Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

11 files changed, 82 insertions, 22 deletions

diff --git a/kernel/block/bio.c b/kernel/block/bio.c
index d4d144363..46e2cc1d4 100644
--- a/kernel/block/bio.c
+++ b/kernel/block/bio.c
@@ -584,6 +584,8 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
 	bio->bi_rw = bio_src->bi_rw;
 	bio->bi_iter = bio_src->bi_iter;
 	bio->bi_io_vec = bio_src->bi_io_vec;
+
+	bio_clone_blkcg_association(bio, bio_src);
 }
 EXPORT_SYMBOL(__bio_clone_fast);
 
@@ -689,6 +691,8 @@ integrity_clone:
 		}
 	}
 
+	bio_clone_blkcg_association(bio, bio_src);
+
 	return bio;
 }
 EXPORT_SYMBOL(bio_clone_bioset);
@@ -2014,6 +2018,17 @@ void bio_disassociate_task(struct bio *bio)
 	}
 }
 
+/**
+ * bio_clone_blkcg_association - clone blkcg association from src to dst bio
+ * @dst: destination bio
+ * @src: source bio
+ */
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
+{
+	if (src->bi_css)
+		WARN_ON(bio_associate_blkcg(dst, src->bi_css));
+}
+
 #endif /* CONFIG_BLK_CGROUP */
 
 static void __init biovec_init_slabs(void)
diff --git a/kernel/block/blk-cgroup.c b/kernel/block/blk-cgroup.c
index 5a37188b5..9d359e05f 100644
--- a/kernel/block/blk-cgroup.c
+++ b/kernel/block/blk-cgroup.c
@@ -1331,10 +1331,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
 			struct blkcg_policy_data *cpd;
 
 			cpd = pol->cpd_alloc_fn(GFP_KERNEL);
-			if (!cpd) {
-				mutex_unlock(&blkcg_pol_mutex);
+			if (!cpd)
 				goto err_free_cpds;
-			}
 
 			blkcg->cpd[pol->plid] = cpd;
 			cpd->blkcg = blkcg;
diff --git a/kernel/block/blk-core.c b/kernel/block/blk-core.c
index 2f7afb98e..52d2fe2fe 100644
--- a/kernel/block/blk-core.c
+++ b/kernel/block/blk-core.c
@@ -518,7 +518,9 @@ EXPORT_SYMBOL_GPL(blk_queue_bypass_end);
 
 void blk_set_queue_dying(struct request_queue *q)
 {
-	queue_flag_set_unlocked(QUEUE_FLAG_DYING, q);
+	spin_lock_irq(q->queue_lock);
+	queue_flag_set(QUEUE_FLAG_DYING, q);
+	spin_unlock_irq(q->queue_lock);
 
 	if (q->mq_ops)
 		blk_mq_wake_waiters(q);
@@ -2192,7 +2194,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
 	if (q->mq_ops) {
 		if (blk_queue_io_stat(q))
 			blk_account_io_start(rq, true);
-		blk_mq_insert_request(rq, false, true, true);
+		blk_mq_insert_request(rq, false, true, false);
 		return 0;
 	}
 
diff --git a/kernel/block/blk-map.c b/kernel/block/blk-map.c
index f565e11f4..69953bd97 100644
--- a/kernel/block/blk-map.c
+++ b/kernel/block/blk-map.c
@@ -90,6 +90,9 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 	if (!iter || !iter->count)
 		return -EINVAL;
 
+	if (!iter_is_iovec(iter))
+		return -EINVAL;
+
 	iov_for_each(iov, i, *iter) {
 		unsigned long uaddr = (unsigned long) iov.iov_base;
 
diff --git a/kernel/block/blk-merge.c b/kernel/block/blk-merge.c
index b966db8f3..7225511cf 100644
--- a/kernel/block/blk-merge.c
+++ b/kernel/block/blk-merge.c
@@ -92,9 +92,31 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 	bool do_split = true;
 	struct bio *new = NULL;
 	const unsigned max_sectors = get_max_io_size(q, bio);
+	unsigned bvecs = 0;
 
