bcache: Convert writeback to a kthread
This simplifies the writeback flow control quite a bit - previously, it
was conceptually two coroutines, refill_dirty() and read_dirty(). This
makes the code quite a bit more straightforward.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 3496188..60516bf 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -56,11 +56,30 @@
in_use <= CUTOFF_WRITEBACK;
}
+static inline void bch_writeback_queue(struct cached_dev *dc)
+{
+ wake_up_process(dc->writeback_thread);
+}
+
+static inline void bch_writeback_add(struct cached_dev *dc)
+{
+ if (!atomic_read(&dc->has_dirty) &&
+ !atomic_xchg(&dc->has_dirty, 1)) {
+ atomic_inc(&dc->count);
+
+ if (BDEV_STATE(&dc->sb) != BDEV_STATE_DIRTY) {
+ SET_BDEV_STATE(&dc->sb, BDEV_STATE_DIRTY);
+ /* XXX: should do this synchronously */
+ bch_write_bdev_super(dc, NULL);
+ }
+
+ bch_writeback_queue(dc);
+ }
+}
+
void bcache_dev_sectors_dirty_add(struct cache_set *, unsigned, uint64_t, int);
-void bch_writeback_queue(struct cached_dev *);
-void bch_writeback_add(struct cached_dev *);
void bch_sectors_dirty_init(struct cached_dev *dc);
-void bch_cached_dev_writeback_init(struct cached_dev *);
+int bch_cached_dev_writeback_init(struct cached_dev *);
#endif