Merge tag 'for-5.5/drivers-20191121' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "Here are the main block driver updates for 5.5. Nothing major in here,
  mostly just fixes. This contains:

   - a set of bcache changes via Coly

   - MD changes from Song

   - loop unmap write-zeroes fix (Darrick)

   - spelling fixes (Geert)

   - zoned additions cleanups to null_blk/dm (Ajay)

   - allow null_blk online submit queue changes (Bart)

   - NVMe changes via Keith, nothing major here either"

* tag 'for-5.5/drivers-20191121' of git://git.kernel.dk/linux-block: (56 commits)
  Revert "bcache: fix fifo index swapping condition in journal_pin_cmp()"
  drivers/md/raid5-ppl.c: use the new spelling of RWH_WRITE_LIFE_NOT_SET
  drivers/md/raid5.c: use the new spelling of RWH_WRITE_LIFE_NOT_SET
  bcache: don't export symbols
  bcache: remove the extra cflags for request.o
  bcache: at least try to shrink 1 node in bch_mca_scan()
  bcache: add idle_max_writeback_rate sysfs interface
  bcache: add code comments in bch_btree_leaf_dirty()
  bcache: fix deadlock in bcache_allocator
  bcache: add code comment bch_keylist_pop() and bch_keylist_pop_front()
  bcache: deleted code comments for dead code in bch_data_insert_keys()
  bcache: add more accurate error messages in read_super()
  bcache: fix static checker warning in bcache_device_free()
  bcache: fix a lost wake-up problem caused by mca_cannibalize_lock
  bcache: fix fifo index swapping condition in journal_pin_cmp()
  md/raid10: prevent access of uninitialized resync_pages offset
  md: avoid invalid memory access for array sb->dev_roles
  md/raid1: avoid soft lockup under high load
  null_blk: add zone open, close, and finish support
  dm: add zone open, close and finish support
  ...

46 files changed, 595 insertions, 352 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index f6f77eaa7217..ef6e251857c8 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -417,18 +417,20 @@ out_free_page:
 	return ret;
 }
 
-static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos)
+static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
+			int mode)
 {
 	/*
-	 * We use punch hole to reclaim the free space used by the
-	 * image a.k.a. discard. However we do not support discard if
-	 * encryption is enabled, because it may give an attacker
-	 * useful information.
+	 * We use fallocate to manipulate the space mappings used by the image
+	 * a.k.a. discard/zerorange. However we do not support this if
+	 * encryption is enabled, because it may give an attacker useful
+	 * information.
 	 */
 	struct file *file = lo->lo_backing_file;
-	int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 	int ret;
 
+	mode |= FALLOC_FL_KEEP_SIZE;
+
 	if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) {
 		ret = -EOPNOTSUPP;
 		goto out;
@@ -596,9 +598,17 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
 	switch (req_op(rq)) {
 	case REQ_OP_FLUSH:
 		return lo_req_flush(lo, rq);
-	case REQ_OP_DISCARD:
 	case REQ_OP_WRITE_ZEROES:
-		return lo_discard(lo, rq, pos);
+		/*
+		 * If the caller doesn't want deallocation, call zeroout to
+		 * write zeroes the range.  Otherwise, punch them out.
+		 */
+		return lo_fallocate(lo, rq, pos,
+			(rq->cmd_flags & REQ_NOUNMAP) ?
+				FALLOC_FL_ZERO_RANGE :
+				FALLOC_FL_PUNCH_HOLE);
+	case REQ_OP_DISCARD:
+		return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
 	case REQ_OP_WRITE:
 		if (lo->transfer)
 			return lo_write_transfer(lo, rq, pos);
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 964f78cfffa0..f6bafa9a68b9 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -129,7 +129,7 @@ struct mtip_compat_ide_task_request_s {
 /*
  * This function check_for_surprise_removal is called
  * while card is removed from the system and it will
- * read the vendor id from the configration space
+ * read the vendor id from the configuration space
  *
  * @pdev Pointer to the pci_dev structure.
  *
diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index a235c45e22a7..93c2a3d403da 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -96,6 +96,8 @@ int null_zone_report(struct gendisk *disk, sector_t sector,
 blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 				enum req_opf op, sector_t sector,
 				sector_t nr_sectors);
+size_t null_zone_valid_read_len(struct nullb *nullb,
+				sector_t sector, unsigned int len);
 #else
 static inline int null_zone_init(struct nullb_device *dev)
 {
@@ -115,5 +117,11 @@ static inline blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 {
 	return BLK_STS_NOTSUPP;
 }
+static inline size_t null_zone_valid_read_len(struct nullb *nullb,
+					      sector_t sector,
+					      unsigned int len)
+{
+	return len;
+}
 #endif /* CONFIG_BLK_DEV_ZONED */
 #endif /* __NULL_BLK_H */
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 0e7da5015ccd..ea7a4d6b7848 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -227,7 +227,7 @@ static ssize_t nullb_device_uint_attr_store(unsigned int *val,
 	int result;
 
