+static int __readpage_endio_check(struct inode *inode,
+ struct btrfs_io_bio *io_bio,
+ int icsum, struct page *page,
+ int pgoff, u64 start, size_t len)
+{
+ char *kaddr;
+ u32 csum_expected;
+ u32 csum = ~(u32)0;
+ static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ csum_expected = *(((u32 *)io_bio->csum) + icsum);
+
+ kaddr = kmap_atomic(page);
+ csum = btrfs_csum_data(kaddr + pgoff, csum, len);
+ btrfs_csum_final(csum, (char *)&csum);
+ if (csum != csum_expected)
+ goto zeroit;
+
+ kunmap_atomic(kaddr);
+ return 0;
+zeroit:
+ if (__ratelimit(&_rs))
+ btrfs_info(BTRFS_I(inode)->root->fs_info,
+ "csum failed ino %llu off %llu csum %u expected csum %u",
+ btrfs_ino(inode), start, csum, csum_expected);
+ memset(kaddr + pgoff, 1, len);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr);
+ if (csum_expected == 0)
+ return 0;
+ return -EIO;
+}
+