitmap = data;
+	bitmap_super_t *sb;
+
+	if (!bitmap)
+		return -ENOENT;
+
+	sb = kmap_local_page(bitmap->storage.sb_page);
+	stats->sync_size = le64_to_cpu(sb->sync_size);
+	kunmap_local(sb);
+
+	counts = &bitmap->counts;
+	stats->missing_pages = counts->missing_pages;
+	stats->pages = counts->pages;
+
+	storage = &bitmap->storage;
+	stats->file_pages = storage->file_pages;
+	stats->file = storage->file;
+
+	stats->behind_writes = atomic_read(&bitmap->behind_writes);
+	stats->behind_wait = wq_has_sleeper(&bitmap->behind_wait);
+	stats->events_cleared = bitmap->events_cleared;
+	return 0;
+}
+
+static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
+			   int chunksize, bool init)
 {
 	/* If chunk_size is 0, choose an appropriate chunk size.
 	 * Then possibly allocate new storage space.
···
 	spin_unlock_irq(&bitmap->counts.lock);
 
 	if (!init) {
-		md_bitmap_unplug(bitmap);
+		__bitmap_unplug(bitmap);
 		bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
 	}
 	ret = 0;
 err:
 	return ret;
 }
-EXPORT_SYMBOL_GPL(md_bitmap_resize);
+
+static int bitmap_resize(struct mddev *mddev, sector_t blocks, int chunksize,
+			 bool init)
+{
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
+		return 0;
+
+	return __bitmap_resize(bitmap, blocks, chunksize, init);
+}
 
 static ssize_t
 location_show(struct mddev *mddev, char *page)
···
 			goto out;
 		}
 
-		md_bitmap_destroy(mddev);
+		bitmap_destroy(mddev);
 		mddev->bitmap_info.offset = 0;
 		if (mddev->bitmap_info.file) {
 			struct file *f = mddev->bitmap_info.file;
···
 	} else {
 		/* No bitmap, OK to set a location */
 		long long offset;
-		struct bitmap *bitmap;
 
 		if (strncmp(buf, "none", 4) == 0)
 			/* nothing to be done */;
···
 			}
 
 			mddev->bitmap_info.offset = offset;
-			bitmap = md_bitmap_create(mddev, -1);
-			if (IS_ERR(bitmap)) {
-				rv = PTR_ERR(bitmap);
+			rv = bitmap_create(mddev, -1);
+			if (rv)
 				goto out;
-			}
 
-			mddev->bitmap = bitmap;
-			rv = md_bitmap_load(mddev);
+			rv = bitmap_load(mddev);
 			if (rv) {
 				mddev->bitmap_info.offset = 0;
-				md_bitmap_destroy(mddev);
+				bitmap_destroy(mddev);
 				goto out;
 			}
 		}
···
 static ssize_t
 space_store(struct mddev *mddev, const char *buf, size_t len)
 {
+	struct bitmap *bitmap;
 	unsigned long sectors;
 	int rv;
 
···
 	if (sectors == 0)
 		return -EINVAL;
 
-	if (mddev->bitmap &&
-	    sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
+	bitmap = mddev->bitmap;
+	if (bitmap && sectors < (bitmap->storage.bytes + 511) >> 9)
 		return -EFBIG; /* Bitmap is too big for this small space */
 
 	/* could make sure it isn't too big, but that isn't really
···
 			mddev_create_serial_pool(mddev, rdev);
 	}
 	if (old_mwb != backlog)
-		md_bitmap_update_sb(mddev->bitmap);
+		bitmap_update_sb(mddev->bitmap);
 
 	mddev_unlock_and_resume(mddev);
 	return len;
···
 static ssize_t can_clear_show(struct mddev *mddev, char *page)
 {
 	int len;
+	struct bitmap *bitmap;
+
 	spin_lock(&mddev->lock);
-	if (mddev->bitmap)
-		len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
-					     "false" : "true"));
+	bitmap = mddev->bitmap;
+	if (bitmap)
+		len = sprintf(page, "%s\n", (bitmap->need_sync ? "false" :
+								 "true"));
 	else
 		len = sprintf(page, "\n");
 	spin_unlock(&mddev->lock);
···
 
 static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
 {
-	if (mddev->bitmap == NULL)
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (!bitmap)
 		return -ENOENT;
-	if (strncmp(buf, "false", 5) == 0)
-		mddev->bitmap->need_sync = 1;
-	else if (strncmp(buf, "true", 4) == 0) {
+
+	if (strncmp(buf, "false", 5) == 0) {
+		bitmap->need_sync = 1;
+		return len;
+	}
+
+	if (strncmp(buf, "true", 4) == 0) {
 		if (mddev->degraded)
 			return -EBUSY;
-		mddev->bitmap->need_sync = 0;
-	} else
-		return -EINVAL;
-	return len;
+		bitmap->need_sync = 0;
+		return len;
+	}
+
+	return -EINVAL;
 }
 
 static struct md_sysfs_entry bitmap_can_clear =
···
 behind_writes_used_show(struct mddev *mddev, char *page)
 {
 	ssize_t ret;
+	struct bitmap *bitmap;
+
 	spin_lock(&mddev->lock);
-	if (mddev->bitmap == NULL)
+	bitmap = mddev->bitmap;
+	if (!bitmap)
 		ret = sprintf(page, "0\n");
 	else
-		ret = sprintf(page, "%lu\n",
-			      mddev->bitmap->behind_writes_used);
+		ret = sprintf(page, "%lu\n", bitmap->behind_writes_used);
 	spin_unlock(&mddev->lock);
+
 	return ret;
 }
 
 static ssize_t
 behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
 {
-	if (mddev->bitmap)
-		mddev->bitmap->behind_writes_used = 0;
+	struct bitmap *bitmap = mddev->bitmap;
+
+	if (bitmap)
+		bitmap->behind_writes_used = 0;
 	return len;
 }
 
···
 	.name = "bitmap",
 	.attrs = md_bitmap_attrs,
 };
+
+static struct bitmap_operations bitmap_ops = {
+	.enabled		= bitmap_enabled,
+	.create			= bitmap_create,
+	.resize			= bitmap_resize,
+	.load			= bitmap_load,
+	.destroy		= bitmap_destroy,
+	.flush			= bitmap_flush,
+	.write_all		= bitmap_write_all,
+	.dirty_bits		= bitmap_dirty_bits,
+	.unplug			= bitmap_unplug,
+	.daemon_work		= bitmap_daemon_work,
+	.wait_behind_writes	= bitmap_wait_behind_writes,
+
+	.startwrite		= bitmap_startwrite,
+	.endwrite		= bitmap_endwrite,
+	.start_sync		= bitmap_start_sync,
+	.end_sync		= bitmap_end_sync,
+	.cond_end_sync		= bitmap_cond_end_sync,
+	.close_sync		= bitmap_close_sync,
+
+	.update_sb		= bitmap_update_sb,
+	.get_stats		= bitmap_get_stats,
+
+	.sync_with_cluster	= bitmap_sync_with_cluster,
+	.get_from_slot		= bitmap_get_from_slot,
+	.copy_from_slot		= bitmap_copy_from_slot,
+	.set_pages		= bitmap_set_pages,
+	.free			= md_bitmap_free,
+};
+
+void mddev_set_bitmap_ops(struct mddev *mddev)
+{
+	mddev->bitmap_ops = &bitmap_ops;
+}

drivers/md/md-bitmap.h

···
 #ifndef BITMAP_H
 #define BITMAP_H 1
 
-#define BITMAP_MAJOR_LO 3
-/* version 4 insists the bitmap is in little-endian order
- * with version 3, it is host-endian which is non-portable
- * Version 5 is currently set only for clustered devices
- */
-#define BITMAP_MAJOR_HI 4
-#define BITMAP_MAJOR_CLUSTERED 5
-#define	BITMAP_MAJOR_HOSTENDIAN 3
-
-/*
- * in-memory bitmap:
- *
- * Use 16 bit block counters to track pending writes to each "chunk".
- * The 2 high order bits are special-purpose, the first is a flag indicating
- * whether a resync is needed.  The second is a flag indicating whether a
- * resync is active.
- * This means that the counter is actually 14 bits:
- *
- * +--------+--------+------------------------------------------------+
- * | resync | resync |               counter                          |
- * | needed | active |                                                |
- * |  (0-1) |  (0-1) |              (0-16383)                         |
- * +--------+--------+------------------------------------------------+
- *
- * The "resync needed" bit is set when:
- *    a '1' bit is read from storage at startup.
- *    a write request fails on some drives
- *    a resync is aborted on a chunk with 'resync active' set
- * It is cleared (and resync-active set) when a resync starts across all drives
- * of the chunk.
- *
- *
- * The "resync active" bit is set when:
- *    a resync is started on all drives, and resync_needed is set.
- *       resync_needed will be cleared (as long as resync_active wasn't already set).
- * It is cleared when a resync completes.
- *
- * The counter counts pending write requests, plus the on-disk bit.
- * When the counter is '1' and the resync bits are clear, the on-disk
- * bit can be cleared as well, thus setting the counter to 0.
- * When we set a bit, or in the counter (to start a write), if the fields is
- * 0, we first set the disk bit and set the counter to 1.
- *
- * If the counter is 0, the on-disk bit is clear and the stripe is clean
- * Anything that dirties the stripe pushes the counter to 2 (at least)
- * and sets the on-disk bit (lazily).
- * If a periodic sweep find the counter at 2, it is decremented to 1.
- * If the sweep find the counter at 1, the on-disk bit is cleared and the
- * counter goes to zero.
- *
- * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block
- * counters as a fallback when "page" memory cannot be allocated:
- *
- * Normal case (page memory allocated):
- *
- *     page pointer (32-bit)
- *
- *     [ ] ------+
- *               |
- *               +-------> [   ][   ]..[   ] (4096 byte page == 2048 counters)
- *                          c1   c2    c2048
- *
- * Hijacked case (page memory allocation failed):
- *
- *     hijacked page pointer (32-bit)
- *
- *     [		  ][		  ] (no page memory allocated)
- *      counter #1 (16-bit) counter #2 (16-bit)
- *
- */
-
-#ifdef __KERNEL__
-
-#define PAGE_BITS (PAGE_SIZE << 3)
-#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3)
+#define BITMAP_MAGIC 0x6d746962
 
 typedef __u16 bitmap_counter_t;
 #define COUNTER_BITS 16
···
 #define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1)))
 #define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2)))
 #define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1)
-#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
-#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK)
-#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX)
-
-/* how many counters per page? */
-#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS)
-/* same, except a shift value for more efficient bitops */
-#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT)
-/* same, except a mask value for more efficient bitops */
-#define PAGE_COUNTER_MASK  (PAGE_COUNTER_RATIO - 1)
-
-#define BITMAP_BLOCK_SHIFT 9
-
-#endif
-
-/*
- * bitmap structures:
- */
-
-#define BITMAP_MAGIC 0x6d746962
 
 /* use these for bitmap->flags and bitmap->sb->state bit-fields */
 enum bitmap_state {
···
  *    devices.  For raid10 it is the size of the array.
  */
 
-#ifdef __KERNEL__
+struct md_bitmap_stats {
+	u64		events_cleared;
+	int		behind_writes;
+	bool		behind_wait;
 
-/* the in-memory bitmap is represented by bitmap_pages */
-struct bitmap_page {
-	/*
-	 * map points to the actual memory page
-	 */
-	char *map;
-	/*
-	 * in emergencies (when map cannot be alloced), hijack the map
-	 * pointer and use it as two counters itself
-	 */
-	unsigned int hijacked:1;
-	/*
-	 * If any counter in this page is '1' or '2' - and so could be
-	 * cleared then that page is marked as 'pending'
-	 */
-	unsigned int pending:1;
-	/*
-	 * count of dirty bits on the page
-	 */
-	unsigned int  count:30;
+	unsigned long	missing_pages;
+	unsigned long	file_pages;
+	unsigned long	sync_size;
+	unsigned long	pages;
+	struct file	*file;
 };
 
-/* the main bitmap structure - one per mddev */
-struct bitmap {
+struct bitmap_operations {
+	bool (*enabled)(struct mddev *mddev);
+	int (*create)(struct mddev *mddev, int slot);
+	int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize,
+		      bool init);
 
-	struct bitmap_counts {
-		spinlock_t lock;
-		struct bitmap_page *bp;
-		unsigned long pages;		/* total number of pages
-						 * in the bitmap */
-		unsigned long missing_pages;	/* number of pages
-						 * not yet allocated */
-		unsigned long chunkshift;	/* chunksize = 2^chunkshift
-						 * (for bitops) */
-		unsigned long chunks;		/* Total number of data
-						 * chunks for the array */
-	} counts;
+	int (*load)(struct mddev *mddev);
+	void (*destroy)(struct mddev *mddev);
+	void (*flush)(struct mddev *mddev);
+	void (*write_all)(struct mddev *mddev);
+	void (*dirty_bits)(struct mddev *mddev, unsigned long s,
+			   unsigned long e);
+	void (*unplug)(struct mddev *mddev, bool sync);
+	void (*daemon_work)(struct mddev *mddev);
+	void (*wait_behind_writes)(struct mddev *mddev);
 
-	struct mddev *mddev; /* the md device that the bitmap is for */
+	int (*startwrite)(struct mddev *mddev, sector_t offset,
+			  unsigned long sectors, bool behind);
+	void (*endwrite)(struct mddev *mddev, sector_t offset,
+			 unsigned long sectors, bool success, bool behind);
+	bool (*start_sync)(struct mddev *mddev, sector_t offset,
+			   sector_t *blocks, bool degraded);
+	void (*end_sync)(struct mddev *mddev, sector_t offset, sector_t *blocks);
+	void (*cond_end_sync)(struct mddev *mddev, sector_t sector, bool force);
+	void (*close_sync)(struct mddev *mddev);
 
