btrfs: scrub: clean up temporary page variables in scrub_checksum_super

Add proper variable for the scrub page and use it instead of repeatedly
dereferencing the other structures.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index abb39c5..aecaf5c 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1904,23 +1904,23 @@ static int scrub_checksum_super(struct scrub_block *sblock)
        struct btrfs_fs_info *fs_info = sctx->fs_info;
        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
        u8 calculated_csum[BTRFS_CSUM_SIZE];
-       struct page *page;
+       struct scrub_page *spage;
        char *kaddr;
        int fail_gen = 0;
        int fail_cor = 0;
 
        BUG_ON(sblock->page_count < 1);
-       page = sblock->pagev[0]->page;
-       kaddr = page_address(page);
+       spage = sblock->pagev[0];
+       kaddr = page_address(spage->page);
        s = (struct btrfs_super_block *)kaddr;
 
-       if (sblock->pagev[0]->logical != btrfs_super_bytenr(s))
+       if (spage->logical != btrfs_super_bytenr(s))
                ++fail_cor;
 
-       if (sblock->pagev[0]->generation != btrfs_super_generation(s))
+       if (spage->generation != btrfs_super_generation(s))
                ++fail_gen;
 
-       if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
+       if (!scrub_check_fsid(s->fsid, spage))
                ++fail_cor;
 
        shash->tfm = fs_info->csum_shash;
@@ -1941,10 +1941,10 @@ static int scrub_checksum_super(struct scrub_block *sblock)
                ++sctx->stat.super_errors;
                spin_unlock(&sctx->stat_lock);
                if (fail_cor)
-                       btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+                       btrfs_dev_stat_inc_and_print(spage->dev,
                                BTRFS_DEV_STAT_CORRUPTION_ERRS);
                else
-                       btrfs_dev_stat_inc_and_print(sblock->pagev[0]->dev,
+                       btrfs_dev_stat_inc_and_print(spage->dev,
                                BTRFS_DEV_STAT_GENERATION_ERRS);
        }