include/linux/fscache.h

25 #define fscache_cookie_valid(cookie) (cookie)
27 #define fscache_cookie_enabled(cookie) (cookie && !test_bit(FSCACHE_COOKIE_DISABLED, &cookie->flags))
32 #define fscache_cookie_valid(cookie) (0)
34 #define fscache_cookie_enabled(cookie) (0)
56 	FSCACHE_COOKIE_STATE_QUIESCENT,		/* The cookie is uncached */
62 	FSCACHE_COOKIE_STATE_LRU_DISCARDING,	/* The cookie is being discarded by the LRU */
63 	FSCACHE_COOKIE_STATE_WITHDRAWING,	/* The cookie is being withdrawn */
64 	FSCACHE_COOKIE_STATE_RELINQUISHING,	/* The cookie is being relinquished */
65 	FSCACHE_COOKIE_STATE_DROPPED,		/* The cookie has been dropped */
70  * Volume representation cookie.
96  * Data file representation cookie.
104 	atomic_t			n_active;	/* number of active users of cookie */
118 #define FSCACHE_COOKIE_RELINQUISHED	0		/* T if cookie has been relinquished */
119 #define FSCACHE_COOKIE_RETIRED		1		/* T if this cookie has retired on relinq */
120 #define FSCACHE_COOKIE_IS_CACHING	2		/* T if this cookie is cached */
121 #define FSCACHE_COOKIE_NO_DATA_TO_READ	3		/* T if this cookie has nothing to read */
123 #define FSCACHE_COOKIE_HAS_BEEN_CACHED	5		/* T if cookie needs withdraw-on-relinq */
124 #define FSCACHE_COOKIE_DISABLED		6		/* T if cookie has been disabled */
125 #define FSCACHE_COOKIE_LOCAL_WRITE	7		/* T if cookie has been modified locally */
127 #define FSCACHE_COOKIE_DO_RELINQUISH	9		/* T if this cookie needs relinquishment */
128 #define FSCACHE_COOKIE_DO_WITHDRAW	10		/* T if this cookie needs withdrawing */
129 #define FSCACHE_COOKIE_DO_LRU_DISCARD	11		/* T if this cookie needs LRU discard */
130 #define FSCACHE_COOKIE_DO_PREP_TO_WRITE	12		/* T if cookie needs write preparation */
131 #define FSCACHE_COOKIE_HAVE_DATA	13		/* T if this cookie has data stored */
132 #define FSCACHE_COOKIE_IS_HASHED	14		/* T if this cookie is hashed */
133 #define FSCACHE_COOKIE_DO_INVALIDATE	15		/* T if cookie needs invalidation */
192  * Returns a cookie pointer on success, -ENOMEM if out of memory or -EBUSY if a
194  * cookie pointer and can be returned if caching is refused.
210  * @volume: The volume cookie
228  * fscache_acquire_cookie - Acquire a cookie to represent a cache object
229  * @volume: The volume in which to locate/create this cookie
231  * @index_key: The index key for this cookie
233  * @aux_data: The auxiliary data for the cookie (may be NULL)
237  * Acquire a cookie to represent a data file within the given cache volume.
260  * fscache_use_cookie - Request usage of cookie attached to an object
261  * @cookie: The cookie representing the cache object
264  * Request usage of the cookie attached to an object.  The caller should tell
268 static inline void fscache_use_cookie(struct fscache_cookie *cookie,
271 	if (fscache_cookie_valid(cookie))
272 		__fscache_use_cookie(cookie, will_modify);
276  * fscache_unuse_cookie - Cease usage of cookie attached to an object
277  * @cookie: The cookie representing the cache object
281  * Cease usage of the cookie attached to an object.  When the users count
282  * reaches zero then the cookie relinquishment will be permitted to proceed.
284 static inline void fscache_unuse_cookie(struct fscache_cookie *cookie,
288 	if (fscache_cookie_valid(cookie))
289 		__fscache_unuse_cookie(cookie, aux_data, object_size);
293  * fscache_relinquish_cookie - Return the cookie to the cache, maybe discarding
295  * @cookie: The cookie being returned
296  * @retire: True if the cache object the cookie represents is to be discarded
298  * This function returns a cookie to the cache, forcibly discarding the
305 void fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
307 	if (fscache_cookie_valid(cookie))
308 		__fscache_relinquish_cookie(cookie, retire);
312  * Find the auxiliary data on a cookie.
314 static inline void *fscache_get_aux(struct fscache_cookie *cookie)
316 	if (cookie->aux_len <= sizeof(cookie->inline_aux))
317 		return cookie->inline_aux;
319 		return cookie->aux;
323  * Update the auxiliary data on a cookie.
326 void fscache_update_aux(struct fscache_cookie *cookie,
329 	void *p = fscache_get_aux(cookie);
332 		memcpy(p, aux_data, cookie->aux_len);
334 		cookie->object_size = *object_size;
342 void __fscache_update_cookie(struct fscache_cookie *cookie, const void *aux_data,
348 	fscache_update_aux(cookie, aux_data, object_size);
350 	set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &cookie->flags);
355  * @cookie: The cookie representing the cache object
356  * @aux_data: The updated auxiliary data for the cookie (may be NULL)
360  * cookie.  The auxiliary data on the cookie will be updated first if @aux_data
368 void fscache_update_cookie(struct fscache_cookie *cookie, const void *aux_data,
371 	if (fscache_cookie_enabled(cookie))
372 		__fscache_update_cookie(cookie, aux_data, object_size);
377  * @cookie: The cookie representing the cache object
386 void fscache_resize_cookie(struct fscache_cookie *cookie, loff_t new_size)
388 	if (fscache_cookie_enabled(cookie))
389 		__fscache_resize_cookie(cookie, new_size);
394  * @cookie: The cookie representing the cache object
395  * @aux_data: The updated auxiliary data for the cookie (may be NULL)
401  * increments inval_counter on the cookie which can be used by the caller to
405  * to a direct I/O write and will cause caching to be disabled on this cookie
412 void fscache_invalidate(struct fscache_cookie *cookie,
415 	if (fscache_cookie_enabled(cookie))
416 		__fscache_invalidate(cookie, aux_data, size, flags);
434  * @cookie: The cookie representing the cache object
438  * attached; @cookie indicates the cache object that will be accessed.
440  * @cres->inval_counter is set from @cookie->inval_counter for comparison at
451 				 struct fscache_cookie *cookie)
453 	if (fscache_cookie_enabled(cookie))
454 		return __fscache_begin_read_operation(cres, cookie);
519  * @cookie: The cookie representing the cache object
523  * attached; @cookie indicates the cache object that will be accessed.
525  * @cres->inval_counter is set from @cookie->inval_counter for comparison at
536 				  struct fscache_cookie *cookie)
538 	if (fscache_cookie_enabled(cookie))
539 		return __fscache_begin_write_operation(cres, cookie);
593  * @cookie: The cookie representing the cache object
614 static inline void fscache_write_to_cache(struct fscache_cookie *cookie,
622 		__fscache_write_to_cache(cookie, mapping, start, len, i_size,
631  * @cookie: The cookie corresponding to the file
637 void fscache_note_page_release(struct fscache_cookie *cookie)
644 	if (cookie &&
645 	    test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) &&
646 	    test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags))
647 		clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);