-	__u64	events_cleared;
-	int need_sync;
+	void (*update_sb)(void *data);
+	int (*get_stats)(void *data, struct md_bitmap_stats *stats);
 
-	struct bitmap_storage {
-		struct file *file;		/* backing disk file */
-		struct page *sb_page;		/* cached copy of the bitmap
-						 * file superblock */
-		unsigned long sb_index;
-		struct page **filemap;		/* list of cache pages for
-						 * the file */
-		unsigned long *filemap_attr;	/* attributes associated
-						 * w/ filemap pages */
-		unsigned long file_pages;	/* number of pages in the file*/
-		unsigned long bytes;		/* total bytes in the bitmap */
-	} storage;
-
-	unsigned long flags;
-
-	int allclean;
-
-	atomic_t behind_writes;
-	unsigned long behind_writes_used; /* highest actual value at runtime */
-
-	/*
-	 * the bitmap daemon - periodically wakes up and sweeps the bitmap
-	 * file, cleaning up bits and flushing out pages to disk as necessary
-	 */
-	unsigned long daemon_lastrun; /* jiffies of last run */
-	unsigned long last_end_sync; /* when we lasted called end_sync to
-				      * update bitmap with resync progress */
-
-	atomic_t pending_writes; /* pending writes to the bitmap file */
-	wait_queue_head_t write_wait;
-	wait_queue_head_t overflow_wait;
-	wait_queue_head_t behind_wait;
-
-	struct kernfs_node *sysfs_can_clear;
-	int cluster_slot;		/* Slot offset for clustered env */
+	void (*sync_with_cluster)(struct mddev *mddev,
+				  sector_t old_lo, sector_t old_hi,
+				  sector_t new_lo, sector_t new_hi);
+	void *(*get_from_slot)(struct mddev *mddev, int slot);
+	int (*copy_from_slot)(struct mddev *mddev, int slot, sector_t *lo,
+			      sector_t *hi, bool clear_bits);
+	void (*set_pages)(void *data, unsigned long pages);
+	void (*free)(void *data);
 };
 
 /* the bitmap API */
-
-/* these are used only by md/bitmap */
-struct bitmap *md_bitmap_create(struct mddev *mddev, int slot);
-int md_bitmap_load(struct mddev *mddev);
-void md_bitmap_flush(struct mddev *mddev);
-void md_bitmap_destroy(struct mddev *mddev);
-
-void md_bitmap_print_sb(struct bitmap *bitmap);
-void md_bitmap_update_sb(struct bitmap *bitmap);
-void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap);
-
-int  md_bitmap_setallbits(struct bitmap *bitmap);
-void md_bitmap_write_all(struct bitmap *bitmap);
-
-void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
-
-/* these are exported */
-int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset,
-			 unsigned long sectors, int behind);
-void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
-			unsigned long sectors, int success, int behind);
-int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int degraded);
-void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted);
-void md_bitmap_close_sync(struct bitmap *bitmap);
-void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force);
-void md_bitmap_sync_with_cluster(struct mddev *mddev,
-				 sector_t old_lo, sector_t old_hi,
-				 sector_t new_lo, sector_t new_hi);
-
-void md_bitmap_unplug(struct bitmap *bitmap);
-void md_bitmap_unplug_async(struct bitmap *bitmap);
-void md_bitmap_daemon_work(struct mddev *mddev);
-
-int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
-		     int chunksize, int init);
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot);
-int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
-			     sector_t *lo, sector_t *hi, bool clear_bits);
-void md_bitmap_free(struct bitmap *bitmap);
-void md_bitmap_wait_behind_writes(struct mddev *mddev);
-
-static inline bool md_bitmap_enabled(struct bitmap *bitmap)
-{
-	return bitmap && bitmap->storage.filemap &&
-	       !test_bit(BITMAP_STALE, &bitmap->flags);
-}
-
-#endif
+void mddev_set_bitmap_ops(struct mddev *mddev);
 
 #endif

drivers/md/md-cluster.c

···
 					str, ret);
 			goto clear_bit;
 		}
-		ret = md_bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
+		ret = mddev->bitmap_ops->copy_from_slot(mddev, slot, &lo, &hi, true);
 		if (ret) {
 			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
 			goto clear_bit;
···
 	 * we don't want to trigger lots of WARN.
 	 */
 	if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
-		md_bitmap_sync_with_cluster(mddev, cinfo->sync_low,
-					    cinfo->sync_hi, lo, hi);
+		mddev->bitmap_ops->sync_with_cluster(mddev, cinfo->sync_low,
+						     cinfo->sync_hi, lo, hi);
 	cinfo->sync_low = lo;
 	cinfo->sync_hi = hi;
 
···
 		break;
 	case BITMAP_RESIZE:
 		if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
-			ret = md_bitmap_resize(mddev->bitmap,
-					    le64_to_cpu(msg->high), 0, 0);
+			ret = mddev->bitmap_ops->resize(mddev,
+							le64_to_cpu(msg->high),
+							0, false);
 		break;
 	default:
 		ret = -1;
···
 		}
 
 		/* Read the disk bitmap sb and check if it needs recovery */
-		ret = md_bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
+		ret = mddev->bitmap_ops->copy_from_slot(mddev, i, &lo, &hi, false);
 		if (ret) {
 			pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
 			lockres_free(bm_lockres);
···
 
 static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
 {
-	struct bitmap_counts *counts;
-	char str[64];
-	struct dlm_lock_resource *bm_lockres;
-	struct bitmap *bitmap = mddev->bitmap;
-	unsigned long my_pages = bitmap->counts.pages;
+	void *bitmap = mddev->bitmap;
+	struct md_bitmap_stats stats;
+	unsigned long my_pages;
 	int i, rv;
 
+	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
+	if (rv)
+		return rv;
+
+	my_pages = stats.pages;
 	/*
 	 * We need to ensure all the nodes can grow to a larger
 	 * bitmap size before make the reshaping.
···
 		return rv;
 
 	for (i = 0; i < mddev->bitmap_info.nodes; i++) {
+		struct dlm_lock_resource *bm_lockres;
+		char str[64];
+
 		if (i == md_cluster_ops->slot_number(mddev))
 			continue;
 
-		bitmap = get_bitmap_from_slot(mddev, i);
+		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
 		if (IS_ERR(bitmap)) {
 			pr_err("can't get bitmap from slot %d\n", i);
 			bitmap = NULL;
 			goto out;
 		}
-		counts = &bitmap->counts;
 
+		rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
+		if (rv)
+			goto out;
 		/*
 		 * If we can hold the bitmap lock of one node then
 		 * the slot is not occupied, update the pages.
···
 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 		if (!rv)
-			counts->pages = my_pages;
+			mddev->bitmap_ops->set_pages(bitmap, my_pages);
 		lockres_free(bm_lockres);
 
-		if (my_pages != counts->pages)
+		if (my_pages != stats.pages)
 			/*
 			 * Let's revert the bitmap size if one node
 			 * can't resize bitmap
 			 */
 			goto out;
-		md_bitmap_free(bitmap);
+		mddev->bitmap_ops->free(bitmap);
 	}
 
 	return 0;
 out:
-	md_bitmap_free(bitmap);
+	mddev->bitmap_ops->free(bitmap);
 	update_bitmap_size(mddev, oldsize);
 	return -1;
 }
···
  */
 static int cluster_check_sync_size(struct mddev *mddev)
 {
-	int i, rv;
-	bitmap_super_t *sb;
-	unsigned long my_sync_size, sync_size = 0;
-	int node_num = mddev->bitmap_info.nodes;
 	int current_slot = md_cluster_ops->slot_number(mddev);
-	struct bitmap *bitmap = mddev->bitmap;
-	char str[64];
+	int node_num = mddev->bitmap_info.nodes;
 	struct dlm_lock_resource *bm_lockres;
+	struct md_bitmap_stats stats;
+	void *bitmap = mddev->bitmap;
+	unsigned long sync_size = 0;
+	unsigned long my_sync_size;
+	char str[64];
+	int i, rv;
 
-	sb = kmap_atomic(bitmap->storage.sb_page);
-	my_sync_size = sb->sync_size;
-	kunmap_atomic(sb);
+	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
+	if (rv)
+		return rv;
+
+	my_sync_size = stats.sync_size;
 
 	for (i = 0; i < node_num; i++) {
 		if (i == current_slot)
 			continue;
 
-		bitmap = get_bitmap_from_slot(mddev, i);
+		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
 		if (IS_ERR(bitmap)) {
 			pr_err("can't get bitmap from slot %d\n", i);
 			return -1;
···
 		bm_lockres = lockres_init(mddev, str, NULL, 1);
 		if (!bm_lockres) {
 			pr_err("md-cluster: Cannot initialize %s\n", str);
-			md_bitmap_free(bitmap);
+			mddev->bitmap_ops->free(bitmap);
 			return -1;
 		}
 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 		if (!rv)
-			md_bitmap_update_sb(bitmap);
+			mddev->bitmap_ops->update_sb(bitmap);
 		lockres_free(bm_lockres);
 
-		sb = kmap_atomic(bitmap->storage.sb_page);
-		if (sync_size == 0)
-			sync_size = sb->sync_size;
-		else if (sync_size != sb->sync_size) {
-			kunmap_atomic(sb);
-			md_bitmap_free(bitmap);
+		rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
+		if (rv) {
+			mddev->bitmap_ops->free(bitmap);
+			return rv;
+		}
+
+		if (sync_size == 0) {
+			sync_size = stats.sync_size;
+		} else if (sync_size != stats.sync_size) {
+			mddev->bitmap_ops->free(bitmap);
 			return -1;
 		}
-		kunmap_atomic(sb);
-		md_bitmap_free(bitmap);
+		mddev->bitmap_ops->free(bitmap);
 	}
 
 	return (my_sync_size == sync_size) ? 0 : -1;
···
 	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
 		if (sn == (cinfo->slot_number - 1))
 			continue;
-		err = md_bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
+		err = mddev->bitmap_ops->copy_from_slot(mddev, sn, &lo, &hi, false);
 		if (err) {
 			pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
 			goto out;

drivers/md/md.c

···
 	return 0;
 }
 
-/*
- * Generic flush handling for md
- */
-
-static void md_end_flush(struct bio *bio)
-{
-	struct md_rdev *rdev = bio->bi_private;
-	struct mddev *mddev = rdev->mddev;
-
-	bio_put(bio);
-
-	rdev_dec_pending(rdev, mddev);
-
-	if (atomic_dec_and_test(&mddev->flush_pending))
-		/* The pre-request flush has finished */
-		queue_work(md_wq, &mddev->flush_work);
-}
-
-static void md_submit_flush_data(struct work_struct *ws);
-
-static void submit_flushes(struct work_struct *ws)
-{
-	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
-	struct md_rdev *rdev;
-
-	mddev->start_flush = ktime_get_boottime();
-	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
-	atomic_set(&mddev->flush_pending, 1);
-	rcu_read_lock();
-	rdev_for_each_rcu(rdev, mddev)
-		if (rdev->raid_disk >= 0 &&
-		    !test_bit(Faulty, &rdev->flags)) {
-			struct bio *bi;
-
-			atomic_inc(&rdev->nr_pending);
-			rcu_read_unlock();
-			bi = bio_alloc_bioset(rdev->bdev, 0,
-					      REQ_OP_WRITE | REQ_PREFLUSH,
-					      GFP_NOIO, &mddev->bio_set);
-			bi->bi_end_io = md_end_flush;
-			bi->bi_private = rdev;
-			atomic_inc(&mddev->flush_pending);
-			submit_bio(bi);
-			rcu_read_lock();
-		}
-	rcu_read_unlock();
-	if (atomic_dec_and_test(&mddev->flush_pending))
-		queue_work(md_wq, &mddev->flush_work);
-}
-
-static void md_submit_flush_data(struct work_struct *ws)
-{
-	struct mddev *mddev = container_of(ws, struct mddev, flush_work);
-	struct bio *bio = mddev->flush_bio;
-
-	/*
-	 * must reset flush_bio before calling into md_handle_request to avoid a
-	 * deadlock, because other bios passed md_handle_request suspend check
-	 * could wait for this and below md_handle_request could wait for those
-	 * bios because of suspend check
-	 */
-	spin_lock_irq(&mddev->lock);
-	mddev->prev_flush_start = mddev->start_flush;
-	mddev->flush_bio = NULL;
-	spin_unlock_irq(&mddev->lock);
-	wake_up(&mddev->sb_wait);
-
-	if (bio->bi_iter.bi_size == 0) {
-		/* an empty barrier - all done */
-		bio_endio(bio);
-	} else {
-		bio->bi_opf &= ~REQ_PREFLUSH;
-
-		/*
-		 * make_requst() will never return error here, it only
-		 * returns error in raid5_make_request() by dm-raid.
-		 * Since dm always splits data and flush operation into
-		 * two separate io, io size of flush submitted by dm
-		 * always is 0, make_request() will not be called here.
-		 */
-		if (WARN_ON_ONCE(!mddev->pers->make_request(mddev, bio)))
-			bio_io_error(bio);
-	}
-
-	/* The pair is percpu_ref_get() from md_flush_request() */
-	percpu_ref_put(&mddev->active_io);
-}
-
-/*
- * Manages consolidation of flushes and submitting any flushes needed for
- * a bio with REQ_PREFLUSH.  Returns true if the bio is finished or is
- * being finished in another context.  Returns false if the flushing is
- * complete but still needs the I/O portion of the bio to be processed.
- */
 bool md_flush_request(struct mddev *mddev, struct bio *bio)
 {
-	ktime_t req_start = ktime_get_boottime();
-	spin_lock_irq(&mddev->lock);
-	/* flush requests wait until ongoing flush completes,
-	 * hence coalescing all the pending requests.
+	struct md_rdev *rdev;
+	struct bio *new;
+
+	/*
+	 * md_flush_reqeust() should be called under md_handle_request() and
+	 * 'active_io' is already grabbed. Hence it's safe to get rdev directly
+	 * without rcu protection.
 	 */
-	wait_event_lock_irq(mddev->sb_wait,
-			    !mddev->flush_bio ||
-			    ktime_before(req_start, mddev->prev_flush_start),
-			    mddev->lock);
-	/* new request after previous flush is completed */
-	if (ktime_after(req_start, mddev->prev_flush_start)) {
-		WARN_ON(mddev->flush_bio);
-		/*
-		 * Grab a reference to make sure mddev_suspend() will wait for
-		 * this flush to be done.
-		 *
-		 * md_flush_reqeust() is called under md_handle_request() and
-		 * 'active_io' is already grabbed, hence percpu_ref_is_zero()
-		 * won't pass, percpu_ref_tryget_live() can't be used because
-		 * percpu_ref_kill() can be called by mddev_suspend()
-		 * concurrently.
-		 */
-		WARN_ON(percpu_ref_is_zero(&mddev->active_io));
-		percpu_ref_get(&mddev->active_io);
-		mddev->flush_bio = bio;
-		spin_unlock_irq(&mddev->lock);
-		INIT_WORK(&mddev->flush_work, submit_flushes);
-		queue_work(md_wq, &mddev->flush_work);
-		return true;
+	WARN_ON(percpu_ref_is_zero(&mddev->active_io));
+
+	rdev_for_each(rdev, mddev) {
+		if (rdev->raid_disk < 0 || test_bit(Faulty, &rdev->flags))
+			continue;
+
+		new = bio_alloc_bioset(rdev->bdev, 0,
+				       REQ_OP_WRITE | REQ_PREFLUSH, GFP_NOIO,
+				       &mddev->bio_set);
+		bio_chain(new, bio);
+		submit_bio(new);
 	}
 