 	result = kstrtouint(page, 0, &tmp);
-	if (result)
+	if (result < 0)
 		return result;
 
 	*val = tmp;
@@ -241,7 +241,7 @@ static ssize_t nullb_device_ulong_attr_store(unsigned long *val,
 	unsigned long tmp;
 
 	result = kstrtoul(page, 0, &tmp);
-	if (result)
+	if (result < 0)
 		return result;
 
 	*val = tmp;
@@ -255,7 +255,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
 	int result;
 
 	result = kstrtobool(page,  &tmp);
-	if (result)
+	if (result < 0)
 		return result;
 
 	*val = tmp;
@@ -263,7 +263,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
 }
 
 /* The following macro should only be used with TYPE = {uint, ulong, bool}. */
-#define NULLB_DEVICE_ATTR(NAME, TYPE)						\
+#define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY)					\
 static ssize_t									\
 nullb_device_##NAME##_show(struct config_item *item, char *page)		\
 {										\
@@ -274,31 +274,57 @@ static ssize_t									\
 nullb_device_##NAME##_store(struct config_item *item, const char *page,		\
 			    size_t count)					\
 {										\
-	if (test_bit(NULLB_DEV_FL_CONFIGURED, &to_nullb_device(item)->flags))	\
-		return -EBUSY;							\
-	return nullb_device_##TYPE##_attr_store(				\
-			&to_nullb_device(item)->NAME, page, count);		\
+	int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;	\
+	struct nullb_device *dev = to_nullb_device(item);			\
+	TYPE new_value;								\
+	int ret;								\
+										\
+	ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);	\
+	if (ret < 0)								\
+		return ret;							\
+	if (apply_fn)								\
+		ret = apply_fn(dev, new_value);					\
+	else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) 		\
+		ret = -EBUSY;							\
+	if (ret < 0)								\
+		return ret;							\
+	dev->NAME = new_value;							\
+	return count;								\
 }										\
 CONFIGFS_ATTR(nullb_device_, NAME);
 
-NULLB_DEVICE_ATTR(size, ulong);
-NULLB_DEVICE_ATTR(completion_nsec, ulong);
-NULLB_DEVICE_ATTR(submit_queues, uint);
-NULLB_DEVICE_ATTR(home_node, uint);
-NULLB_DEVICE_ATTR(queue_mode, uint);
-NULLB_DEVICE_ATTR(blocksize, uint);
-NULLB_DEVICE_ATTR(irqmode, uint);
-NULLB_DEVICE_ATTR(hw_queue_depth, uint);
-NULLB_DEVICE_ATTR(index, uint);
-NULLB_DEVICE_ATTR(blocking, bool);
-NULLB_DEVICE_ATTR(use_per_node_hctx, bool);
-NULLB_DEVICE_ATTR(memory_backed, bool);
-NULLB_DEVICE_ATTR(discard, bool);
-NULLB_DEVICE_ATTR(mbps, uint);
-NULLB_DEVICE_ATTR(cache_size, ulong);
-NULLB_DEVICE_ATTR(zoned, bool);
-NULLB_DEVICE_ATTR(zone_size, ulong);
-NULLB_DEVICE_ATTR(zone_nr_conv, uint);
+static int nullb_apply_submit_queues(struct nullb_device *dev,
+				     unsigned int submit_queues)
+{
+	struct nullb *nullb = dev->nullb;
+	struct blk_mq_tag_set *set;
+
+	if (!nullb)
+		return 0;
+
+	set = nullb->tag_set;
+	blk_mq_update_nr_hw_queues(set, submit_queues);
+	return set->nr_hw_queues == submit_queues ? 0 : -ENOMEM;
+}
+
+NULLB_DEVICE_ATTR(size, ulong, NULL);
+NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL);
+NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues);
+NULLB_DEVICE_ATTR(home_node, uint, NULL);
+NULLB_DEVICE_ATTR(queue_mode, uint, NULL);
+NULLB_DEVICE_ATTR(blocksize, uint, NULL);
+NULLB_DEVICE_ATTR(irqmode, uint, NULL);
+NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL);
+NULLB_DEVICE_ATTR(index, uint, NULL);
+NULLB_DEVICE_ATTR(blocking, bool, NULL);
+NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL);
+NULLB_DEVICE_ATTR(memory_backed, bool, NULL);
+NULLB_DEVICE_ATTR(discard, bool, NULL);
+NULLB_DEVICE_ATTR(mbps, uint, NULL);
+NULLB_DEVICE_ATTR(cache_size, ulong, NULL);
+NULLB_DEVICE_ATTR(zoned, bool, NULL);
+NULLB_DEVICE_ATTR(zone_size, ulong, NULL);
+NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL);
 
