232 	struct file_region *rg, *nrg, *trg;  in region_add()  local
236 	list_for_each_entry(rg, head, link)  in region_add()
237 		if (f <= rg->to)  in region_add()
241 	if (f > rg->from)  in region_add()
242 		f = rg->from;  in region_add()
245 	nrg = rg;  in region_add()
246 	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {  in region_add()
247 		if (&rg->link == head)  in region_add()
249 		if (rg->from > t)  in region_add()
255 		if (rg->to > t)  in region_add()
256 			t = rg->to;  in region_add()
257 		if (rg != nrg) {  in region_add()
258 			list_del(&rg->link);  in region_add()
259 			kfree(rg);  in region_add()
271 	struct file_region *rg, *nrg = NULL;  in region_chg()  local
277 	list_for_each_entry(rg, head, link)  in region_chg()
278 		if (f <= rg->to)  in region_chg()
284 	if (&rg->link == head || t < rg->from) {  in region_chg()
297 		list_add(&nrg->link, rg->link.prev);  in region_chg()
303 	if (f > rg->from)  in region_chg()
304 		f = rg->from;  in region_chg()
308 	list_for_each_entry(rg, rg->link.prev, link) {  in region_chg()
309 		if (&rg->link == head)  in region_chg()
311 		if (rg->from > t)  in region_chg()
317 		if (rg->to > t) {  in region_chg()
318 			chg += rg->to - t;  in region_chg()
319 			t = rg->to;  in region_chg()
321 		chg -= rg->to - rg->from;  in region_chg()
337 	struct file_region *rg, *trg;  in region_truncate()  local
342 	list_for_each_entry(rg, head, link)  in region_truncate()
343 		if (end <= rg->to)  in region_truncate()
345 	if (&rg->link == head)  in region_truncate()
349 	if (end > rg->from) {  in region_truncate()
350 		chg = rg->to - end;  in region_truncate()
351 		rg->to = end;  in region_truncate()
352 		rg = list_entry(rg->link.next, typeof(*rg), link);  in region_truncate()
356 	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {  in region_truncate()
357 		if (&rg->link == head)  in region_truncate()
359 		chg += rg->to - rg->from;  in region_truncate()
360 		list_del(&rg->link);  in region_truncate()
361 		kfree(rg);  in region_truncate()
372 	struct file_region *rg;  in region_count()  local
377 	list_for_each_entry(rg, head, link) {  in region_count()
381 		if (rg->to <= f)  in region_count()
383 		if (rg->from >= t)  in region_count()
386 		seg_from = max(rg->from, f);  in region_count()
387 		seg_to = min(rg->to, t);  in region_count()