From: Hannes Reinecke <hare@suse.de>
Date: Tue, 2 Jun 2020 13:09:54 +0200
Subject: [PATCH] dm zoned: select reclaim zone based on device index
Git-commit: 69875d443bc3bb1b2e1f77fe3da5ad5c8c729aa2
Patch-mainline: v5.8-rc1
References: bsc#1175995,jsc#SLE-15608

per-device reclaim should select zones on that device only.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/md/dm-zoned-metadata.c | 50 +++++++++++++++++-------------------------
 drivers/md/dm-zoned-reclaim.c  |  3 ++-
 drivers/md/dm-zoned-target.c   |  1 +
 drivers/md/dm-zoned.h          |  5 ++++-
 4 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 1a6cdab3e4ef..0cb90799b8ce 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1938,7 +1938,7 @@ static void dmz_wait_for_reclaim(struct dmz_metadata *zmd, struct dm_zone *zone)
  * Select a cache or random write zone for reclaim.
  */
 static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
-						    bool idle)
+						    unsigned int idx, bool idle)
 {
 	struct dm_zone *dzone = NULL;
 	struct dm_zone *zone;
@@ -1948,24 +1948,17 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
 	if (zmd->nr_cache) {
 		zone_list = &zmd->map_cache_list;
 		/* Try to relaim random zones, too, when idle */
-		if (idle && list_empty(zone_list)) {
-			int i;
-
-			for (i = 1; i < zmd->nr_devs; i++) {
-				zone_list = &zmd->dev[i].map_rnd_list;
-				if (!list_empty(zone_list))
-					break;
-			}
-		}
-	} else {
-		/* Otherwise the random zones are on the first disk */
-		zone_list = &zmd->dev[0].map_rnd_list;
-	}
+		if (idle && list_empty(zone_list))
+			zone_list = &zmd->dev[idx].map_rnd_list;
+	} else
+		zone_list = &zmd->dev[idx].map_rnd_list;
 
 	list_for_each_entry(zone, zone_list, link) {
-		if (dmz_is_buf(zone))
+		if (dmz_is_buf(zone)) {
 			dzone = zone->bzone;
-		else
+			if (dzone->dev->dev_idx != idx)
+				continue;
+		} else
 			dzone = zone;
 		if (dmz_lock_zone_reclaim(dzone))
 			return dzone;
@@ -1977,20 +1970,16 @@ static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
 /*
  * Select a buffered sequential zone for reclaim.
  */
-static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
+static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd,
+						    unsigned int idx)
 {
 	struct dm_zone *zone;
-	int i;
-
-	for (i = 0; i < zmd->nr_devs; i++) {
-		struct dmz_dev *dev = &zmd->dev[i];
 
-		list_for_each_entry(zone, &dev->map_seq_list, link) {
-			if (!zone->bzone)
-				continue;
-			if (dmz_lock_zone_reclaim(zone))
-				return zone;
-		}
+	list_for_each_entry(zone, &zmd->dev[idx].map_seq_list, link) {
+		if (!zone->bzone)
+			continue;
+		if (dmz_lock_zone_reclaim(zone))
+			return zone;
 	}
 
 	return NULL;
@@ -1999,7 +1988,8 @@ static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd)
 /*
  * Select a zone for reclaim.
  */
-struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle)
+struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
+					 unsigned int dev_idx, bool idle)
 {
 	struct dm_zone *zone;
 
@@ -2013,9 +2003,9 @@ struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle)
 	 */
 	dmz_lock_map(zmd);
 	if (list_empty(&zmd->reserved_seq_zones_list))
-		zone = dmz_get_seq_zone_for_reclaim(zmd);
+		zone = dmz_get_seq_zone_for_reclaim(zmd, dev_idx);
 	else
-		zone = dmz_get_rnd_zone_for_reclaim(zmd, idle);
+		zone = dmz_get_rnd_zone_for_reclaim(zmd, dev_idx, idle);
 	dmz_unlock_map(zmd);
 
 	return zone;
diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
index 5a04e34d17a9..2261b4dd60b7 100644
--- a/drivers/md/dm-zoned-reclaim.c
+++ b/drivers/md/dm-zoned-reclaim.c
@@ -370,7 +370,8 @@ static int dmz_do_reclaim(struct dmz_reclaim *zrc)
 	int ret;
 
 	/* Get a data zone */
-	dzone = dmz_get_zone_for_reclaim(zmd, dmz_target_idle(zrc));
+	dzone = dmz_get_zone_for_reclaim(zmd, zrc->dev_idx,
+					 dmz_target_idle(zrc));
 	if (!dzone) {
 		DMDEBUG("(%s/%u): No zone found to reclaim",
 			dmz_metadata_label(zmd), zrc->dev_idx);
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index fc30c78dffdb..a907a9446c0b 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -738,6 +738,7 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path,
 		dev = &dmz->dev[idx];
 	}
 	dev->bdev = bdev;
+	dev->dev_idx = idx;
 	(void)bdevname(dev->bdev, dev->name);
 
 	dev->capacity = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
diff --git a/drivers/md/dm-zoned.h b/drivers/md/dm-zoned.h
index ec020bb1caf7..22f11440b423 100644
--- a/drivers/md/dm-zoned.h
+++ b/drivers/md/dm-zoned.h
@@ -61,6 +61,8 @@ struct dmz_dev {
 
 	sector_t		capacity;
 
+	unsigned int		dev_idx;
+
 	unsigned int		nr_zones;
 	unsigned int		zone_offset;
 
@@ -243,7 +245,8 @@ static inline void dmz_activate_zone(struct dm_zone *zone)
 
 int dmz_lock_zone_reclaim(struct dm_zone *zone);
 void dmz_unlock_zone_reclaim(struct dm_zone *zone);
-struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd, bool idle);
+struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
+					 unsigned int dev_idx, bool idle);
 
 struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
 				      unsigned int chunk, int op);
-- 
2.16.4