btrfs: remove parameter dev_extent_len from scrub_stripe()

For scrub_stripe() we can easily calculate the dev extent length as we
have the full info of the chunk.

Thus there is no need to pass @dev_extent_len from the caller, and we
introduce a helper, btrfs_calc_stripe_length(), to do the calculation
from extent_map structure.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/scrub.c

@@ -3418,20 +3418,22 @@ static int scrub_simple_stripe(struct scrub_ctx *sctx,
 
 static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 					   struct btrfs_block_group *bg,
-					   struct map_lookup *map,
+					   struct extent_map *em,
 					   struct btrfs_device *scrub_dev,
-					   int stripe_index, u64 dev_extent_len)
+					   int stripe_index)
 {
 	struct btrfs_path *path;
 	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct btrfs_root *root;
 	struct btrfs_root *csum_root;
 	struct blk_plug plug;
+	struct map_lookup *map = em->map_lookup;
 	const u64 profile = map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK;
 	const u64 chunk_logical = bg->start;
 	int ret;
 	u64 physical = map->stripes[stripe_index].physical;
-	const u64 physical_end = physical + dev_extent_len;
+	const u64 dev_stripe_len = btrfs_calc_stripe_length(em);
+	const u64 physical_end = physical + dev_stripe_len;
 	u64 logical;
 	u64 logic_end;
 	/* The logical increment after finishing one stripe */
@@ -3558,8 +3560,8 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 		physical += map->stripe_len;
 		spin_lock(&sctx->stat_lock);
 		if (stop_loop)
-			sctx->stat.last_physical = map->stripes[stripe_index].physical +
-						   dev_extent_len;
+			sctx->stat.last_physical =
+				map->stripes[stripe_index].physical + dev_stripe_len;
 		else
 			sctx->stat.last_physical = physical;
 		spin_unlock(&sctx->stat_lock);
@@ -3628,8 +3630,7 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
 	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, bg, map, scrub_dev, i,
-					   dev_extent_len);
+			ret = scrub_stripe(sctx, bg, em, scrub_dev, i);
 			if (ret)
 				goto out;
 		}

fs/btrfs/volumes.c

@@ -6939,11 +6939,12 @@ static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info,
 			      devid, uuid);
 }
 
-static u64 calc_stripe_length(u64 type, u64 chunk_len, int num_stripes)
+u64 btrfs_calc_stripe_length(const struct extent_map *em)
 {
-	const int data_stripes = calc_data_stripes(type, num_stripes);
+	const struct map_lookup *map = em->map_lookup;
+	const int data_stripes = calc_data_stripes(map->type, map->num_stripes);
 
-	return div_u64(chunk_len, data_stripes);
+	return div_u64(em->len, data_stripes);
 }
 
 #if BITS_PER_LONG == 32
@@ -7082,8 +7083,7 @@ static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf,
 	map->type = type;
 	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
 	map->verified_stripes = 0;
-	em->orig_block_len = calc_stripe_length(type, em->len,
-						map->num_stripes);
+	em->orig_block_len = btrfs_calc_stripe_length(em);
 	for (i = 0; i < num_stripes; i++) {
 		map->stripes[i].physical =
 			btrfs_stripe_offset_nr(leaf, chunk, i);
@@ -7984,7 +7984,7 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 	}
 
 	map = em->map_lookup;
-	stripe_len = calc_stripe_length(map->type, em->len, map->num_stripes);
+	stripe_len = btrfs_calc_stripe_length(em);
 	if (physical_len != stripe_len) {
 		btrfs_err(fs_info,
 "dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu",

fs/btrfs/volumes.h

@@ -633,6 +633,7 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 			   u64 logical, u64 len);
 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 				    u64 logical);
+u64 btrfs_calc_stripe_length(const struct extent_map *em);
 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
 				     struct btrfs_block_group *bg);
 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);