[PATCH] btrfs: zoned: skip ZONE FINISH of conventional zones

[Johannes Thumshirn <jth@kernel.org>]

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Don't call ZONE FINISH for conventional zones as this will result in I/O
errors. Instead check if the zone that needs finishing is a conventional
zone and if yes skip it.

Also factor out the actual handling of finishing a single zone into a
helper function, as do_zone_finish() is growing ever bigger and the
indentations levels are getting higher.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

---
This is a preparation patch for Naohiro's patch titled:
"btrfs: zoned: limit active zones to max_open_zones"
which can be found at:
https://lore.kernel.org/linux-btrfs/47f7423f53492e0ee1cd40f204db8354efb8d6b1.1752652539.git.naohiro.aota@wdc.com
---
 fs/btrfs/zoned.c | 55 ++++++++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index eeb049994cfe..ddacdb75d45c 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -2257,6 +2257,40 @@ static void wait_eb_writebacks(struct btrfs_block_group *block_group)
 	rcu_read_unlock();
 }
 
+static int call_zone_finish(struct btrfs_block_group *block_group,
+			    struct btrfs_io_stripe *stripe)
+{
+	struct btrfs_device *device = stripe->dev;
+	const u64 physical = stripe->physical;
+	struct btrfs_zoned_device_info *zinfo = device->zone_info;
+	int ret;
+
+	if (!device->bdev)
+		return 0;
+
+	if (zinfo->max_active_zones == 0)
+		return 0;
+
+	if (btrfs_dev_is_sequential(device, physical)) {
+		unsigned int nofs_flags;
+
+		nofs_flags = memalloc_nofs_save();
+		ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
+				       physical >> SECTOR_SHIFT,
+				       zinfo->zone_size >> SECTOR_SHIFT);
+		memalloc_nofs_restore(nofs_flags);
+
+		if (ret)
+			return ret;
+	}
+
+	if (!(block_group->flags & BTRFS_BLOCK_GROUP_DATA))
+		zinfo->reserved_active_zones++;
+	btrfs_dev_clear_active_zone(device, physical);
+
+	return 0;
+}
+
 static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written)
 {
 	struct btrfs_fs_info *fs_info = block_group->fs_info;
@@ -2341,31 +2375,12 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
 	down_read(&dev_replace->rwsem);
 	map = block_group->physical_map;
 	for (i = 0; i < map->num_stripes; i++) {
-		struct btrfs_device *device = map->stripes[i].dev;
-		const u64 physical = map->stripes[i].physical;
-		struct btrfs_zoned_device_info *zinfo = device->zone_info;
-		unsigned int nofs_flags;
-
-		if (!device->bdev)
-			continue;
-
-		if (zinfo->max_active_zones == 0)
-			continue;
-
-		nofs_flags = memalloc_nofs_save();
-		ret = blkdev_zone_mgmt(device->bdev, REQ_OP_ZONE_FINISH,
-				       physical >> SECTOR_SHIFT,
-				       zinfo->zone_size >> SECTOR_SHIFT);
-		memalloc_nofs_restore(nofs_flags);
 
+		ret = call_zone_finish(block_group, &map->stripes[i]);
 		if (ret) {
 			up_read(&dev_replace->rwsem);
 			return ret;
 		}
-
-		if (!(block_group->flags & BTRFS_BLOCK_GROUP_DATA))
-			zinfo->reserved_active_zones++;
-		btrfs_dev_clear_active_zone(device, physical);
 	}
 	up_read(&dev_replace->rwsem);
 
-- 
2.50.1