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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /block/blk-core.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c119
1 files changed, 68 insertions, 51 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 4c6e9ced9..627ed0c59 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -32,12 +32,12 @@
#include <linux/delay.h>
#include <linux/ratelimit.h>
#include <linux/pm_runtime.h>
+#include <linux/blk-cgroup.h>
#define CREATE_TRACE_POINTS
#include <trace/events/block.h>
#include "blk.h"
-#include "blk-cgroup.h"
#include "blk-mq.h"
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
@@ -48,8 +48,6 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
DEFINE_IDA(blk_queue_ida);
-int trap_non_toi_io;
-
/*
* For the allocated request tables
*/
@@ -65,6 +63,31 @@ struct kmem_cache *blk_requestq_cachep;
*/
static struct workqueue_struct *kblockd_workqueue;
+static void blk_clear_congested(struct request_list *rl, int sync)
+{
+#ifdef CONFIG_CGROUP_WRITEBACK
+ clear_wb_congested(rl->blkg->wb_congested, sync);
+#else
+ /*
+ * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't
+ * flip its congestion state for events on other blkcgs.
+ */
+ if (rl == &rl->q->root_rl)
+ clear_wb_congested(rl->q->backing_dev_info.wb.congested, sync);
+#endif
+}
+
+static void blk_set_congested(struct request_list *rl, int sync)
+{
+#ifdef CONFIG_CGROUP_WRITEBACK
+ set_wb_congested(rl->blkg->wb_congested, sync);
+#else
+ /* see blk_clear_congested() */
+ if (rl == &rl->q->root_rl)
+ set_wb_congested(rl->q->backing_dev_info.wb.congested, sync);
+#endif
+}
+
void blk_queue_congestion_threshold(struct request_queue *q)
{
int nr;
@@ -287,6 +310,7 @@ inline void __blk_run_queue_uncond(struct request_queue *q)
q->request_fn(q);
q->request_fn_active--;
}
+EXPORT_SYMBOL_GPL(__blk_run_queue_uncond);
/**
* __blk_run_queue - run a single device queue
@@ -623,8 +647,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
- q->backing_dev_info.state = 0;
- q->backing_dev_info.capabilities = 0;
+ q->backing_dev_info.capabilities = BDI_CAP_CGROUP_WRITEBACK;
q->backing_dev_info.name = "block";
q->node = node_id;
@@ -847,13 +870,8 @@ static void __freed_request(struct request_list *rl, int sync)
{
struct request_queue *q = rl->q;
- /*
- * bdi isn't aware of blkcg yet. As all async IOs end up root
- * blkcg anyway, just use root blkcg state.
- */
- if (rl == &q->root_rl &&
- rl->count[sync] < queue_congestion_off_threshold(q))
- blk_clear_queue_congested(q, sync);
+ if (rl->count[sync] < queue_congestion_off_threshold(q))
+ blk_clear_congested(rl, sync);
if (rl->count[sync] + 1 <= q->nr_requests) {
if (waitqueue_active(&rl->wait[sync]))
@@ -886,25 +904,25 @@ static void freed_request(struct request_list *rl, unsigned int flags)
int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
{
struct request_list *rl;
+ int on_thresh, off_thresh;
spin_lock_irq(q->queue_lock);
q->nr_requests = nr;
blk_queue_congestion_threshold(q);
+ on_thresh = queue_congestion_on_threshold(q);
+ off_thresh = queue_congestion_off_threshold(q);
- /* congestion isn't cgroup aware and follows root blkcg for now */
- rl = &q->root_rl;
-
- if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
- blk_set_queue_congested(q, BLK_RW_SYNC);
- else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
- blk_clear_queue_congested(q, BLK_RW_SYNC);
+ blk_queue_for_each_rl(rl, q) {
+ if (rl->count[BLK_RW_SYNC] >= on_thresh)
+ blk_set_congested(rl, BLK_RW_SYNC);
+ else if (rl->count[BLK_RW_SYNC] < off_thresh)
+ blk_clear_congested(rl, BLK_RW_SYNC);
- if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
- blk_set_queue_congested(q, BLK_RW_ASYNC);
- else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
- blk_clear_queue_congested(q, BLK_RW_ASYNC);
+ if (rl->count[BLK_RW_ASYNC] >= on_thresh)
+ blk_set_congested(rl, BLK_RW_ASYNC);
+ else if (rl->count[BLK_RW_ASYNC] < off_thresh)
+ blk_clear_congested(rl, BLK_RW_ASYNC);
- blk_queue_for_each_rl(rl, q) {
if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
blk_set_rl_full(rl, BLK_RW_SYNC);
} else {
@@ -1014,12 +1032,7 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
}
}
}
- /*
- * bdi isn't aware of blkcg yet. As all async IOs end up
- * root blkcg anyway, just use root blkcg state.