 static ssize_t nullb_device_power_show(struct config_item *item, char *page)
 {
@@ -996,6 +1022,16 @@ next:
 	return 0;
 }
 
+static void nullb_fill_pattern(struct nullb *nullb, struct page *page,
+			       unsigned int len, unsigned int off)
+{
+	void *dst;
+
+	dst = kmap_atomic(page);
+	memset(dst + off, 0xFF, len);
+	kunmap_atomic(dst);
+}
+
 static void null_handle_discard(struct nullb *nullb, sector_t sector, size_t n)
 {
 	size_t temp;
@@ -1036,10 +1072,24 @@ static int null_transfer(struct nullb *nullb, struct page *page,
 	unsigned int len, unsigned int off, bool is_write, sector_t sector,
 	bool is_fua)
 {
+	struct nullb_device *dev = nullb->dev;
+	unsigned int valid_len = len;
 	int err = 0;
 
 	if (!is_write) {
-		err = copy_from_nullb(nullb, page, off, sector, len);
+		if (dev->zoned)
+			valid_len = null_zone_valid_read_len(nullb,
+				sector, len);
+
+		if (valid_len) {
+			err = copy_from_nullb(nullb, page, off,
+				sector, valid_len);
+			off += valid_len;
+			len -= valid_len;
+		}
+
+		if (len)
+			nullb_fill_pattern(nullb, page, len, off);
 		flush_dcache_page(page);
 	} else {
 		flush_dcache_page(page);
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 3d7fdea872f8..02f41a3bc4cb 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -84,6 +84,24 @@ int null_zone_report(struct gendisk *disk, sector_t sector,
 	return 0;
 }
 
+size_t null_zone_valid_read_len(struct nullb *nullb,
+				sector_t sector, unsigned int len)
+{
+	struct nullb_device *dev = nullb->dev;
+	struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
+	unsigned int nr_sectors = len >> SECTOR_SHIFT;
+
+	/* Read must be below the write pointer position */
+	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL ||
+	    sector + nr_sectors <= zone->wp)
+		return len;
+
+	if (sector > zone->wp)
+		return 0;
+
+	return (zone->wp - sector) << SECTOR_SHIFT;
+}
+
 static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 		     unsigned int nr_sectors)
 {
@@ -118,14 +136,14 @@ static blk_status_t null_zone_write(struct nullb_cmd *cmd, sector_t sector,
 	return BLK_STS_OK;
 }
 
-static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
+static blk_status_t null_zone_mgmt(struct nullb_cmd *cmd, enum req_opf op,
+				   sector_t sector)
 {
 	struct nullb_device *dev = cmd->nq->dev;
-	unsigned int zno = null_zone_no(dev, sector);
-	struct blk_zone *zone = &dev->zones[zno];
+	struct blk_zone *zone = &dev->zones[null_zone_no(dev, sector)];
 	size_t i;
 
