[PATCH v7 1/3] bcache: add dirty_data in struct bcache_device

[mingzhe <mingzhe.zou@easystack.cn>]

Currently, the dirty_data of cached_dev and flash_dev depend on the stripe.

Since the flash device supports resize, it may cause a bug (resize the flash
from 1T to 2T, and nr_stripes from 1 to 2).

The patch add dirty_data in struct bcache_device, we can get the value of
dirty_data quickly and fixes the bug of resize flash device.

Signed-off-by: mingzhe <mingzhe.zou@easystack.cn>

---
Changelog:
v7: Fix up the bug abort git am patch.
v1: Original verison.
---
 drivers/md/bcache/bcache.h    | 1 +
 drivers/md/bcache/writeback.c | 2 ++
 drivers/md/bcache/writeback.h | 7 +------
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index aebb7ef10e63..db3439d65582 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -268,6 +268,7 @@ struct bcache_device {
 	unsigned int		stripe_size;
 	atomic_t		*stripe_sectors_dirty;
 	unsigned long		*full_dirty_stripes;
+	atomic_long_t		dirty_sectors;
 
 	struct bio_set		bio_split;
 
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index d4a5fc0650bb..65c997b25cca 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -607,6 +607,8 @@ void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
 	if (stripe < 0)
 		return;
 
+	atomic_long_add(nr_sectors, &d->dirty_sectors);
+
 	if (UUID_FLASH_ONLY(&c->uuids[inode]))
 		atomic_long_add(nr_sectors, &c->flash_dev_dirty_sectors);
 
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 31df716951f6..a5bb1caa6c6e 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -48,12 +48,7 @@ struct bch_dirty_init_state {
 
 static inline uint64_t bcache_dev_sectors_dirty(struct bcache_device *d)
 {
-	uint64_t i, ret = 0;
-
-	for (i = 0; i < d->nr_stripes; i++)
-		ret += atomic_read(d->stripe_sectors_dirty + i);
-
-	return ret;
+	return atomic_long_read(&d->dirty_sectors);
 }
 
 static inline int offset_to_stripe(struct bcache_device *d,
-- 
2.17.1.windows.2