Merge tag 'v5.0-rc6' into for-5.1/block

Pull in 5.0-rc6 to avoid a dumb merge conflict with fs/iomap.c.
This is needed since io_uring is now based on the block branch,
to avoid a conflict between the multi-page bvecs and the bits
of io_uring that touch the core block parts.

* tag 'v5.0-rc6': (525 commits)
  Linux 5.0-rc6
  x86/mm: Make set_pmd_at() paravirt aware
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  MAINTAINERS: unify reference to xen-devel list
  x86/mm/cpa: Fix set_mce_nospec()
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment
  net: dsa: b53: Fix for failure when irq is not defined in dt
  blktrace: Show requests without sector
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
  geneve: should not call rt6_lookup() when ipv6 was disabled
  KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
  KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
  kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
  signal: Better detection of synchronous signals
  ...

5 files changed, 57 insertions, 11 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 3c5f61ceeb67..6b78ec56a4f2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -462,6 +462,10 @@ static void blk_rq_timed_out_timer(struct timer_list *t)
 	kblockd_schedule_work(&q->timeout_work);
 }
 
+static void blk_timeout_work(struct work_struct *work)
+{
+}
+
 /**
  * blk_alloc_queue_node - allocate a request queue
  * @gfp_mask: memory allocation flags
@@ -505,7 +509,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	timer_setup(&q->backing_dev_info->laptop_mode_wb_timer,
 		    laptop_mode_timer_fn, 0);
 	timer_setup(&q->timeout, blk_rq_timed_out_timer, 0);
-	INIT_WORK(&q->timeout_work, NULL);
+	INIT_WORK(&q->timeout_work, blk_timeout_work);
 	INIT_LIST_HEAD(&q->icq_list);
 #ifdef CONFIG_BLK_CGROUP
 	INIT_LIST_HEAD(&q->blkg_list);
diff --git a/block/blk-flush.c b/block/blk-flush.c
index a3fc7191c694..6e0f2d97fc6d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -335,7 +335,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
 	blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error);
 	spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
 
-	blk_mq_run_hw_queue(hctx, true);
+	blk_mq_sched_restart(hctx);
 }
 
 /**
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index fc714ef402a6..2620baa1f699 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -72,6 +72,7 @@
 #include <linux/sched/loadavg.h>
 #include <linux/sched/signal.h>
 #include <trace/events/block.h>
+#include <linux/blk-mq.h>
 #include "blk-rq-qos.h"
 #include "blk-stat.h"
 
@@ -591,6 +592,7 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 	u64 now = ktime_to_ns(ktime_get());
 	bool issue_as_root = bio_issue_as_root_blkg(bio);
 	bool enabled = false;
+	int inflight = 0;
 
 	blkg = bio->bi_blkg;
 	if (!blkg || !bio_flagged(bio, BIO_TRACKED))
@@ -601,6 +603,9 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 		return;
 
 	enabled = blk_iolatency_enabled(iolat->blkiolat);
+	if (!enabled)
+		return;
+
 	while (blkg && blkg->parent) {
 		iolat = blkg_to_lat(blkg);
 		if (!iolat) {
@@ -609,8 +614,9 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
 		}
 		rqw = &iolat->rq_wait;
 
-		atomic_dec(&rqw->inflight);
-		if (!enabled || iolat->min_lat_nsec == 0)
+		inflight = atomic_dec_return(&rqw->inflight);
+		WARN_ON_ONCE(inflight < 0);
+		if (iolat->min_lat_nsec == 0)
 			goto next;
 		iolatency_record_time(iolat, &bio->bi_issue, now,
 				      issue_as_root);
@@ -754,10 +760,13 @@ int blk_iolatency_init(struct request_queue *q)
 	return 0;
 }
 
