[PATCH v4 08/28] libmultipath: Add mpath_bdev_report_zones()

[John Garry <john.g.garry@oracle.com>]

From: John Garry <john.garry@linux.dev>

Add a multipath handler for block_device_operations.report_zones

Signed-off-by: John Garry <john.g.garry@oracle.com>
---
 lib/multipath.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/lib/multipath.c b/lib/multipath.c
index 3ff4f42a096c2..0232f51f64742 100644
--- a/lib/multipath.c
+++ b/lib/multipath.c
@@ -44,6 +44,30 @@ int mpath_get_iopolicy(char *buf, int iopolicy)
 }
 EXPORT_SYMBOL_GPL(mpath_get_iopolicy);
 
+#ifdef CONFIG_BLK_DEV_ZONED
+static int mpath_bdev_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, struct blk_report_zones_args *args)
+{
+	struct mpath_head *mpath_head = mpath_gendisk_to_head(disk);
+	struct mpath_device *mpath_device;
+	int srcu_idx, ret = -EWOULDBLOCK;
+
+	srcu_idx = srcu_read_lock(&mpath_head->srcu);
+	mpath_device = mpath_find_path(mpath_head);
+	if (mpath_device) {
+		if (mpath_device->disk->fops->report_zones)
+			ret = mpath_device->disk->fops->report_zones
+				(mpath_device->disk, sector, nr_zones, args);
+		else
+			ret = -EOPNOTSUPP;
+	}
+	srcu_read_unlock(&mpath_head->srcu, srcu_idx);
+	return ret;
+}
+#else
+#define mpath_bdev_report_zones	NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
+
 void mpath_synchronize(struct mpath_head *mpath_head)
 {
 	synchronize_srcu(&mpath_head->srcu);
@@ -459,6 +483,7 @@ const struct block_device_operations mpath_ops = {
 	.open		= mpath_bdev_open,
 	.release	= mpath_bdev_release,
 	.submit_bio	= mpath_bdev_submit_bio,
+	.report_zones	= mpath_bdev_report_zones,
 };
 EXPORT_SYMBOL_GPL(mpath_ops);
 
-- 
2.43.7