 	bio_for_each_segment(bv, bio, iter) {
 		/*
+		 * With arbitrary bio size, the incoming bio may be very
+		 * big. We have to split the bio into small bios so that
+		 * each holds at most BIO_MAX_PAGES bvecs because
+		 * bio_clone() can fail to allocate big bvecs.
+		 *
+		 * It should have been better to apply the limit per
+		 * request queue in which bio_clone() is involved,
+		 * instead of globally. The biggest blocker is the
+		 * bio_clone() in bio bounce.
+		 *
+		 * If bio is splitted by this reason, we should have
+		 * allowed to continue bios merging, but don't do
+		 * that now for making the change simple.
+		 *
+		 * TODO: deal with bio bounce's bio_clone() gracefully
+		 * and convert the global limit into per-queue limit.
+		 */
+		if (bvecs++ >= BIO_MAX_PAGES)
+			goto split;
+
+		/*
 		 * If the queue doesn't support SG gaps and adding this
 		 * offset would create a gap, disallow it.
 		 */
diff --git a/kernel/block/blk-mq.c b/kernel/block/blk-mq.c
index 7cdf19e4a..2e21e4c04 100644
--- a/kernel/block/blk-mq.c
+++ b/kernel/block/blk-mq.c
@@ -621,8 +621,10 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
 		 * If a request wasn't started before the queue was
 		 * marked dying, kill it here or it'll go unnoticed.
 		 */
-		if (unlikely(blk_queue_dying(rq->q)))
-			blk_mq_complete_request(rq, -EIO);
+		if (unlikely(blk_queue_dying(rq->q))) {
+			rq->errors = -EIO;
+			blk_mq_end_request(rq, rq->errors);
+		}
 		return;
 	}
 	if (rq->cmd_flags & REQ_NO_TIMEOUT)
@@ -798,7 +800,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
 		switch (ret) {
 		case BLK_MQ_RQ_QUEUE_OK:
 			queued++;
-			continue;
+			break;
 		case BLK_MQ_RQ_QUEUE_BUSY:
 			list_add(&rq->queuelist, &rq_list);
 			__blk_mq_requeue_request(rq);
@@ -860,7 +862,7 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
 		return WORK_CPU_UNBOUND;
 
 	if (--hctx->next_cpu_batch <= 0) {
-		int cpu = hctx->next_cpu, next_cpu;
+		int next_cpu;
 
 		next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
 		if (next_cpu >= nr_cpu_ids)
@@ -868,8 +870,6 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
 
 		hctx->next_cpu = next_cpu;
 		hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
-
-		return cpu;
 	}
 
 	return hctx->next_cpu;
@@ -1331,9 +1331,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 		blk_mq_put_ctx(data.ctx);
 		if (!old_rq)
 			goto done;
-		if (!blk_mq_direct_issue_request(old_rq, &cookie))
-			goto done;
-		blk_mq_insert_request(old_rq, false, true, true);
+		if (test_bit(BLK_MQ_S_STOPPED, &data.hctx->state) ||
+		    blk_mq_direct_issue_request(old_rq, &cookie) != 0)
+			blk_mq_insert_request(old_rq, false, true, true);
 		goto done;
 	}
 
diff --git a/kernel/block/bsg.c b/kernel/block/bsg.c
index d214e929c..b9a53615b 100644
--- a/kernel/block/bsg.c
+++ b/kernel/block/bsg.c
@@ -655,6 +655,9 @@ bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 
 	dprintk("%s: write %Zd bytes\n", bd->name, count);
 
+	if (unlikely(segment_eq(get_fs(), KERNEL_DS)))
+		return -EINVAL;
+
 	bsg_set_block(bd, file);
 
 	bytes_written = 0;
diff --git a/kernel/block/cfq-iosched.c b/kernel/block/cfq-iosched.c
index 1f9093e90..e04a7b849 100644
--- a/kernel/block/cfq-iosched.c
+++ b/kernel/block/cfq-iosched.c
@@ -1572,7 +1572,7 @@ static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
 {
 	struct cfq_group_data *cgd;
 
