Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...

1 files changed, 71 insertions, 20 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 51c1d407d93c..dd305c65ffb0 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -45,6 +45,52 @@ static void disk_add_events(struct gendisk *disk);
 static void disk_del_events(struct gendisk *disk);
 static void disk_release_events(struct gendisk *disk);
 
+void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
+{
+	if (q->mq_ops)
+		return;
+
+	atomic_inc(&part->in_flight[rw]);
+	if (part->partno)
+		atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
+}
+
+void part_dec_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
+{
+	if (q->mq_ops)
+		return;
+
+	atomic_dec(&part->in_flight[rw]);
+	if (part->partno)
+		atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
+}
+
+void part_in_flight(struct request_queue *q, struct hd_struct *part,
+		    unsigned int inflight[2])
+{
+	if (q->mq_ops) {
+		blk_mq_in_flight(q, part, inflight);
+		return;
+	}
+
+	inflight[0] = atomic_read(&part->in_flight[0]) +
+			atomic_read(&part->in_flight[1]);
+	if (part->partno) {
+		part = &part_to_disk(part)->part0;
+		inflight[1] = atomic_read(&part->in_flight[0]) +
+				atomic_read(&part->in_flight[1]);
+	}
+}
+
+struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
+{
+	struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
+
+	if (unlikely(partno < 0 || partno >= ptbl->len))
+		return NULL;
+	return rcu_dereference(ptbl->part[partno]);
+}
+
 /**
  * disk_get_part - get partition
  * @disk: disk to look partition from
@@ -61,21 +107,12 @@ static void disk_release_events(struct gendisk *disk);
  */
 struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
 {
-	struct hd_struct *part = NULL;
-	struct disk_part_tbl *ptbl;
-
-	if (unlikely(partno < 0))
-		return NULL;
+	struct hd_struct *part;
 
 	rcu_read_lock();
-
-	ptbl = rcu_dereference(disk->part_tbl);
-	if (likely(partno < ptbl->len)) {
-		part = rcu_dereference(ptbl->part[partno]);
-		if (part)
-			get_device(part_to_dev(part));
-	}
-
+	part = __disk_get_part(disk, partno);
+	if (part)
+		get_device(part_to_dev(part));
 	rcu_read_unlock();
 
 	return part;
@@ -1098,12 +1135,13 @@ static const struct attribute_group *disk_attr_groups[] = {
  * original ptbl is freed using RCU callback.
  *
  * LOCKING:
- * Matching bd_mutx locked.
+ * Matching bd_mutex locked or the caller is the only user of @disk.
  */
 static void disk_replace_part_tbl(struct gendisk *disk,
 				  struct disk_part_tbl *new_ptbl)
 {
-	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+	struct disk_part_tbl *old_ptbl =
+		rcu_dereference_protected(disk->part_tbl, 1);
 
 	rcu_assign_pointer(disk->part_tbl, new_ptbl);
 
@@ -1122,14 +1160,16 @@ static void disk_replace_part_tbl(struct gendisk *disk,
  * uses RCU to allow unlocked dereferencing for stats and other stuff.
  *
  * LOCKING:
- * Matching bd_mutex locked, might sleep.
+ * Matching bd_mutex locked or the caller is the only user of @disk.
+ * Might sleep.
  *
  * RETURNS:
  * 0 on success, -errno on failure.
  */
 int disk_expand_part_tbl(struct gendisk *disk, int partno)
 {
-	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+	struct disk_part_tbl *old_ptbl =
+		rcu_dereference_protected(disk->part_tbl, 1);
 	struct disk_part_tbl *new_ptbl;
 	int len = old_ptbl ? old_ptbl->len : 0;
 	int i, target;
@@ -1212,6 +1252,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 	struct disk_part_iter piter;
 	struct hd_struct *hd;
 	char buf[BDEVNAME_SIZE];
+	unsigned int inflight[2];
 	int cpu;
 
 	/*
@@ -1225,8 +1266,9 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 	disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
 	while ((hd = disk_part_iter_next(&piter))) {
 		cpu = part_stat_lock();
-		part_round_stats(cpu, hd);
+		part_round_stats(gp->queue, cpu, hd);
 		part_stat_unlock();
+		part_in_flight(gp->queue, hd, inflight);
 		seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
 			   "%u %lu %lu %lu %u %u %u %u\n",
 			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
@@ -1239,7 +1281,7 @@ static int diskstats_show(struct seq_file *seqf, void *v)
 			   part_stat_read(hd, merges[WRITE]),
 			   part_stat_read(hd, sectors[WRITE]),
 			   jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
-			   part_in_flight(hd),
+			   inflight[0],
 			   jiffies_to_msecs(part_stat_read(hd, io_ticks)),
 			   jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 			);
@@ -1321,6 +1363,14 @@ EXPORT_SYMBOL(alloc_disk);
 struct gendisk *alloc_disk_node(int minors, int node_id)
 {
 	struct gendisk *disk;
+	struct disk_part_tbl *ptbl;
+
+	if (minors > DISK_MAX_PARTS) {
+		printk(KERN_ERR
+			"block: can't allocated more than %d partitions\n",
+			DISK_MAX_PARTS);
+		minors = DISK_MAX_PARTS;
+	}
 
 	disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
 	if (disk) {
@@ -1334,7 +1384,8 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
 			kfree(disk);
 			return NULL;
 		}
-		disk->part_tbl->part[0] = &disk->part0;
+		ptbl = rcu_dereference_protected(disk->part_tbl, 1);
+		rcu_assign_pointer(ptbl->part[0], &disk->part0);
 
 		/*
 		 * set_capacity() and get_capacity() currently don't use