- */
- if (rl == &q->root_rl)
- blk_set_queue_congested(q, is_sync);
+ blk_set_congested(rl, is_sync);
}
/*
@@ -1527,7 +1540,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- unsigned int *request_count)
+ unsigned int *request_count,
+ struct request **same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
@@ -1547,8 +1561,16 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
list_for_each_entry_reverse(rq, plug_list, queuelist) {
int el_ret;
- if (rq->q == q)
+ if (rq->q == q) {
(*request_count)++;
+ /*
+ * Only blk-mq multiple hardware queues case checks the
+ * rq in the same queue, there should be only one such
+ * rq in a queue
+ **/
+ if (same_queue_rq)
+ *same_queue_rq = rq;
+ }
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
@@ -1613,7 +1635,7 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio)
* any locks.
*/
if (!blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count))
+ blk_attempt_plug_merge(q, bio, &request_count, NULL))
return;
spin_lock_irq(q->queue_lock);
@@ -1720,8 +1742,6 @@ static void handle_bad_sector(struct bio *bio)
bio->bi_rw,
(unsigned long long)bio_end_sector(bio),
(long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9));
-
- set_bit(BIO_EOF, &bio->bi_flags);
}
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -1968,9 +1988,6 @@ void submit_bio(int rw, struct bio *bio)
{
bio->bi_rw |= rw;
- if (unlikely(trap_non_toi_io))
- BUG_ON(!(bio->bi_flags & BIO_TOI));
-
/*
* If it's a regular read/write or a barrier with data attached,
* go through the normal accounting stuff before submission.
@@ -3039,21 +3056,20 @@ void blk_start_plug(struct blk_plug *plug)
{
struct task_struct *tsk = current;
+ /*
+ * If this is a nested plug, don't actually assign it.
+ */
+ if (tsk->plug)
+ return;
+
INIT_LIST_HEAD(&plug->list);
INIT_LIST_HEAD(&plug->mq_list);
INIT_LIST_HEAD(&plug->cb_list);
-
/*
- * If this is a nested plug, don't actually assign it. It will be
- * flushed on its own.
+ * Store ordering should not be needed here, since a potential
+ * preempt will imply a full memory barrier
*/
- if (!tsk->plug) {
- /*
- * Store ordering should not be needed here, since a potential
- * preempt will imply a full memory barrier
- */
- tsk->plug = plug;
- }
+ tsk->plug = plug;
}
EXPORT_SYMBOL(blk_start_plug);
@@ -3200,10 +3216,11 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
void blk_finish_plug(struct blk_plug *plug)
{
+ if (plug != current->plug)
+ return;
blk_flush_plug_list(plug, false);
- if (plug == current->plug)
- current->plug = NULL;
+ current->plug = NULL;
}
EXPORT_SYMBOL(blk_finish_plug);
@@ -3353,7 +3370,7 @@ EXPORT_SYMBOL(blk_post_runtime_resume);
int __init blk_dev_init(void)
{
BUILD_BUG_ON(__REQ_NR_BITS > 8 *
- sizeof(((struct request *)0)->cmd_flags));
+ FIELD_SIZEOF(struct request, cmd_flags));
/* used for unplugging and affects IO latency/throughput - HIGHPRI */
kblockd_workqueue = alloc_workqueue("kblockd",