hi, Shenghui:
Why not in uuid_io() just like:
...
for (i = 0; i < KEY_PTRS(k); i++) {
struct bio *bio = bch_bbio_alloc(c);
atomic_long_add( KEY_SIZE(k), &ca->meta_sectors_written);
bio->bi_size = KEY_SIZE(k) << 9;
...
}
----
Tang Junhui
Shenghui Wang <shhuiw@xxxxxxxxxxx> 于2018年9月7日周五 下午6:41写道：
>
> 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 <shhuiw@xxxxxxxxxxx>
> ---
> 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;
> --
> 2.18.0
>