-	switch (req_op(cmd->rq)) {
+	switch (op) {
 	case REQ_OP_ZONE_RESET_ALL:
 		for (i = 0; i < dev->nr_zones; i++) {
 			if (zone[i].type == BLK_ZONE_TYPE_CONVENTIONAL)
@@ -141,6 +159,29 @@ static blk_status_t null_zone_reset(struct nullb_cmd *cmd, sector_t sector)
 		zone->cond = BLK_ZONE_COND_EMPTY;
 		zone->wp = zone->start;
 		break;
+	case REQ_OP_ZONE_OPEN:
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+			return BLK_STS_IOERR;
+		if (zone->cond == BLK_ZONE_COND_FULL)
+			return BLK_STS_IOERR;
+
+		zone->cond = BLK_ZONE_COND_EXP_OPEN;
+		break;
+	case REQ_OP_ZONE_CLOSE:
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+			return BLK_STS_IOERR;
+		if (zone->cond == BLK_ZONE_COND_FULL)
+			return BLK_STS_IOERR;
+
+		zone->cond = BLK_ZONE_COND_CLOSED;
+		break;
+	case REQ_OP_ZONE_FINISH:
+		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+			return BLK_STS_IOERR;
+
+		zone->cond = BLK_ZONE_COND_FULL;
+		zone->wp = zone->start + zone->len;
+		break;
 	default:
 		return BLK_STS_NOTSUPP;
 	}
@@ -155,7 +196,10 @@ blk_status_t null_handle_zoned(struct nullb_cmd *cmd, enum req_opf op,
 		return null_zone_write(cmd, sector, nr_sectors);
 	case REQ_OP_ZONE_RESET:
 	case REQ_OP_ZONE_RESET_ALL:
-		return null_zone_reset(cmd, sector);
+	case REQ_OP_ZONE_OPEN:
+	case REQ_OP_ZONE_CLOSE:
+	case REQ_OP_ZONE_FINISH:
+		return null_zone_mgmt(cmd, op, sector);
 	default:
 		return BLK_STS_OK;
 	}
diff --git a/drivers/md/bcache/Makefile b/drivers/md/bcache/Makefile
index d26b35195825..fd714628da6a 100644
--- a/drivers/md/bcache/Makefile
+++ b/drivers/md/bcache/Makefile
@@ -5,5 +5,3 @@ obj-$(CONFIG_BCACHE)	+= bcache.o
 bcache-y		:= alloc.o bset.o btree.o closure.o debug.o extents.o\
 	io.o journal.o movinggc.o request.o stats.o super.o sysfs.o trace.o\
 	util.o writeback.o
-
-CFLAGS_request.o	+= -Iblock
diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index 6f776823b9ba..a1df0d95151c 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -377,7 +377,10 @@ retry_invalidate:
 			if (!fifo_full(&ca->free_inc))
 				goto retry_invalidate;
 
-			bch_prio_write(ca);
+			if (bch_prio_write(ca, false) < 0) {
+				ca->invalidate_needs_gc = 1;
+				wake_up_gc(ca->set);
+			}
 		}
 	}
 out:
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 013e35a9e317..9198c1b480d9 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -582,6 +582,7 @@ struct cache_set {
 	 */
 	wait_queue_head_t	btree_cache_wait;
 	struct task_struct	*btree_cache_alloc_lock;
+	spinlock_t		btree_cannibalize_lock;
 
 	/*
 	 * When we free a btree node, we increment the gen of the bucket the
@@ -723,6 +724,7 @@ struct cache_set {
 	unsigned int		gc_always_rewrite:1;
 	unsigned int		shrinker_disabled:1;
 	unsigned int		copy_gc_enabled:1;
+	unsigned int		idle_max_writeback_rate_enabled:1;
 
 #define BUCKET_HASH_BITS	12
 	struct hlist_head	bucket_hash[1 << BUCKET_HASH_BITS];
@@ -977,7 +979,7 @@ bool bch_cached_dev_error(struct cached_dev *dc);
 __printf(2, 3)
 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...);
 
-void bch_prio_write(struct cache *ca);
+int bch_prio_write(struct cache *ca, bool wait);
 void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent);
 
 extern struct workqueue_struct *bcache_wq;
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 08768796b543..cffcdc9feefb 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -155,6 +155,7 @@ int __bch_keylist_realloc(struct keylist *l, unsigned int u64s)
 	return 0;
 }
 
+/* Pop the top key of keylist by pointing l->top to its previous key */
 struct bkey *bch_keylist_pop(struct keylist *l)
 {
 	struct bkey *k = l->keys;
@@ -168,6 +169,7 @@ struct bkey *bch_keylist_pop(struct keylist *l)
 	return l->top = k;
 }
 