-	/* flush was performed for some other bio while we waited. */
-	spin_unlock_irq(&mddev->lock);
-	if (bio->bi_iter.bi_size == 0) {
-		/* pure flush without data - all done */
+	if (bio_sectors(bio) == 0) {
 		bio_endio(bio);
 		return true;
 	}
···
 	atomic_set(&mddev->openers, 0);
 	atomic_set(&mddev->sync_seq, 0);
 	spin_lock_init(&mddev->lock);
-	atomic_set(&mddev->flush_pending, 0);
 	init_waitqueue_head(&mddev->sb_wait);
 	init_waitqueue_head(&mddev->recovery_wait);
 	mddev->reshape_position = MaxSector;
···
 	mddev->resync_min = 0;
 	mddev->resync_max = MaxSector;
 	mddev->level = LEVEL_NONE;
+	mddev_set_bitmap_ops(mddev);
 
 	INIT_WORK(&mddev->sync_work, md_start_sync);
 	INIT_WORK(&mddev->del_work, mddev_delayed_delete);
···
 	return ret;
 }
 
+static u64 md_bitmap_events_cleared(struct mddev *mddev)
+{
+	struct md_bitmap_stats stats;
+	int err;
+
+	err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
+	if (err)
+		return 0;
+
+	return stats.events_cleared;
+}
+
 /*
  * validate_super for 0.90.0
  * note: we are not using "freshest" for 0.9 superblock
···
 		/* if adding to array with a bitmap, then we can accept an
 		 * older device ... but not too old.
 		 */
-		if (ev1 < mddev->bitmap->events_cleared)
+		if (ev1 < md_bitmap_events_cleared(mddev))
 			return 0;
 		if (ev1 < mddev->events)
 			set_bit(Bitmap_sync, &rdev->flags);
···
 		/* If adding to array with a bitmap, then we can accept an
 		 * older device, but not too old.
 		 */
-		if (ev1 < mddev->bitmap->events_cleared)
+		if (ev1 < md_bitmap_events_cleared(mddev))
 			return 0;
 		if (ev1 < mddev->events)
 			set_bit(Bitmap_sync, &rdev->flags);
···
 			 unsigned long long new_offset)
 {
 	/* All necessary checks on new >= old have been done */
-	struct bitmap *bitmap;
 	if (new_offset >= rdev->data_offset)
 		return 1;
 
···
 	 */
 	if (rdev->sb_start + (32+4)*2 > new_offset)
 		return 0;
-	bitmap = rdev->mddev->bitmap;
-	if (bitmap && !rdev->mddev->bitmap_info.file &&
-	    rdev->sb_start + rdev->mddev->bitmap_info.offset +
-	    bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
-		return 0;
+
+	if (!rdev->mddev->bitmap_info.file) {
+		struct mddev *mddev = rdev->mddev;
+		struct md_bitmap_stats stats;
+		int err;
+
+		err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
+		if (!err && rdev->sb_start + mddev->bitmap_info.offset +
+		    stats.file_pages * (PAGE_SIZE >> 9) > new_offset)
+			return 0;
+	}
+
 	if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
 		return 0;
 
···
 
 	mddev_add_trace_msg(mddev, "md md_update_sb");
 rewrite:
-	md_bitmap_update_sb(mddev->bitmap);
+	mddev->bitmap_ops->update_sb(mddev->bitmap);
 	rdev_for_each(rdev, mddev) {
 		if (rdev->sb_loaded != 1)
 			continue; /* no noise on spare devices */
···
 __ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
 
 static ssize_t
+new_level_show(struct mddev *mddev, char *page)
+{
+	return sprintf(page, "%d\n", mddev->new_level);
+}
+
+static ssize_t
+new_level_store(struct mddev *mddev, const char *buf, size_t len)
+{
+	unsigned int n;
+	int err;
+
+	err = kstrtouint(buf, 10, &n);
+	if (err < 0)
+		return err;
+	err = mddev_lock(mddev);
+	if (err)
+		return err;
+
+	mddev->new_level = n;
+	md_update_sb(mddev, 1);
+
+	mddev_unlock(mddev);
+	return len;
+}
+static struct md_sysfs_entry md_new_level =
+__ATTR(new_level, 0664, new_level_show, new_level_store);
+
+static ssize_t
 layout_show(struct mddev *mddev, char *page)
 {
 	/* just a number, not meaningful for all levels */
···
 	/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
 	while (*buf) {
 		chunk = end_chunk = simple_strtoul(buf, &end, 0);
-		if (buf == end) break;
+		if (buf == end)
+			break;
+
 		if (*end == '-') { /* range */
 			buf = end + 1;
 			end_chunk = simple_strtoul(buf, &end, 0);
-			if (buf == end) break;
+			if (buf == end)
+				break;
 		}
-		if (*end && !isspace(*end)) break;
-		md_bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
+
+		if (*end && !isspace(*end))
+			break;
+
+		mddev->bitmap_ops->dirty_bits(mddev, chunk, end_chunk);
 		buf = skip_spaces(end);
 	}
-	md_bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
+	mddev->bitmap_ops->unplug(mddev, true); /* flush the bits to disk */
 out:
 	mddev_unlock(mddev);
 	return len;
···
 
 static struct attribute *md_default_attrs[] = {
 	&md_level.attr,
+	&md_new_level.attr,
 	&md_layout.attr,
 	&md_raid_disks.attr,
 	&md_uuid.attr,
···
 	}
 	if (err == 0 && pers->sync_request &&
 	    (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
-		struct bitmap *bitmap;
-
-		bitmap = md_bitmap_create(mddev, -1);
-		if (IS_ERR(bitmap)) {
-			err = PTR_ERR(bitmap);
+		err = mddev->bitmap_ops->create(mddev, -1);
+		if (err)
 			pr_warn("%s: failed to create bitmap (%d)\n",
 				mdname(mddev), err);
-		} else
-			mddev->bitmap = bitmap;
-
 	}
 	if (err)
 		goto bitmap_abort;
···
 		pers->free(mddev, mddev->private);
 	mddev->private = NULL;
 	module_put(pers->owner);
-	md_bitmap_destroy(mddev);
+	mddev->bitmap_ops->destroy(mddev);
 abort:
 	bioset_exit(&mddev->io_clone_set);
 exit_sync_set:
···
 	err = md_run(mddev);
 	if (err)
 		goto out;
-	err = md_bitmap_load(mddev);
+
+	err = mddev->bitmap_ops->load(mddev);
 	if (err) {
-		md_bitmap_destroy(mddev);
+		mddev->bitmap_ops->destroy(mddev);
 		goto out;
 	}
 
···
 		mddev->pers->quiesce(mddev, 1);
 		mddev->pers->quiesce(mddev, 0);
 	}
-	md_bitmap_flush(mddev);
+
+	mddev->bitmap_ops->flush(mddev);
 
 	if (md_is_rdwr(mddev) &&
 	    ((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
···
 
 static void mddev_detach(struct mddev *mddev)
 {
-	md_bitmap_wait_behind_writes(mddev);
+	mddev->bitmap_ops->wait_behind_writes(mddev);
 	if (mddev->pers && mddev->pers->quiesce && !is_md_suspended(mddev)) {
 		mddev->pers->quiesce(mddev, 1);
 		mddev->pers->quiesce(mddev, 0);
···
 static void __md_stop(struct mddev *mddev)
 {
 	struct md_personality *pers = mddev->pers;
-	md_bitmap_destroy(mddev);
+
+	mddev->bitmap_ops->destroy(mddev);
 	mddev_detach(mddev);
 	spin_lock(&mddev->lock);
 	mddev->pers = NULL;
···
 	err = 0;
 	if (mddev->pers) {
 		if (fd >= 0) {
-			struct bitmap *bitmap;
+			err = mddev->bitmap_ops->create(mddev, -1);
+			if (!err)
+				err = mddev->bitmap_ops->load(mddev);
 
-			bitmap = md_bitmap_create(mddev, -1);
-			if (!IS_ERR(bitmap)) {
-				mddev->bitmap = bitmap;
-				err = md_bitmap_load(mddev);
-			} else
-				err = PTR_ERR(bitmap);
 			if (err) {
-				md_bitmap_destroy(mddev);
+				mddev->bitmap_ops->destroy(mddev);
 				fd = -1;
 			}
 		} else if (fd < 0) {
-			md_bitmap_destroy(mddev);
+			mddev->bitmap_ops->destroy(mddev);
 		}
 	}
+
 	if (fd < 0) {
 		struct file *f = mddev->bitmap_info.file;
 		if (f) {
···
 			goto err;
 		}
 		if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
-			struct bitmap *bitmap;
 			/* add the bitmap */
 			if (mddev->bitmap) {
 				rv = -EEXIST;
···
 				mddev->bitmap_info.default_offset;
 			mddev->bitmap_info.space =
 				mddev->bitmap_info.default_space;
-			bitmap = md_bitmap_create(mddev, -1);
-			if (!IS_ERR(bitmap)) {
-				mddev->bitmap = bitmap;
-				rv = md_bitmap_load(mddev);
-			} else
-				rv = PTR_ERR(bitmap);
+			rv = mddev->bitmap_ops->create(mddev, -1);
+			if (!rv)
+				rv = mddev->bitmap_ops->load(mddev);
+
 			if (rv)
-				md_bitmap_destroy(mddev);
+				mddev->bitmap_ops->destroy(mddev);
 		} else {
-			/* remove the bitmap */
-			if (!mddev->bitmap) {
-				rv = -ENOENT;
+			struct md_bitmap_stats stats;
+
+			rv = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
+			if (rv)
 				goto err;
-			}
-			if (mddev->bitmap->storage.file) {
+
+			if (stats.file) {
 				rv = -EINVAL;
 				goto err;
 			}
+
 			if (mddev->bitmap_info.nodes) {
 				/* hold PW on all the bitmap lock */
 				if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
···
 				module_put(md_cluster_mod);
 				mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
 			}
-			md_bitmap_destroy(mddev);
+			mddev->bitmap_ops->destroy(mddev);
 			mddev->bitmap_info.offset = 0;
 		}
 	}
···
 	spin_unlock(&all_mddevs_lock);
 }
 
+static void md_bitmap_status(struct seq_file *seq, struct mddev *mddev)
+{
+	struct md_bitmap_stats stats;
+	unsigned long used_pages;
+	unsigned long chunk_kb;
+	int err;
+
+	err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
+	if (err)
+		return;
+
+	chunk_kb = mddev->bitmap_info.chunksize >> 10;
+	used_pages = stats.pages - stats.missing_pages;
+
+	seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], %lu%s chunk",
+		   used_pages, stats.pages, used_pages << (PAGE_SHIFT - 10),
+		   chunk_kb ? chunk_kb : mddev->bitmap_info.chunksize,
+		   chunk_kb ? "KB" : "B");
+
+	if (stats.file) {
+		seq_puts(seq, ", file: ");
+		seq_file_path(seq, stats.file, " \t\n");
+	}
+
+	seq_putc(seq, '\n');
+}
+
 static int md_seq_show(struct seq_file *seq, void *v)
 {
 	struct mddev *mddev;
···
 	spin_unlock(&all_mddevs_lock);
 	spin_lock(&mddev->lock);
 	if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
-		seq_printf(seq, "%s : %sactive", mdname(mddev),
-						mddev->pers ? "" : "in");
+		seq_printf(seq, "%s : ", mdname(mddev));
 		if (mddev->pers) {
+			if (test_bit(MD_BROKEN, &mddev->flags))
+				seq_printf(seq, "broken");
+			else
+				seq_printf(seq, "active");
 			if (mddev->ro == MD_RDONLY)
 				seq_printf(seq, " (read-only)");
 			if (mddev->ro == MD_AUTO_READ)
 				seq_printf(seq, " (auto-read-only)");
 			seq_printf(seq, " %s", mddev->pers->name);
+		} else {
+			seq_printf(seq, "inactive");
 		}
 
 		sectors = 0;
···
 		} else
 			seq_printf(seq, "\n       ");
 
