5 files changed, 35 insertions, 26 deletions

diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index ce13c272c3..48ce750bf7 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -129,12 +129,9 @@ static inline bool can_inc_bucket_gen(struct bucket *b)
 
 bool bch_can_invalidate_bucket(struct cache *ca, struct bucket *b)
 {
-	BUG_ON(!ca->set->gc_mark_valid);
-
-	return (!GC_MARK(b) ||
-		GC_MARK(b) == GC_MARK_RECLAIMABLE) &&
-		!atomic_read(&b->pin) &&
-		can_inc_bucket_gen(b);
+	return (ca->set->gc_mark_valid || b->reclaimable_in_gc) &&
+	       ((!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE) &&
+	       !atomic_read(&b->pin) && can_inc_bucket_gen(b));
 }
 
 void __bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
@@ -148,6 +145,7 @@ void __bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
 	bch_inc_gen(ca, b);
 	b->prio = INITIAL_PRIO;
 	atomic_inc(&b->pin);
+	b->reclaimable_in_gc = 0;
 }
 
 static void bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
@@ -352,8 +350,7 @@ static int bch_allocator_thread(void *arg)
 		 */
 
 retry_invalidate:
-		allocator_wait(ca, ca->set->gc_mark_valid &&
-			       !ca->invalidate_needs_gc);
+		allocator_wait(ca, !ca->invalidate_needs_gc);
 		invalidate_buckets(ca);
 
 		/*
@@ -501,8 +498,8 @@ int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
 
 	ca = c->cache;
 	b = bch_bucket_alloc(ca, reserve, wait);
-	if (b == -1)
-		goto err;
+	if (b < 0)
+		return -1;
 
 	k->ptr[0] = MAKE_PTR(ca->buckets[b].gen,
 			     bucket_to_sector(c, b),
@@ -511,10 +508,6 @@ int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
 	SET_KEY_PTRS(k, 1);
 
 	return 0;
-err:
-	bch_bucket_free(c, k);
-	bkey_put(c, k);
-	return -1;
 }
 
 int bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 4e6afa8992..1d33e40d26 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -200,6 +200,7 @@ struct bucket {
 	uint8_t		gen;
 	uint8_t		last_gc; /* Most out of date gen in the btree */
 	uint16_t	gc_mark; /* Bitfield used by GC. See below for field */
+	uint16_t	reclaimable_in_gc:1;
 };
 
 /*
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index d011a7154d..4e6ccf2c8a 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1741,18 +1741,20 @@ static void btree_gc_start(struct cache_set *c)
 
 	mutex_lock(&c->bucket_lock);
 
-	c->gc_mark_valid = 0;
 	c->gc_done = ZERO_KEY;
 
 	ca = c->cache;
 	for_each_bucket(b, ca) {
 		b->last_gc = b->gen;
+		if (bch_can_invalidate_bucket(ca, b))
+			b->reclaimable_in_gc = 1;
 		if (!atomic_read(&b->pin)) {
 			SET_GC_MARK(b, 0);
 			SET_GC_SECTORS_USED(b, 0);
 		}
 	}
 
+	c->gc_mark_valid = 0;
 	mutex_unlock(&c->bucket_lock);
 }
 
@@ -1809,6 +1811,9 @@ static void bch_btree_gc_finish(struct cache_set *c)
 	for_each_bucket(b, ca) {
 		c->need_gc	= max(c->need_gc, bucket_gc_gen(b));
 
+		if (b->reclaimable_in_gc)
+			b->reclaimable_in_gc = 0;
+
 		if (atomic_read(&b->pin))
 			continue;
 
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 83d112bd2b..af345dc6fd 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -369,10 +369,24 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
 	struct io *i;
 
 	if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
-	    c->gc_stats.in_use > CUTOFF_CACHE_ADD ||
 	    (bio_op(bio) == REQ_OP_DISCARD))
 		goto skip;
 
+	if (c->gc_stats.in_use > CUTOFF_CACHE_ADD) {
+		/*
+		 * If cached buckets are all clean now, 'true' will be
+		 * returned and all requests will bypass the cache device.
+		 * Then c->sectors_to_gc has no chance to be negative, and
+		 * gc thread won't wake up and caching won't work forever.
+		 * Here call force_wake_up_gc() to avoid such aftermath.
+		 */
+		if (BDEV_STATE(&dc->sb) == BDEV_STATE_CLEAN &&
+		    c->gc_mark_valid)
+			force_wake_up_gc(c);
+
+		goto skip;
+	}
+
 	if (mode == CACHE_MODE_NONE ||
 	    (mode == CACHE_MODE_WRITEAROUND &&
 	     op_is_write(bio_op(bio))))
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index b0819be048..4d11fc664c 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -171,7 +171,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
 	struct page *page;
 	unsigned int i;
 
-	page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
+	page = read_cache_page_gfp(bdev->bd_mapping,
 				   SB_OFFSET >> PAGE_SHIFT, GFP_KERNEL);
 	if (IS_ERR(page))
 		return "IO error";
@@ -881,8 +881,8 @@ static void bcache_device_free(struct bcache_device *d)
 		bcache_device_detach(d);
 
 	if (disk) {
-		ida_simple_remove(&bcache_device_idx,
-				  first_minor_to_idx(disk->first_minor));
+		ida_free(&bcache_device_idx,
+			 first_minor_to_idx(disk->first_minor));
 		put_disk(disk);
 	}
 
@@ -940,8 +940,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 	if (!d->full_dirty_stripes)
 		goto out_free_stripe_sectors_dirty;
 
-	idx = ida_simple_get(&bcache_device_idx, 0,
-				BCACHE_DEVICE_IDX_MAX, GFP_KERNEL);
+	idx = ida_alloc_max(&bcache_device_idx, BCACHE_DEVICE_IDX_MAX - 1,
+			    GFP_KERNEL);
 	if (idx < 0)
 		goto out_free_full_dirty_stripes;
 
@@ -986,7 +986,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 out_bioset_exit:
 	bioset_exit(&d->bio_split);
 out_ida_remove:
-	ida_simple_remove(&bcache_device_idx, idx);
+	ida_free(&bcache_device_idx, idx);
 out_free_full_dirty_stripes:
 	kvfree(d->full_dirty_stripes);
 out_free_stripe_sectors_dirty:
@@ -2555,10 +2555,6 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 	if (IS_ERR(bdev_file))
 		goto out_free_sb;
 
-	err = "failed to set blocksize";
-	if (set_blocksize(file_bdev(bdev_file), 4096))
-		goto out_blkdev_put;
-
 	err = read_super(sb, file_bdev(bdev_file), &sb_disk);
 	if (err)
 		goto out_blkdev_put;