+/* Pop the bottom key of keylist and update l->top_p */
 void bch_keylist_pop_front(struct keylist *l)
 {
 	l->top_p -= bkey_u64s(l->keys);
@@ -309,7 +311,6 @@ void bch_btree_keys_free(struct btree_keys *b)
 	t->tree = NULL;
 	t->data = NULL;
 }
-EXPORT_SYMBOL(bch_btree_keys_free);
 
 int bch_btree_keys_alloc(struct btree_keys *b,
 			 unsigned int page_order,
@@ -342,7 +343,6 @@ err:
 	bch_btree_keys_free(b);
 	return -ENOMEM;
 }
-EXPORT_SYMBOL(bch_btree_keys_alloc);
 
 void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
 			 bool *expensive_debug_checks)
@@ -361,7 +361,6 @@ void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
 	 * any more.
 	 */
 }
-EXPORT_SYMBOL(bch_btree_keys_init);
 
 /* Binary tree stuff for auxiliary search trees */
 
@@ -678,7 +677,6 @@ void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
 
 	bch_bset_build_unwritten_tree(b);
 }
-EXPORT_SYMBOL(bch_bset_init_next);
 
 /*
  * Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
@@ -732,7 +730,6 @@ void bch_bset_build_written_tree(struct btree_keys *b)
 	     j = inorder_next(j, t->size))
 		make_bfloat(t, j);
 }
-EXPORT_SYMBOL(bch_bset_build_written_tree);
 
 /* Insert */
 
@@ -780,7 +777,6 @@ fix_right:	do {
 			j = j * 2 + 1;
 		} while (j < t->size);
 }
-EXPORT_SYMBOL(bch_bset_fix_invalidated_key);
 
 static void bch_bset_fix_lookup_table(struct btree_keys *b,
 				      struct bset_tree *t,
@@ -855,7 +851,6 @@ bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
 
 	return b->ops->key_merge(b, l, r);
 }
-EXPORT_SYMBOL(bch_bkey_try_merge);
 
 void bch_bset_insert(struct btree_keys *b, struct bkey *where,
 		     struct bkey *insert)
@@ -875,7 +870,6 @@ void bch_bset_insert(struct btree_keys *b, struct bkey *where,
 	bkey_copy(where, insert);
 	bch_bset_fix_lookup_table(b, t, where);
 }
-EXPORT_SYMBOL(bch_bset_insert);
 
 unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
 			      struct bkey *replace_key)
@@ -931,7 +925,6 @@ copy:	bkey_copy(m, k);
 merged:
 	return status;
 }
-EXPORT_SYMBOL(bch_btree_insert_key);
 
 /* Lookup */
 
@@ -1077,7 +1070,6 @@ struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
 
 	return i.l;
 }
-EXPORT_SYMBOL(__bch_bset_search);
 
 /* Btree iterator */
 
@@ -1132,7 +1124,6 @@ struct bkey *bch_btree_iter_init(struct btree_keys *b,
 {
 	return __bch_btree_iter_init(b, iter, search, b->set);
 }
-EXPORT_SYMBOL(bch_btree_iter_init);
 
 static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
 						 btree_iter_cmp_fn *cmp)
@@ -1165,7 +1156,6 @@ struct bkey *bch_btree_iter_next(struct btree_iter *iter)
 	return __bch_btree_iter_next(iter, btree_iter_cmp);
 
 }
-EXPORT_SYMBOL(bch_btree_iter_next);
 
 struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
 					struct btree_keys *b, ptr_filter_fn fn)
@@ -1196,7 +1186,6 @@ int bch_bset_sort_state_init(struct bset_sort_state *state,
 
 	return mempool_init_page_pool(&state->pool, 1, page_order);
 }
-EXPORT_SYMBOL(bch_bset_sort_state_init);
 
 static void btree_mergesort(struct btree_keys *b, struct bset *out,
 			    struct btree_iter *iter,
@@ -1313,7 +1302,6 @@ void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
 
