btrfs: scrub: setup all fields for sblock_to_check

scrub_setup_recheck_block() isn't setup all necessary fields for
sblock_to_check because history reason.

So current code need more arguments in severial functions,
and more local variables, just to passing these lacked values to
necessary place.

This patch setup above fields to sblock_to_check in
scrub_setup_recheck_block(), for:
1: more cleanup for function arg, local variable
2: to make sblock_to_check complete, then we can use sblock_to_check
   without concern about some uninitialized member.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/scrub.c

@@ -1318,6 +1318,9 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
 	u64 length = original_sblock->page_count * PAGE_SIZE;
 	u64 logical = original_sblock->pagev[0]->logical;
+	u64 generation = original_sblock->pagev[0]->generation;
+	u64 flags = original_sblock->pagev[0]->flags;
+	u64 have_csum = original_sblock->pagev[0]->have_csum;
 	struct scrub_recover *recover;
 	struct btrfs_bio *bbio;
 	u64 sublen;
@@ -1372,6 +1375,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 
 			sblock = sblocks_for_recheck + mirror_index;
 			sblock->sctx = sctx;
+
 			page = kzalloc(sizeof(*page), GFP_NOFS);
 			if (!page) {
 leave_nomem:
@@ -1383,7 +1387,15 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 			}
 			scrub_page_get(page);
 			sblock->pagev[page_index] = page;
+			page->sblock = sblock;
+			page->flags = flags;
+			page->generation = generation;
 			page->logical = logical;
+			page->have_csum = have_csum;
+			if (have_csum)
+				memcpy(page->csum,
+				       original_sblock->pagev[0]->csum,
+				       sctx->csum_size);
 
 			scrub_stripe_index_and_offset(logical,
 						      bbio->map_type,