1 files changed, 101 insertions, 133 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index cf82ea6f54fb..2e9a322773f2 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -39,21 +39,20 @@ struct scrub_block;
 struct scrub_ctx;
 
 /*
- * the following three values only influence the performance.
+ * The following three values only influence the performance.
+ *
  * The last one configures the number of parallel and outstanding I/O
- * operations. The first two values configure an upper limit for the number
+ * operations. The first one configures an upper limit for the number
  * of (dynamically allocated) pages that are added to a bio.
  */
-#define SCRUB_PAGES_PER_RD_BIO	32	/* 128k per bio */
-#define SCRUB_PAGES_PER_WR_BIO	32	/* 128k per bio */
-#define SCRUB_BIOS_PER_SCTX	64	/* 8MB per device in flight */
+#define SCRUB_PAGES_PER_BIO	32	/* 128KiB per bio for x86 */
+#define SCRUB_BIOS_PER_SCTX	64	/* 8MiB per device in flight for x86 */
 
 /*
- * the following value times PAGE_SIZE needs to be large enough to match the
+ * The following value times PAGE_SIZE needs to be large enough to match the
  * largest node/leaf/sector size that shall be supported.
- * Values larger than BTRFS_STRIPE_LEN are not supported.
  */
-#define SCRUB_MAX_PAGES_PER_BLOCK	16	/* 64k per node/leaf/sector */
+#define SCRUB_MAX_PAGES_PER_BLOCK	(BTRFS_MAX_METADATA_BLOCKSIZE / SZ_4K)
 
 struct scrub_recover {
 	refcount_t		refs;
@@ -73,8 +72,8 @@ struct scrub_page {
 	u64			physical_for_dev_replace;
 	atomic_t		refs;
 	u8			mirror_num;
-	int			have_csum:1;
-	int			io_error:1;
+	unsigned int		have_csum:1;
+	unsigned int		io_error:1;
 	u8			csum[BTRFS_CSUM_SIZE];
 
 	struct scrub_recover	*recover;
@@ -88,11 +87,7 @@ struct scrub_bio {
 	blk_status_t		status;
 	u64			logical;
 	u64			physical;
-#if SCRUB_PAGES_PER_WR_BIO >= SCRUB_PAGES_PER_RD_BIO
-	struct scrub_page	*pagev[SCRUB_PAGES_PER_WR_BIO];
-#else
-	struct scrub_page	*pagev[SCRUB_PAGES_PER_RD_BIO];
-#endif
+	struct scrub_page	*pagev[SCRUB_PAGES_PER_BIO];
 	int			page_count;
 	int			next_free;
 	struct btrfs_work	work;
@@ -163,7 +158,7 @@ struct scrub_ctx {
 	struct list_head	csum_list;
 	atomic_t		cancel_req;
 	int			readonly;
-	int			pages_per_rd_bio;
+	int			pages_per_bio;
 
 	/* State of IO submission throttling affecting the associated device */
 	ktime_t			throttle_deadline;
@@ -174,7 +169,6 @@ struct scrub_ctx {
 
 	struct scrub_bio        *wr_curr_bio;
 	struct mutex            wr_lock;
-	int                     pages_per_wr_bio; /* <= SCRUB_PAGES_PER_WR_BIO */
 	struct btrfs_device     *wr_tgtdev;
 	bool                    flush_all_writes;
 
@@ -578,7 +572,7 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
 		goto nomem;
 	refcount_set(&sctx->refs, 1);
 	sctx->is_dev_replace = is_dev_replace;
-	sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
+	sctx->pages_per_bio = SCRUB_PAGES_PER_BIO;
 	sctx->curr = -1;
 	sctx->fs_info = fs_info;
 	INIT_LIST_HEAD(&sctx->csum_list);
@@ -616,7 +610,6 @@ static noinline_for_stack struct scrub_ctx *scrub_setup_ctx(
 	sctx->wr_curr_bio = NULL;
 	if (is_dev_replace) {
 		WARN_ON(!fs_info->dev_replace.tgtdev);
-		sctx->pages_per_wr_bio = SCRUB_PAGES_PER_WR_BIO;
 		sctx->wr_tgtdev = fs_info->dev_replace.tgtdev;
 		sctx->flush_all_writes = false;
 	}
@@ -758,7 +751,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 
 	eb = path->nodes[0];
 	ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
-	item_size = btrfs_item_size_nr(eb, path->slots[0]);
+	item_size = btrfs_item_size(eb, path->slots[0]);
 
