/*
- * linux/drivers/block/ll_rw_blk.c
- *
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1994, Karl Keyte: Added support for disk statistics
* Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY;
- blk_queue_max_sectors(q, MAX_SECTORS);
+ blk_queue_max_sectors(q, SAFE_MAX_SECTORS);
blk_queue_hardsect_size(q, 512);
blk_queue_dma_alignment(q, 511);
blk_queue_congestion_threshold(q);
printk("%s: set to minimum %d\n", __FUNCTION__, max_sectors);
}
- q->max_sectors = q->max_hw_sectors = max_sectors;
+ if (BLK_DEF_MAX_SECTORS > max_sectors)
+ q->max_hw_sectors = q->max_sectors = max_sectors;
+ else {
+ q->max_sectors = BLK_DEF_MAX_SECTORS;
+ q->max_hw_sectors = max_sectors;
+ }
}
EXPORT_SYMBOL(blk_queue_max_sectors);
void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b)
{
/* zero is "infinity" */
- t->max_sectors = t->max_hw_sectors =
- min_not_zero(t->max_sectors,b->max_sectors);
+ t->max_sectors = min_not_zero(t->max_sectors,b->max_sectors);
+ t->max_hw_sectors = min_not_zero(t->max_hw_sectors,b->max_hw_sectors);
t->max_phys_segments = min(t->max_phys_segments,b->max_phys_segments);
t->max_hw_segments = min(t->max_hw_segments,b->max_hw_segments);
EXPORT_SYMBOL(blk_queue_invalidate_tags);
-static char *rq_flags[] = {
+static const char * const rq_flags[] = {
"REQ_RW",
"REQ_FAILFAST",
"REQ_SORTED",
static int ll_back_merge_fn(request_queue_t *q, struct request *req,
struct bio *bio)
{
+ unsigned short max_sectors;
int len;
- if (req->nr_sectors + bio_sectors(bio) > q->max_sectors) {
+ if (unlikely(blk_pc_request(req)))
+ max_sectors = q->max_hw_sectors;
+ else
+ max_sectors = q->max_sectors;
+
+ if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
req->flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
static int ll_front_merge_fn(request_queue_t *q, struct request *req,
struct bio *bio)
{
+ unsigned short max_sectors;
int len;
- if (req->nr_sectors + bio_sectors(bio) > q->max_sectors) {
+ if (unlikely(blk_pc_request(req)))
+ max_sectors = q->max_hw_sectors;
+ else
+ max_sectors = q->max_sectors;
+
+
+ if (req->nr_sectors + bio_sectors(bio) > max_sectors) {
req->flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
{
struct request *rq = NULL;
struct request_list *rl = &q->rq;
- struct io_context *ioc = current_io_context(GFP_ATOMIC);
- int priv;
+ struct io_context *ioc = NULL;
+ int may_queue, priv;
- if (rl->count[rw]+1 >= q->nr_requests) {
- /*
- * The queue will fill after this allocation, so set it as
- * full, and mark this process as "batching". This process
- * will be allowed to complete a batch of requests, others
- * will be blocked.
- */
- if (!blk_queue_full(q, rw)) {
- ioc_set_batching(q, ioc);
- blk_set_queue_full(q, rw);
- }
- }
-
- switch (elv_may_queue(q, rw, bio)) {
- case ELV_MQUEUE_NO:
- goto rq_starved;
- case ELV_MQUEUE_MAY:
- break;
- case ELV_MQUEUE_MUST:
- goto get_rq;
- }
+ may_queue = elv_may_queue(q, rw, bio);
+ if (may_queue == ELV_MQUEUE_NO)
+ goto rq_starved;
- if (blk_queue_full(q, rw) && !ioc_batching(q, ioc)) {
- /*
- * The queue is full and the allocating process is not a
- * "batcher", and not exempted by the IO scheduler
- */
- goto out;
+ if (rl->count[rw]+1 >= queue_congestion_on_threshold(q)) {
+ if (rl->count[rw]+1 >= q->nr_requests) {
+ ioc = current_io_context(GFP_ATOMIC);
+ /*
+ * The queue will fill after this allocation, so set
+ * it as full, and mark this process as "batching".
+ * This process will be allowed to complete a batch of
+ * requests, others will be blocked.
+ */
+ if (!blk_queue_full(q, rw)) {
+ ioc_set_batching(q, ioc);
+ blk_set_queue_full(q, rw);
+ } else {
+ if (may_queue != ELV_MQUEUE_MUST
+ && !ioc_batching(q, ioc)) {
+ /*
+ * The queue is full and the allocating
+ * process is not a "batcher", and not
+ * exempted by the IO scheduler
+ */
+ goto out;
+ }
+ }
+ }
+ set_queue_congested(q, rw);
}
-get_rq:
/*
* Only allow batching queuers to allocate up to 50% over the defined
* limit of requests, otherwise we could have thousands of requests
rl->count[rw]++;
rl->starved[rw] = 0;
- if (rl->count[rw] >= queue_congestion_on_threshold(q))
- set_queue_congested(q, rw);
priv = !test_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
if (priv)
spin_unlock_irq(q->queue_lock);
rq = blk_alloc_request(q, rw, bio, priv, gfp_mask);
- if (!rq) {
+ if (unlikely(!rq)) {
/*
* Allocation failed presumably due to memory. Undo anything
* we might have messed up.
goto out;
}
+ /*
+ * ioc may be NULL here, and ioc_batching will be false. That's
+ * OK, if the queue is under the request limit then requests need
+ * not count toward the nr_batch_requests limit. There will always
+ * be some limit enforced by BLK_BATCH_TIME.
+ */
if (ioc_batching(q, ioc))
ioc->nr_batch_requests--;
struct bio *bio;
int reading;
- if (len > (q->max_sectors << 9))
+ if (len > (q->max_hw_sectors << 9))
return -EINVAL;
if (!len || !ubuf)
return -EINVAL;
{
struct bio *bio;
- if (len > (q->max_sectors << 9))
+ if (len > (q->max_hw_sectors << 9))
return -EINVAL;
if (!len || !kbuf)
return -EINVAL;
generic_unplug_device(q);
}
+EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
+
/**
* blk_execute_rq - insert a request into queue for execution
* @q: queue to insert the request in
/*
* queue lock must be held
*/
-static void __blk_put_request(request_queue_t *q, struct request *req)
+void __blk_put_request(request_queue_t *q, struct request *req)
{
struct request_list *rl = req->rl;
}
}
+EXPORT_SYMBOL_GPL(__blk_put_request);
+
void blk_put_request(struct request *req)
{
unsigned long flags;
projects / mirror_ubuntu-bionic-kernel.git / blobdiff