q->make_request_fn = mfn;
q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
- q->backing_dev_info.memory_backed = 0;
+ q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY;
blk_queue_max_sectors(q, MAX_SECTORS);
blk_queue_hardsect_size(q, 512);
blk_queue_dma_alignment(q, 511);
EXPORT_SYMBOL(blk_queue_make_request);
+static inline void rq_init(request_queue_t *q, struct request *rq)
+{
+ INIT_LIST_HEAD(&rq->queuelist);
+
+ rq->errors = 0;
+ rq->rq_status = RQ_ACTIVE;
+ rq->bio = rq->biotail = NULL;
+ rq->buffer = NULL;
+ rq->ref_count = 1;
+ rq->q = q;
+ rq->waiting = NULL;
+ rq->special = NULL;
+ rq->data_len = 0;
+ rq->data = NULL;
+ rq->sense = NULL;
+ rq->end_io = NULL;
+ rq->end_io_data = NULL;
+}
+
/**
* blk_queue_ordered - does this queue support ordered writes
* @q: the request queue
**/
void blk_queue_ordered(request_queue_t *q, int flag)
{
- if (flag)
- set_bit(QUEUE_FLAG_ORDERED, &q->queue_flags);
- else
- clear_bit(QUEUE_FLAG_ORDERED, &q->queue_flags);
+ switch (flag) {
+ case QUEUE_ORDERED_NONE:
+ if (q->flush_rq)
+ kmem_cache_free(request_cachep, q->flush_rq);
+ q->flush_rq = NULL;
+ q->ordered = flag;
+ break;
+ case QUEUE_ORDERED_TAG:
+ q->ordered = flag;
+ break;
+ case QUEUE_ORDERED_FLUSH:
+ q->ordered = flag;
+ if (!q->flush_rq)
+ q->flush_rq = kmem_cache_alloc(request_cachep,
+ GFP_KERNEL);
+ break;
+ default:
+ printk("blk_queue_ordered: bad value %d\n", flag);
+ break;
+ }
}
EXPORT_SYMBOL(blk_queue_ordered);
EXPORT_SYMBOL(blk_queue_issue_flush_fn);
+/*
+ * Cache flushing for ordered writes handling
+ */
+static void blk_pre_flush_end_io(struct request *flush_rq)
+{
+ struct request *rq = flush_rq->end_io_data;
+ request_queue_t *q = rq->q;
+
+ rq->flags |= REQ_BAR_PREFLUSH;
+
+ if (!flush_rq->errors)
+ elv_requeue_request(q, rq);
+ else {
+ q->end_flush_fn(q, flush_rq);
+ clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags);
+ q->request_fn(q);
+ }
+}
+
+static void blk_post_flush_end_io(struct request *flush_rq)
+{
+ struct request *rq = flush_rq->end_io_data;
+ request_queue_t *q = rq->q;
+
+ rq->flags |= REQ_BAR_POSTFLUSH;
+
+ q->end_flush_fn(q, flush_rq);
+ clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags);
+ q->request_fn(q);
+}
+
+struct request *blk_start_pre_flush(request_queue_t *q, struct request *rq)
+{
+ struct request *flush_rq = q->flush_rq;
+
+ BUG_ON(!blk_barrier_rq(rq));
+
+ if (test_and_set_bit(QUEUE_FLAG_FLUSH, &q->queue_flags))
+ return NULL;
+
+ rq_init(q, flush_rq);
+ flush_rq->elevator_private = NULL;
+ flush_rq->flags = REQ_BAR_FLUSH;
+ flush_rq->rq_disk = rq->rq_disk;
+ flush_rq->rl = NULL;
+
+ /*
+ * prepare_flush returns 0 if no flush is needed, just mark both
+ * pre and post flush as done in that case
+ */
+ if (!q->prepare_flush_fn(q, flush_rq)) {
+ rq->flags |= REQ_BAR_PREFLUSH | REQ_BAR_POSTFLUSH;
+ clear_bit(QUEUE_FLAG_FLUSH, &q->queue_flags);
+ return rq;
+ }
+
+ /*
+ * some drivers dequeue requests right away, some only after io
+ * completion. make sure the request is dequeued.
