Merge tag 'for-5.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "This brings updates of space handling, performance improvements or bug
  fixes. The subpage block size and zoned mode features have reached
  state where they're usable but with limitations.

  Performance or related:

   - do not block on deleted block group mutex in the cleaner, avoids
     some long stalls

   - improved flushing: make it work better with ticket space
     reservations and avoid excessive transaction commits in some
     scenarios, slightly improves throughput for random write load

   - preemptive background flushing: separate the logic from ticket
     reservations, improve the accounting and decisions when to flush in
     low space conditions

   - less lock contention related to running delayed refs, let just one
     thread do the flushing when there are many inside transaction
     commit

   - dbench workload improvements: avoid unnecessary work when logging
     inodes, fewer fallbacks to transaction commit and thus less waiting
     for it (+7% throughput, -20% latency)

  Core:

   - subpage block size
      - currently read-only support
      - refactor and generalize code where sectorsize is assumed to be
        page size, add the subpage handling everywhere
      - the read-write support is on the way, page sizes are still
        limited to 4K or 64K

   - zoned mode, first working version but with limitations
      - SMR/ZBC/ZNS friendly allocation mode, utilizing the "no fixed
        location for structures" and chunked allocation
      - superblock as the only fixed data structure needs special
        handling, uses 2 consecutive zones as a ring buffer
      - tree-log support with a dedicated block group to avoid unordered
        writes
      - emulated zones on non-zoned devices
      - not yet working
      - all non-single block group profiles, requires more zone write
        pointer synchronization between the multiple block groups
      - fitrim due to dependency on space cache, can be implemented

  Fixes:

   - ref-verify: proper tree owner and node level tracking

   - fix pinned byte accounting, causing some early ENOSPC now more
     likely due to other changes in delayed refs

  Other:

   - error handling fixes and improvements

   - more error injection points

   - more function documentation

   - more and updated tracepoints

   - subset of W=1 checked by default

   - update comments to allow more automatic kdoc parameter checks"

* tag 'for-5.12-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (144 commits)
  btrfs: zoned: enable to mount ZONED incompat flag
  btrfs: zoned: deal with holes writing out tree-log pages
  btrfs: zoned: reorder log node allocation on zoned filesystem
  btrfs: zoned: serialize log transaction on zoned filesystems
  btrfs: zoned: extend zoned allocator to use dedicated tree-log block group
  btrfs: split alloc_log_tree()
  btrfs: zoned: relocate block group to repair IO failure in zoned filesystems
  btrfs: zoned: enable relocation on a zoned filesystem
  btrfs: zoned: support dev-replace in zoned filesystems
  btrfs: zoned: implement copying for zoned device-replace
  btrfs: zoned: implement cloning for zoned device-replace
  btrfs: zoned: mark block groups to copy for device-replace
  btrfs: zoned: do not use async metadata checksum on zoned filesystems
  btrfs: zoned: wait for existing extents before truncating
  btrfs: zoned: serialize metadata IO
  btrfs: zoned: introduce dedicated data write path for zoned filesystems
  btrfs: zoned: enable zone append writing for direct IO
  btrfs: zoned: use ZONE_APPEND write for zoned mode
  btrfs: save irq flags when looking up an ordered extent
  btrfs: zoned: cache if block group is on a sequential zone
  ...

1 files changed, 308 insertions, 56 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d6c24c8ad749..b8fab44394f5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -669,10 +669,6 @@ static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices,
 	clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state);
 	device->mode = flags;
 
-	ret = btrfs_get_dev_zone_info(device);
-	if (ret != 0)
-		goto error_free_page;
-
 	fs_devices->open_devices++;
 	if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) &&
 	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
@@ -1418,11 +1414,62 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
 		 * make sure to start at an offset of at least 1MB.
 		 */
 		return max_t(u64, start, SZ_1M);
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		/*
+		 * We don't care about the starting region like regular
+		 * allocator, because we anyway use/reserve the first two zones
+		 * for superblock logging.
+		 */
+		return ALIGN(start, device->zone_info->zone_size);
 	default:
 		BUG();
 	}
 }
 
