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-rw-r--r--block/blk-cgroup.c69
-rw-r--r--block/blk-rq-qos.c14
-rw-r--r--block/blk-rq-qos.h17
-rw-r--r--block/blk-wbt.c6
-rw-r--r--block/elevator.c3
5 files changed, 73 insertions, 36 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b6f20be0fc78..5d21027b1faf 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1362,7 +1362,7 @@ int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
struct blkg_policy_data *pd_prealloc = NULL;
- struct blkcg_gq *blkg;
+ struct blkcg_gq *blkg, *pinned_blkg = NULL;
int ret;
if (blkcg_policy_enabled(q, pol))
@@ -1370,49 +1370,82 @@ int blkcg_activate_policy(struct request_queue *q,
if (queue_is_mq(q))
blk_mq_freeze_queue(q);
-pd_prealloc:
- if (!pd_prealloc) {
- pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q, &blkcg_root);
- if (!pd_prealloc) {
- ret = -ENOMEM;
- goto out_bypass_end;
- }
- }
-
+retry:
spin_lock_irq(&q->queue_lock);
- /* blkg_list is pushed at the head, reverse walk to init parents first */
+ /* blkg_list is pushed at the head, reverse walk to allocate parents first */
list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
struct blkg_policy_data *pd;
if (blkg->pd[pol->plid])
continue;
- pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q, &blkcg_root);
- if (!pd)
- swap(pd, pd_prealloc);
+ /* If prealloc matches, use it; otherwise try GFP_NOWAIT */
+ if (blkg == pinned_blkg) {
+ pd = pd_prealloc;
+ pd_prealloc = NULL;
+ } else {
+ pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q,
+ blkg->blkcg);
+ }
+
if (!pd) {
+ /*
+ * GFP_NOWAIT failed. Free the existing one and
+ * prealloc for @blkg w/ GFP_KERNEL.
+ */
+ if (pinned_blkg)
+ blkg_put(pinned_blkg);
+ blkg_get(blkg);
+ pinned_blkg = blkg;
+
spin_unlock_irq(&q->queue_lock);
- goto pd_prealloc;
+
+ if (pd_prealloc)
+ pol->pd_free_fn(pd_prealloc);
+ pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q,
+ blkg->blkcg);
+ if (pd_prealloc)
+ goto retry;
+ else
+ goto enomem;
}
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
- if (pol->pd_init_fn)
- pol->pd_init_fn(pd);
}
+ /* all allocated, init in the same order */
+ if (pol->pd_init_fn)
+ list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
+ pol->pd_init_fn(blkg->pd[pol->plid]);
+
__set_bit(pol->plid, q->blkcg_pols);
ret = 0;
spin_unlock_irq(&q->queue_lock);
-out_bypass_end:
+out:
if (queue_is_mq(q))
blk_mq_unfreeze_queue(q);
+ if (pinned_blkg)
+ blkg_put(pinned_blkg);
if (pd_prealloc)
pol->pd_free_fn(pd_prealloc);
return ret;
+
+enomem:
+ /* alloc failed, nothing's initialized yet, free everything */
+ spin_lock_irq(&q->queue_lock);
+ list_for_each_entry(blkg, &q->blkg_list, q_node) {
+ if (blkg->pd[pol->plid]) {
+ pol->pd_free_fn(blkg->pd[pol->plid]);
+ blkg->pd[pol->plid] = NULL;
+ }
+ }
+ spin_unlock_irq(&q->queue_lock);
+ ret = -ENOMEM;
+ goto out;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
index 61b635bc2a31..656460636ad3 100644
--- a/block/blk-rq-qos.c
+++ b/block/blk-rq-qos.c
@@ -160,24 +160,27 @@ bool rq_depth_calc_max_depth(struct rq_depth *rqd)
return ret;
}
-void rq_depth_scale_up(struct rq_depth *rqd)
+/* Returns true on success and false if scaling up wasn't possible */
+bool rq_depth_scale_up(struct rq_depth *rqd)
{
/*
* Hit max in previous round, stop here
*/
if (rqd->scaled_max)
- return;
+ return false;
rqd->scale_step--;
rqd->scaled_max = rq_depth_calc_max_depth(rqd);
+ return true;
}
/*
* Scale rwb down. If 'hard_throttle' is set, do it quicker, since we
- * had a latency violation.
+ * had a latency violation. Returns true on success and returns false if
+ * scaling down wasn't possible.
*/
-void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
+bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
{
/*
* Stop scaling down when we've hit the limit. This also prevents
@@ -185,7 +188,7 @@ void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
* keep up.
*/
if (rqd->max_depth == 1)
- return;
+ return false;
if (rqd->scale_step < 0 && hard_throttle)
rqd->scale_step = 0;
@@ -194,6 +197,7 @@ void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle)
rqd->scaled_max = false;
rq_depth_calc_max_depth(rqd);
+ return true;
}
struct rq_qos_wait_data {
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 08a09dbe0f4b..2bc43e94f4c4 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -108,16 +108,13 @@ static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
{
- struct rq_qos *cur, *prev = NULL;
- for (cur = q->rq_qos; cur; cur = cur->next) {
- if (cur == rqos) {
- if (prev)
- prev->next = rqos->next;
- else
- q->rq_qos = cur;
+ struct rq_qos **cur;
+
+ for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
+ if (*cur == rqos) {
+ *cur = rqos->next;
break;
}
- prev = cur;
}
blk_mq_debugfs_unregister_rqos(rqos);
@@ -130,8 +127,8 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data,
acquire_inflight_cb_t *acquire_inflight_cb,
cleanup_cb_t *cleanup_cb);
bool rq_wait_inc_below(struct rq_wait *rq_wait, unsigned int limit);
-void rq_depth_scale_up(struct rq_depth *rqd);
-void rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
+bool rq_depth_scale_up(struct rq_depth *rqd);
+bool rq_depth_scale_down(struct rq_depth *rqd, bool hard_throttle);
bool rq_depth_calc_max_depth(struct rq_depth *rqd);
void __rq_qos_cleanup(struct rq_qos *rqos, struct bio *bio);
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 8af553a0ba00..8641ba9793c5 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -308,7 +308,8 @@ static void calc_wb_limits(struct rq_wb *rwb)
static void scale_up(struct rq_wb *rwb)
{
- rq_depth_scale_up(&rwb->rq_depth);
+ if (!rq_depth_scale_up(&rwb->rq_depth))
+ return;
calc_wb_limits(rwb);
rwb->unknown_cnt = 0;
rwb_wake_all(rwb);
@@ -317,7 +318,8 @@ static void scale_up(struct rq_wb *rwb)
static void scale_down(struct rq_wb *rwb, bool hard_throttle)
{
- rq_depth_scale_down(&rwb->rq_depth, hard_throttle);
+ if (!rq_depth_scale_down(&rwb->rq_depth, hard_throttle))
+ return;
calc_wb_limits(rwb);
rwb->unknown_cnt = 0;
rwb_trace_step(rwb, "scale down");
diff --git a/block/elevator.c b/block/elevator.c
index 5437059c9261..076ba7308e65 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -616,7 +616,8 @@ out:
static inline bool elv_support_iosched(struct request_queue *q)
{
- if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
+ if (!q->mq_ops ||
+ (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED)))
return false;
return true;
}