58 static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer)  in fill_read_buffer()  argument
63 	if (!buffer->page)  in fill_read_buffer()
64 		buffer->page = (char *) get_zeroed_page(GFP_KERNEL);  in fill_read_buffer()
65 	if (!buffer->page)  in fill_read_buffer()
70 		count = buffer->attr->show(buffer->item, buffer->page);  in fill_read_buffer()
77 	buffer->needs_read_fill = 0;  in fill_read_buffer()
78 	buffer->count = count;  in fill_read_buffer()
85  *	@buf:	buffer to fill.
93  *	We call fill_read_buffer() to allocate and fill the buffer from the
95  *	the beginning of the file). That should fill the entire buffer with
97  *	We then call flush_read_buffer() to copy the buffer to userspace
104 	struct configfs_buffer *buffer = file->private_data;  in configfs_read_file()  local
107 	mutex_lock(&buffer->mutex);  in configfs_read_file()
108 	if (buffer->needs_read_fill) {  in configfs_read_file()
109 		retval = fill_read_buffer(file, buffer);  in configfs_read_file()
114 		 __func__, count, *ppos, buffer->page);  in configfs_read_file()
115 	retval = simple_read_from_buffer(buf, count, ppos, buffer->page,  in configfs_read_file()
116 					 buffer->count);  in configfs_read_file()
118 	mutex_unlock(&buffer->mutex);  in configfs_read_file()
125  *	@buf:	buffer to fill.
133  *	We check whether we need to refill the buffer. If so we will
135  *	will pass a NULL as a buffer pointer, which the attributes' method
136  *	will use to return the size of the buffer required. If no error
137  *	occurs we will allocate the buffer using vmalloc and call
138  *	attr->read() again passing that buffer as an argument.
147 	struct configfs_buffer *buffer = file->private_data;  in configfs_read_bin_file()  local
151 	mutex_lock(&buffer->mutex);  in configfs_read_bin_file()
154 	if (buffer->write_in_progress) {  in configfs_read_bin_file()
158 	buffer->read_in_progress = true;  in configfs_read_bin_file()
160 	if (buffer->needs_read_fill) {  in configfs_read_bin_file()
164 			len = buffer->bin_attr->read(buffer->item, NULL, 0);  in configfs_read_bin_file()
174 		if (buffer->cb_max_size && len > buffer->cb_max_size) {  in configfs_read_bin_file()
179 		buffer->bin_buffer = vmalloc(len);  in configfs_read_bin_file()
180 		if (buffer->bin_buffer == NULL) {  in configfs_read_bin_file()
184 		buffer->bin_buffer_size = len;  in configfs_read_bin_file()
186 		/* perform second read to fill buffer */  in configfs_read_bin_file()
189 			len = buffer->bin_attr->read(buffer->item,  in configfs_read_bin_file()
190 						     buffer->bin_buffer, len);  in configfs_read_bin_file()
196 			vfree(buffer->bin_buffer);  in configfs_read_bin_file()
197 			buffer->bin_buffer_size = 0;  in configfs_read_bin_file()
198 			buffer->bin_buffer = NULL;  in configfs_read_bin_file()
202 		buffer->needs_read_fill = 0;  in configfs_read_bin_file()
205 	retval = simple_read_from_buffer(buf, count, ppos, buffer->bin_buffer,  in configfs_read_bin_file()
206 					buffer->bin_buffer_size);  in configfs_read_bin_file()
208 	mutex_unlock(&buffer->mutex);  in configfs_read_bin_file()
214  *	fill_write_buffer - copy buffer from userspace.
215  *	@buffer:	data buffer for file.
219  *	Allocate @buffer->page if it hasn't been already, then
220  *	copy the user-supplied buffer into it.
224 fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size_t count)  in fill_write_buffer()  argument
228 	if (!buffer->page)  in fill_write_buffer()
229 		buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);  in fill_write_buffer()
230 	if (!buffer->page)  in fill_write_buffer()
235 	error = copy_from_user(buffer->page,buf,count);  in fill_write_buffer()
236 	buffer->needs_read_fill = 1;  in fill_write_buffer()
239 	buffer->page[count] = 0;  in fill_write_buffer()
244 flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count)  in flush_write_buffer()  argument
251 		res = buffer->attr->store(buffer->item, buffer->page, count);  in flush_write_buffer()
268  *	write, so we don't support them. We expect the entire buffer to come
271  *	the value you're changing, then write entire buffer back.