 	EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
 }
-EXPORT_SYMBOL(bch_btree_sort_partial);
 
 void bch_btree_sort_and_fix_extents(struct btree_keys *b,
 				    struct btree_iter *iter,
@@ -1366,7 +1354,6 @@ void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
 out:
 	bch_bset_build_written_tree(b);
 }
-EXPORT_SYMBOL(bch_btree_sort_lazy);
 
 void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
 {
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index ba434d9ac720..14d6c33b0957 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -543,6 +543,11 @@ static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref)
 
 	set_btree_node_dirty(b);
 
+	/*
+	 * w->journal is always the oldest journal pin of all bkeys
+	 * in the leaf node, to make sure the oldest jset seq won't
+	 * be increased before this btree node is flushed.
+	 */
 	if (journal_ref) {
 		if (w->journal &&
 		    journal_pin_cmp(b->c, w->journal, journal_ref)) {
@@ -723,6 +728,8 @@ static unsigned long bch_mca_scan(struct shrinker *shrink,
 	 * IO can always make forward progress:
 	 */
 	nr /= c->btree_pages;
+	if (nr == 0)
+		nr = 1;
 	nr = min_t(unsigned long, nr, mca_can_free(c));
 
 	i = 0;
@@ -884,15 +891,17 @@ out:
 
 static int mca_cannibalize_lock(struct cache_set *c, struct btree_op *op)
 {
-	struct task_struct *old;
-
-	old = cmpxchg(&c->btree_cache_alloc_lock, NULL, current);
-	if (old && old != current) {
+	spin_lock(&c->btree_cannibalize_lock);
+	if (likely(c->btree_cache_alloc_lock == NULL)) {
+		c->btree_cache_alloc_lock = current;
+	} else if (c->btree_cache_alloc_lock != current) {
 		if (op)
 			prepare_to_wait(&c->btree_cache_wait, &op->wait,
 					TASK_UNINTERRUPTIBLE);
+		spin_unlock(&c->btree_cannibalize_lock);
 		return -EINTR;
 	}
+	spin_unlock(&c->btree_cannibalize_lock);
 
 	return 0;
 }
@@ -927,10 +936,12 @@ static struct btree *mca_cannibalize(struct cache_set *c, struct btree_op *op,
  */
 static void bch_cannibalize_unlock(struct cache_set *c)
 {
+	spin_lock(&c->btree_cannibalize_lock);
 	if (c->btree_cache_alloc_lock == current) {
 		c->btree_cache_alloc_lock = NULL;
 		wake_up(&c->btree_cache_wait);
 	}
+	spin_unlock(&c->btree_cannibalize_lock);
 }
 
 static struct btree *mca_alloc(struct cache_set *c, struct btree_op *op,
diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
index c12cd809ab19..0164a1fe94a9 100644
--- a/drivers/md/bcache/closure.c
+++ b/drivers/md/bcache/closure.c
@@ -45,7 +45,6 @@ void closure_sub(struct closure *cl, int v)
 {
 	closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
 }
-EXPORT_SYMBOL(closure_sub);
 
 /*
  * closure_put - decrement a closure's refcount
@@ -54,7 +53,6 @@ void closure_put(struct closure *cl)
 {
 	closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
 }
-EXPORT_SYMBOL(closure_put);
 
 /*
  * closure_wake_up - wake up all closures on a wait list, without memory barrier
@@ -76,7 +74,6 @@ void __closure_wake_up(struct closure_waitlist *wait_list)
 		closure_sub(cl, CLOSURE_WAITING + 1);
 	}
 }
-EXPORT_SYMBOL(__closure_wake_up);
 
 /**
  * closure_wait - add a closure to a waitlist
@@ -96,7 +93,6 @@ bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
 
 	return true;
 }
-EXPORT_SYMBOL(closure_wait);
 
 struct closure_syncer {
 	struct task_struct	*task;
@@ -131,7 +127,6 @@ void __sched __closure_sync(struct closure *cl)
 
 	__set_current_state(TASK_RUNNING);
 }
-EXPORT_SYMBOL(__closure_sync);
 
 #ifdef CONFIG_BCACHE_CLOSURES_DEBUG
 
@@ -149,7 +144,6 @@ void closure_debug_create(struct closure *cl)
 	list_add(&cl->all, &closure_list);
 	spin_unlock_irqrestore(&closure_list_lock, flags);
 }
-EXPORT_SYMBOL(closure_debug_create);
 
 void closure_debug_destroy(struct closure *