+static bool dev_extent_hole_check_zoned(struct btrfs_device *device,
+					u64 *hole_start, u64 *hole_size,
+					u64 num_bytes)
+{
+	u64 zone_size = device->zone_info->zone_size;
+	u64 pos;
+	int ret;
+	bool changed = false;
+
+	ASSERT(IS_ALIGNED(*hole_start, zone_size));
+
+	while (*hole_size > 0) {
+		pos = btrfs_find_allocatable_zones(device, *hole_start,
+						   *hole_start + *hole_size,
+						   num_bytes);
+		if (pos != *hole_start) {
+			*hole_size = *hole_start + *hole_size - pos;
+			*hole_start = pos;
+			changed = true;
+			if (*hole_size < num_bytes)
+				break;
+		}
+
+		ret = btrfs_ensure_empty_zones(device, pos, num_bytes);
+
+		/* Range is ensured to be empty */
+		if (!ret)
+			return changed;
+
+		/* Given hole range was invalid (outside of device) */
+		if (ret == -ERANGE) {
+			*hole_start += *hole_size;
+			*hole_size = 0;
+			return 1;
+		}
+
+		*hole_start += zone_size;
+		*hole_size -= zone_size;
+		changed = true;
+	}
+
+	return changed;
+}
+
 /**
  * dev_extent_hole_check - check if specified hole is suitable for allocation
  * @device:	the device which we have the hole
@@ -1430,7 +1477,7 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start)
  * @hole_size:	the size of the hole
  * @num_bytes:	the size of the free space that we need
  *
- * This function may modify @hole_start and @hole_end to reflect the suitable
+ * This function may modify @hole_start and @hole_size to reflect the suitable
  * position for allocation. Returns 1 if hole position is updated, 0 otherwise.
  */
 static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
@@ -1439,24 +1486,39 @@ static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start,
 	bool changed = false;
 	u64 hole_end = *hole_start + *hole_size;
 
-	/*
-	 * Check before we set max_hole_start, otherwise we could end up
-	 * sending back this offset anyway.
-	 */
-	if (contains_pending_extent(device, hole_start, *hole_size)) {
-		if (hole_end >= *hole_start)
-			*hole_size = hole_end - *hole_start;
-		else
-			*hole_size = 0;
-		changed = true;
-	}
+	for (;;) {
+		/*
+		 * Check before we set max_hole_start, otherwise we could end up
+		 * sending back this offset anyway.
+		 */
+		if (contains_pending_extent(device, hole_start, *hole_size)) {
+			if (hole_end >= *hole_start)
+				*hole_size = hole_end - *hole_start;
+			else
+				*hole_size = 0;
+			changed = true;
+		}
+
+		switch (device->fs_devices->chunk_alloc_policy) {
+		case BTRFS_CHUNK_ALLOC_REGULAR:
+			/* No extra check */
+			break;
+		case BTRFS_CHUNK_ALLOC_ZONED:
+			if (dev_extent_hole_check_zoned(device, hole_start,
+							hole_size, num_bytes)) {
+				changed = true;
+				/*
+				 * The changed hole can contain pending extent.
+				 * Loop again to check that.
+				 */
+				continue;
+			}
+			break;
+		default:
+			BUG();
+		}
 
-	switch (device->fs_devices->chunk_alloc_policy) {
-	case BTRFS_CHUNK_ALLOC_REGULAR:
-		/* No extra check */
 		break;
-	default:
-		BUG();
 	}
 
 	return changed;
@@ -1509,6 +1571,9 @@ static int find_free_dev_extent_start(struct btrfs_device *device,
 
 	search_start = dev_extent_search_start(device, search_start);
 
+	WARN_ON(device->zone_info &&
+		!IS_ALIGNED(num_bytes, device->zone_info->zone_size));
+
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
@@ -4668,11 +4733,10 @@ again:
 		}
 
 		ret = btrfs_previous_item(root, path, 0, key.type);
-		if (ret)
-			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
-		if (ret < 0)
-			goto done;
 		if (ret) {
+			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+			if (ret < 0)
+				goto done;
 			ret = 0;
 			btrfs_release_path(path);
 			break;
@@ -4904,6 +4968,37 @@ static void init_alloc_chunk_ctl_policy_regular(
 	ctl->dev_extent_min = BTRFS_STRIPE_LEN * ctl->dev_stripes;
 }
 