 	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
 		do {
@@ -852,8 +845,8 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 	have_csum = sblock_to_check->pagev[0]->have_csum;
 	dev = sblock_to_check->pagev[0]->dev;
 
-	if (btrfs_is_zoned(fs_info) && !sctx->is_dev_replace)
-		return btrfs_repair_one_zone(fs_info, logical);
+	if (!sctx->is_dev_replace && btrfs_repair_one_zone(fs_info, logical))
+		return 0;
 
 	/*
 	 * We must use GFP_NOFS because the scrub task might be waiting for a
@@ -1313,7 +1306,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 		recover->bioc = bioc;
 		recover->map_length = mapped_length;
 
-		BUG_ON(page_index >= SCRUB_MAX_PAGES_PER_BLOCK);
+		ASSERT(page_index < SCRUB_MAX_PAGES_PER_BLOCK);
 
 		nmirrors = min(scrub_nr_raid_mirrors(bioc), BTRFS_MAX_MIRRORS);
 
@@ -1675,7 +1668,7 @@ again:
 		sbio->dev = sctx->wr_tgtdev;
 		bio = sbio->bio;
 		if (!bio) {
-			bio = btrfs_bio_alloc(sctx->pages_per_wr_bio);
+			bio = btrfs_bio_alloc(sctx->pages_per_bio);
 			sbio->bio = bio;
 		}
 
@@ -1708,7 +1701,7 @@ again:
 	sbio->pagev[sbio->page_count] = spage;
 	scrub_page_get(spage);
 	sbio->page_count++;
-	if (sbio->page_count == sctx->pages_per_wr_bio)
+	if (sbio->page_count == sctx->pages_per_bio)
 		scrub_wr_submit(sctx);
 	mutex_unlock(&sctx->wr_lock);
 
@@ -1755,7 +1748,7 @@ static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
 	struct scrub_ctx *sctx = sbio->sctx;
 	int i;
 
-	WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
+	ASSERT(sbio->page_count <= SCRUB_PAGES_PER_BIO);
 	if (sbio->status) {
 		struct btrfs_dev_replace *dev_replace =
 			&sbio->sctx->fs_info->dev_replace;
@@ -2101,7 +2094,7 @@ again:
 		sbio->dev = spage->dev;
 		bio = sbio->bio;
 		if (!bio) {
-			bio = btrfs_bio_alloc(sctx->pages_per_rd_bio);
+			bio = btrfs_bio_alloc(sctx->pages_per_bio);
 			sbio->bio = bio;
 		}
 
@@ -2135,7 +2128,7 @@ again:
 	scrub_block_get(sblock); /* one for the page added to the bio */
 	atomic_inc(&sblock->outstanding_pages);
 	sbio->page_count++;
-	if (sbio->page_count == sctx->pages_per_rd_bio)
+	if (sbio->page_count == sctx->pages_per_bio)
 		scrub_submit(sctx);
 
 	return 0;
@@ -2297,7 +2290,7 @@ leave_nomem:
 			scrub_block_put(sblock);
 			return -ENOMEM;
 		}
-		BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+		ASSERT(index < SCRUB_MAX_PAGES_PER_BLOCK);
 		scrub_page_get(spage);
 		sblock->pagev[index] = spage;
 		spage->sblock = sblock;
@@ -2369,7 +2362,7 @@ static void scrub_bio_end_io_worker(struct btrfs_work *work)
 	struct scrub_ctx *sctx = sbio->sctx;
 	int i;
 
-	BUG_ON(sbio->page_count > SCRUB_PAGES_PER_RD_BIO);
+	ASSERT(sbio->page_count <= SCRUB_PAGES_PER_BIO);
 	if (sbio->status) {
 		for (i = 0; i < sbio->page_count; i++) {
 			struct scrub_page *spage = sbio->pagev[i];
@@ -2631,7 +2624,7 @@ leave_nomem:
 			scrub_block_put(sblock);
 			return -ENOMEM;
 		}
-		BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK);
+		ASSERT(index < SCRUB_MAX_PAGES_PER_BLOCK);
 		/* For scrub block */
 		scrub_page_get(spage);
 		sblock->pagev[index] = spage;
@@ -2892,15 +2885,15 @@ static void scrub_parity_put(struct scrub_parity *sparity)
 static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 						  struct map_lookup *map,
 						  struct btrfs_device *sdev,
-						  struct btrfs_path *path,
 						  u64 logic_start,
 						  u64 logic_end)
 {
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_root *csum_root = fs_info->csum_root;
+	struct btrfs_root *root = btrfs_extent_root(fs_info, logic_start);
+	struct btrfs_root *csum_root;
 	struct btrfs_extent_item *extent;
 	struct btrfs_io_context *bioc = NULL;
+	struct btrfs_path *path;
 	u64 flags;
 	int ret;
 	int slot;
@@ -2919,6 +2912,16 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 	int extent_mirror_num;
 	int stop_loop = 0;
 