277 	struct configfs_buffer *buffer = file->private_data;  in configfs_write_file()  local
280 	mutex_lock(&buffer->mutex);  in configfs_write_file()
281 	len = fill_write_buffer(buffer, buf, count);  in configfs_write_file()
283 		len = flush_write_buffer(file, buffer, len);  in configfs_write_file()
286 	mutex_unlock(&buffer->mutex);  in configfs_write_file()
298  *	We buffer the consecutive writes (binary attribute files do not
299  *	support lseek) in a continuously growing buffer, but we don't
307 	struct configfs_buffer *buffer = file->private_data;  in configfs_write_bin_file()  local
311 	mutex_lock(&buffer->mutex);  in configfs_write_bin_file()
314 	if (buffer->read_in_progress) {  in configfs_write_bin_file()
318 	buffer->write_in_progress = true;  in configfs_write_bin_file()
320 	/* buffer grows? */  in configfs_write_bin_file()
321 	if (*ppos + count > buffer->bin_buffer_size) {  in configfs_write_bin_file()
323 		if (buffer->cb_max_size &&  in configfs_write_bin_file()
324 			*ppos + count > buffer->cb_max_size) {  in configfs_write_bin_file()
336 		if (buffer->bin_buffer) {  in configfs_write_bin_file()
337 			memcpy(tbuf, buffer->bin_buffer,  in configfs_write_bin_file()
338 				buffer->bin_buffer_size);  in configfs_write_bin_file()
339 			vfree(buffer->bin_buffer);  in configfs_write_bin_file()
343 		memset(tbuf + buffer->bin_buffer_size, 0,  in configfs_write_bin_file()
344 			*ppos + count - buffer->bin_buffer_size);  in configfs_write_bin_file()
345 		buffer->bin_buffer = tbuf;  in configfs_write_bin_file()
346 		buffer->bin_buffer_size = *ppos + count;  in configfs_write_bin_file()
349 	len = simple_write_to_buffer(buffer->bin_buffer,  in configfs_write_bin_file()
350 			buffer->bin_buffer_size, ppos, buf, count);  in configfs_write_bin_file()
352 	mutex_unlock(&buffer->mutex);  in configfs_write_bin_file()
361 	struct configfs_buffer *buffer;  in __configfs_open_file()  local
365 	buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL);  in __configfs_open_file()
366 	if (!buffer)  in __configfs_open_file()
375 	buffer->item = to_item(dentry->d_parent);  in __configfs_open_file()
376 	if (!buffer->item)  in __configfs_open_file()
384 		buffer->bin_attr = to_bin_attr(dentry);  in __configfs_open_file()
385 		buffer->cb_max_size = buffer->bin_attr->cb_max_size;  in __configfs_open_file()
387 		buffer->attr = attr;  in __configfs_open_file()
390 	buffer->owner = attr->ca_owner;  in __configfs_open_file()
393 	if (!try_module_get(buffer->owner))  in __configfs_open_file()
397 	if (!buffer->item->ci_type)  in __configfs_open_file()
400 	buffer->ops = buffer->item->ci_type->ct_item_ops;  in __configfs_open_file()
411 		if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write)  in __configfs_open_file()
424 		if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read)  in __configfs_open_file()
428 	mutex_init(&buffer->mutex);  in __configfs_open_file()
429 	buffer->needs_read_fill = 1;  in __configfs_open_file()
430 	buffer->read_in_progress = false;  in __configfs_open_file()
431 	buffer->write_in_progress = false;  in __configfs_open_file()
432 	file->private_data = buffer;  in __configfs_open_file()
437 	module_put(buffer->owner);  in __configfs_open_file()
439 	config_item_put(buffer->item);  in __configfs_open_file()
442 	kfree(buffer);  in __configfs_open_file()
449 	struct configfs_buffer *buffer = filp->private_data;  in configfs_release()  local
451 	module_put(buffer->owner);  in configfs_release()
452 	if (buffer->page)  in configfs_release()
453 		free_page((unsigned long)buffer->page);  in configfs_release()
454 	mutex_destroy(&buffer->mutex);  in configfs_release()
455 	kfree(buffer);  in configfs_release()
471 	struct configfs_buffer *buffer = file->private_data;  in configfs_release_bin_file()  local
473 	buffer->read_in_progress = false;  in configfs_release_bin_file()
475 	if (buffer->write_in_progress) {  in configfs_release_bin_file()
477 		buffer->write_in_progress = false;  in configfs_release_bin_file()
482 			buffer->bin_attr->write(buffer->item,  in configfs_release_bin_file()
483 					buffer->bin_buffer,  in configfs_release_bin_file()
484 					buffer->bin_buffer_size);  in configfs_release_bin_file()
488 		vfree(buffer->bin_buffer);  in configfs_release_bin_file()
489 		buffer->bin_buffer = NULL;  in configfs_release_bin_file()
490 		buffer->bin_buffer_size = 0;  in configfs_release_bin_file()
491 		buffer->needs_read_fill = 1;  in configfs_release_bin_file()