From: Shenghui Wang <[email protected]> UUIDs are considered as metadata. __uuid_write should add the number of buckets (in sectors) written to disk to ca->meta_sectors_written. Currently only 1 bucket is used in uuid write.
Steps to test: 1) create a fresh backing device and a fresh cache device separately. The backing device didn't attach to any cache set. 2) cd /sys/block/<cache device>/bcache cat metadata_written // record the output value cat bucket_size 3) attach the backing device to cache set 4) cat metadata_written The output value is almost the same as the value in step 2 before the change. After the change, the value is bigger about 1 bucket size. Signed-off-by: Shenghui Wang <[email protected]> Reviewed-by: Tang Junhui <[email protected]> Signed-off-by: Coly Li <[email protected]> --- drivers/md/bcache/super.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 94c756c66bd7..448e531e8c2d 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -417,6 +417,7 @@ static int __uuid_write(struct cache_set *c) { BKEY_PADDED(key) k; struct closure cl; + struct cache *ca; closure_init_stack(&cl); lockdep_assert_held(&bch_register_lock); @@ -428,6 +429,10 @@ static int __uuid_write(struct cache_set *c) uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl); closure_sync(&cl); + /* Only one bucket used for uuid write */ + ca = PTR_CACHE(c, &k.key, 0); + atomic_long_add(ca->sb.bucket_size, &ca->meta_sectors_written); + bkey_copy(&c->uuid_bucket, &k.key); bkey_put(c, &k.key); return 0; -- 2.19.0
