ext2: fix fs corruption when trying to remove a non-empty directory with IO error

We got issue as follows:
[home]# mount /dev/sdd test
[home]# cd test
[test]# ls
dir1 lost+found
[test]# rmdir dir1
ext2_empty_dir: inject fault
[test]# ls
lost+found
[test]# cd ..
[home]# umount test
[home]# fsck.ext2 -fn /dev/sdd
e2fsck 1.42.9 (28-Dec-2013)
Pass 1: Checking inodes, blocks, and sizes
Inode 4065, i_size is 0, should be 1024. Fix? no

Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Unconnected directory inode 4065 (/???)
Connect to /lost+found? no

'..' in ... (4065) is / (2), should be <The NULL inode> (0).
Fix? no

Pass 4: Checking reference counts
Inode 2 ref count is 3, should be 4. Fix? no

Inode 4065 ref count is 2, should be 3. Fix? no

Pass 5: Checking group summary information

/dev/sdd: ********** WARNING: Filesystem still has errors **********

/dev/sdd: 14/128016 files (0.0% non-contiguous), 18477/512000 blocks

Reason is same with commit 7aab5c84a0f6. We can't assume directory
is empty when read directory entry failed.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ye Bin <[e-mail]>
Signed-off-by: Jan Kara <[e-mail]>

fs/ext2/dir.c

···
 	void *page_addr = NULL;
 	struct page *page = NULL;
 	unsigned long i, npages = dir_pages(inode);
-	int dir_has_error = 0;
 
 	for (i = 0; i < npages; i++) {
 		char *kaddr;
 		ext2_dirent * de;
-		page = ext2_get_page(inode, i, dir_has_error, &page_addr);
+		page = ext2_get_page(inode, i, 0, &page_addr);
 
-		if (IS_ERR(page)) {
-			dir_has_error = 1;
-			continue;
-		}
+		if (IS_ERR(page))
+			goto not_empty;
 
 		kaddr = page_addr;
 		de = (ext2_dirent *)kaddr;