+ */
+ if (!list_empty(&rq->queuelist))
+ blkdev_dequeue_request(rq);
+
+ elv_deactivate_request(q, rq);
+
+ flush_rq->end_io_data = rq;
+ flush_rq->end_io = blk_pre_flush_end_io;
+
+ __elv_add_request(q, flush_rq, ELEVATOR_INSERT_FRONT, 0);
+ return flush_rq;
+}
+
+static void blk_start_post_flush(request_queue_t *q, struct request *rq)
+{
+ struct request *flush_rq = q->flush_rq;
+
+ BUG_ON(!blk_barrier_rq(rq));
+
+ rq_init(q, flush_rq);
+ flush_rq->elevator_private = NULL;
+ flush_rq->flags = REQ_BAR_FLUSH;
+ flush_rq->rq_disk = rq->rq_disk;
+ flush_rq->rl = NULL;
+
+ if (q->prepare_flush_fn(q, flush_rq)) {
+ flush_rq->end_io_data = rq;
+ flush_rq->end_io = blk_post_flush_end_io;
+
+ __elv_add_request(q, flush_rq, ELEVATOR_INSERT_FRONT, 0);
+ q->request_fn(q);
+ }
+}
+
+static inline int blk_check_end_barrier(request_queue_t *q, struct request *rq,
+ int sectors)
+{
+ if (sectors > rq->nr_sectors)
+ sectors = rq->nr_sectors;
+
+ rq->nr_sectors -= sectors;
+ return rq->nr_sectors;
+}
+
+static int __blk_complete_barrier_rq(request_queue_t *q, struct request *rq,
+ int sectors, int queue_locked)
+{
+ if (q->ordered != QUEUE_ORDERED_FLUSH)
+ return 0;
+ if (!blk_fs_request(rq) || !blk_barrier_rq(rq))
+ return 0;
+ if (blk_barrier_postflush(rq))
+ return 0;
+
+ if (!blk_check_end_barrier(q, rq, sectors)) {
+ unsigned long flags = 0;
+
+ if (!queue_locked)
+ spin_lock_irqsave(q->queue_lock, flags);
+
+ blk_start_post_flush(q, rq);
+
+ if (!queue_locked)
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+
+ return 1;
+}
+
+/**
+ * blk_complete_barrier_rq - complete possible barrier request
+ * @q: the request queue for the device
+ * @rq: the request
+ * @sectors: number of sectors to complete
+ *
+ * Description:
+ * Used in driver end_io handling to determine whether to postpone
+ * completion of a barrier request until a post flush has been done. This
+ * is the unlocked variant, used if the caller doesn't already hold the
+ * queue lock.
+ **/
+int blk_complete_barrier_rq(request_queue_t *q, struct request *rq, int sectors)
+{
+ return __blk_complete_barrier_rq(q, rq, sectors, 0);
+}
+EXPORT_SYMBOL(blk_complete_barrier_rq);
+
+/**
+ * blk_complete_barrier_rq_locked - complete possible barrier request
+ * @q: the request queue for the device
+ * @rq: the request
+ * @sectors: number of sectors to complete
+ *
+ * Description:
+ * See blk_complete_barrier_rq(). This variant must be used if the caller
+ * holds the queue lock.