-		md_bitmap_status(seq, mddev->bitmap);
+		md_bitmap_status(seq, mddev);
 
 		seq_printf(seq, "\n");
 	}
···
 	BUG_ON(mddev->ro == MD_RDONLY);
 	if (mddev->ro == MD_AUTO_READ) {
 		/* need to switch to read/write */
-		flush_work(&mddev->sync_work);
 		mddev->ro = MD_RDWR;
 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 		md_wakeup_thread(mddev->thread);
···
 	 * stored on all devices. So make sure all bitmap pages get written.
 	 */
 	if (spares)
-		md_bitmap_write_all(mddev->bitmap);
+		mddev->bitmap_ops->write_all(mddev);
 
 	name = test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ?
 			"reshape" : "resync";
···
 void md_check_recovery(struct mddev *mddev)
 {
 	if (mddev->bitmap)
-		md_bitmap_daemon_work(mddev);
+		mddev->bitmap_ops->daemon_work(mddev);
 
 	if (signal_pending(current)) {
 		if (mddev->pers->sync_request && !mddev->external) {
···
 		if (ret)
 			pr_info("md-cluster: resize failed\n");
 		else
-			md_bitmap_update_sb(mddev->bitmap);
+			mddev->bitmap_ops->update_sb(mddev->bitmap);
 	}
 
 	/* Check for change of roles in the active devices */

drivers/md/md.h

···
 	struct percpu_ref		writes_pending;
 	int				sync_checkers;	/* # of threads checking writes_pending */
 
-	struct bitmap			*bitmap; /* the bitmap for the device */
+	void				*bitmap; /* the bitmap for the device */
+	struct bitmap_operations	*bitmap_ops;
 	struct {
 		struct file		*file; /* the bitmap file */
 		loff_t			offset; /* offset from superblock of
···
 						   */
 	struct bio_set			io_clone_set;
 
-	/* Generic flush handling.
-	 * The last to finish preflush schedules a worker to submit
-	 * the rest of the request (without the REQ_PREFLUSH flag).
-	 */
-	struct bio *flush_bio;
-	atomic_t flush_pending;
-	ktime_t start_flush, prev_flush_start; /* prev_flush_start is when the previous completed
-						* flush was started.
-						*/
-	struct work_struct flush_work;
 	struct work_struct event_work;	/* used by dm to report failure event */
 	mempool_t *serial_info_pool;
 	void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);

drivers/md/raid1-10.c

···
 	 * If bitmap is not enabled, it's safe to submit the io directly, and
 	 * this can get optimal performance.
 	 */
-	if (!md_bitmap_enabled(mddev->bitmap)) {
+	if (!mddev->bitmap_ops->enabled(mddev)) {
 		raid1_submit_write(bio);
 		return true;
 	}
···
  * while current io submission must wait for bitmap io to be done. In order to
  * avoid such deadlock, submit bitmap io asynchronously.
  */
-static inline void raid1_prepare_flush_writes(struct bitmap *bitmap)
+static inline void raid1_prepare_flush_writes(struct mddev *mddev)
 {
-	if (current->bio_list)
-		md_bitmap_unplug_async(bitmap);
-	else
-		md_bitmap_unplug(bitmap);
+	mddev->bitmap_ops->unplug(mddev, current->bio_list == NULL);
 }
 
 /*

drivers/md/raid1.c

···
 
 static void close_write(struct r1bio *r1_bio)
 {
+	struct mddev *mddev = r1_bio->mddev;
+
 	/* it really is the end of this request */
 	if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
 		bio_free_pages(r1_bio->behind_master_bio);
 		bio_put(r1_bio->behind_master_bio);
 		r1_bio->behind_master_bio = NULL;
 	}
+
 	/* clear the bitmap if all writes complete successfully */
-	md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
-			   r1_bio->sectors,
-			   !test_bit(R1BIO_Degraded, &r1_bio->state),
-			   test_bit(R1BIO_BehindIO, &r1_bio->state));
-	md_write_end(r1_bio->mddev);
+	mddev->bitmap_ops->endwrite(mddev, r1_bio->sector, r1_bio->sectors,
+				    !test_bit(R1BIO_Degraded, &r1_bio->state),
+				    test_bit(R1BIO_BehindIO, &r1_bio->state));
+	md_write_end(mddev);
 }
 
 static void r1_bio_write_done(struct r1bio *r1_bio)
···
 static void flush_bio_list(struct r1conf *conf, struct bio *bio)
 {
 	/* flush any pending bitmap writes to disk before proceeding w/ I/O */
-	raid1_prepare_flush_writes(conf->mddev->bitmap);
+	raid1_prepare_flush_writes(conf->mddev);
 	wake_up_barrier(conf);
 
 	while (bio) { /* submit pending writes */
···
 	struct r1conf *conf = mddev->private;
 	struct raid1_info *mirror;
 	struct bio *read_bio;
-	struct bitmap *bitmap = mddev->bitmap;
 	const enum req_op op = bio_op(bio);
 	const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
 	int max_sectors;
 	int rdisk;
 	bool r1bio_existed = !!r1_bio;
-	char b[BDEVNAME_SIZE];
 
 	/*
 	 * If r1_bio is set, we are blocking the raid1d thread
···
 	 * emergency memory if needed.
 	 */
 	gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
-
-	if (r1bio_existed) {
-		/* Need to get the block device name carefully */
-		struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
-
-		if (rdev)
-			snprintf(b, sizeof(b), "%pg", rdev->bdev);
-		else
-			strcpy(b, "???");
-	}
 
 	/*
 	 * Still need barrier for READ in case that whole
···
 	 * used and no empty request is available.
 	 */
 	rdisk = read_balance(conf, r1_bio, &max_sectors);
-
 	if (rdisk < 0) {
 		/* couldn't find anywhere to read from */
-		if (r1bio_existed) {
-			pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
+		if (r1bio_existed)
+			pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
 					    mdname(mddev),
-					    b,
-					    (unsigned long long)r1_bio->sector);
-		}
+					    conf->mirrors[r1_bio->read_disk].rdev->bdev,
+					    r1_bio->sector);
 		raid_end_bio_io(r1_bio);
 		return;
 	}
···
 				    (unsigned long long)r1_bio->sector,
 				    mirror->rdev->bdev);
 
-	if (test_bit(WriteMostly, &mirror->rdev->flags) &&
-	    bitmap) {
+	if (test_bit(WriteMostly, &mirror->rdev->flags)) {
 		/*
 		 * Reading from a write-mostly device must take care not to
 		 * over-take any writes that are 'behind'
 		 */
 		mddev_add_trace_msg(mddev, "raid1 wait behind writes");
-		wait_event(bitmap->behind_wait,
-			   atomic_read(&bitmap->behind_writes) == 0);
+		mddev->bitmap_ops->wait_behind_writes(mddev);
 	}
 
 	if (max_sectors < bio_sectors(bio)) {
···
 	struct r1conf *conf = mddev->private;
 	struct r1bio *r1_bio;
 	int i, disks;
-	struct bitmap *bitmap = mddev->bitmap;
 	unsigned long flags;
 	struct md_rdev *blocked_rdev;
 	int first_clone;
···
 	 * at a time and thus needs a new bio that can fit the whole payload
 	 * this bio in page sized chunks.
 	 */
-	if (write_behind && bitmap)
+	if (write_behind && mddev->bitmap)
 		max_sectors = min_t(int, max_sectors,
 				    BIO_MAX_VECS * (PAGE_SIZE >> 9));
 	if (max_sectors < bio_sectors(bio)) {
···
 			continue;
 
 		if (first_clone) {
+			unsigned long max_write_behind =
+				mddev->bitmap_info.max_write_behind;
+			struct md_bitmap_stats stats;
+			int err;
+
 			/* do behind I/O ?
 			 * Not if there are too many, or cannot
 			 * allocate memory, or a reader on WriteMostly
 			 * is waiting for behind writes to flush */
-			if (bitmap && write_behind &&
-			    (atomic_read(&bitmap->behind_writes)
-			     < mddev->bitmap_info.max_write_behind) &&
-			    !waitqueue_active(&bitmap->behind_wait)) {
+			err = mddev->bitmap_ops->get_stats(mddev->bitmap, &stats);
+			if (!err && write_behind && !stats.behind_wait &&
+			    stats.behind_writes < max_write_behind)
 				alloc_behind_master_bio(r1_bio, bio);
-			}
 
-			md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
-					     test_bit(R1BIO_BehindIO, &r1_bio->state));
+			mddev->bitmap_ops->startwrite(
+				mddev, r1_bio->sector, r1_bio->sectors,
+				test_bit(R1BIO_BehindIO, &r1_bio->state));
 			first_clone = 0;
 		}
 
···
 
 	/* make sure these bits don't get cleared. */
 	do {
-		md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
+		mddev->bitmap_ops->end_sync(mddev, s, &sync_blocks);
 		s += sync_blocks;
 		sectors_to_go -= sync_blocks;
 	} while (sectors_to_go > 0);
···
 	int wonly = -1;
 	int write_targets = 0, read_targets = 0;
 	sector_t sync_blocks;
-	int still_degraded = 0;
+	bool still_degraded = false;
 	int good_sectors = RESYNC_SECTORS;
 	int min_bad = 0; /* number of sectors that are bad in all devices */
 	int idx = sector_to_idx(sector_nr);
···
 		 * We can find the current addess in mddev->curr_resync
 		 */
 		if (mddev->curr_resync < max_sector) /* aborted */
-			md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
-					   &sync_blocks, 1);
+			mddev->bitmap_ops->end_sync(mddev, mddev->curr_resync,
+						    &sync_blocks);
 		else /* completed sync */
 			conf->fullsync = 0;
 
-		md_bitmap_close_sync(mddev->bitmap);
+		mddev->bitmap_ops->close_sync(mddev);
 		close_sync(conf);
 
 		if (mddev_is_clustered(mddev)) {
···
 	/* before building a request, check if we can skip these blocks..
 	 * This call the bitmap_start_sync doesn't actually record anything
 	 */
-	if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+	if (!mddev->bitmap_ops->start_sync(mddev, sector_nr, &sync_blocks, true) &&
 	    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
 		/* We can skip this block, and probably several more */
 		*skipped = 1;
···
 	 * sector_nr + two times RESYNC_SECTORS
 	 */
 
-	md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
-		mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
-
+	mddev->bitmap_ops->cond_end_sync(mddev, sector_nr,
+		mddev_is_clustered(mddev) &&
+		(sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
 
 	if (raise_barrier(conf, sector_nr))
 		return 0;
···
 		if (rdev == NULL ||
 		    test_bit(Faulty, &rdev->flags)) {
 			if (i < conf->raid_disks)
-				still_degraded = 1;
+				still_degraded = true;
 		} else if (!test_bit(In_sync, &rdev->flags)) {
 			bio->bi_opf = REQ_OP_WRITE;
 			bio->bi_end_io = end_sync_write;
···
 		if (len == 0)
 			break;
 		if (sync_blocks == 0) {
-			if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
-						  &sync_blocks, still_degraded) &&
+			if (!mddev->bitmap_ops->start_sync(mddev, sector_nr,
+						&sync_blocks, still_degraded) &&
 			    !conf->fullsync &&
 			    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
 				break;
···
 	 * worth it.
 	 */
 	sector_t newsize = raid1_size(mddev, sectors, 0);
+	int ret;
+
 	if (mddev->external_size &&
 	    mddev->array_sectors > newsize)
 		return -EINVAL;
-	if (mddev->bitmap) {
-		int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
-		if (ret)
-			return ret;
-	}
+
+	ret = mddev->bitmap_ops->resize(mddev, newsize, 0, false);
+	if (ret)
+		return ret;
+
 	md_set_array_sectors(mddev, newsize);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > mddev->dev_sectors) {

drivers/md/raid10.c

···
 
 static void close_write(struct r10bio *r10_bio)
 {
+	struct mddev *mddev = r10_bio->mddev;
+
 	/* clear the bitmap if all writes complete successfully */
-	md_bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
-			   r10_bio->sectors,
-			   !test_bit(R10BIO_Degraded, &r10_bio->state),
-			   0);
-	md_write_end(r10_bio->mddev);
+	mddev->bitmap_ops->endwrite(mddev, r10_bio->sector, r10_bio->sectors,
+				    !test_bit(R10BIO_Degraded, &r10_bio->state),
+				    false);
+	md_write_end(mddev);
 }
 
 static void one_write_done(struct r10bio *r10_bio)
···
 		__set_current_state(TASK_RUNNING);
 
 		blk_start_plug(&plug);
-		raid1_prepare_flush_writes(conf->mddev->bitmap);
+		raid1_prepare_flush_writes(conf->mddev);
 		wake_up(&conf->wait_barrier);
 
 		while (bio) { /* submit pending writes */
···
 
 	/* we aren't scheduling, so we can do the write-out directly. */
 	bio = bio_list_get(&plug->pending);
-	raid1_prepare_flush_writes(mddev->bitmap);
+	raid1_prepare_flush_writes(mddev);
 	wake_up_barrier(conf);
 
 	while (bio) { /* submit pending writes */
···
 	md_account_bio(mddev, &bio);
 	r10_bio->master_bio = bio;
 	atomic_set(&r10_bio->remaining, 1);
-	md_bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
+	mddev->bitmap_ops->startwrite(mddev, r10_bio->sector, r10_bio->sectors,
+				      false);
 
 	for (i = 0; i < conf->copies; i++) {
 		if (r10_bio->devs[i].bio)
···
 			s = PAGE_SIZE >> 9;
 
 		rdev = conf->mirrors[dr].rdev;
-		addr = r10_bio->devs[0].addr + sect,
+		addr = r10_bio->devs[0].addr + sect;
 		ok = sync_page_io(rdev,
 				  addr,
 				  s << 9,
···
 
 		if (mddev->curr_resync < max_sector) { /* aborted */
 			if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
-				md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
-						   &sync_blocks, 1);
+				mddev->bitmap_ops->end_sync(mddev,
+							    mddev->curr_resync,
+							    &sync_blocks);
 			else for (i = 0; i < conf->geo.raid_disks; i++) {
 				sector_t sect =
 					raid10_find_virt(conf, mddev->curr_resync, i);
-				md_bitmap_end_sync(mddev->bitmap, sect,
-						   &sync_blocks, 1);
+
+				mddev->bitmap_ops->end_sync(mddev, sect,
+							    &sync_blocks);
 			}
 		} else {
 			/* completed sync */
···
 			}
 			conf->fullsync = 0;
 		}
-		md_bitmap_close_sync(mddev->bitmap);
+		mddev->bitmap_ops->close_sync(mddev);
 		close_sync(conf);
 		*skipped = 1;
 		return sectors_skipped;
···
 		r10_bio = NULL;
 
 		for (i = 0 ; i < conf->geo.raid_disks; i++) {
-			int still_degraded;
+			bool still_degraded;
 			struct r10bio *rb2;
 			sector_t sect;
-			int must_sync;
+			bool must_sync;
 			int any_working;
 			struct raid10_info *mirror = &conf->mirrors[i];
 			struct md_rdev *mrdev, *mreplace;
···
 			if (!mrdev && !mreplace)
 				continue;
 