+static void init_alloc_chunk_ctl_policy_zoned(
+				      struct btrfs_fs_devices *fs_devices,
+				      struct alloc_chunk_ctl *ctl)
+{
+	u64 zone_size = fs_devices->fs_info->zone_size;
+	u64 limit;
+	int min_num_stripes = ctl->devs_min * ctl->dev_stripes;
+	int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies;
+	u64 min_chunk_size = min_data_stripes * zone_size;
+	u64 type = ctl->type;
+
+	ctl->max_stripe_size = zone_size;
+	if (type & BTRFS_BLOCK_GROUP_DATA) {
+		ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE,
+						 zone_size);
+	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
+		ctl->max_chunk_size = ctl->max_stripe_size;
+	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+		ctl->max_chunk_size = 2 * ctl->max_stripe_size;
+		ctl->devs_max = min_t(int, ctl->devs_max,
+				      BTRFS_MAX_DEVS_SYS_CHUNK);
+	}
+
+	/* We don't want a chunk larger than 10% of writable space */
+	limit = max(round_down(div_factor(fs_devices->total_rw_bytes, 1),
+			       zone_size),
+		    min_chunk_size);
+	ctl->max_chunk_size = min(limit, ctl->max_chunk_size);
+	ctl->dev_extent_min = zone_size * ctl->dev_stripes;
+}
+
 static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
 				 struct alloc_chunk_ctl *ctl)
 {
@@ -4924,6 +5019,9 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices,
 	case BTRFS_CHUNK_ALLOC_REGULAR:
 		init_alloc_chunk_ctl_policy_regular(fs_devices, ctl);
 		break;
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl);
+		break;
 	default:
 		BUG();
 	}
@@ -5050,6 +5148,38 @@ static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl,
 	return 0;
 }
 
+static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl,
+				    struct btrfs_device_info *devices_info)
+{
+	u64 zone_size = devices_info[0].dev->zone_info->zone_size;
+	/* Number of stripes that count for block group size */
+	int data_stripes;
+
+	/*
+	 * It should hold because:
+	 *    dev_extent_min == dev_extent_want == zone_size * dev_stripes
+	 */
+	ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min);
+
+	ctl->stripe_size = zone_size;
+	ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
+	data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
+
+	/* stripe_size is fixed in zoned filesysmte. Reduce ndevs instead. */
+	if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) {
+		ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies,
+					     ctl->stripe_size) + ctl->nparity,
+				     ctl->dev_stripes);
+		ctl->num_stripes = ctl->ndevs * ctl->dev_stripes;
+		data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies;
+		ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size);
+	}
+
+	ctl->chunk_size = ctl->stripe_size * data_stripes;
+
+	return 0;
+}
+
 static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
 			      struct alloc_chunk_ctl *ctl,
 			      struct btrfs_device_info *devices_info)
@@ -5077,6 +5207,8 @@ static int decide_stripe_size(struct btrfs_fs_devices *fs_devices,
 	switch (fs_devices->chunk_alloc_policy) {
 	case BTRFS_CHUNK_ALLOC_REGULAR:
 		return decide_stripe_size_regular(ctl, devices_info);
+	case BTRFS_CHUNK_ALLOC_ZONED:
+		return decide_stripe_size_zoned(ctl, devices_info);
 	default:
 		BUG();
 	}
@@ -5841,9 +5973,29 @@ static int get_extra_mirror_from_replace(struct btrfs_fs_info *fs_info,
 	return ret;
 }
 
+static bool is_block_group_to_copy(struct btrfs_fs_info *fs_info, u64 logical)
+{
+	struct btrfs_block_group *cache;
+	bool ret;
+
+	/* Non zoned filesystem does not use "to_copy" flag */
+	if (!btrfs_is_zoned(fs_info))
+		return false;
+
+	cache = btrfs_lookup_block_group(fs_info, logical);
+
+	spin_lock(&cache->lock);
+	ret = cache->to_copy;
+	spin_unlock(&cache->lock);
+
+	btrfs_put_block_group(cache);
+	return ret;
+}
+
 static void handle_ops_on_dev_replace(enum btrfs_map_op op,
 				      struct btrfs_bio **bbio_ret,
 				      struct btrfs_dev_replace *dev_replace,
+				      u64 logical,
 				      int *num_stripes_ret, int *max_errors_ret)
 {
 	struct btrfs_bio *bbio = *bbio_ret;
@@ -5857,6 +6009,13 @@ static void handle_ops_on_dev_replace(enum btrfs_map_op op,
 		int index_where_to_add;
 
 		/*
+		 * A block group which have "to_copy" set will eventually
+		 * copied by dev-replace process. We can avoid cloning IO here.
+		 */
+		if (is_block_group_to_copy(dev_replace->srcdev->fs_info, logical))
+			return;
+
+		/*
 		 * duplicate the write operations while the dev replace
 		 * procedure is running. Since the copying of the old disk to
 		 * the new disk takes place at run time while the filesystem is
@@ -5941,23 +6100,24 @@ static bool need_full_stripe(enum btrfs_map_op op)
 }
 
