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-rw-r--r--block/blk-core.c42
1 files changed, 15 insertions, 27 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 080204a10fcf..71894e143b91 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -855,15 +855,11 @@ static struct request *__get_request(struct request_queue *q, int rw_flags,
{
struct request *rq;
struct request_list *rl = &q->rq;
- struct elevator_type *et;
- struct io_context *ioc;
+ struct elevator_type *et = q->elevator->type;
+ struct io_context *ioc = rq_ioc(bio);
struct io_cq *icq = NULL;
const bool is_sync = rw_is_sync(rw_flags) != 0;
- bool retried = false;
int may_queue;
-retry:
- et = q->elevator->type;
- ioc = rq_ioc(bio);
if (unlikely(blk_queue_dead(q)))
return NULL;
@@ -875,20 +871,6 @@ retry:
if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) {
if (rl->count[is_sync]+1 >= q->nr_requests) {
/*
- * We want ioc to record batching state. If it's
- * not already there, creating a new one requires
- * dropping queue_lock, which in turn requires
- * retesting conditions to avoid queue hang.
- */
- if (!ioc && !retried) {
- spin_unlock_irq(q->queue_lock);
- create_io_context(gfp_mask, q->node);
- spin_lock_irq(q->queue_lock);
- retried = true;
- goto retry;
- }
-
- /*
* 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
@@ -955,12 +937,8 @@ retry:
/* init elvpriv */
if (rw_flags & REQ_ELVPRIV) {
if (unlikely(et->icq_cache && !icq)) {
- create_io_context(gfp_mask, q->node);
- ioc = rq_ioc(bio);
- if (!ioc)
- goto fail_elvpriv;
-
- icq = ioc_create_icq(ioc, q, gfp_mask);
+ if (ioc)
+ icq = ioc_create_icq(ioc, q, gfp_mask);
if (!icq)
goto fail_elvpriv;
}
@@ -1071,7 +1049,6 @@ retry:
* to allocate at least one request, and up to a big batch of them
* for a small period time. See ioc_batching, ioc_set_batching
*/
- create_io_context(GFP_NOIO, q->node);
ioc_set_batching(q, current->io_context);
spin_lock_irq(q->queue_lock);
@@ -1086,6 +1063,9 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
BUG_ON(rw != READ && rw != WRITE);
+ /* create ioc upfront */
+ create_io_context(gfp_mask, q->node);
+
spin_lock_irq(q->queue_lock);
rq = get_request(q, rw, NULL, gfp_mask);
if (!rq)
@@ -1698,6 +1678,14 @@ generic_make_request_checks(struct bio *bio)
goto end_io;
}
+ /*
+ * Various block parts want %current->io_context and lazy ioc
+ * allocation ends up trading a lot of pain for a small amount of
+ * memory. Just allocate it upfront. This may fail and block
+ * layer knows how to live with it.
+ */
+ create_io_context(GFP_ATOMIC, q->node);
+
if (blk_throtl_bio(q, bio))
return false; /* throttled, will be resubmitted later */

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