X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=block%2Felevator.c;h=96a61e029ce5e7858d2e024c08eff817b5a998d6;hb=d5bee775137c56ed993f1b3c9d66c268b3525d7d;hp=6c3fc8a10bf210f8cfcb8def13981c6274246b11;hpb=e7e37ee9c547213d726b29c2510cbb6696050405;p=linux-2.6-omap-h63xx.git diff --git a/block/elevator.c b/block/elevator.c index 6c3fc8a10bf..96a61e029ce 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -64,7 +64,7 @@ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio) } EXPORT_SYMBOL(elv_rq_merge_ok); -inline int elv_try_merge(struct request *__rq, struct bio *bio) +static inline int elv_try_merge(struct request *__rq, struct bio *bio) { int ret = ELEVATOR_NO_MERGE; @@ -80,7 +80,6 @@ inline int elv_try_merge(struct request *__rq, struct bio *bio) return ret; } -EXPORT_SYMBOL(elv_try_merge); static struct elevator_type *elevator_find(const char *name) { @@ -140,28 +139,16 @@ static int elevator_attach(request_queue_t *q, struct elevator_type *e, static char chosen_elevator[16]; -static void elevator_setup_default(void) +static int __init elevator_setup(char *str) { - struct elevator_type *e; - /* - * If default has not been set, use the compiled-in selection. + * Be backwards-compatible with previous kernels, so users + * won't get the wrong elevator. */ - if (!chosen_elevator[0]) - strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED); - - /* - * If the given scheduler is not available, fall back to no-op. - */ - if ((e = elevator_find(chosen_elevator))) - elevator_put(e); + if (!strcmp(str, "as")) + strcpy(chosen_elevator, "anticipatory"); else - strcpy(chosen_elevator, "noop"); -} - -static int __init elevator_setup(char *str) -{ - strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); + strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1); return 0; } @@ -178,14 +165,16 @@ int elevator_init(request_queue_t *q, char *name) q->end_sector = 0; q->boundary_rq = NULL; - elevator_setup_default(); + if (name && !(e = elevator_get(name))) + return -EINVAL; - if (!name) - name = chosen_elevator; + if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator))) + printk("I/O scheduler %s not found\n", chosen_elevator); - e = elevator_get(name); - if (!e) - return -EINVAL; + if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) { + printk("Default I/O scheduler not found, using no-op\n"); + e = elevator_get("noop"); + } eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL); if (!eq) { @@ -304,15 +293,7 @@ void elv_requeue_request(request_queue_t *q, struct request *rq) rq->flags &= ~REQ_STARTED; - /* - * if this is the flush, requeue the original instead and drop the flush - */ - if (rq->flags & REQ_BAR_FLUSH) { - clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags); - rq = rq->end_io_data; - } - - __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); + __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE, 0); } static void elv_drain_elevator(request_queue_t *q) @@ -332,7 +313,18 @@ static void elv_drain_elevator(request_queue_t *q) void __elv_add_request(request_queue_t *q, struct request *rq, int where, int plug) { + struct list_head *pos; + unsigned ordseq; + + if (q->ordcolor) + rq->flags |= REQ_ORDERED_COLOR; + if (rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)) { + /* + * toggle ordered color + */ + q->ordcolor ^= 1; + /* * barriers implicitly indicate back insertion */ @@ -393,6 +385,30 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where, q->elevator->ops->elevator_add_req_fn(q, rq); break; + case ELEVATOR_INSERT_REQUEUE: + /* + * If ordered flush isn't in progress, we do front + * insertion; otherwise, requests should be requeued + * in ordseq order. + */ + rq->flags |= REQ_SOFTBARRIER; + + if (q->ordseq == 0) { + list_add(&rq->queuelist, &q->queue_head); + break; + } + + ordseq = blk_ordered_req_seq(rq); + + list_for_each(pos, &q->queue_head) { + struct request *pos_rq = list_entry_rq(pos); + if (ordseq <= blk_ordered_req_seq(pos_rq)) + break; + } + + list_add_tail(&rq->queuelist, pos); + break; + default: printk(KERN_ERR "%s: bad insertion point %d\n", __FUNCTION__, where); @@ -422,25 +438,16 @@ static inline struct request *__elv_next_request(request_queue_t *q) { struct request *rq; - if (unlikely(list_empty(&q->queue_head) && - !q->elevator->ops->elevator_dispatch_fn(q, 0))) - return NULL; - - rq = list_entry_rq(q->queue_head.next); - - /* - * if this is a barrier write and the device has to issue a - * flush sequence to support it, check how far we are - */ - if (blk_fs_request(rq) && blk_barrier_rq(rq)) { - BUG_ON(q->ordered == QUEUE_ORDERED_NONE); + while (1) { + while (!list_empty(&q->queue_head)) { + rq = list_entry_rq(q->queue_head.next); + if (blk_do_ordered(q, &rq)) + return rq; + } - if (q->ordered == QUEUE_ORDERED_FLUSH && - !blk_barrier_preflush(rq)) - rq = blk_start_pre_flush(q, rq); + if (!q->elevator->ops->elevator_dispatch_fn(q, 0)) + return NULL; } - - return rq; } struct request *elv_next_request(request_queue_t *q) @@ -498,7 +505,7 @@ struct request *elv_next_request(request_queue_t *q) blkdev_dequeue_request(rq); rq->flags |= REQ_QUIET; end_that_request_chunk(rq, 0, nr_bytes); - end_that_request_last(rq); + end_that_request_last(rq, 0); } else { printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__, ret); @@ -597,6 +604,20 @@ void elv_completed_request(request_queue_t *q, struct request *rq) if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn) e->ops->elevator_completed_req_fn(q, rq); } + + /* + * Check if the queue is waiting for fs requests to be + * drained for flush sequence. + */ + if (unlikely(q->ordseq)) { + struct request *first_rq = list_entry_rq(q->queue_head.next); + if (q->in_flight == 0 && + blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN && + blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) { + blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0); + q->request_fn(q); + } + } } int elv_register_queue(struct request_queue *q) @@ -631,8 +652,10 @@ int elv_register(struct elevator_type *e) spin_unlock_irq(&elv_list_lock); printk(KERN_INFO "io scheduler %s registered", e->elevator_name); - if (!strcmp(e->elevator_name, chosen_elevator)) - printk(" (default)"); + if (!strcmp(e->elevator_name, chosen_elevator) || + (!*chosen_elevator && + !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) + printk(" (default)"); printk("\n"); return 0; }