diff options
authorTang Junhui <>2017-09-07 01:28:53 +0800
committerJens Axboe <>2017-09-07 13:32:29 -0600
commit175206cf9ab63161dec74d9cd7f9992e062491f5 (patch)
parentbf09375337077b692d21d062c30697c86f2872d3 (diff)
bcache: initialize dirty stripes in flash_dev_run()for-4.14/block-postmerge
bcache uses a Proportion-Differentiation Controller algorithm to control writeback rate to cached devices. In the PD controller algorithm, dirty stripes of thin flash device should not be counted in, because flash only volumes never write back dirty data. Currently dirty stripe counter for thin flash device is not initialized when the thin flash device starts. Which means the following calculation in PD controller will reference an undefined dirty stripes number, and all cached devices attached to the same cache set where the thin flash device lies on may have an inaccurate writeback rate. This patch calles bch_sectors_dirty_init() in flash_dev_run(), to correctly initialize dirty stripe counter when the thin flash device starts to run. This patch also does following parameter data type change, -void bch_sectors_dirty_init(struct cached_dev *dc); +void bch_sectors_dirty_init(struct bcache_device *); to call this function conveniently in flash_dev_run(). (Commit log is composed by Coly Li) Signed-off-by: Tang Junhui <> Reviewed-by: Coly Li <> Cc: Signed-off-by: Jens Axboe <>
3 files changed, 7 insertions, 6 deletions
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 1ae63374366c..fc0a31b13ac4 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1026,7 +1026,7 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c)
if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
- bch_sectors_dirty_init(dc);
+ bch_sectors_dirty_init(&dc->disk);
atomic_set(&dc->has_dirty, 1);
@@ -1230,6 +1230,7 @@ static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
goto err;
bcache_device_attach(d, c, u - c->uuids);
+ bch_sectors_dirty_init(d);
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 34131439e28c..e663ca082183 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -482,17 +482,17 @@ static int sectors_dirty_init_fn(struct btree_op *_op, struct btree *b,
-void bch_sectors_dirty_init(struct cached_dev *dc)
+void bch_sectors_dirty_init(struct bcache_device *d)
struct sectors_dirty_init op;
bch_btree_op_init(&op.op, -1);
- op.inode = dc->;
+ op.inode = d->id;
- bch_btree_map_keys(&op.op, dc->disk.c, &KEY(op.inode, 0, 0),
+ bch_btree_map_keys(&op.op, d->c, &KEY(op.inode, 0, 0),
sectors_dirty_init_fn, 0);
- dc->disk.sectors_dirty_last = bcache_dev_sectors_dirty(&dc->disk);
+ d->sectors_dirty_last = bcache_dev_sectors_dirty(d);
void bch_cached_dev_writeback_init(struct cached_dev *dc)
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 8789b9c8c484..e35421d20d2e 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -103,7 +103,7 @@ static inline void bch_writeback_add(struct cached_dev *dc)
void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
-void bch_sectors_dirty_init(struct cached_dev *dc);
+void bch_sectors_dirty_init(struct bcache_device *);
void bch_cached_dev_writeback_init(struct cached_dev *);
int bch_cached_dev_writeback_start(struct cached_dev *);