 /*
- * btrfs_get_io_geometry - calculates the geomery of a particular (address, len)
- *		       tuple. This information is used to calculate how big a
- *		       particular bio can get before it straddles a stripe.
+ * Calculate the geometry of a particular (address, len) tuple. This
+ * information is used to calculate how big a particular bio can get before it
+ * straddles a stripe.
  *
- * @fs_info - the filesystem
- * @logical - address that we want to figure out the geometry of
- * @len	    - the length of IO we are going to perform, starting at @logical
- * @op      - type of operation - write or read
- * @io_geom - pointer used to return values
+ * @fs_info: the filesystem
+ * @em:      mapping containing the logical extent
+ * @op:      type of operation - write or read
+ * @logical: address that we want to figure out the geometry of
+ * @len:     the length of IO we are going to perform, starting at @logical
+ * @io_geom: pointer used to return values
  *
  * Returns < 0 in case a chunk for the given logical address cannot be found,
  * usually shouldn't happen unless @logical is corrupted, 0 otherwise.
  */
-int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
-			u64 logical, u64 len, struct btrfs_io_geometry *io_geom)
+int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *em,
+			  enum btrfs_map_op op, u64 logical, u64 len,
+			  struct btrfs_io_geometry *io_geom)
 {
-	struct extent_map *em;
 	struct map_lookup *map;
 	u64 offset;
 	u64 stripe_offset;
@@ -5965,14 +6125,9 @@ int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	u64 stripe_len;
 	u64 raid56_full_stripe_start = (u64)-1;
 	int data_stripes;
-	int ret = 0;
 
 	ASSERT(op != BTRFS_MAP_DISCARD);
 
-	em = btrfs_get_chunk_map(fs_info, logical, len);
-	if (IS_ERR(em))
-		return PTR_ERR(em);
-
 	map = em->map_lookup;
 	/* Offset of this logical address in the chunk */
 	offset = logical - em->start;
@@ -5986,8 +6141,7 @@ int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 		btrfs_crit(fs_info,
 "stripe math has gone wrong, stripe_offset=%llu offset=%llu start=%llu logical=%llu stripe_len=%llu",
 			stripe_offset, offset, em->start, logical, stripe_len);
-		ret = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	/* stripe_offset is the offset of this block in its stripe */
@@ -6034,10 +6188,7 @@ int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
 	io_geom->stripe_offset = stripe_offset;
 	io_geom->raid56_stripe_offset = raid56_full_stripe_start;
 
-out:
-	/* once for us */
-	free_extent_map(em);
-	return ret;
+	return 0;
 }
 
 static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
@@ -6070,12 +6221,13 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 	ASSERT(bbio_ret);
 	ASSERT(op != BTRFS_MAP_DISCARD);
 
-	ret = btrfs_get_io_geometry(fs_info, op, logical, *length, &geom);
+	em = btrfs_get_chunk_map(fs_info, logical, *length);
+	ASSERT(!IS_ERR(em));
+
+	ret = btrfs_get_io_geometry(fs_info, em, op, logical, *length, &geom);
 	if (ret < 0)
 		return ret;
 
-	em = btrfs_get_chunk_map(fs_info, logical, *length);
-	ASSERT(!IS_ERR(em));
 	map = em->map_lookup;
 
 	*length = geom.len;
@@ -6251,8 +6403,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
 
 	if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
 	    need_full_stripe(op)) {
-		handle_ops_on_dev_replace(op, &bbio, dev_replace, &num_stripes,
-					  &max_errors);
+		handle_ops_on_dev_replace(op, &bbio, dev_replace, logical,
+					  &num_stripes, &max_errors);
 	}
 
 	*bbio_ret = bbio;
@@ -6323,7 +6475,7 @@ static void btrfs_end_bio(struct bio *bio)
 			struct btrfs_device *dev = btrfs_io_bio(bio)->device;
 
 			ASSERT(dev->bdev);
-			if (bio_op(bio) == REQ_OP_WRITE)
+			if (btrfs_op(bio) == BTRFS_MAP_WRITE)
 				btrfs_dev_stat_inc_and_print(dev,
 						BTRFS_DEV_STAT_WRITE_ERRS);
 			else if (!(bio->bi_opf & REQ_RAHEAD))
@@ -6375,6 +6527,20 @@ static void submit_stripe_bio(struct btrfs_bio *bbio, struct bio *bio,
 	btrfs_io_bio(bio)->device = dev;
 	bio->bi_end_io = btrfs_end_bio;
 	bio->bi_iter.bi_sector = physical >> 9;
+	/*
+	 * For zone append writing, bi_sector must point the beginning of the
+	 * zone
+	 */
+	if (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		if (btrfs_dev_is_sequential(dev, physical)) {
+			u64 zone_start = round_down(physical, fs_info->zone_size);
+
+			bio->bi_iter.bi_sector = zone_start >> SECTOR_SHIFT;
+		} else {
+			bio->bi_opf &= ~REQ_OP_ZONE_APPEND;
+			bio->bi_opf |= REQ_OP_WRITE;
+		}
+	}
 	btrfs_debug_in_rcu(fs_info,
 	"btrfs_map_bio: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
 		bio_op(bio), bio->bi_opf, bio->bi_iter.bi_sector,
@@ -6436,10 +6602,10 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 	atomic_set(&bbio->stripes_pending, bbio->num_stripes);
 