-			still_degraded = 0;
+			still_degraded = false;
 			/* want to reconstruct this device */
 			rb2 = r10_bio;
 			sect = raid10_find_virt(conf, sector_nr, i);
···
 			 * we only need to recover the block if it is set in
 			 * the bitmap
 			 */
-			must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
-							 &sync_blocks, 1);
+			must_sync = mddev->bitmap_ops->start_sync(mddev, sect,
+								  &sync_blocks,
+								  true);
 			if (sync_blocks < max_sync)
 				max_sync = sync_blocks;
 			if (!must_sync &&
···
 				struct md_rdev *rdev = conf->mirrors[j].rdev;
 
 				if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
-					still_degraded = 1;
+					still_degraded = false;
 					break;
 				}
 			}
 
-			must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
-							 &sync_blocks, still_degraded);
+			must_sync = mddev->bitmap_ops->start_sync(mddev, sect,
+						&sync_blocks, still_degraded);
 
 			any_working = 0;
 			for (j=0; j<conf->copies;j++) {
···
 		 * safety reason, which ensures curr_resync_completed is
 		 * updated in bitmap_cond_end_sync.
 		 */
-		md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
+		mddev->bitmap_ops->cond_end_sync(mddev, sector_nr,
 					mddev_is_clustered(mddev) &&
 					(sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
 
-		if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
-					  &sync_blocks, mddev->degraded) &&
+		if (!mddev->bitmap_ops->start_sync(mddev, sector_nr,
+						   &sync_blocks,
+						   mddev->degraded) &&
 		    !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
 						 &mddev->recovery)) {
 			/* We can skip this block */
···
 	 */
 	struct r10conf *conf = mddev->private;
 	sector_t oldsize, size;
+	int ret;
 
 	if (mddev->reshape_position != MaxSector)
 		return -EBUSY;
···
 	if (mddev->external_size &&
 	    mddev->array_sectors > size)
 		return -EINVAL;
-	if (mddev->bitmap) {
-		int ret = md_bitmap_resize(mddev->bitmap, size, 0, 0);
-		if (ret)
-			return ret;
-	}
+
+	ret = mddev->bitmap_ops->resize(mddev, size, 0, false);
+	if (ret)
+		return ret;
+
 	md_set_array_sectors(mddev, size);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > oldsize) {
···
 		newsize = raid10_size(mddev, 0, conf->geo.raid_disks);
 
 		if (!mddev_is_clustered(mddev)) {
-			ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
+			ret = mddev->bitmap_ops->resize(mddev, newsize, 0, false);
 			if (ret)
 				goto abort;
 			else
···
 
 		/*
 		 * some node is already performing reshape, and no need to
-		 * call md_bitmap_resize again since it should be called when
+		 * call bitmap_ops->resize again since it should be called when
 		 * receiving BITMAP_RESIZE msg
 		 */
 		if ((sb && (le32_to_cpu(sb->feature_map) &
 			    MD_FEATURE_RESHAPE_ACTIVE)) || (oldsize == newsize))
 			goto out;
 
-		ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
+		ret = mddev->bitmap_ops->resize(mddev, newsize, 0, false);
 		if (ret)
 			goto abort;
 
 		ret = md_cluster_ops->resize_bitmaps(mddev, newsize, oldsize);
 		if (ret) {
-			md_bitmap_resize(mddev->bitmap, oldsize, 0, 0);
+			mddev->bitmap_ops->resize(mddev, oldsize, 0, false);
 			goto abort;
 		}
 	}

drivers/md/raid5-cache.c

···
 		if (sh->dev[i].written) {
 			set_bit(R5_UPTODATE, &sh->dev[i].flags);
 			r5c_return_dev_pending_writes(conf, &sh->dev[i]);
-			md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
-					   RAID5_STRIPE_SECTORS(conf),
-					   !test_bit(STRIPE_DEGRADED, &sh->state),
-					   0);
+			conf->mddev->bitmap_ops->endwrite(conf->mddev,
+					sh->sector, RAID5_STRIPE_SECTORS(conf),
+					!test_bit(STRIPE_DEGRADED, &sh->state),
+					false);
 		}
 	}
 }
···
 {
 	struct r5l_log *log = READ_ONCE(conf->log);
 	int i;
-	int do_wakeup = 0;
 	sector_t tree_index;
 	void __rcu **pslot;
 	uintptr_t refcount;
···
 	for (i = sh->disks; i--; ) {
 		clear_bit(R5_InJournal, &sh->dev[i].flags);
 		if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
-			do_wakeup = 1;
+			wake_up_bit(&sh->dev[i].flags, R5_Overlap);
 	}
 
 	/*
···
 	if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
 		if (atomic_dec_and_test(&conf->pending_full_writes))
 			md_wakeup_thread(conf->mddev->thread);
-
-	if (do_wakeup)
-		wake_up(&conf->wait_for_overlap);
 
 	spin_lock_irq(&log->stripe_in_journal_lock);
 	list_del_init(&sh->r5c);

drivers/md/raid5.c

···
 		for (i = disks; i--; ) {
 			struct r5dev *dev = &sh->dev[i];
 			if (test_and_clear_bit(R5_Overlap, &dev->flags))
-				wake_up(&sh->raid_conf->wait_for_overlap);
+				wake_up_bit(&dev->flags, R5_Overlap);
 		}
 	}
 	local_unlock(&conf->percpu->lock);
···
 		 * With PPL only writes to consecutive data chunks within a
 		 * stripe are allowed because for a single stripe_head we can
 		 * only have one PPL entry at a time, which describes one data
-		 * range. Not really an overlap, but wait_for_overlap can be
+		 * range. Not really an overlap, but R5_Overlap can be
 		 * used to handle this.
 		 */
 		sector_t sector;
···
 		 */
 		set_bit(STRIPE_BITMAP_PENDING, &sh->state);
 		spin_unlock_irq(&sh->stripe_lock);
-		md_bitmap_startwrite(conf->mddev->bitmap, sh->sector,
-				     RAID5_STRIPE_SECTORS(conf), 0);
+		conf->mddev->bitmap_ops->startwrite(conf->mddev, sh->sector,
+					RAID5_STRIPE_SECTORS(conf), false);
 		spin_lock_irq(&sh->stripe_lock);
 		clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
 		if (!sh->batch_head) {
···
 		log_stripe_write_finished(sh);
 
 		if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
-			wake_up(&conf->wait_for_overlap);
+			wake_up_bit(&sh->dev[i].flags, R5_Overlap);
 
 		while (bi && bi->bi_iter.bi_sector <
 			sh->dev[i].sector + RAID5_STRIPE_SECTORS(conf)) {
···
 			bi = nextbi;
 		}
 		if (bitmap_end)
-			md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
-					   RAID5_STRIPE_SECTORS(conf), 0, 0);
+			conf->mddev->bitmap_ops->endwrite(conf->mddev,
+					sh->sector, RAID5_STRIPE_SECTORS(conf),
+					false, false);
 		bitmap_end = 0;
 		/* and fail all 'written' */
 		bi = sh->dev[i].written;
···
 			sh->dev[i].toread = NULL;
 			spin_unlock_irq(&sh->stripe_lock);
 			if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
-				wake_up(&conf->wait_for_overlap);
+				wake_up_bit(&sh->dev[i].flags, R5_Overlap);
 			if (bi)
 				s->to_read--;
 			while (bi && bi->bi_iter.bi_sector <
···
 			}
 		}
 		if (bitmap_end)
-			md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
-					   RAID5_STRIPE_SECTORS(conf), 0, 0);
+			conf->mddev->bitmap_ops->endwrite(conf->mddev,
+					sh->sector, RAID5_STRIPE_SECTORS(conf),
+					false, false);
 		/* If we were in the middle of a write the parity block might
 		 * still be locked - so just clear all R5_LOCKED flags
 		 */
···
 	BUG_ON(sh->batch_head);
 	clear_bit(STRIPE_SYNCING, &sh->state);
 	if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
-		wake_up(&conf->wait_for_overlap);
+		wake_up_bit(&sh->dev[sh->pd_idx].flags, R5_Overlap);
 	s->syncing = 0;
 	s->replacing = 0;
 	/* There is nothing more to do for sync/check/repair.
···
 					bio_endio(wbi);
 					wbi = wbi2;
 				}
-				md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
-						   RAID5_STRIPE_SECTORS(conf),
-						   !test_bit(STRIPE_DEGRADED, &sh->state),
-						   0);
+				conf->mddev->bitmap_ops->endwrite(conf->mddev,
+					sh->sector, RAID5_STRIPE_SECTORS(conf),
+					!test_bit(STRIPE_DEGRADED, &sh->state),
+					false);
 				if (head_sh->batch_head) {
 					sh = list_first_entry(&sh->batch_list,
 							      struct stripe_head,
···
 {
 	struct stripe_head *sh, *next;
 	int i;
-	int do_wakeup = 0;
 
 	list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) {
 
···
 		spin_unlock_irq(&sh->stripe_lock);
 		for (i = 0; i < sh->disks; i++) {
 			if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
-				do_wakeup = 1;
+				wake_up_bit(&sh->dev[i].flags, R5_Overlap);
 			sh->dev[i].flags = head_sh->dev[i].flags &
 				(~((1 << R5_WriteError) | (1 << R5_Overlap)));
 		}
···
 	spin_unlock_irq(&head_sh->stripe_lock);
 	for (i = 0; i < head_sh->disks; i++)
 		if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
-			do_wakeup = 1;
+			wake_up_bit(&head_sh->dev[i].flags, R5_Overlap);
 	if (head_sh->state & handle_flags)
 		set_bit(STRIPE_HANDLE, &head_sh->state);
-
-	if (do_wakeup)
-		wake_up(&head_sh->raid_conf->wait_for_overlap);
 }
 
 static void handle_stripe(struct stripe_head *sh)
···
 		md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), 1);
 		clear_bit(STRIPE_SYNCING, &sh->state);
 		if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
-			wake_up(&conf->wait_for_overlap);
+			wake_up_bit(&sh->dev[sh->pd_idx].flags, R5_Overlap);
 	}
 
 	/* If the failed drives are just a ReadError, then we might need
···
 	} else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
 		clear_bit(STRIPE_EXPAND_READY, &sh->state);
 		atomic_dec(&conf->reshape_stripes);
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 		md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), 1);
 	}
 
···
 		int d;
 	again:
 		sh = raid5_get_active_stripe(conf, NULL, logical_sector, 0);
-		prepare_to_wait(&conf->wait_for_overlap, &w,
-				TASK_UNINTERRUPTIBLE);
 		set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
 		if (test_bit(STRIPE_SYNCING, &sh->state)) {
 			raid5_release_stripe(sh);
-			schedule();
+			wait_on_bit(&sh->dev[sh->pd_idx].flags, R5_Overlap,
+				    TASK_UNINTERRUPTIBLE);
 			goto again;
 		}
 		clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
···
 				set_bit(R5_Overlap, &sh->dev[d].flags);
 				spin_unlock_irq(&sh->stripe_lock);
 				raid5_release_stripe(sh);
-				schedule();
+				wait_on_bit(&sh->dev[d].flags, R5_Overlap,
+					    TASK_UNINTERRUPTIBLE);
 				goto again;
 			}
 		}
 		set_bit(STRIPE_DISCARD, &sh->state);
-		finish_wait(&conf->wait_for_overlap, &w);
 		sh->overwrite_disks = 0;
 		for (d = 0; d < conf->raid_disks; d++) {
 			if (d == sh->pd_idx || d == sh->qd_idx)
···
 		}
 		spin_unlock_irq(&sh->stripe_lock);
 		if (conf->mddev->bitmap) {
-			for (d = 0;
-			     d < conf->raid_disks - conf->max_degraded;
+			for (d = 0; d < conf->raid_disks - conf->max_degraded;
 			     d++)
-				md_bitmap_startwrite(mddev->bitmap,
-						     sh->sector,
-						     RAID5_STRIPE_SECTORS(conf),
-						     0);
+				mddev->bitmap_ops->startwrite(mddev, sh->sector,
+					RAID5_STRIPE_SECTORS(conf), false);
 			sh->bm_seq = conf->seq_flush + 1;
 			set_bit(STRIPE_BIT_DELAY, &sh->state);
 		}
···
 		struct bio *bi, int forwrite, int previous)
 {
 	int dd_idx;
-	int ret = 1;
 
 	spin_lock_irq(&sh->stripe_lock);
 
