56 	struct squashfs_cache_entry *entry;  in squashfs_cache_get()  local
62 			if (cache->entry[i].block == block) {  in squashfs_cache_get()
84 			 * At least one unused cache entry.  A simple  in squashfs_cache_get()
85 			 * round-robin strategy is used to choose the entry to  in squashfs_cache_get()
90 				if (cache->entry[i].refcount == 0)  in squashfs_cache_get()
96 			entry = &cache->entry[i];  in squashfs_cache_get()
99 			 * Initialise chosen cache entry, and fill it in from  in squashfs_cache_get()
103 			entry->block = block;  in squashfs_cache_get()
104 			entry->refcount = 1;  in squashfs_cache_get()
105 			entry->pending = 1;  in squashfs_cache_get()
106 			entry->num_waiters = 0;  in squashfs_cache_get()
107 			entry->error = 0;  in squashfs_cache_get()
110 			entry->length = squashfs_read_data(sb, block, length,  in squashfs_cache_get()
111 				&entry->next_index, entry->actor);  in squashfs_cache_get()
115 			if (entry->length < 0)  in squashfs_cache_get()
116 				entry->error = entry->length;  in squashfs_cache_get()
118 			entry->pending = 0;  in squashfs_cache_get()
121 			 * While filling this entry one or more other processes  in squashfs_cache_get()
125 			if (entry->num_waiters) {  in squashfs_cache_get()
127 				wake_up_all(&entry->wait_queue);  in squashfs_cache_get()
137 		 * previously unused there's one less cache entry available  in squashfs_cache_get()
140 		entry = &cache->entry[i];  in squashfs_cache_get()
141 		if (entry->refcount == 0)  in squashfs_cache_get()
143 		entry->refcount++;  in squashfs_cache_get()
146 		 * If the entry is currently being filled in by another process  in squashfs_cache_get()
149 		if (entry->pending) {  in squashfs_cache_get()
150 			entry->num_waiters++;  in squashfs_cache_get()
152 			wait_event(entry->wait_queue, !entry->pending);  in squashfs_cache_get()
161 		cache->name, i, entry->block, entry->refcount, entry->error);  in squashfs_cache_get()
163 	if (entry->error)  in squashfs_cache_get()
164 		ERROR("Unable to read %s cache entry [%llx]\n", cache->name,  in squashfs_cache_get()
166 	return entry;  in squashfs_cache_get()
171  * Release cache entry, once usage count is zero it can be reused.
173 void squashfs_cache_put(struct squashfs_cache_entry *entry)  in squashfs_cache_put()  argument
175 	struct squashfs_cache *cache = entry->cache;  in squashfs_cache_put()
178 	entry->refcount--;  in squashfs_cache_put()
179 	if (entry->refcount == 0) {  in squashfs_cache_put()
205 		if (cache->entry[i].data) {  in squashfs_cache_delete()
207 				kfree(cache->entry[i].data[j]);  in squashfs_cache_delete()
208 			kfree(cache->entry[i].data);  in squashfs_cache_delete()
210 		kfree(cache->entry[i].actor);  in squashfs_cache_delete()
213 	kfree(cache->entry);  in squashfs_cache_delete()
220  * size block_size.  To avoid vmalloc fragmentation issues each entry
234 	cache->entry = kcalloc(entries, sizeof(*(cache->entry)), GFP_KERNEL);  in squashfs_cache_init()
235 	if (cache->entry == NULL) {  in squashfs_cache_init()
253 		struct squashfs_cache_entry *entry = &cache->entry[i];  in squashfs_cache_init()  local
255 		init_waitqueue_head(&cache->entry[i].wait_queue);  in squashfs_cache_init()
256 		entry->cache = cache;  in squashfs_cache_init()
257 		entry->block = SQUASHFS_INVALID_BLK;  in squashfs_cache_init()
258 		entry->data = kcalloc(cache->pages, sizeof(void *), GFP_KERNEL);  in squashfs_cache_init()
259 		if (entry->data == NULL) {  in squashfs_cache_init()
260 			ERROR("Failed to allocate %s cache entry\n", name);  in squashfs_cache_init()
265 			entry->data[j] = kmalloc(PAGE_SIZE, GFP_KERNEL);  in squashfs_cache_init()
266 			if (entry->data[j] == NULL) {  in squashfs_cache_init()
272 		entry->actor = squashfs_page_actor_init(entry->data,  in squashfs_cache_init()
274 		if (entry->actor == NULL) {  in squashfs_cache_init()
275 			ERROR("Failed to allocate %s cache entry\n", name);  in squashfs_cache_init()
289  * Copy up to length bytes from cache entry to buffer starting at offset bytes
290  * into the cache entry.  If there's not length bytes then copy the number of
293 int squashfs_copy_data(void *buffer, struct squashfs_cache_entry *entry,  in squashfs_copy_data()  argument
301 		return min(length, entry->length - offset);  in squashfs_copy_data()
303 	while (offset < entry->length) {  in squashfs_copy_data()
304 		void *buff = entry->data[offset / PAGE_SIZE]  in squashfs_copy_data()
306 		int bytes = min_t(int, entry->length - offset,  in squashfs_copy_data()
336 	struct squashfs_cache_entry *entry;  in squashfs_read_metadata()  local
344 		entry = squashfs_cache_get(sb, msblk->block_cache, *block, 0);  in squashfs_read_metadata()
345 		if (entry->error) {  in squashfs_read_metadata()
346 			res = entry->error;  in squashfs_read_metadata()
348 		} else if (*offset >= entry->length) {  in squashfs_read_metadata()
353 		bytes = squashfs_copy_data(buffer, entry, *offset, length);  in squashfs_read_metadata()
359 		if (*offset == entry->length) {  in squashfs_read_metadata()
360 			*block = entry->next_index;  in squashfs_read_metadata()
364 		squashfs_cache_put(entry);  in squashfs_read_metadata()
370 	squashfs_cache_put(entry);  in squashfs_read_metadata()