+ **/
+int blk_complete_barrier_rq_locked(request_queue_t *q, struct request *rq,
+ int sectors)
+{
+ return __blk_complete_barrier_rq(q, rq, sectors, 1);
+}
+EXPORT_SYMBOL(blk_complete_barrier_rq_locked);
+
/**
* blk_queue_bounce_limit - set bounce buffer limit for queue
* @q: the request queue for the device
* blk_queue_init_tags - initialize the queue tag info
* @q: the request queue for the device
* @depth: the maximum queue depth supported
+ * @tags: the tag to use
**/
int blk_queue_init_tags(request_queue_t *q, int depth,
struct blk_queue_tag *tags)
spin_lock_irqsave(q->queue_lock, flags);
blk_remove_plug(q);
- q->request_fn(q);
+ if (!elv_queue_empty(q))
+ q->request_fn(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_run_queue);
if (q->queue_tags)
__blk_queue_free_tags(q);
+ blk_queue_ordered(q, QUEUE_ORDERED_NONE);
+
kmem_cache_free(requestq_cachep, q);
}
if (blk_init_free_list(q))
goto out_init;
+ /*
+ * if caller didn't supply a lock, they get per-queue locking with
+ * our embedded lock
+ */
+ if (!lock) {
+ spin_lock_init(&q->__queue_lock);
+ lock = &q->__queue_lock;
+ }
+
q->request_fn = rfn;
q->back_merge_fn = ll_back_merge_fn;
q->front_merge_fn = ll_front_merge_fn;
if (ioc_batching(q, ioc))
ioc->nr_batch_requests--;
- INIT_LIST_HEAD(&rq->queuelist);
-
- rq->errors = 0;
- rq->rq_status = RQ_ACTIVE;
- rq->bio = rq->biotail = NULL;
- rq->buffer = NULL;
- rq->ref_count = 1;
- rq->q = q;
+ rq_init(q, rq);
rq->rl = rl;
- rq->waiting = NULL;
- rq->special = NULL;
- rq->data_len = 0;
- rq->data = NULL;
- rq->sense = NULL;
-
out:
put_io_context(ioc);
return rq;
/**
* blk_rq_unmap_user - unmap a request with user data
* @rq: request to be unmapped
- * @ubuf: user buffer
+ * @bio: bio for the request
* @ulen: length of user buffer
*
* Description:
}
rq->flags |= REQ_NOMERGE;
- if (!rq->waiting)
- rq->waiting = &wait;
+ rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
generic_unplug_device(q);
- wait_for_completion(rq->waiting);
+ wait_for_completion(&wait);
rq->waiting = NULL;
if (rq->errors)
/*
* queue lock must be held
*/
-void __blk_put_request(request_queue_t *q, struct request *req)
+static void __blk_put_request(request_queue_t *q, struct request *req)
{
struct request_list *rl = req->rl;
EXPORT_SYMBOL(blk_put_request);
+/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ */
+void blk_end_sync_rq(struct request *rq)
+{
+ struct completion *waiting = rq->waiting;
+
+ rq->waiting = NULL;
+ __blk_put_request(rq->q, rq);
+
+ /*
+ * complete last, if this is a stack request the process (and thus
+ * the rq pointer) could be invalid right after this complete()
+ */
+ complete(waiting);
+}
+EXPORT_SYMBOL(blk_end_sync_rq);
+
/**
* blk_congestion_wait - wait for a queue to become uncongested
* @rw: READ or WRITE
static int __make_request(request_queue_t *q, struct bio *bio)
{
struct request *req, *freereq = NULL;
- int el_ret, rw, nr_sectors, cur_nr_sectors, barrier, err;
+ int el_ret, rw, nr_sectors, cur_nr_sectors, barrier, err, sync;
sector_t sector;
sector = bio->bi_sector;
cur_nr_sectors = bio_cur_sectors(bio);
rw = bio_data_dir(bio);
+ sync = bio_sync(bio);
/*
* low level driver can indicate that it wants pages above a
spin_lock_prefetch(q->queue_lock);
barrier = bio_barrier(bio);
- if (barrier && !(q->queue_flags & (1 << QUEUE_FLAG_ORDERED))) {
+ if (barrier && (q->ordered == QUEUE_ORDERED_NONE)) {
err = -EOPNOTSUPP;
goto end_io;
}
out:
if (freereq)
__blk_put_request(q, freereq);
- if (bio_sync(bio))
+ if (sync)
__generic_unplug_device(q);
spin_unlock_irq(q->queue_lock);
void end_that_request_last(struct request *req)
{
struct gendisk *disk = req->rq_disk;
- struct completion *waiting = req->waiting;
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
disk_round_stats(disk);
disk->in_flight--;
}
- __blk_put_request(req->q, req);
- /* Do this LAST! The structure may be freed immediately afterwards */
- if (waiting)
- complete(waiting);
+ if (req->end_io)
+ req->end_io(req);
+ else
+ __blk_put_request(req->q, req);
}
EXPORT_SYMBOL(end_that_request_last);
git://git.onelab.eu / linux-2.6.git / blobdiff