···
 
 		if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
 			set_bit(R5_Overlap, &dev->flags);
-			ret = 0;
-			continue;
+			spin_unlock_irq(&sh->stripe_lock);
+			raid5_release_stripe(sh);
+			/* release batch_last before wait to avoid risk of deadlock */
+			if (ctx->batch_last) {
+				raid5_release_stripe(ctx->batch_last);
+				ctx->batch_last = NULL;
+			}
+			md_wakeup_thread(conf->mddev->thread);
+			wait_on_bit(&dev->flags, R5_Overlap, TASK_UNINTERRUPTIBLE);
+			return 0;
 		}
 	}
-
-	if (!ret)
-		goto out;
 
 	for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
 		struct r5dev *dev = &sh->dev[dd_idx];
···
 			  RAID5_STRIPE_SHIFT(conf), ctx->sectors_to_do);
 	}
 
-out:
 	spin_unlock_irq(&sh->stripe_lock);
-	return ret;
+	return 1;
 }
 
 enum reshape_loc {
···
 		goto out_release;
 	}
 
-	if (test_bit(STRIPE_EXPANDING, &sh->state) ||
-	    !add_all_stripe_bios(conf, ctx, sh, bi, rw, previous)) {
-		/*
-		 * Stripe is busy expanding or add failed due to
-		 * overlap. Flush everything and wait a while.
-		 */
+	if (test_bit(STRIPE_EXPANDING, &sh->state)) {
 		md_wakeup_thread(mddev->thread);
 		ret = STRIPE_SCHEDULE_AND_RETRY;
 		goto out_release;
+	}
+
+	if (!add_all_stripe_bios(conf, ctx, sh, bi, rw, previous)) {
+		ret = STRIPE_RETRY;
+		goto out;
 	}
 
 	if (stripe_can_batch(sh)) {
···
 static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
 {
 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	bool on_wq;
 	struct r5conf *conf = mddev->private;
 	sector_t logical_sector;
 	struct stripe_request_ctx ctx = {};
···
 	 * sequential IO pattern. We don't bother with the optimization when
 	 * reshaping as the performance benefit is not worth the complexity.
 	 */
-	if (likely(conf->reshape_progress == MaxSector))
+	if (likely(conf->reshape_progress == MaxSector)) {
 		logical_sector = raid5_bio_lowest_chunk_sector(conf, bi);
+		on_wq = false;
+	} else {
+		add_wait_queue(&conf->wait_for_reshape, &wait);
+		on_wq = true;
+	}
 	s = (logical_sector - ctx.first_sector) >> RAID5_STRIPE_SHIFT(conf);
 
-	add_wait_queue(&conf->wait_for_overlap, &wait);
 	while (1) {
 		res = make_stripe_request(mddev, conf, &ctx, logical_sector,
 					  bi);
···
 			continue;
 
 		if (res == STRIPE_SCHEDULE_AND_RETRY) {
+			WARN_ON_ONCE(!on_wq);
 			/*
 			 * Must release the reference to batch_last before
 			 * scheduling and waiting for work to be done,
···
 		logical_sector = ctx.first_sector +
 			(s << RAID5_STRIPE_SHIFT(conf));
 	}
-	remove_wait_queue(&conf->wait_for_overlap, &wait);
+	if (unlikely(on_wq))
+		remove_wait_queue(&conf->wait_for_reshape, &wait);
 
 	if (ctx.batch_last)
 		raid5_release_stripe(ctx.batch_last);
···
 	     : (safepos < writepos && readpos > writepos)) ||
 	    time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
 		/* Cannot proceed until we've updated the superblock... */
-		wait_event(conf->wait_for_overlap,
+		wait_event(conf->wait_for_reshape,
 			   atomic_read(&conf->reshape_stripes)==0
 			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
 		if (atomic_read(&conf->reshape_stripes) != 0)
···
 		spin_lock_irq(&conf->device_lock);
 		conf->reshape_safe = mddev->reshape_position;
 		spin_unlock_irq(&conf->device_lock);
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 		sysfs_notify_dirent_safe(mddev->sysfs_completed);
 	}
 
···
 	    (sector_nr - mddev->curr_resync_completed) * 2
 	    >= mddev->resync_max - mddev->curr_resync_completed) {
 		/* Cannot proceed until we've updated the superblock... */
-		wait_event(conf->wait_for_overlap,
+		wait_event(conf->wait_for_reshape,
 			   atomic_read(&conf->reshape_stripes) == 0
 			   || test_bit(MD_RECOVERY_INTR, &mddev->recovery));
 		if (atomic_read(&conf->reshape_stripes) != 0)
···
 		spin_lock_irq(&conf->device_lock);
 		conf->reshape_safe = mddev->reshape_position;
 		spin_unlock_irq(&conf->device_lock);
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 		sysfs_notify_dirent_safe(mddev->sysfs_completed);
 	}
 ret:
···
 	struct r5conf *conf = mddev->private;
 	struct stripe_head *sh;
 	sector_t sync_blocks;
-	int still_degraded = 0;
+	bool still_degraded = false;
 	int i;
 
 	if (sector_nr >= max_sector) {
···
 		}
 
 		if (mddev->curr_resync < max_sector) /* aborted */
-			md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
-					   &sync_blocks, 1);
+			mddev->bitmap_ops->end_sync(mddev, mddev->curr_resync,
+						    &sync_blocks);
 		else /* completed sync */
 			conf->fullsync = 0;
-		md_bitmap_close_sync(mddev->bitmap);
+		mddev->bitmap_ops->close_sync(mddev);
 
 		return 0;
 	}
 
 	/* Allow raid5_quiesce to complete */
-	wait_event(conf->wait_for_overlap, conf->quiesce != 2);
+	wait_event(conf->wait_for_reshape, conf->quiesce != 2);
 
 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
 		return reshape_request(mddev, sector_nr, skipped);
···
 	}
 	if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
 	    !conf->fullsync &&
-	    !md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+	    !mddev->bitmap_ops->start_sync(mddev, sector_nr, &sync_blocks,
+					   true) &&
 	    sync_blocks >= RAID5_STRIPE_SECTORS(conf)) {
 		/* we can skip this block, and probably more */
 		do_div(sync_blocks, RAID5_STRIPE_SECTORS(conf));
···
 		return sync_blocks * RAID5_STRIPE_SECTORS(conf);
 	}
 
-	md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, false);
+	mddev->bitmap_ops->cond_end_sync(mddev, sector_nr, false);
 
 	sh = raid5_get_active_stripe(conf, NULL, sector_nr,
 				     R5_GAS_NOBLOCK);
···
 		struct md_rdev *rdev = conf->disks[i].rdev;
 
 		if (rdev == NULL || test_bit(Faulty, &rdev->flags))
-			still_degraded = 1;
+			still_degraded = true;
 	}
 
-	md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
+	mddev->bitmap_ops->start_sync(mddev, sector_nr, &sync_blocks,
+				      still_degraded);
 
 	set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
 	set_bit(STRIPE_HANDLE, &sh->state);
···
 			/* Now is a good time to flush some bitmap updates */
 			conf->seq_flush++;
 			spin_unlock_irq(&conf->device_lock);
-			md_bitmap_unplug(mddev->bitmap);
+			mddev->bitmap_ops->unplug(mddev, true);
 			spin_lock_irq(&conf->device_lock);
 			conf->seq_write = conf->seq_flush;
 			activate_bit_delay(conf, conf->temp_inactive_list);
···
 
 	init_waitqueue_head(&conf->wait_for_quiescent);
 	init_waitqueue_head(&conf->wait_for_stripe);
-	init_waitqueue_head(&conf->wait_for_overlap);
+	init_waitqueue_head(&conf->wait_for_reshape);
 	INIT_LIST_HEAD(&conf->handle_list);
 	INIT_LIST_HEAD(&conf->loprio_list);
 	INIT_LIST_HEAD(&conf->hold_list);
···
 	 */
 	sector_t newsize;
 	struct r5conf *conf = mddev->private;
+	int ret;
 
 	if (raid5_has_log(conf) || raid5_has_ppl(conf))
 		return -EINVAL;
···
 	if (mddev->external_size &&
 	    mddev->array_sectors > newsize)
 		return -EINVAL;
-	if (mddev->bitmap) {
-		int ret = md_bitmap_resize(mddev->bitmap, sectors, 0, 0);
-		if (ret)
-			return ret;
-	}
+
+	ret = mddev->bitmap_ops->resize(mddev, sectors, 0, false);
+	if (ret)
+		return ret;
+
 	md_set_array_sectors(mddev, newsize);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > mddev->dev_sectors) {
···
 			    !test_bit(In_sync, &rdev->flags))
 				rdev->recovery_offset = MaxSector;
 		spin_unlock_irq(&conf->device_lock);
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 
 		mddev_update_io_opt(conf->mddev,
 			conf->raid_disks - conf->max_degraded);
···
 		conf->quiesce = 1;
 		unlock_all_device_hash_locks_irq(conf);
 		/* allow reshape to continue */
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 	} else {
 		/* re-enable writes */
 		lock_all_device_hash_locks_irq(conf);
 		conf->quiesce = 0;
 		wake_up(&conf->wait_for_quiescent);
-		wake_up(&conf->wait_for_overlap);
+		wake_up(&conf->wait_for_reshape);
 		unlock_all_device_hash_locks_irq(conf);
 	}
 	log_quiesce(conf, quiesce);
···
 {
 	struct r5conf *conf = mddev->private;
 
-	wake_up(&conf->wait_for_overlap);
+	wake_up(&conf->wait_for_reshape);
 }
 
 static struct md_personality raid6_personality =

drivers/md/raid5.h

···
 	struct llist_head	released_stripes;
 	wait_queue_head_t	wait_for_quiescent;
 	wait_queue_head_t	wait_for_stripe;
-	wait_queue_head_t	wait_for_overlap;
+	wait_queue_head_t	wait_for_reshape;
 	unsigned long		cache_state;
 	struct shrinker		*shrinker;
 	int			pool_size; /* number of disks in stripeheads in pool */

drivers/nvme/common/keyring.c

···
 }
 EXPORT_SYMBOL_GPL(nvme_keyring_id);
 
+static bool nvme_tls_psk_revoked(struct key *psk)
+{
+	return test_bit(KEY_FLAG_REVOKED, &psk->flags) ||
+		test_bit(KEY_FLAG_INVALIDATED, &psk->flags);
+}
+
+struct key *nvme_tls_key_lookup(key_serial_t key_id)
+{
+	struct key *key = key_lookup(key_id);
+
+	if (IS_ERR(key)) {
+		pr_err("key id %08x not found\n", key_id);
+		return key;
+	}
+	if (nvme_tls_psk_revoked(key)) {
+		pr_err("key id %08x revoked\n", key_id);
+		return ERR_PTR(-EKEYREVOKED);
+	}
+	return key;
+}
+EXPORT_SYMBOL_GPL(nvme_tls_key_lookup);
+
 static void nvme_tls_psk_describe(const struct key *key, struct seq_file *m)
 {
 	seq_puts(m, key->description);
···
 		pr_debug("%s: no key description\n", __func__);
 		return false;
 	}
-	match_len = strlen(key->description);
-	pr_debug("%s: id %s len %zd\n", __func__, key->description, match_len);
-
 	if (!match_data->raw_data) {
 		pr_debug("%s: no match data\n", __func__);
 		return false;
 	}
 	match_id = match_data->raw_data;
+	match_len = strlen(match_id);
 	pr_debug("%s: match '%s' '%s' len %zd\n",
 		 __func__, match_id, key->description, match_len);
 	return !memcmp(key->description, match_id, match_len);
···
 
 static struct key *nvme_tls_psk_lookup(struct key *keyring,
 		const char *hostnqn, const char *subnqn,
-		int hmac, bool generated)
+		u8 hmac, u8 psk_ver, bool generated)
 {
 	char *identity;
 	size_t identity_len = (NVMF_NQN_SIZE) * 2 + 11;
···
 	if (!identity)
 		return ERR_PTR(-ENOMEM);
 
-	snprintf(identity, identity_len, "NVMe0%c%02d %s %s",
-		 generated ? 'G' : 'R', hmac, hostnqn, subnqn);
+	snprintf(identity, identity_len, "NVMe%u%c%02u %s %s",
+		 psk_ver, generated ? 'G' : 'R', hmac, hostnqn, subnqn);
 
 	if (!keyring)
 		keyring = nvme_keyring;
···
 /*
  * NVMe PSK priority list
  *
- * 'Retained' PSKs (ie 'generated == false')
- * should be preferred to 'generated' PSKs,
- * and SHA-384 should be preferred to SHA-256.
+ * 'Retained' PSKs (ie 'generated == false') should be preferred to 'generated'
+ * PSKs, PSKs with hash (psk_ver 1) should be preferred to PSKs without hash
+ * (psk_ver 0), and SHA-384 should be preferred to SHA-256.
  */
 static struct nvme_tls_psk_priority_list {
 	bool generated;
+	u8 psk_ver;
 	enum nvme_tcp_tls_cipher cipher;
 } nvme_tls_psk_prio[] = {
 	{ .generated = false,
+	  .psk_ver = 1,
 	  .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
 	{ .generated = false,
+	  .psk_ver = 1,
+	  .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+	{ .generated = false,
+	  .psk_ver = 0,
+	  .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+	{ .generated = false,
+	  .psk_ver = 0,
 	  .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
 	{ .generated = true,
+	  .psk_ver = 1,
 	  .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
 	{ .generated = true,
+	  .psk_ver = 1,
+	  .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
+	{ .generated = true,
+	  .psk_ver = 0,
+	  .cipher = NVME_TCP_TLS_CIPHER_SHA384, },
+	{ .generated = true,
+	  .psk_ver = 0,
 	  .cipher = NVME_TCP_TLS_CIPHER_SHA256, },
 };
 
