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-rw-r--r--block/deadline-iosched.c21
1 files changed, 7 insertions, 14 deletions
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index cb94c838087a..a054eef8dff6 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -306,27 +306,20 @@ dispatch_writes:
306dispatch_find_request: 306dispatch_find_request:
307 /* 307 /*
308 * we are not running a batch, find best request for selected data_dir 308 * we are not running a batch, find best request for selected data_dir
309 * and start a new batch
310 */ 309 */
311 if (deadline_check_fifo(dd, data_dir)) { 310 if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
312 /* An expired request exists - satisfy it */ 311 /*
312 * A deadline has expired, the last request was in the other
313 * direction, or we have run out of higher-sectored requests.
314 * Start again from the request with the earliest expiry time.
315 */
313 rq = rq_entry_fifo(dd->fifo_list[data_dir].next); 316 rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
314 } else if (dd->next_rq[data_dir]) { 317 } else {
315 /* 318 /*
316 * The last req was the same dir and we have a next request in 319 * The last req was the same dir and we have a next request in
317 * sort order. No expired requests so continue on from here. 320 * sort order. No expired requests so continue on from here.
318 */ 321 */
319 rq = dd->next_rq[data_dir]; 322 rq = dd->next_rq[data_dir];
320 } else {
321 struct rb_node *node;
322 /*
323 * The last req was the other direction or we have run out of
324 * higher-sectored requests. Go back to the lowest sectored
325 * request (1 way elevator) and start a new batch.
326 */
327 node = rb_first(&dd->sort_list[data_dir]);
328 if (node)
329 rq = rb_entry_rq(node);
330 } 323 }
331 324
332 dd->batching = 0; 325 dd->batching = 0;