Re: [PATCH 4/5] mbcache: use consistent type for entry count

[Jan Kara <jack@suse.cz>]

On Sat 26-11-16 22:18:00, Eric Biggers wrote:
> mbcache used several different types to represent the number of entries
> in the cache.  For consistency within mbcache and with the shrinker API,
> always use unsigned long.
> 
> This does not change behavior for current mbcache users (ext2 and ext4)
> since they limit the entry count to a value which easily fits in an int.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>

OK, why not. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/mbcache.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/mbcache.c b/fs/mbcache.c
> index 07c5d7d..bf65906 100644
> --- a/fs/mbcache.c
> +++ b/fs/mbcache.c
> @@ -29,7 +29,7 @@ struct mb_cache {
>  	/* log2 of hash table size */
>  	int			c_bucket_bits;
>  	/* Maximum entries in cache to avoid degrading hash too much */
> -	int			c_max_entries;
> +	unsigned long		c_max_entries;
>  	/* Protects c_list, c_entry_count */
>  	spinlock_t		c_list_lock;
>  	struct list_head	c_list;
> @@ -43,7 +43,7 @@ struct mb_cache {
>  static struct kmem_cache *mb_entry_cache;
>  
>  static unsigned long mb_cache_shrink(struct mb_cache *cache,
> -				     unsigned int nr_to_scan);
> +				     unsigned long nr_to_scan);
>  
>  static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
>  							u32 key)
> @@ -274,11 +274,11 @@ static unsigned long mb_cache_count(struct shrinker *shrink,
>  
>  /* Shrink number of entries in cache */
>  static unsigned long mb_cache_shrink(struct mb_cache *cache,
> -				     unsigned int nr_to_scan)
> +				     unsigned long nr_to_scan)
>  {
>  	struct mb_cache_entry *entry;
>  	struct hlist_bl_head *head;
> -	unsigned int shrunk = 0;
> +	unsigned long shrunk = 0;
>  
>  	spin_lock(&cache->c_list_lock);
>  	while (nr_to_scan-- && !list_empty(&cache->c_list)) {
> @@ -316,10 +316,9 @@ static unsigned long mb_cache_shrink(struct mb_cache *cache,
>  static unsigned long mb_cache_scan(struct shrinker *shrink,
>  				   struct shrink_control *sc)
>  {
> -	int nr_to_scan = sc->nr_to_scan;
>  	struct mb_cache *cache = container_of(shrink, struct mb_cache,
>  					      c_shrink);
> -	return mb_cache_shrink(cache, nr_to_scan);
> +	return mb_cache_shrink(cache, sc->nr_to_scan);
>  }
>  
>  /* We shrink 1/X of the cache when we have too many entries in it */
> @@ -341,8 +340,8 @@ static void mb_cache_shrink_worker(struct work_struct *work)
>  struct mb_cache *mb_cache_create(int bucket_bits)
>  {
>  	struct mb_cache *cache;
> -	int bucket_count = 1 << bucket_bits;
> -	int i;
> +	unsigned long bucket_count = 1UL << bucket_bits;
> +	unsigned long i;
>  
>  	cache = kzalloc(sizeof(struct mb_cache), GFP_KERNEL);
>  	if (!cache)
> -- 
> 2.8.0.rc3.226.g39d4020
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR