[11/19] bcache: Subtract dirty sectors of thin flash from cache_sectors in calculating writeback rate

Commit Message

[e-mail] June 28, 2017, 12:29 a.m. UTC

Since dirty sectors of thin flash cannot be used to cache data for backend
device, so we should subtract it in calculating writeback rate.

Signed-off-by: Tang Junhui <[e-mail]>
Cc: [e-mail]
---
 drivers/md/bcache/writeback.c |  2 +-
 drivers/md/bcache/writeback.h | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 4ac8b13..25289e4 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -21,7 +21,7 @@ 
 static void __update_writeback_rate(struct cached_dev *dc)
 {
 	struct cache_set *c = dc->disk.c;
-	uint64_t cache_sectors = c->nbuckets * c->sb.bucket_size;
+	uint64_t cache_sectors = c->nbuckets * c->sb.bucket_size - bcache_flash_devs_sectors_dirty(c);
 	uint64_t cache_dirty_target =
 		div_u64(cache_sectors * dc->writeback_percent, 100);
 
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index c2ab4b4..24ff589 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -14,6 +14,25 @@  static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
 	return ret;
 }
 
+static inline uint64_t  bcache_flash_devs_sectors_dirty(struct cache_set *c)
+{
+	uint64_t i, ret = 0;
+
+	mutex_lock(&bch_register_lock);
+
+	for (i = 0; i < c->nr_uuids; i++) {
+		struct bcache_device *d = c->devices[i];
+
+		if (!d || !UUID_FLASH_ONLY(&c->uuids[i]))
+			continue;
+	   ret += bcache_dev_sectors_dirty(d);
+	}
+
+	mutex_unlock(&bch_register_lock);
+
+	return ret;
+}
+
 static inline unsigned offset_to_stripe(struct bcache_device *d,
 					uint64_t offset)
 {