Btrfs: modify repair_io_failure and make it suit direct io

The original code of repair_io_failure was just used for buffered read,
because it got some filesystem data from page structure, it is safe for
the page in the page cache. But when we do a direct read, the pages in bio
are not in the page cache, that is there is no filesystem data in the page
structure. In order to implement direct read data repair, we need modify
repair_io_failure and pass all filesystem data it need by function
parameters.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/scrub.c

@@ -682,6 +682,7 @@ static int scrub_fixup_readpage(u64 inum, u64 offset, u64 root, void *fixup_ctx)
 		fs_info = BTRFS_I(inode)->root->fs_info;
 		ret = repair_io_failure(fs_info, offset, PAGE_SIZE,
 					fixup->logical, page,
+					offset - page_offset(page),
 					fixup->mirror_num);
 		unlock_page(page);
 		corrected = !ret;