static struct request *
deadline_find_drq_hash(struct deadline_data *dd, sector_t offset)
{
struct list_head *hash_list = &dd->hash[DL_HASH_FN(offset)];
struct list_head *entry, *next = hash_list->next;
while ((entry = next) != hash_list) {
struct deadline_rq *drq = list_entry_hash(entry);
struct request *__rq = drq->request;
next = entry->next;
BUG_ON(!ON_HASH(drq));
if (!rq_mergeable(__rq)) {
__deadline_del_drq_hash(drq);
continue;
}
if (rq_hash_key(__rq) == offset)
return __rq;
}
return NULL;
}
/*
* can we safely merge with this request?
*/
int elv_rq_merge_ok(struct request *rq, struct bio *bio)
{
if (!rq_mergeable(rq))
return 0;
/*
* Don't merge file system requests and discard requests
*/
<<<<<<< HEAD
/*
* add drq to rbtree and fifo
*/
static inline void
deadline_add_request(struct request_queue *q, struct request *rq)
{
struct deadline_data *dd = q->elevator->elevator_data;
struct deadline_rq *drq = RQ_DATA(rq);
const int data_dir = rq_data_dir(drq->request);
deadline_add_drq_rb(dd, drq);
/*
* set expire time (only used for reads) and add to fifo list
*/
drq->expires = jiffies + dd->fifo_expire[data_dir];
list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]);
if (rq_mergeable(rq)) {
deadline_add_drq_hash(dd, drq);
if (!q->last_merge)
q->last_merge = rq;
}
}
bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
{
struct request_queue *q = rq->q;
if (!rq_mergeable(rq) || !bio_mergeable(bio))
return false;
if (!blk_check_merge_flags(rq->cmd_flags, bio->bi_rw))
return false;
/* different data direction or already started, don't merge */
if (bio_data_dir(bio) != rq_data_dir(rq))
return false;
/* must be same device and not a special request */
if (rq->rq_disk != bio->bi_bdev->bd_disk || req_no_special_merge(rq))
return false;
/* only merge integrity protected bio into ditto rq */
if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
return false;
/* must be using the same buffer */
if (rq->cmd_flags & REQ_WRITE_SAME &&
!blk_write_same_mergeable(rq->bio, bio))
return false;
/* Only check gaps if the bio carries data */
if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && bio_has_data(bio)) {
struct bio_vec *bprev;
bprev = &rq->biotail->bi_io_vec[rq->biotail->bi_vcnt - 1];
if (bvec_gap_to_prev(bprev, bio->bi_io_vec[0].bv_offset))
return false;
}
return true;
}
/*
* Has to be called with the request spinlock acquired
*/
static int attempt_merge(struct request_queue *q, struct request *req,
struct request *next)
{
if (!rq_mergeable(req) || !rq_mergeable(next))
return 0;
if (!blk_check_merge_flags(req->cmd_flags, next->cmd_flags))
return 0;
/*
* not contiguous
*/
if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
return 0;
if (rq_data_dir(req) != rq_data_dir(next)
|| req->rq_disk != next->rq_disk
|| req_no_special_merge(next))
return 0;
if (req->cmd_flags & REQ_WRITE_SAME &&
!blk_write_same_mergeable(req->bio, next->bio))
return 0;
/*
* If we are allowed to merge, then append bio list
* from next to rq and release next. merge_requests_fn
* will have updated segment counts, update sector
* counts here.
*/
if (!ll_merge_requests_fn(q, req, next))
return 0;
/*
* If failfast settings disagree or any of the two is already
* a mixed merge, mark both as mixed before proceeding. This
* makes sure that all involved bios have mixable attributes
* set properly.
*/
if ((req->cmd_flags | next->cmd_flags) & REQ_MIXED_MERGE ||
(req->cmd_flags & REQ_FAILFAST_MASK) !=
(next->cmd_flags & REQ_FAILFAST_MASK)) {
blk_rq_set_mixed_merge(req);
blk_rq_set_mixed_merge(next);
}
/*
* At this point we have either done a back merge
* or front merge. We need the smaller start_time of
* the merged requests to be the current request
* for accounting purposes.
*/
if (time_after(req->start_time, next->start_time))
req->start_time = next->start_time;
req->biotail->bi_next = next->bio;
req->biotail = next->biotail;
req->__data_len += blk_rq_bytes(next);
elv_merge_requests(q, req, next);
/*
* 'next' is going away, so update stats accordingly
*/
blk_account_io_merge(next);
req->ioprio = ioprio_best(req->ioprio, next->ioprio);
if (blk_rq_cpu_valid(next))
req->cpu = next->cpu;
/* owner-ship of bio passed from next to req */
next->bio = NULL;
__blk_put_request(q, next);
return 1;
}
