Messages in this thread | | | Date | Sat, 30 Oct 2021 23:19:01 +0800 | Subject | Re: [PATCH] bcache: kill macro MAX_CACHES_PER_SET | From | Coly Li <> |
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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@wangsu.com> > --- > 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];
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