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authorJens Axboe <axboe@kernel.dk>2017-06-22 21:55:24 -0600
committerJens Axboe <axboe@kernel.dk>2017-06-22 21:55:24 -0600
commitf95a0d6a95b12a79b7492da7ab687ae4cd741124 (patch)
tree503ad30af40e94bbc090fc7de45a051030646141 /block
parenta9590fe148c03cb4157b56255357419cb4e14124 (diff)
parent8e8320c9315c47a6a090188720ccff32a6a6ba18 (diff)
downloadlinux-f95a0d6a95b12a79b7492da7ab687ae4cd741124.tar.bz2
Merge commit '8e8320c9315c' into for-4.13/block
Pull in the fix for shared tags, as it conflicts with the pending changes in for-4.13/block. We already pulled in v4.12-rc5 to solve other conflicts or get fixes that went into 4.12, so not a lot of changes in this merge. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/blk-mq-sched.c58
-rw-r--r--block/blk-mq-sched.h9
-rw-r--r--block/blk-mq.c16
-rw-r--r--block/blk-sysfs.c34
4 files changed, 81 insertions, 36 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 191bf82d185e..7f0dc48ffb40 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -50,6 +50,45 @@ void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio)
rq->elv.icq = icq;
}
+/*
+ * Mark a hardware queue as needing a restart. For shared queues, maintain
+ * a count of how many hardware queues are marked for restart.
+ */
+static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
+ } else
+ set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+}
+
+static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return false;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (test_and_clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
+ } else
+ clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+
+ if (blk_mq_hctx_has_pending(hctx)) {
+ blk_mq_run_hw_queue(hctx, true);
+ return true;
+ }
+
+ return false;
+}
+
void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
@@ -238,18 +277,6 @@ static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
return true;
}
-static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
-{
- if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) {
- clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
- if (blk_mq_hctx_has_pending(hctx)) {
- blk_mq_run_hw_queue(hctx, true);
- return true;
- }
- }
- return false;
-}
-
/**
* list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list
* @pos: loop cursor.
@@ -281,6 +308,13 @@ void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx)
unsigned int i, j;
if (set->flags & BLK_MQ_F_TAG_SHARED) {
+ /*
+ * If this is 0, then we know that no hardware queues
+ * have RESTART marked. We're done.
+ */
+ if (!atomic_read(&queue->shared_hctx_restart))
+ return;
+
rcu_read_lock();
list_for_each_entry_rcu_rr(q, queue, &set->tag_list,
tag_set_list) {
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index e117edd039b1..9267d0b7c197 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -91,15 +91,6 @@ static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
return false;
}
-/*
- * Mark a hardware queue as needing a restart.
- */
-static inline void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
-{
- if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
- set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
-}
-
static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx)
{
return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c56b64ae1741..05dfa3f270ae 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2112,20 +2112,30 @@ static void blk_mq_map_swqueue(struct request_queue *q,
}
}
+/*
+ * Caller needs to ensure that we're either frozen/quiesced, or that
+ * the queue isn't live yet.
+ */
static void queue_set_hctx_shared(struct request_queue *q, bool shared)
{
struct blk_mq_hw_ctx *hctx;
int i;
queue_for_each_hw_ctx(q, hctx, i) {
- if (shared)
+ if (shared) {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
hctx->flags |= BLK_MQ_F_TAG_SHARED;
- else
+ } else {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+ }
}
}
-static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set,
+ bool shared)
{
struct request_queue *q;
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 283da7fbe034..27aceab1cc31 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -777,24 +777,25 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head)
}
/**
- * blk_release_queue: - release a &struct request_queue when it is no longer needed
- * @kobj: the kobj belonging to the request queue to be released
+ * __blk_release_queue - release a request queue when it is no longer needed
+ * @work: pointer to the release_work member of the request queue to be released
*
* Description:
- * blk_release_queue is the pair to blk_init_queue() or
- * blk_queue_make_request(). It should be called when a request queue is
- * being released; typically when a block device is being de-registered.
- * Currently, its primary task it to free all the &struct request
- * structures that were allocated to the queue and the queue itself.
+ * blk_release_queue is the counterpart of blk_init_queue(). It should be
+ * called when a request queue is being released; typically when a block
+ * device is being de-registered. Its primary task it to free the queue
+ * itself.
*
- * Note:
+ * Notes:
* The low level driver must have finished any outstanding requests first
* via blk_cleanup_queue().
- **/
-static void blk_release_queue(struct kobject *kobj)
+ *
+ * Although blk_release_queue() may be called with preemption disabled,
+ * __blk_release_queue() may sleep.
+ */
+static void __blk_release_queue(struct work_struct *work)
{
- struct request_queue *q =
- container_of(kobj, struct request_queue, kobj);
+ struct request_queue *q = container_of(work, typeof(*q), release_work);
if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
blk_stat_remove_callback(q, q->poll_cb);
@@ -834,6 +835,15 @@ static void blk_release_queue(struct kobject *kobj)
call_rcu(&q->rcu_head, blk_free_queue_rcu);
}
+static void blk_release_queue(struct kobject *kobj)
+{
+ struct request_queue *q =
+ container_of(kobj, struct request_queue, kobj);
+
+ INIT_WORK(&q->release_work, __blk_release_queue);
+ schedule_work(&q->release_work);
+}
+
static const struct sysfs_ops queue_sysfs_ops = {
.show = queue_attr_show,
.store = queue_attr_store,