diff options
Diffstat (limited to 'include/linux/fscache-cache.h')
| -rw-r--r-- | include/linux/fscache-cache.h | 55 |
1 files changed, 39 insertions, 16 deletions
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h index 9ff516b1b9a0..d32f70611a00 100644 --- a/include/linux/fscache-cache.h +++ b/include/linux/fscache-cache.h @@ -97,7 +97,8 @@ struct fscache_operation { #define FSCACHE_OP_WAITING 4 /* cleared when op is woken */ #define FSCACHE_OP_EXCLUSIVE 5 /* exclusive op, other ops must wait */ #define FSCACHE_OP_DEC_READ_CNT 6 /* decrement object->n_reads on destruction */ -#define FSCACHE_OP_KEEP_FLAGS 0x0070 /* flags to keep when repurposing an op */ +#define FSCACHE_OP_UNUSE_COOKIE 7 /* call fscache_unuse_cookie() on completion */ +#define FSCACHE_OP_KEEP_FLAGS 0x00f0 /* flags to keep when repurposing an op */ enum fscache_operation_state state; atomic_t usage; @@ -314,6 +315,7 @@ struct fscache_cache_ops { struct fscache_cookie { atomic_t usage; /* number of users of this cookie */ atomic_t n_children; /* number of children of this cookie */ + atomic_t n_active; /* number of active users of netfs ptrs */ spinlock_t lock; spinlock_t stores_lock; /* lock on page store tree */ struct hlist_head backing_objects; /* object(s) backing this file/index */ @@ -326,11 +328,11 @@ struct fscache_cookie { unsigned long flags; #define FSCACHE_COOKIE_LOOKING_UP 0 /* T if non-index cookie being looked up still */ -#define FSCACHE_COOKIE_CREATING 1 /* T if non-index object being created still */ -#define FSCACHE_COOKIE_NO_DATA_YET 2 /* T if new object with no cached data yet */ -#define FSCACHE_COOKIE_UNAVAILABLE 3 /* T if cookie is unavailable (error, etc) */ -#define FSCACHE_COOKIE_WAITING_ON_READS 4 /* T if cookie is waiting on reads */ -#define FSCACHE_COOKIE_INVALIDATING 5 /* T if cookie is being invalidated */ +#define FSCACHE_COOKIE_NO_DATA_YET 1 /* T if new object with no cached data yet */ +#define FSCACHE_COOKIE_UNAVAILABLE 2 /* T if cookie is unavailable (error, etc) */ +#define FSCACHE_COOKIE_INVALIDATING 3 /* T if cookie is being invalidated */ +#define FSCACHE_COOKIE_RELINQUISHED 4 /* T if cookie has been relinquished */ +#define FSCACHE_COOKIE_RETIRED 5 /* T if cookie was retired */ }; extern struct fscache_cookie fscache_fsdef_index; @@ -392,10 +394,9 @@ struct fscache_object { #define FSCACHE_OBJECT_LOCK 0 /* T if object is busy being processed */ #define FSCACHE_OBJECT_PENDING_WRITE 1 /* T if object has pending write */ #define FSCACHE_OBJECT_WAITING 2 /* T if object is waiting on its parent */ -#define FSCACHE_OBJECT_RETIRE 3 /* T if object should be retired */ -#define FSCACHE_OBJECT_IS_LIVE 4 /* T if object is not withdrawn or relinquished */ -#define FSCACHE_OBJECT_IS_LOOKED_UP 5 /* T if object has been looked up */ -#define FSCACHE_OBJECT_IS_AVAILABLE 6 /* T if object has become active */ +#define FSCACHE_OBJECT_IS_LIVE 3 /* T if object is not withdrawn or relinquished */ +#define FSCACHE_OBJECT_IS_LOOKED_UP 4 /* T if object has been looked up */ +#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */ struct list_head cache_link; /* link in cache->object_list */ struct hlist_node cookie_link; /* link in cookie->backing_objects */ @@ -415,16 +416,11 @@ struct fscache_object { extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *, struct fscache_cache *); +extern void fscache_object_destroy(struct fscache_object *); extern void fscache_object_lookup_negative(struct fscache_object *object); extern void fscache_obtained_object(struct fscache_object *object); -#ifdef CONFIG_FSCACHE_OBJECT_LIST -extern void fscache_object_destroy(struct fscache_object *object); -#else -#define fscache_object_destroy(object) do {} while(0) -#endif - static inline bool fscache_object_is_live(struct fscache_object *object) { return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags); @@ -512,6 +508,33 @@ static inline void fscache_end_io(struct fscache_retrieval *op, op->end_io_func(page, op->context, error); } +/** + * fscache_use_cookie - Request usage of cookie attached to an object + * @object: Object description + * + * Request usage of the cookie attached to an object. NULL is returned if the + * relinquishment had reduced the cookie usage count to 0. + */ +static inline bool fscache_use_cookie(struct fscache_object *object) +{ + struct fscache_cookie *cookie = object->cookie; + return atomic_inc_not_zero(&cookie->n_active) != 0; +} + +/** + * fscache_unuse_cookie - Cease usage of cookie attached to an object + * @object: Object description + * + * Cease usage of the cookie attached to an object. When the users count + * reaches zero then the cookie relinquishment will be permitted to proceed. + */ +static inline void fscache_unuse_cookie(struct fscache_object *object) +{ + struct fscache_cookie *cookie = object->cookie; + if (atomic_dec_and_test(&cookie->n_active)) + wake_up_atomic_t(&cookie->n_active); +} + /* * out-of-line cache backend functions */ |