+	path = btrfs_alloc_path();
+	if (!path) {
+		spin_lock(&sctx->stat_lock);
+		sctx->stat.malloc_errors++;
+		spin_unlock(&sctx->stat_lock);
+		return -ENOMEM;
+	}
+	path->search_commit_root = 1;
+	path->skip_locking = 1;
+
 	ASSERT(map->stripe_len <= U32_MAX);
 	nsectors = map->stripe_len >> fs_info->sectorsize_bits;
 	bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
@@ -2928,6 +2931,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.malloc_errors++;
 		spin_unlock(&sctx->stat_lock);
+		btrfs_free_path(path);
 		return -ENOMEM;
 	}
 
@@ -3060,6 +3064,7 @@ again:
 			extent_dev = bioc->stripes[0].dev;
 			btrfs_put_bioc(bioc);
 
+			csum_root = btrfs_csum_root(fs_info, extent_logical);
 			ret = btrfs_lookup_csums_range(csum_root,
 						extent_logical,
 						extent_logical + extent_len - 1,
@@ -3116,7 +3121,7 @@ out:
 	scrub_wr_submit(sctx);
 	mutex_unlock(&sctx->wr_lock);
 
-	btrfs_release_path(path);
+	btrfs_free_path(path);
 	return ret < 0 ? ret : 0;
 }
 
@@ -3161,17 +3166,18 @@ static int sync_write_pointer_for_zoned(struct scrub_ctx *sctx, u64 logical,
 }
 
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
+					   struct btrfs_block_group *bg,
 					   struct map_lookup *map,
 					   struct btrfs_device *scrub_dev,
-					   int num, u64 base, u64 length,
-					   struct btrfs_block_group *cache)
+					   int stripe_index, u64 dev_extent_len)
 {
-	struct btrfs_path *path, *ppath;
+	struct btrfs_path *path;
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
-	struct btrfs_root *root = fs_info->extent_root;
-	struct btrfs_root *csum_root = fs_info->csum_root;
+	struct btrfs_root *root;
+	struct btrfs_root *csum_root;
 	struct btrfs_extent_item *extent;
 	struct blk_plug plug;
+	const u64 chunk_logical = bg->start;
 	u64 flags;
 	int ret;
 	int slot;
@@ -3183,10 +3189,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	u64 physical_end;
 	u64 generation;
 	int mirror_num;
-	struct reada_control *reada1;
-	struct reada_control *reada2;
 	struct btrfs_key key;
-	struct btrfs_key key_end;
 	u64 increment = map->stripe_len;
 	u64 offset;
 	u64 extent_logical;
@@ -3202,25 +3205,26 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	int extent_mirror_num;
 	int stop_loop = 0;
 
-	physical = map->stripes[num].physical;
+	physical = map->stripes[stripe_index].physical;
 	offset = 0;
-	nstripes = div64_u64(length, map->stripe_len);
+	nstripes = div64_u64(dev_extent_len, map->stripe_len);
 	mirror_num = 1;
 	increment = map->stripe_len;
 	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
-		offset = map->stripe_len * num;
+		offset = map->stripe_len * stripe_index;
 		increment = map->stripe_len * map->num_stripes;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
 		int factor = map->num_stripes / map->sub_stripes;
-		offset = map->stripe_len * (num / map->sub_stripes);
+		offset = map->stripe_len * (stripe_index / map->sub_stripes);
 		increment = map->stripe_len * factor;
-		mirror_num = num % map->sub_stripes + 1;
+		mirror_num = stripe_index % map->sub_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
-		mirror_num = num % map->num_stripes + 1;
+		mirror_num = stripe_index % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		mirror_num = num % map->num_stripes + 1;
+		mirror_num = stripe_index % map->num_stripes + 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		get_raid56_logic_offset(physical, num, map, &offset, NULL);
+		get_raid56_logic_offset(physical, stripe_index, map, &offset,
+					NULL);
 		increment = map->stripe_len * nr_data_stripes(map);
 	}
 
@@ -3228,12 +3232,6 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	if (!path)
 		return -ENOMEM;
 
-	ppath = btrfs_alloc_path();
-	if (!ppath) {
-		btrfs_free_path(path);
-		return -ENOMEM;
-	}
-
 	/*
 	 * work on commit root. The related disk blocks are static as
 	 * long as COW is applied. This means, it is save to rewrite
@@ -3241,20 +3239,14 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	 */
 	path->search_commit_root = 1;
 	path->skip_locking = 1;
+	path->reada = READA_FORWARD;
 
