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authorTejun Heo <tj@kernel.org>2009-04-23 11:05:18 +0900
committerJens Axboe <jens.axboe@oracle.com>2009-04-28 07:37:34 +0200
commit158dbda0068e63c7cce7bd47c123bd1dfa5a902c (patch)
tree2665f31350ba4f0875c7611c980b0831c22d8c98 /block/elevator.c
parent5efccd17ceb0fc43837a331297c2c407969d7201 (diff)
downloadlinux-158dbda0068e63c7cce7bd47c123bd1dfa5a902c.tar.bz2
block: reorganize request fetching functions
Impact: code reorganization elv_next_request() and elv_dequeue_request() are public block layer interface than actual elevator implementation. They mostly deal with how requests interact with block layer and low level drivers at the beginning of rqeuest processing whereas __elv_next_request() is the actual eleveator request fetching interface. Move the two functions to blk-core.c. This prepares for further interface cleanup. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c128
1 files changed, 0 insertions, 128 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 2e0fb21485b7..b03b8752e18b 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -53,7 +53,6 @@ static const int elv_hash_shift = 6;
(hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
#define ELV_HASH_ENTRIES (1 << elv_hash_shift)
#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
-#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
DEFINE_TRACE(block_rq_insert);
DEFINE_TRACE(block_rq_issue);
@@ -310,22 +309,6 @@ void elevator_exit(struct elevator_queue *e)
}
EXPORT_SYMBOL(elevator_exit);
-static void elv_activate_rq(struct request_queue *q, struct request *rq)
-{
- struct elevator_queue *e = q->elevator;
-
- if (e->ops->elevator_activate_req_fn)
- e->ops->elevator_activate_req_fn(q, rq);
-}
-
-static void elv_deactivate_rq(struct request_queue *q, struct request *rq)
-{
- struct elevator_queue *e = q->elevator;
-
- if (e->ops->elevator_deactivate_req_fn)
- e->ops->elevator_deactivate_req_fn(q, rq);
-}
-
static inline void __elv_rqhash_del(struct request *rq)
{
hlist_del_init(&rq->hash);
@@ -758,117 +741,6 @@ void elv_add_request(struct request_queue *q, struct request *rq, int where,
}
EXPORT_SYMBOL(elv_add_request);
-static inline struct request *__elv_next_request(struct request_queue *q)
-{
- struct request *rq;
-
- 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->elevator->ops->elevator_dispatch_fn(q, 0))
- return NULL;
- }
-}
-
-struct request *elv_next_request(struct request_queue *q)
-{
- struct request *rq;
- int ret;
-
- while ((rq = __elv_next_request(q)) != NULL) {
- if (!(rq->cmd_flags & REQ_STARTED)) {
- /*
- * This is the first time the device driver
- * sees this request (possibly after
- * requeueing). Notify IO scheduler.
- */
- if (blk_sorted_rq(rq))
- elv_activate_rq(q, rq);
-
- /*
- * just mark as started even if we don't start
- * it, a request that has been delayed should
- * not be passed by new incoming requests
- */
- rq->cmd_flags |= REQ_STARTED;
- trace_block_rq_issue(q, rq);
- }
-
- if (!q->boundary_rq || q->boundary_rq == rq) {
- q->end_sector = rq_end_sector(rq);
- q->boundary_rq = NULL;
- }
-
- if (rq->cmd_flags & REQ_DONTPREP)
- break;
-
- if (q->dma_drain_size && rq->data_len) {
- /*
- * make sure space for the drain appears we
- * know we can do this because max_hw_segments
- * has been adjusted to be one fewer than the
- * device can handle
- */
- rq->nr_phys_segments++;
- }
-
- if (!q->prep_rq_fn)
- break;
-
- ret = q->prep_rq_fn(q, rq);
- if (ret == BLKPREP_OK) {
- break;
- } else if (ret == BLKPREP_DEFER) {
- /*
- * the request may have been (partially) prepped.
- * we need to keep this request in the front to
- * avoid resource deadlock. REQ_STARTED will
- * prevent other fs requests from passing this one.
- */
- if (q->dma_drain_size && rq->data_len &&
- !(rq->cmd_flags & REQ_DONTPREP)) {
- /*
- * remove the space for the drain we added
- * so that we don't add it again
- */
- --rq->nr_phys_segments;
- }
-
- rq = NULL;
- break;
- } else if (ret == BLKPREP_KILL) {
- rq->cmd_flags |= REQ_QUIET;
- __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
- } else {
- printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
- break;
- }
- }
-
- return rq;
-}
-EXPORT_SYMBOL(elv_next_request);
-
-void elv_dequeue_request(struct request_queue *q, struct request *rq)
-{
- BUG_ON(list_empty(&rq->queuelist));
- BUG_ON(ELV_ON_HASH(rq));
-
- list_del_init(&rq->queuelist);
-
- /*
- * the time frame between a request being removed from the lists
- * and to it is freed is accounted as io that is in progress at
- * the driver side.
- */
- if (blk_account_rq(rq))
- q->in_flight++;
-}
-
int elv_queue_empty(struct request_queue *q)
{
struct elevator_queue *e = q->elevator;