-static void iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
+/*
+ * return 1 for enabling iolatency, return -1 for disabling iolatency, otherwise
+ * return 0.
+ */
+static int iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
 {
 	struct iolatency_grp *iolat = blkg_to_lat(blkg);
-	struct blk_iolatency *blkiolat = iolat->blkiolat;
 	u64 oldval = iolat->min_lat_nsec;
 
 	iolat->min_lat_nsec = val;
@@ -766,9 +775,10 @@ static void iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
 				    BLKIOLATENCY_MAX_WIN_SIZE);
 
 	if (!oldval && val)
-		atomic_inc(&blkiolat->enabled);
+		return 1;
 	if (oldval && !val)
-		atomic_dec(&blkiolat->enabled);
+		return -1;
+	return 0;
 }
 
 static void iolatency_clear_scaling(struct blkcg_gq *blkg)
@@ -800,6 +810,7 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
 	u64 lat_val = 0;
 	u64 oldval;
 	int ret;
+	int enable = 0;
 
 	ret = blkg_conf_prep(blkcg, &blkcg_policy_iolatency, buf, &ctx);
 	if (ret)
@@ -834,7 +845,12 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
 	blkg = ctx.blkg;
 	oldval = iolat->min_lat_nsec;
 
-	iolatency_set_min_lat_nsec(blkg, lat_val);
+	enable = iolatency_set_min_lat_nsec(blkg, lat_val);
+	if (enable) {
+		WARN_ON_ONCE(!blk_get_queue(blkg->q));
+		blkg_get(blkg);
+	}
+
 	if (oldval != iolat->min_lat_nsec) {
 		iolatency_clear_scaling(blkg);
 	}
@@ -842,6 +858,24 @@ static ssize_t iolatency_set_limit(struct kernfs_open_file *of, char *buf,
 	ret = 0;
 out:
 	blkg_conf_finish(&ctx);
+	if (ret == 0 && enable) {
+		struct iolatency_grp *tmp = blkg_to_lat(blkg);
+		struct blk_iolatency *blkiolat = tmp->blkiolat;
+
+		blk_mq_freeze_queue(blkg->q);
+
+		if (enable == 1)
+			atomic_inc(&blkiolat->enabled);
+		else if (enable == -1)
+			atomic_dec(&blkiolat->enabled);
+		else
+			WARN_ON_ONCE(1);
+
+		blk_mq_unfreeze_queue(blkg->q);
+
+		blkg_put(blkg);
+		blk_put_queue(blkg->q);
+	}
 	return ret ?: nbytes;
 }
 
@@ -977,8 +1011,14 @@ static void iolatency_pd_offline(struct blkg_policy_data *pd)
 {
 	struct iolatency_grp *iolat = pd_to_lat(pd);
 	struct blkcg_gq *blkg = lat_to_blkg(iolat);
+	struct blk_iolatency *blkiolat = iolat->blkiolat;
+	int ret;
 
-	iolatency_set_min_lat_nsec(blkg, 0);
+	ret = iolatency_set_min_lat_nsec(blkg, 0);
+	if (ret == 1)
+		atomic_inc(&blkiolat->enabled);
+	if (ret == -1)
+		atomic_dec(&blkiolat->enabled);
 	iolatency_clear_scaling(blkg);
 }
 
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index c39247c5ddb6..bac34b72b33b 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -836,6 +836,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 static bool debugfs_create_files(struct dentry *parent, void *data,
 				 const struct blk_mq_debugfs_attr *attr)
 {
+	if (IS_ERR_OR_NULL(parent))
+		return false;
+
 	d_inode(parent)->i_private = data;
 
 	for (; attr->name; attr++) {
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 14b7efb94f75..c11353a3749d 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -37,7 +37,6 @@ struct blk_mq_ctx {
 	struct kobject		kobj;
 } ____cacheline_aligned_in_smp;
 
-void blk_mq_freeze_queue(struct request_queue *q);
 void blk_mq_free_queue(struct request_queue *q);
 int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
 void blk_mq_wake_waiters(struct request_queue *q);