1 // SPDX-License-Identifier: GPL-2.0-or-later
17  * netfs_folioq_alloc - Allocate a folio_queue struct
22  * Allocate, initialise and account the folio_queue struct and log a trace line
34 		fq->debug_id = atomic_inc_return(&debug_ids);  in netfs_folioq_alloc()
42  * netfs_folioq_free - Free a folio_queue struct
69 		return -ENOMEM;  in rolling_buffer_init()
71 	roll->head = fq;  in rolling_buffer_init()
72 	roll->tail = fq;  in rolling_buffer_init()
73 	iov_iter_folio_queue(&roll->iter, direction, fq, 0, 0, 0);  in rolling_buffer_init()
82 	struct folio_queue *fq, *head = roll->head;  in rolling_buffer_make_space()
87 	fq = netfs_folioq_alloc(head->rreq_id, GFP_NOFS, netfs_trace_folioq_make_space);  in rolling_buffer_make_space()
89 		return -ENOMEM;  in rolling_buffer_make_space()
90 	fq->prev = head;  in rolling_buffer_make_space()
92 	roll->head = fq;  in rolling_buffer_make_space()
97 		if (roll->iter.folioq == head &&  in rolling_buffer_make_space()
98 		    roll->iter.folioq_slot == folioq_nr_slots(head)) {  in rolling_buffer_make_space()
99 			roll->iter.folioq = fq;  in rolling_buffer_make_space()
100 			roll->iter.folioq_slot = 0;  in rolling_buffer_make_space()
106 	 * [!] NOTE: After we set head->next, the consumer is at liberty to  in rolling_buffer_make_space()
109 	smp_store_release(&head->next, fq);  in rolling_buffer_make_space()
126 		return -ENOMEM;  in rolling_buffer_load_from_ra()
128 	fq = roll->head;  in rolling_buffer_load_from_ra()
129 	vec = (struct page **)fq->vec.folios;  in rolling_buffer_load_from_ra()
130 	nr = __readahead_batch(ractl, vec + folio_batch_count(&fq->vec),  in rolling_buffer_load_from_ra()
131 			       folio_batch_space(&fq->vec));  in rolling_buffer_load_from_ra()
132 	ix = fq->vec.nr;  in rolling_buffer_load_from_ra()
134 	fq->vec.nr = to;  in rolling_buffer_load_from_ra()
139 		fq->orders[ix] = order;  in rolling_buffer_load_from_ra()
145 	WRITE_ONCE(roll->iter.count, roll->iter.count + size);  in rolling_buffer_load_from_ra()
148 	smp_store_release(&roll->next_head_slot, to);  in rolling_buffer_load_from_ra()
162 		return -ENOMEM;  in rolling_buffer_append()
164 	slot = folioq_append(roll->head, folio);  in rolling_buffer_append()
166 		folioq_mark(roll->head, slot);  in rolling_buffer_append()
168 		folioq_mark2(roll->head, slot);  in rolling_buffer_append()
170 	WRITE_ONCE(roll->iter.count, roll->iter.count + size);  in rolling_buffer_append()
173 	smp_store_release(&roll->next_head_slot, slot);  in rolling_buffer_append()
178  * Delete a spent buffer from a rolling queue and return the next in line.  We
184 	struct folio_queue *spent = roll->tail, *next = READ_ONCE(spent->next);  in rolling_buffer_delete_spent()
188 	next->prev = NULL;  in rolling_buffer_delete_spent()
190 	roll->tail = next;  in rolling_buffer_delete_spent()
204 	while ((p = roll->tail)) {  in rolling_buffer_clear()
205 		roll->tail = p->next;  in rolling_buffer_clear()