 	if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
-	    ((bio_op(bio) == REQ_OP_WRITE) || (mirror_num > 1))) {
+	    ((btrfs_op(bio) == BTRFS_MAP_WRITE) || (mirror_num > 1))) {
 		/* In this case, map_length has been set to the length of
 		   a single stripe; not the whole write */
-		if (bio_op(bio) == REQ_OP_WRITE) {
+		if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
 			ret = raid56_parity_write(fs_info, bio, bbio,
 						  map_length);
 		} else {
@@ -6462,7 +6628,7 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 		dev = bbio->stripes[dev_nr].dev;
 		if (!dev || !dev->bdev || test_bit(BTRFS_DEV_STATE_MISSING,
 						   &dev->dev_state) ||
-		    (bio_op(first_bio) == REQ_OP_WRITE &&
+		    (btrfs_op(first_bio) == BTRFS_MAP_WRITE &&
 		    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
 			bbio_error(bbio, first_bio, logical);
 			continue;
@@ -7644,6 +7810,20 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 		ret = -EUCLEAN;
 		goto out;
 	}
+
+	if (dev->zone_info) {
+		u64 zone_size = dev->zone_info->zone_size;
+
+		if (!IS_ALIGNED(physical_offset, zone_size) ||
+		    !IS_ALIGNED(physical_len, zone_size)) {
+			btrfs_err(fs_info,
+"zoned: dev extent devid %llu physical offset %llu len %llu is not aligned to device zone",
+				  devid, physical_offset, physical_len);
+			ret = -EUCLEAN;
+			goto out;
+		}
+	}
+
 out:
 	free_extent_map(em);
 	return ret;
@@ -7800,3 +7980,75 @@ bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr)
 	spin_unlock(&fs_info->swapfile_pins_lock);
 	return node != NULL;
 }
+
+static int relocating_repair_kthread(void *data)
+{
+	struct btrfs_block_group *cache = (struct btrfs_block_group *)data;
+	struct btrfs_fs_info *fs_info = cache->fs_info;
+	u64 target;
+	int ret = 0;
+
+	target = cache->start;
+	btrfs_put_block_group(cache);
+
+	if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) {
+		btrfs_info(fs_info,
+			   "zoned: skip relocating block group %llu to repair: EBUSY",
+			   target);
+		return -EBUSY;
+	}
+
+	mutex_lock(&fs_info->delete_unused_bgs_mutex);
+
+	/* Ensure block group still exists */
+	cache = btrfs_lookup_block_group(fs_info, target);
+	if (!cache)
+		goto out;
+
+	if (!cache->relocating_repair)
+		goto out;
+
+	ret = btrfs_may_alloc_data_chunk(fs_info, target);
+	if (ret < 0)
+		goto out;
+
+	btrfs_info(fs_info,
+		   "zoned: relocating block group %llu to repair IO failure",
+		   target);
+	ret = btrfs_relocate_chunk(fs_info, target);
+
+out:
+	if (cache)
+		btrfs_put_block_group(cache);
+	mutex_unlock(&fs_info->delete_unused_bgs_mutex);
+	btrfs_exclop_finish(fs_info);
+
+	return ret;
+}
+
+int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical)
+{
+	struct btrfs_block_group *cache;
+
+	/* Do not attempt to repair in degraded state */
+	if (btrfs_test_opt(fs_info, DEGRADED))
+		return 0;
+
+	cache = btrfs_lookup_block_group(fs_info, logical);
+	if (!cache)
+		return 0;
+
+	spin_lock(&cache->lock);
+	if (cache->relocating_repair) {
+		spin_unlock(&cache->lock);
+		btrfs_put_block_group(cache);
+		return 0;
+	}
+	cache->relocating_repair = 1;
+	spin_unlock(&cache->lock);
+
+	kthread_run(relocating_repair_kthread, cache,
+		    "btrfs-relocating-repair");
+
+	return 0;
+}