-	ppath->search_commit_root = 1;
-	ppath->skip_locking = 1;
-	/*
-	 * trigger the readahead for extent tree csum tree and wait for
-	 * completion. During readahead, the scrub is officially paused
-	 * to not hold off transaction commits
-	 */
-	logical = base + offset;
+	logical = chunk_logical + offset;
 	physical_end = physical + nstripes * map->stripe_len;
 	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		get_raid56_logic_offset(physical_end, num,
+		get_raid56_logic_offset(physical_end, stripe_index,
 					map, &logic_end, NULL);
-		logic_end += base;
+		logic_end += chunk_logical;
 	} else {
 		logic_end = logical + increment * nstripes;
 	}
@@ -3262,32 +3254,8 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 		   atomic_read(&sctx->bios_in_flight) == 0);
 	scrub_blocked_if_needed(fs_info);
 
-	/* FIXME it might be better to start readahead at commit root */
-	key.objectid = logical;
-	key.type = BTRFS_EXTENT_ITEM_KEY;
-	key.offset = (u64)0;
-	key_end.objectid = logic_end;
-	key_end.type = BTRFS_METADATA_ITEM_KEY;
-	key_end.offset = (u64)-1;
-	reada1 = btrfs_reada_add(root, &key, &key_end);
-
-	if (cache->flags & BTRFS_BLOCK_GROUP_DATA) {
-		key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
-		key.type = BTRFS_EXTENT_CSUM_KEY;
-		key.offset = logical;
-		key_end.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
-		key_end.type = BTRFS_EXTENT_CSUM_KEY;
-		key_end.offset = logic_end;
-		reada2 = btrfs_reada_add(csum_root, &key, &key_end);
-	} else {
-		reada2 = NULL;
-	}
-
-	if (!IS_ERR(reada1))
-		btrfs_reada_wait(reada1);
-	if (!IS_ERR_OR_NULL(reada2))
-		btrfs_reada_wait(reada2);
-
+	root = btrfs_extent_root(fs_info, logical);
+	csum_root = btrfs_csum_root(fs_info, logical);
 
 	/*
 	 * collect all data csums for the stripe to avoid seeking during
@@ -3333,16 +3301,16 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 		}
 
 		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-			ret = get_raid56_logic_offset(physical, num, map,
-						      &logical,
+			ret = get_raid56_logic_offset(physical, stripe_index,
+						      map, &logical,
 						      &stripe_logical);
-			logical += base;
+			logical += chunk_logical;
 			if (ret) {
 				/* it is parity strip */
-				stripe_logical += base;
+				stripe_logical += chunk_logical;
 				stripe_end = stripe_logical + increment;
 				ret = scrub_raid56_parity(sctx, map, scrub_dev,
-							  ppath, stripe_logical,
+							  stripe_logical,
 							  stripe_end);
 				if (ret)
 					goto out;
@@ -3419,13 +3387,13 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 			 * Continuing would prevent reusing its device extents
 			 * for new block groups for a long time.
 			 */
-			spin_lock(&cache->lock);
-			if (cache->removed) {
-				spin_unlock(&cache->lock);
+			spin_lock(&bg->lock);
+			if (bg->removed) {
+				spin_unlock(&bg->lock);
 				ret = 0;
 				goto out;
 			}
-			spin_unlock(&cache->lock);
+			spin_unlock(&bg->lock);
 
 			extent = btrfs_item_ptr(l, slot,
 						struct btrfs_extent_item);
@@ -3504,16 +3472,16 @@ again:
 loop:
 					physical += map->stripe_len;
 					ret = get_raid56_logic_offset(physical,
-							num, map, &logical,
-							&stripe_logical);
-					logical += base;
+							stripe_index, map,
+							&logical, &stripe_logical);
+					logical += chunk_logical;
 
 					if (ret && physical < physical_end) {
-						stripe_logical += base;
+						stripe_logical += chunk_logical;
 						stripe_end = stripe_logical +
 								increment;
 						ret = scrub_raid56_parity(sctx,
-							map, scrub_dev, ppath,
+							map, scrub_dev,
 							stripe_logical,
 							stripe_end);
 						if (ret)
@@ -3543,8 +3511,8 @@ skip:
 		physical += map->stripe_len;
 		spin_lock(&sctx->stat_lock);
 		if (stop_loop)
-			sctx->stat.last_physical = map->stripes[num].physical +
-						   length;
+			sctx->stat.last_physical = map->stripes[stripe_index].physical +
+						   dev_extent_len;
 		else
 			sctx->stat.last_physical = physical;
 		spin_unlock(&sctx->stat_lock);
@@ -3560,14 +3528,14 @@ out:
 
 	blk_finish_plug(&plug);
 	btrfs_free_path(path);
-	btrfs_free_path(ppath);
 
 	if (sctx->is_dev_replace && ret >= 0) {
 		int ret2;
 