···
 
 	for (prio = 0; prio < ARRAY_SIZE(nvme_tls_psk_prio); prio++) {
 		bool generated = nvme_tls_psk_prio[prio].generated;
+		u8 ver = nvme_tls_psk_prio[prio].psk_ver;
 		enum nvme_tcp_tls_cipher cipher = nvme_tls_psk_prio[prio].cipher;
 
 		tls_key = nvme_tls_psk_lookup(keyring, hostnqn, subnqn,
-					      cipher, generated);
+					      cipher, ver, generated);
 		if (!IS_ERR(tls_key)) {
 			tls_key_id = tls_key->serial;
 			key_put(tls_key);

drivers/nvme/host/Kconfig

···
 	bool "NVMe over Fabrics In-Band Authentication in host side"
 	depends on NVME_CORE
 	select NVME_AUTH
+	select NVME_KEYRING if NVME_TCP_TLS
 	help
 	  This provides support for NVMe over Fabrics In-Band Authentication in
 	  host side.

drivers/nvme/host/core.c

···
  * Copyright (c) 2011-2014, Intel Corporation.
  */
 
+#include <linux/async.h>
 #include <linux/blkdev.h>
 #include <linux/blk-mq.h>
 #include <linux/blk-integrity.h>
···
 	cmnd->rw.length =
 		cpu_to_le16((blk_rq_bytes(req) >> ns->head->lba_shift) - 1);
 	cmnd->rw.reftag = 0;
-	cmnd->rw.apptag = 0;
-	cmnd->rw.appmask = 0;
+	cmnd->rw.lbat = 0;
+	cmnd->rw.lbatm = 0;
 
 	if (ns->head->ms) {
 		/*
···
 	}
 }
 
+/**
+ * struct async_scan_info - keeps track of controller & NSIDs to scan
+ * @ctrl:	Controller on which namespaces are being scanned
+ * @next_nsid:	Index of next NSID to scan in ns_list
+ * @ns_list:	Pointer to list of NSIDs to scan
+ *
+ * Note: There is a single async_scan_info structure shared by all instances
+ * of nvme_scan_ns_async() scanning a given controller, so the atomic
+ * operations on next_nsid are critical to ensure each instance scans a unique
+ * NSID.
+ */
+struct async_scan_info {
+	struct nvme_ctrl *ctrl;
+	atomic_t next_nsid;
+	__le32 *ns_list;
+};
+
+static void nvme_scan_ns_async(void *data, async_cookie_t cookie)
+{
+	struct async_scan_info *scan_info = data;
+	int idx;
+	u32 nsid;
+
+	idx = (u32)atomic_fetch_inc(&scan_info->next_nsid);
+	nsid = le32_to_cpu(scan_info->ns_list[idx]);
+
+	nvme_scan_ns(scan_info->ctrl, nsid);
+}
+
 static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
 					unsigned nsid)
 {
···
 	__le32 *ns_list;
 	u32 prev = 0;
 	int ret = 0, i;
+	ASYNC_DOMAIN(domain);
+	struct async_scan_info scan_info;
 
 	ns_list = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
 	if (!ns_list)
 		return -ENOMEM;
 
+	scan_info.ctrl = ctrl;
+	scan_info.ns_list = ns_list;
 	for (;;) {
 		struct nvme_command cmd = {
 			.identify.opcode	= nvme_admin_identify,
···
 			goto free;
 		}
 
+		atomic_set(&scan_info.next_nsid, 0);
 		for (i = 0; i < nr_entries; i++) {
 			u32 nsid = le32_to_cpu(ns_list[i]);
 
 			if (!nsid)	/* end of the list? */
 				goto out;
-			nvme_scan_ns(ctrl, nsid);
+			async_schedule_domain(nvme_scan_ns_async, &scan_info,
+						&domain);
 			while (++prev < nsid)
 				nvme_ns_remove_by_nsid(ctrl, prev);
 		}
+		async_synchronize_full_domain(&domain);
 	}
  out:
 	nvme_remove_invalid_namespaces(ctrl, prev);
  free:
+	async_synchronize_full_domain(&domain);
 	kfree(ns_list);
 	return ret;
 }
···
 
 	if (!subsys || ctrl->instance != subsys->instance)
 		ida_free(&nvme_instance_ida, ctrl->instance);
-	key_put(ctrl->tls_key);
 	nvme_free_cels(ctrl);
 	nvme_mpath_uninit(ctrl);
 	cleanup_srcu_struct(&ctrl->srcu);

drivers/nvme/host/fabrics.c

···
 		return ERR_PTR(-EINVAL);
 	}
 
-	key = key_lookup(key_id);
+	key = nvme_tls_key_lookup(key_id);
 	if (IS_ERR(key))
 		pr_err("key id %08x not found\n", key_id);
 	else

drivers/nvme/host/ioctl.c

···
  * Copyright (c) 2017-2021 Christoph Hellwig.
  */
 #include <linux/bio-integrity.h>
+#include <linux/blk-integrity.h>
 #include <linux/ptrace.h>	/* for force_successful_syscall_return */
 #include <linux/nvme_ioctl.h>
 #include <linux/io_uring/cmd.h>
···
 	struct request_queue *q = req->q;
 	struct nvme_ns *ns = q->queuedata;
 	struct block_device *bdev = ns ? ns->disk->part0 : NULL;
+	bool supports_metadata = bdev && blk_get_integrity(bdev->bd_disk);
+	bool has_metadata = meta_buffer && meta_len;
 	struct bio *bio = NULL;
 	int ret;
+
+	if (has_metadata && !supports_metadata)
+		return -EINVAL;
 
 	if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) {
 		struct iov_iter iter;
···
 		goto out;
 
 	bio = req->bio;
-	if (bdev) {
+	if (bdev)
 		bio_set_dev(bio, bdev);
-		if (meta_buffer && meta_len) {
-			ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
-						     meta_seed);
-			if (ret)
-				goto out_unmap;
-			req->cmd_flags |= REQ_INTEGRITY;
-		}
+
+	if (has_metadata) {
+		ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
+					     meta_seed);
+		if (ret)
+			goto out_unmap;
+		req->cmd_flags |= REQ_INTEGRITY;
 	}
 
 	return ret;
···
 	c.rw.control = cpu_to_le16(io.control);
 	c.rw.dsmgmt = cpu_to_le32(io.dsmgmt);
 	c.rw.reftag = cpu_to_le32(io.reftag);
-	c.rw.apptag = cpu_to_le16(io.apptag);
-	c.rw.appmask = cpu_to_le16(io.appmask);
+	c.rw.lbat = cpu_to_le16(io.apptag);
+	c.rw.lbatm = cpu_to_le16(io.appmask);
 
 	return nvme_submit_user_cmd(ns->queue, &c, io.addr, length, metadata,
 			meta_len, lower_32_bits(io.slba), NULL, 0, 0);

drivers/nvme/host/nvme.h

···
 	struct nvme_dhchap_key *ctrl_key;
 	u16 transaction;
 #endif
-	struct key *tls_key;
+	key_serial_t tls_pskid;
 
 	/* Power saving configuration */
 	u64 ps_max_latency_us;

drivers/nvme/host/rdma.c

···
 	if (control & NVME_RW_PRINFO_PRCHK_REF)
 		domain->sig.dif.ref_remap = true;
 
-	domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.apptag);
-	domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.appmask);
+	domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.lbat);
+	domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.lbatm);
 	domain->sig.dif.app_escape = true;
 	if (pi_type == NVME_NS_DPS_PI_TYPE3)
 		domain->sig.dif.ref_escape = true;
···
 		 */
 		priv.hrqsize = cpu_to_le16(queue->queue_size);
 		priv.hsqsize = cpu_to_le16(queue->ctrl->ctrl.sqsize);
+		/* cntlid should only be set when creating an I/O queue */
+		priv.cntlid = cpu_to_le16(ctrl->ctrl.cntlid);
 	}
 
 	ret = rdma_connect_locked(queue->cm_id, &param);

drivers/nvme/host/sysfs.c

···
 	nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
 #endif
 
-#ifdef CONFIG_NVME_TCP_TLS
-static ssize_t tls_key_show(struct device *dev,
-			    struct device_attribute *attr, char *buf)
-{
-	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
-
-	if (!ctrl->tls_key)
-		return 0;
-	return sysfs_emit(buf, "%08x", key_serial(ctrl->tls_key));
-}
-static DEVICE_ATTR_RO(tls_key);
-#endif
-
 static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_reset_controller.attr,
 	&dev_attr_rescan_controller.attr,
···
 #ifdef CONFIG_NVME_HOST_AUTH
 	&dev_attr_dhchap_secret.attr,
 	&dev_attr_dhchap_ctrl_secret.attr,
-#endif
-#ifdef CONFIG_NVME_TCP_TLS
-	&dev_attr_tls_key.attr,
 #endif
 	&dev_attr_adm_passthru_err_log_enabled.attr,
 	NULL
···
 	if (a == &dev_attr_dhchap_ctrl_secret.attr && !ctrl->opts)
 		return 0;
 #endif
-#ifdef CONFIG_NVME_TCP_TLS
-	if (a == &dev_attr_tls_key.attr &&
-	    (!ctrl->opts || strcmp(ctrl->opts->transport, "tcp")))
-		return 0;
-#endif
 
 	return a->mode;
 }
···
 };
 EXPORT_SYMBOL_GPL(nvme_dev_attrs_group);
 
+#ifdef CONFIG_NVME_TCP_TLS
+static ssize_t tls_key_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (!ctrl->tls_pskid)
+		return 0;
+	return sysfs_emit(buf, "%08x\n", ctrl->tls_pskid);
+}
+static DEVICE_ATTR_RO(tls_key);
+
+static ssize_t tls_configured_key_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct key *key = ctrl->opts->tls_key;
+
+	return sysfs_emit(buf, "%08x\n", key_serial(key));
+}
+static DEVICE_ATTR_RO(tls_configured_key);
+
+static ssize_t tls_keyring_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	struct key *keyring = ctrl->opts->keyring;
+
+	return sysfs_emit(buf, "%s\n", keyring->description);
+}
+static DEVICE_ATTR_RO(tls_keyring);
+
+static struct attribute *nvme_tls_attrs[] = {
+	&dev_attr_tls_key.attr,
+	&dev_attr_tls_configured_key.attr,
+	&dev_attr_tls_keyring.attr,
+};
+
+static umode_t nvme_tls_attrs_are_visible(struct kobject *kobj,
+		struct attribute *a, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (!ctrl->opts || strcmp(ctrl->opts->transport, "tcp"))
+		return 0;
+
+	if (a == &dev_attr_tls_key.attr &&
+	    !ctrl->opts->tls)
+		return 0;
+	if (a == &dev_attr_tls_configured_key.attr &&
+	    !ctrl->opts->tls_key)
+		return 0;
+	if (a == &dev_attr_tls_keyring.attr &&
+	    !ctrl->opts->keyring)
+		return 0;
+
+	return a->mode;
+}
+
+const struct attribute_group nvme_tls_attrs_group = {
+	.attrs		= nvme_tls_attrs,
+	.is_visible	= nvme_tls_attrs_are_visible,
+};
+#endif
+
 const struct attribute_group *nvme_dev_attr_groups[] = {
 	&nvme_dev_attrs_group,
+#ifdef CONFIG_NVME_TCP_TLS
+	&nvme_tls_attrs_group,
+#endif
 	NULL,
 };
 

drivers/nvme/host/tcp.c

···
 
 	bool			hdr_digest;
 	bool			data_digest;
+	bool			tls_enabled;
 	struct ahash_request	*rcv_hash;
 	struct ahash_request	*snd_hash;
 	__le32			exp_ddgst;
···
 	return queue - queue->ctrl->queues;
 }
 
-static inline bool nvme_tcp_tls(struct nvme_ctrl *ctrl)
+/*
+ * Check if the queue is TLS encrypted
+ */
+static inline bool nvme_tcp_queue_tls(struct nvme_tcp_queue *queue)
+{
+	if (!IS_ENABLED(CONFIG_NVME_TCP_TLS))
+		return 0;
+
+	return queue->tls_enabled;
+}
+
+/*
+ * Check if TLS is configured for the controller.
+ */
+static inline bool nvme_tcp_tls_configured(struct nvme_ctrl *ctrl)
 {
 	if (!IS_ENABLED(CONFIG_NVME_TCP_TLS))
 		return 0;
···
 
 static inline bool nvme_tcp_queue_more(struct nvme_tcp_queue *queue)
 {
-	return !nvme_tcp_tls(&queue->ctrl->ctrl) &&
+	return !nvme_tcp_queue_tls(queue) &&
 		nvme_tcp_queue_has_pending(queue);
 }
 
···
 		else
 			msg.msg_flags |= MSG_MORE;
 
