[PATCH RFC v2 for-6.8/block 03/18] bcache: use bdev api in read_super()

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

From: Yu Kuai <yukuai3@xxxxxxxxxx>

On the one hand covert to use folio while reading bdev inode, on the
other hand prevent to access bd_inode directly.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
 drivers/md/bcache/super.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index bfe1685dbae5..23892b32c582 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -168,14 +168,13 @@ static const char *read_super(struct cache_sb *sb, struct 
block_device *bdev,
 {
        const char *err;
        struct cache_sb_disk *s;
-       struct page *page;
+       struct folio *folio;
        unsigned int i;
 
-       page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
-                                  SB_OFFSET >> PAGE_SHIFT, GFP_KERNEL);
-       if (IS_ERR(page))
+       folio = bdev_read_folio(bdev, SB_OFFSET);
+       if (IS_ERR(folio))
                return "IO error";
-       s = page_address(page) + offset_in_page(SB_OFFSET);
+       s = folio_address(folio) + offset_in_folio(folio, SB_OFFSET);
 
        sb->offset              = le64_to_cpu(s->offset);
        sb->version             = le64_to_cpu(s->version);
@@ -272,7 +271,7 @@ static const char *read_super(struct cache_sb *sb, struct 
block_device *bdev,
        *res = s;
        return NULL;
 err:
-       put_page(page);
+       folio_put(folio);
        return err;
 }
 
-- 
2.39.2