From: Tang Junhui <tang.junhui@xxxxxxxxxx>
This patch has been added to the v4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 175206cf9ab63161dec74d9cd7f9992e062491f5 ]
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 <tang.junhui@xxxxxxxxxx>
Reviewed-by: Coly Li <colyli@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
drivers/md/bcache/super.c | 3 ++-
drivers/md/bcache/writeback.c | 8 ++++----
drivers/md/bcache/writeback.h | 2 +-
3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index a7a03a21d78a..2b4fae01381f 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1054,7 +1054,7 @@ 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);
atomic_inc(&dc->count);
bch_writeback_queue(dc);
@@ -1258,6 +1258,7 @@ 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);
bch_flash_dev_request_init(d);
add_disk(d->disk);
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 540256a0df4f..66433fc40afa 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -488,17 +488,17 @@ static int sectors_dirty_init_fn(struct btree_op *_op, struct btree *b,
return MAP_CONTINUE;
}
-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->disk.id;
+ 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 073a042aed24..357658b64794 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -85,7 +85,7 @@ 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 *);
--
2.11.0