-		ret2 = sync_write_pointer_for_zoned(sctx, base + offset,
-						    map->stripes[num].physical,
-						    physical_end);
+		ret2 = sync_write_pointer_for_zoned(sctx,
+				chunk_logical + offset,
+				map->stripes[stripe_index].physical,
+				physical_end);
 		if (ret2)
 			ret = ret2;
 	}
@@ -3576,10 +3544,10 @@ out:
 }
 
 static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
+					  struct btrfs_block_group *bg,
 					  struct btrfs_device *scrub_dev,
-					  u64 chunk_offset, u64 length,
 					  u64 dev_offset,
-					  struct btrfs_block_group *cache)
+					  u64 dev_extent_len)
 {
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct extent_map_tree *map_tree = &fs_info->mapping_tree;
@@ -3589,7 +3557,7 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
 	int ret = 0;
 
 	read_lock(&map_tree->lock);
-	em = lookup_extent_mapping(map_tree, chunk_offset, 1);
+	em = lookup_extent_mapping(map_tree, bg->start, bg->length);
 	read_unlock(&map_tree->lock);
 
 	if (!em) {
@@ -3597,26 +3565,24 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
 		 * Might have been an unused block group deleted by the cleaner
 		 * kthread or relocation.
 		 */
-		spin_lock(&cache->lock);
-		if (!cache->removed)
+		spin_lock(&bg->lock);
+		if (!bg->removed)
 			ret = -EINVAL;
-		spin_unlock(&cache->lock);
+		spin_unlock(&bg->lock);
 
 		return ret;
 	}
-
-	map = em->map_lookup;
-	if (em->start != chunk_offset)
+	if (em->start != bg->start)
 		goto out;
-
-	if (em->len < length)
+	if (em->len < dev_extent_len)
 		goto out;
 
+	map = em->map_lookup;
 	for (i = 0; i < map->num_stripes; ++i) {
 		if (map->stripes[i].dev->bdev == scrub_dev->bdev &&
 		    map->stripes[i].physical == dev_offset) {
-			ret = scrub_stripe(sctx, map, scrub_dev, i,
-					   chunk_offset, length, cache);
+			ret = scrub_stripe(sctx, bg, map, scrub_dev, i,
+					   dev_extent_len);
 			if (ret)
 				goto out;
 		}
@@ -3654,7 +3620,6 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 	struct btrfs_path *path;
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct btrfs_root *root = fs_info->dev_root;
-	u64 length;
 	u64 chunk_offset;
 	int ret = 0;
 	int ro_set;
@@ -3678,6 +3643,8 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 	key.type = BTRFS_DEV_EXTENT_KEY;
 
 	while (1) {
+		u64 dev_extent_len;
+
 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 		if (ret < 0)
 			break;
@@ -3714,9 +3681,9 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 			break;
 
 		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
-		length = btrfs_dev_extent_length(l, dev_extent);
+		dev_extent_len = btrfs_dev_extent_length(l, dev_extent);
 
-		if (found_key.offset + length <= start)
+		if (found_key.offset + dev_extent_len <= start)
 			goto skip;
 
 		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
@@ -3850,13 +3817,14 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 
 		scrub_pause_off(fs_info);
 		down_write(&dev_replace->rwsem);
-		dev_replace->cursor_right = found_key.offset + length;
+		dev_replace->cursor_right = found_key.offset + dev_extent_len;
 		dev_replace->cursor_left = found_key.offset;
 		dev_replace->item_needs_writeback = 1;
 		up_write(&dev_replace->rwsem);
 
-		ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,
-				  found_key.offset, cache);
+		ASSERT(cache->start == chunk_offset);
+		ret = scrub_chunk(sctx, cache, scrub_dev, found_key.offset,
+				  dev_extent_len);
 
 		/*
 		 * flush, submit all pending read and write bios, afterwards
@@ -3937,7 +3905,7 @@ skip_unfreeze:
 			break;
 		}
 skip:
-		key.offset = found_key.offset + length;
+		key.offset = found_key.offset + dev_extent_len;
 		btrfs_release_path(path);
 	}