3 files changed, 144 insertions, 0 deletions

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 92be8092ca4f..0641533597f1 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -852,6 +852,8 @@ static void __blk_release_queue(struct work_struct *work)
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
 
+	blk_queue_free_zone_bitmaps(q);
+
 	if (!q->mq_ops) {
 		if (q->exit_rq_fn)
 			q->exit_rq_fn(q, q->fq->flush_rq);
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 90cf503091d5..13ba2011a306 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/rbtree.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
 
 #include "blk.h"
 
@@ -359,3 +360,138 @@ int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
 	return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
 				  GFP_KERNEL);
 }
+
+static inline unsigned long *blk_alloc_zone_bitmap(int node,
+						   unsigned int nr_zones)
+{
+	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
+			    GFP_NOIO, node);
+}
+
+/*
+ * Allocate an array of struct blk_zone to get nr_zones zone information.
+ * The allocated array may be smaller than nr_zones.
+ */
+static struct blk_zone *blk_alloc_zones(int node, unsigned int *nr_zones)
+{
+	size_t size = *nr_zones * sizeof(struct blk_zone);
+	struct page *page;
+	int order;
+
+	for (order = get_order(size); order > 0; order--) {
+		page = alloc_pages_node(node, GFP_NOIO | __GFP_ZERO, order);
+		if (page) {
+			*nr_zones = min_t(unsigned int, *nr_zones,
+				(PAGE_SIZE << order) / sizeof(struct blk_zone));
+			return page_address(page);
+		}
+	}
+
+	return NULL;
+}
+
+void blk_queue_free_zone_bitmaps(struct request_queue *q)
+{
+	kfree(q->seq_zones_bitmap);
+	q->seq_zones_bitmap = NULL;
+	kfree(q->seq_zones_wlock);
+	q->seq_zones_wlock = NULL;
+}
+
+/**
+ * blk_revalidate_disk_zones - (re)allocate and initialize zone bitmaps
+ * @disk:	Target disk
+ *
+ * Helper function for low-level device drivers to (re) allocate and initialize
+ * a disk request queue zone bitmaps. This functions should normally be called
+ * within the disk ->revalidate method. For BIO based queues, no zone bitmap
+ * is allocated.
+ */
+int blk_revalidate_disk_zones(struct gendisk *disk)
+{
+	struct request_queue *q = disk->queue;
+	unsigned int nr_zones = __blkdev_nr_zones(q, get_capacity(disk));
+	unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
+	unsigned int i, rep_nr_zones = 0, z = 0, nrz;
+	struct blk_zone *zones = NULL;
+	sector_t sector = 0;
+	int ret = 0;
+
+	/*
+	 * BIO based queues do not use a scheduler so only q->nr_zones
+	 * needs to be updated so that the sysfs exposed value is correct.
+	 */
+	if (!queue_is_rq_based(q)) {
+		q->nr_zones = nr_zones;
+		return 0;
+	}
+
+	if (!blk_queue_is_zoned(q) || !nr_zones) {
+		nr_zones = 0;
+		goto update;
+	}
+
+	/* Allocate bitmaps */
+	ret = -ENOMEM;
+	seq_zones_wlock = blk_alloc_zone_bitmap(q->node, nr_zones);
+	if (!seq_zones_wlock)
+		goto out;
+	seq_zones_bitmap = blk_alloc_zone_bitmap(q->node, nr_zones);
+	if (!seq_zones_bitmap)
+		goto out;
+
+	/* Get zone information and initialize seq_zones_bitmap */
+	rep_nr_zones = nr_zones;
+	zones = blk_alloc_zones(q->node, &rep_nr_zones);
+	if (!zones)
+		goto out;
+
+	while (z < nr_zones) {
+		nrz = min(nr_zones - z, rep_nr_zones);
+		ret = blk_report_zones(disk, sector, zones, &nrz, GFP_NOIO);
+		if (ret)
+			goto out;
+		if (!nrz)
+			break;
+		for (i = 0; i < nrz; i++) {
+			if (zones[i].type != BLK_ZONE_TYPE_CONVENTIONAL)
+				set_bit(z, seq_zones_bitmap);
+			z++;
+		}
+		sector += nrz * blk_queue_zone_sectors(q);
+	}
+
+	if (WARN_ON(z != nr_zones)) {
+		ret = -EIO;
+		goto out;
+	}
+
+update:
+	/*
+	 * Install the new bitmaps, making sure the queue is stopped and
+	 * all I/Os are completed (i.e. a scheduler is not referencing the
+	 * bitmaps).
+	 */
+	blk_mq_freeze_queue(q);
+	q->nr_zones = nr_zones;
+	swap(q->seq_zones_wlock, seq_zones_wlock);
+	swap(q->seq_zones_bitmap, seq_zones_bitmap);
+	blk_mq_unfreeze_queue(q);
+
+out:
+	free_pages((unsigned long)zones,
+		   get_order(rep_nr_zones * sizeof(struct blk_zone)));
+	kfree(seq_zones_wlock);
+	kfree(seq_zones_bitmap);
+
+	if (ret) {
+		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
+		blk_mq_freeze_queue(q);
+		blk_queue_free_zone_bitmaps(q);
+		blk_mq_unfreeze_queue(q);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(blk_revalidate_disk_zones);
+
diff --git a/block/blk.h b/block/blk.h
index 93574baaa6b8..a1841b8ff129 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -490,4 +490,10 @@ static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
 
 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
 
+#ifdef CONFIG_BLK_DEV_ZONED
+void blk_queue_free_zone_bitmaps(struct request_queue *q);
+#else
+static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
+#endif
+
 #endif /* BLK_INTERNAL_H */