On 10/29/21 8:59 PM, Lin Feng wrote:
Commit 697e23495c94f0380c1ed8b11f830b92b64c99ea
("bcache: explicitly make cache_set only have single cache")
explicitly makes a cache_set only have single cache and based on the
fact that historily only one cache is ever used in the cache set, so
macro defination for MAX_CACHES_PER_SET as 8 is misleading now.
In fact it should be redefined to 1 and valid number fo sb.nr_in_set
should be 1 and sb.nr_this_dev should always be 0.
But jset's disk layout replies on MAX_CACHES_PER_SET(8), so replace it
with a hardcoded number 8.
Signed-off-by: Lin Feng <linf@xxxxxxxxxx>
---
drivers/md/bcache/bcache.h | 2 +-
drivers/md/bcache/super.c | 4 +---
include/uapi/linux/bcache.h | 4 ++--
3 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 5fc989a6d452..a4a410a178c0 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -833,7 +833,7 @@ static inline uint8_t ptr_stale(struct cache_set *c, const struct bkey *k,
static inline bool ptr_available(struct cache_set *c, const struct bkey *k,
unsigned int i)
{
- return (PTR_DEV(k, i) < MAX_CACHES_PER_SET) && c->cache;
+ return (PTR_DEV(k, i) == 0) && c->cache;
}
/* Btree key macros */
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index f2874c77ff79..2253044c9289 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -140,9 +140,7 @@ static const char *read_super_common(struct cache_sb *sb, struct block_device *
goto err;
err = "Bad cache device number in set";
- if (!sb->nr_in_set ||
- sb->nr_in_set <= sb->nr_this_dev ||
- sb->nr_in_set > MAX_CACHES_PER_SET)
+ if (sb->nr_in_set != 1 || sb->nr_this_dev != 0)
goto err;
err = "Journal buckets not sequential";
Hi Feng,
The above changes are fine to me. But let's keep the below part as what
it is at this moment.
Thanks.
Coly Li
diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h
index cf7399f03b71..4beb3e7826ca 100644
--- a/include/uapi/linux/bcache.h
+++ b/include/uapi/linux/bcache.h
@@ -155,7 +155,6 @@ static inline struct bkey *bkey_idx(const struct bkey *k, unsigned int nr_keys)
#define SB_LABEL_SIZE 32
#define SB_JOURNAL_BUCKETS 256U
/* SB_JOURNAL_BUCKETS must be divisible by BITS_PER_LONG */
-#define MAX_CACHES_PER_SET 8
#define BDEV_DATA_START_DEFAULT 16 /* sectors */
@@ -356,7 +355,8 @@ struct jset {
__u16 btree_level;
__u16 pad[3];
- __u64 prio_bucket[MAX_CACHES_PER_SET];
+ /* only a single cache is available */
+ __u64 prio_bucket[8];
union {
struct bkey start[0];