-	cgd = kzalloc(sizeof(*cgd), GFP_KERNEL);
+	cgd = kzalloc(sizeof(*cgd), gfp);
 	if (!cgd)
 		return NULL;
 	return &cgd->cpd;
@@ -3003,7 +3003,6 @@ static struct request *cfq_check_fifo(struct cfq_queue *cfqq)
 	if (time_before(jiffies, rq->fifo_time))
 		rq = NULL;
 
-	cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
 	return rq;
 }
 
@@ -3377,6 +3376,9 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
 	unsigned int max_dispatch;
 
+	if (cfq_cfqq_must_dispatch(cfqq))
+		return true;
+
 	/*
 	 * Drain async requests before we start sync IO
 	 */
@@ -3468,15 +3470,20 @@ static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 
 	BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
 
+	rq = cfq_check_fifo(cfqq);
+	if (rq)
+		cfq_mark_cfqq_must_dispatch(cfqq);
+
 	if (!cfq_may_dispatch(cfqd, cfqq))
 		return false;
 
 	/*
 	 * follow expired path, else get first next available
 	 */
-	rq = cfq_check_fifo(cfqq);
 	if (!rq)
 		rq = cfqq->next_rq;
+	else
+		cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq);
 
 	/*
 	 * insert request into driver dispatch list
@@ -3944,7 +3951,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
 	 * if the new request is sync, but the currently running queue is
 	 * not, let the sync request have priority.
 	 */
-	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq))
+	if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq) && !cfq_cfqq_must_dispatch(cfqq))
 		return true;
 
 	if (new_cfqq->cfqg != cfqq->cfqg)
diff --git a/kernel/block/genhd.c b/kernel/block/genhd.c
index e5cafa515..a5bed6bc8 100644
--- a/kernel/block/genhd.c
+++ b/kernel/block/genhd.c
@@ -612,7 +612,7 @@ void add_disk(struct gendisk *disk)
 
 	/* Register BDI before referencing it from bdev */
 	bdi = &disk->queue->backing_dev_info;
-	bdi_register_dev(bdi, disk_devt(disk));
+	bdi_register_owner(bdi, disk_to_dev(disk));
 
 	blk_register_region(disk_devt(disk), disk->minors, NULL,
 			    exact_match, exact_lock, disk);
@@ -831,6 +831,7 @@ static void disk_seqf_stop(struct seq_file *seqf, void *v)
 	if (iter) {
 		class_dev_iter_exit(iter);
 		kfree(iter);
+		seqf->private = NULL;
 	}
 }
 
diff --git a/kernel/block/ioprio.c b/kernel/block/ioprio.c
index cc7800e9e..01b811629 100644
--- a/kernel/block/ioprio.c
+++ b/kernel/block/ioprio.c
@@ -150,8 +150,10 @@ static int get_task_ioprio(struct task_struct *p)
 	if (ret)
 		goto out;
 	ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
+	task_lock(p);
 	if (p->io_context)
 		ret = p->io_context->ioprio;
+	task_unlock(p);
 out:
 	return ret;
 }
diff --git a/kernel/block/partition-generic.c b/kernel/block/partition-generic.c
index 746935a59..a241e3900 100644
--- a/kernel/block/partition-generic.c
+++ b/kernel/block/partition-generic.c
@@ -349,15 +349,20 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
 			goto out_del;
 	}
 
+	err = hd_ref_init(p);
+	if (err) {
+		if (flags & ADDPART_FLAG_WHOLEDISK)
+			goto out_remove_file;
+		goto out_del;
+	}
+
 	/* everything is up and running, commence */
 	rcu_assign_pointer(ptbl->part[partno], p);
 
 	/* suppress uevent if the disk suppresses it */
 	if (!dev_get_uevent_suppress(ddev))
 		kobject_uevent(&pdev->kobj, KOBJ_ADD);
-
-	if (!hd_ref_init(p))
-		return p;
+	return p;
 
 out_free_info:
 	free_part_info(p);
@@ -366,6 +371,8 @@ out_free_stats:
 out_free:
 	kfree(p);
 	return ERR_PTR(err);
+out_remove_file:
+	device_remove_file(pdev, &dev_attr_whole_disk);
 out_del:
 	kobject_put(p->holder_dir);
 	device_del(pdev);