-		if (!sendpage_ok(page))
+		if (!sendpages_ok(page, len, offset))
 			msg.msg_flags &= ~MSG_SPLICE_PAGES;
 
 		bvec_set_page(&bvec, page, len, offset);
···
 	memset(&msg, 0, sizeof(msg));
 	iov.iov_base = icresp;
 	iov.iov_len = sizeof(*icresp);
-	if (nvme_tcp_tls(&queue->ctrl->ctrl)) {
+	if (nvme_tcp_queue_tls(queue)) {
 		msg.msg_control = cbuf;
 		msg.msg_controllen = sizeof(cbuf);
 	}
···
 		goto free_icresp;
 	}
 	ret = -ENOTCONN;
-	if (nvme_tcp_tls(&queue->ctrl->ctrl)) {
+	if (nvme_tcp_queue_tls(queue)) {
 		ctype = tls_get_record_type(queue->sock->sk,
 					    (struct cmsghdr *)cbuf);
 		if (ctype != TLS_RECORD_TYPE_DATA) {
···
 		goto out_complete;
 	}
 
-	tls_key = key_lookup(pskid);
+	tls_key = nvme_tls_key_lookup(pskid);
 	if (IS_ERR(tls_key)) {
 		dev_warn(ctrl->ctrl.device, "queue %d: Invalid key %x\n",
 			 qid, pskid);
 		queue->tls_err = -ENOKEY;
 	} else {
-		ctrl->ctrl.tls_key = tls_key;
+		queue->tls_enabled = true;
+		if (qid == 0)
+			ctrl->ctrl.tls_pskid = key_serial(tls_key);
+		key_put(tls_key);
 		queue->tls_err = 0;
 	}
 
···
 	}
 
 	/* If PSKs are configured try to start TLS */
-	if (IS_ENABLED(CONFIG_NVME_TCP_TLS) && pskid) {
+	if (nvme_tcp_tls_configured(nctrl) && pskid) {
 		ret = nvme_tcp_start_tls(nctrl, queue, pskid);
 		if (ret)
 			goto err_init_connect;
···
 	mutex_lock(&queue->queue_lock);
 	if (test_and_clear_bit(NVME_TCP_Q_LIVE, &queue->flags))
 		__nvme_tcp_stop_queue(queue);
+	/* Stopping the queue will disable TLS */
+	queue->tls_enabled = false;
 	mutex_unlock(&queue->queue_lock);
 }
 
···
 	int ret;
 	key_serial_t pskid = 0;
 
-	if (nvme_tcp_tls(ctrl)) {
+	if (nvme_tcp_tls_configured(ctrl)) {
 		if (ctrl->opts->tls_key)
 			pskid = key_serial(ctrl->opts->tls_key);
-		else
+		else {
 			pskid = nvme_tls_psk_default(ctrl->opts->keyring,
 						      ctrl->opts->host->nqn,
 						      ctrl->opts->subsysnqn);
-		if (!pskid) {
-			dev_err(ctrl->device, "no valid PSK found\n");
-			return -ENOKEY;
+			if (!pskid) {
+				dev_err(ctrl->device, "no valid PSK found\n");
+				return -ENOKEY;
+			}
 		}
 	}
 
···
 {
 	int i, ret;
 
-	if (nvme_tcp_tls(ctrl) && !ctrl->tls_key) {
+	if (nvme_tcp_tls_configured(ctrl) && !ctrl->tls_pskid) {
 		dev_err(ctrl->device, "no PSK negotiated\n");
 		return -ENOKEY;
 	}
+
 	for (i = 1; i < ctrl->queue_count; i++) {
 		ret = nvme_tcp_alloc_queue(ctrl, i,
-				key_serial(ctrl->tls_key));
+				ctrl->tls_pskid);
 		if (ret)
 			goto out_free_queues;
 	}
···
 	if (remove)
 		nvme_unquiesce_admin_queue(ctrl);
 	nvme_tcp_destroy_admin_queue(ctrl, remove);
+	if (ctrl->tls_pskid) {
+		dev_dbg(ctrl->device, "Wipe negotiated TLS_PSK %08x\n",
+			ctrl->tls_pskid);
+		ctrl->tls_pskid = 0;
+	}
 }
 
 static void nvme_tcp_teardown_io_queues(struct nvme_ctrl *ctrl,

drivers/nvme/target/admin-cmd.c

···
 
 	if (nvme_is_fabrics(cmd))
 		return nvmet_parse_fabrics_admin_cmd(req);
-	if (unlikely(!nvmet_check_auth_status(req)))
-		return NVME_SC_AUTH_REQUIRED | NVME_STATUS_DNR;
 	if (nvmet_is_disc_subsys(nvmet_req_subsys(req)))
 		return nvmet_parse_discovery_cmd(req);
 

drivers/nvme/target/auth.c

···
 	unsigned char key_hash;
 	char *dhchap_secret;
 
+	if (!strlen(secret)) {
+		if (set_ctrl) {
+			kfree(host->dhchap_ctrl_secret);
+			host->dhchap_ctrl_secret = NULL;
+			host->dhchap_ctrl_key_hash = 0;
+		} else {
+			kfree(host->dhchap_secret);
+			host->dhchap_secret = NULL;
+			host->dhchap_key_hash = 0;
+		}
+		return 0;
+	}
 	if (sscanf(secret, "DHHC-1:%hhd:%*s", &key_hash) != 1)
 		return -EINVAL;
 	if (key_hash > 3) {

drivers/nvme/target/rdma.c

···
 	if (control & NVME_RW_PRINFO_PRCHK_REF)
 		domain->sig.dif.ref_remap = true;
 
-	domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.apptag);
-	domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.appmask);
+	domain->sig.dif.app_tag = le16_to_cpu(cmd->rw.lbat);
+	domain->sig.dif.apptag_check_mask = le16_to_cpu(cmd->rw.lbatm);
 	domain->sig.dif.app_escape = true;
 	if (pi_type == NVME_NS_DPS_PI_TYPE3)
 		domain->sig.dif.ref_escape = true;

fs/btrfs/bio.c

···
 
 static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info,
 					 struct btrfs_bio *orig_bbio,
-					 u64 map_length, bool use_append)
+					 u64 map_length)
 {
 	struct btrfs_bio *bbio;
 	struct bio *bio;
 
-	if (use_append) {
-		unsigned int nr_segs;
-
-		bio = bio_split_rw(&orig_bbio->bio, &fs_info->limits, &nr_segs,
-				   &btrfs_clone_bioset, map_length);
-	} else {
-		bio = bio_split(&orig_bbio->bio, map_length >> SECTOR_SHIFT,
-				GFP_NOFS, &btrfs_clone_bioset);
-	}
+	bio = bio_split(&orig_bbio->bio, map_length >> SECTOR_SHIFT, GFP_NOFS,
+			&btrfs_clone_bioset);
 	bbio = btrfs_bio(bio);
 	btrfs_bio_init(bbio, fs_info, NULL, orig_bbio);
 	bbio->inode = orig_bbio->inode;
···
 	return true;
 }
 
+static u64 btrfs_append_map_length(struct btrfs_bio *bbio, u64 map_length)
+{
+	unsigned int nr_segs;
+	int sector_offset;
+
+	map_length = min(map_length, bbio->fs_info->max_zone_append_size);
+	sector_offset = bio_split_rw_at(&bbio->bio, &bbio->fs_info->limits,
+					&nr_segs, map_length);
+	if (sector_offset)
+		return sector_offset << SECTOR_SHIFT;
+	return map_length;
+}
+
 static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 {
 	struct btrfs_inode *inode = bbio->inode;
···
 
 	map_length = min(map_length, length);
 	if (use_append)
-		map_length = min(map_length, fs_info->max_zone_append_size);
+		map_length = btrfs_append_map_length(bbio, map_length);
 
 	if (map_length < length) {
-		bbio = btrfs_split_bio(fs_info, bbio, map_length, use_append);
+		bbio = btrfs_split_bio(fs_info, bbio, map_length);
 		bio = &bbio->bio;
 	}
 

include/linux/bio.h

···
 void bio_trim(struct bio *bio, sector_t offset, sector_t size);
 extern struct bio *bio_split(struct bio *bio, int sectors,
 			     gfp_t gfp, struct bio_set *bs);
-struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
-		unsigned *segs, struct bio_set *bs, unsigned max_bytes);
+int bio_split_rw_at(struct bio *bio, const struct queue_limits *lim,
+		unsigned *segs, unsigned max_bytes);
 
 /**
  * bio_next_split - get next @sectors from a bio, splitting if necessary

include/linux/blkdev.h

···
 	return q->limits.max_segment_size;
 }
 
-static inline unsigned int queue_limits_max_zone_append_sectors(struct queue_limits *l)
+static inline unsigned int
+queue_limits_max_zone_append_sectors(const struct queue_limits *l)
 {
 	unsigned int max_sectors = min(l->chunk_sectors, l->max_hw_sectors);
 

include/linux/mm.h

···
 void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
 				      bool make_dirty);
 void unpin_user_pages(struct page **pages, unsigned long npages);
+void unpin_user_folio(struct folio *folio, unsigned long npages);
 void unpin_folios(struct folio **folios, unsigned long nfolios);
 
 static inline bool is_cow_mapping(vm_flags_t flags)

include/linux/net.h

···
 	return !PageSlab(page) && page_count(page) >= 1;
 }
 
+/*
+ * Check sendpage_ok on contiguous pages.
+ */
+static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
+{
+	struct page *p = page + (offset >> PAGE_SHIFT);
+	size_t count = 0;
+
+	while (count < len) {
+		if (!sendpage_ok(p))
+			return false;
+
+		p++;
+		count += PAGE_SIZE;
+	}
+
+	return true;
+}
+
 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 		   size_t num, size_t len);
 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,

include/linux/nvme-keyring.h

···
 		const char *hostnqn, const char *subnqn);
 
 key_serial_t nvme_keyring_id(void);
-
+struct key *nvme_tls_key_lookup(key_serial_t key_id);
 #else
 
 static inline key_serial_t nvme_tls_psk_default(struct key *keyring,
···
 static inline key_serial_t nvme_keyring_id(void)
 {
 	return 0;
+}
+static inline struct key *nvme_tls_key_lookup(key_serial_t key_id)
+{
+	return ERR_PTR(-ENOTSUPP);
 }
 #endif /* !CONFIG_NVME_KEYRING */
 #endif /* _NVME_KEYRING_H */

include/linux/nvme-rdma.h

···
 	NVME_RDMA_CM_NO_RSC		= 0x06,
 	NVME_RDMA_CM_INVALID_IRD	= 0x07,
 	NVME_RDMA_CM_INVALID_ORD	= 0x08,
+	NVME_RDMA_CM_INVALID_CNTLID	= 0x09,
 };
 
 static inline const char *nvme_rdma_cm_msg(enum nvme_rdma_cm_status status)
···
 		return "invalid IRD";
 	case NVME_RDMA_CM_INVALID_ORD:
 		return "Invalid ORD";
+	case NVME_RDMA_CM_INVALID_CNTLID:
+		return "invalid controller ID";
 	default:
 		return "unrecognized reason";
 	}
···
 	__le16		qid;
 	__le16		hrqsize;
 	__le16		hsqsize;
-	u8		rsvd[24];
+	__le16		cntlid;
+	u8		rsvd[22];
 };
 
 /**

include/linux/nvme.h

···
 	__le16			control;
 	__le32			dsmgmt;
 	__le32			reftag;
-	__le16			apptag;
-	__le16			appmask;
+	__le16			lbat;
+	__le16			lbatm;
 };
 
 enum {
···
 	__le16			control;
 	__le32			dsmgmt;
 	__le32			reftag;
-	__le16			apptag;
-	__le16			appmask;
+	__le16			lbat;
+	__le16			lbatm;
 };
 
 enum nvme_zone_mgmt_action {

include/uapi/linux/nbd.h

···
 	NBD_CMD_WRITE = 1,
 	NBD_CMD_DISC = 2,
 	NBD_CMD_FLUSH = 3,
-	NBD_CMD_TRIM = 4
+	NBD_CMD_TRIM = 4,
 	/* userspace defines additional extension commands */
+	NBD_CMD_WRITE_ZEROES = 6,
 };
 
 /* values for flags field, these are server interaction specific. */
···
 #define NBD_FLAG_READ_ONLY	(1 << 1) /* device is read-only */
 #define NBD_FLAG_SEND_FLUSH	(1 << 2) /* can flush writeback cache */
 #define NBD_FLAG_SEND_FUA	(1 << 3) /* send FUA (forced unit access) */
-/* there is a gap here to match userspace */
+#define NBD_FLAG_ROTATIONAL	(1 << 4) /* device is rotational */
 #define NBD_FLAG_SEND_TRIM	(1 << 5) /* send trim/discard */
+#define NBD_FLAG_SEND_WRITE_ZEROES (1 << 6) /* supports WRITE_ZEROES */
+/* there is a gap here to match userspace */
 #define NBD_FLAG_CAN_MULTI_CONN	(1 << 8)	/* Server supports multiple connections per export. */
 
 /* values for cmd flags in the upper 16 bits of request type */
 #define NBD_CMD_FLAG_FUA	(1 << 16) /* FUA (forced unit access) op */
+#define NBD_CMD_FLAG_NO_HOLE	(1 << 17) /* Do not punch a hole for WRITE_ZEROES */
 
 /* These are client behavior specific flags. */
 #define NBD_CFLAG_DESTROY_ON_DISCONNECT	(1 << 0) /* delete the nbd device on

mm/gup.c

···
 EXPORT_SYMBOL(unpin_user_pages);
 
 /**
+ * unpin_user_folio() - release pages of a folio
+ * @folio:  pointer to folio to be released
+ * @npages: number of pages of same folio
+ *
+ * Release npages of the folio
+ */
+void unpin_user_folio(struct folio *folio, unsigned long npages)
+{
+	gup_put_folio(folio, npages, FOLL_PIN);
+}
+EXPORT_SYMBOL(unpin_user_folio);
+
+/**
  * unpin_folios() - release an array of gup-pinned folios.
  * @folios:  array of folios to be marked dirty and released.
  * @nfolios: number of folios in the @folios array.