Messages in this thread |  | | Date | Mon, 1 Nov 2021 10:28:17 +0800 | Subject | Re: [PATCH] bcache: kill macro MAX_CACHES_PER_SET | From | Lin Feng <> |
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Hi Coly,
OK, I will send another patch but keep MAX_CACHES_PER_SET, thanks :)
linfeng
On 10/30/21 23:19, Coly Li wrote: > 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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